1de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** 2001 September 15
3de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The author disclaims copyright to this source code.  In place of
5de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a legal notice, here is a blessing:
6de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**    May you do good and not evil.
8de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**    May you find forgiveness for yourself and forgive others.
9de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**    May you share freely, never taking more than you give.
10de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
11de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*************************************************************************
12de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This header file defines the interface that the SQLite library
13de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** presents to client programs.  If a C-function, structure, datatype,
14de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or constant definition does not appear in this file, then it is
15de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not a published API of SQLite, is subject to change without
16de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** notice, and should not be referenced by programs that use SQLite.
17de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
18de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Some of the definitions that are in this file are marked as
19de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** "experimental".  Experimental interfaces are normally new
20de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** features recently added to SQLite.  We do not anticipate changes
21de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to experimental interfaces but reserve the right to make minor changes
22de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if experience from use "in the wild" suggest such changes are prudent.
23de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
24de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The official C-language API documentation for SQLite is derived
25de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from comments in this file.  This file is the authoritative source
26de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on how SQLite interfaces are suppose to operate.
27de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
28de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The name of this file under configuration management is "sqlite.h.in".
29de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The makefile makes some minor changes to this file (such as inserting
30de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the version number) and changes its name to "sqlite3.h" as
31de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** part of the build process.
32de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
33de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifndef _SQLITE3_H_
34de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define _SQLITE3_H_
35de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#include <stdarg.h>     /* Needed for the definition of va_list */
36de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
37de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
38de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Make sure we can call this stuff from C++.
39de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
40de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef __cplusplus
41de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noriextern "C" {
42de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
43de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
44de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
45de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
46de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Add the ability to override 'extern'
47de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
48de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifndef SQLITE_EXTERN
49de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori# define SQLITE_EXTERN extern
50de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
51de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
52de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifndef SQLITE_API
53de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori# define SQLITE_API
54de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
55de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
56de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
57de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
58de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These no-op macros are used in front of interfaces to mark those
59de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interfaces as either deprecated or experimental.  New applications
60de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** should not use deprecated interfaces - they are support for backwards
61de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compatibility only.  Application writers should be aware that
62de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** experimental interfaces are subject to change in point releases.
63de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
64de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These macros used to resolve to various kinds of compiler magic that
65de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** would generate warning messages when they were used.  But that
66de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compiler magic ended up generating such a flurry of bug reports
67de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that we have taken it all out and gone back to using simple
68de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** noop macros.
69de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
70de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DEPRECATED
71de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_EXPERIMENTAL
72de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
73de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
74de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Ensure these symbols were not defined by some previous header file.
75de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
76de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef SQLITE_VERSION
77de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori# undef SQLITE_VERSION
78de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
79de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef SQLITE_VERSION_NUMBER
80de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori# undef SQLITE_VERSION_NUMBER
81de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
82de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
83de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
84de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Compile-Time Library Version Numbers
85de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
86de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
87de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** evaluates to a string literal that is the SQLite version in the
88de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** format "X.Y.Z" where X is the major version number (always 3 for
89de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite3) and Y is the minor version number and Z is the release number.)^
90de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
91de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
92de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** numbers used in [SQLITE_VERSION].)^
93de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
94de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be larger than the release from which it is derived.  Either Y will
95de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be held constant and Z will be incremented or else Y will be incremented
96de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and Z will be reset to zero.
97de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
98de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Since version 3.6.18, SQLite source code has been stored in the
99de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <a href="http://www.fossil-scm.org/">Fossil configuration management
100de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to
101de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a string which identifies a particular check-in of SQLite
102de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** within its configuration management system.  ^The SQLITE_SOURCE_ID
103de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** string contains the date and time of the check-in (UTC) and an SHA1
104de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** hash of the entire source tree.
105de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
106de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_libversion()],
107de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_libversion_number()], [sqlite3_sourceid()],
108de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite_version()] and [sqlite_source_id()].
109de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1109bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown#define SQLITE_VERSION        "3.8.6"
1119bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown#define SQLITE_VERSION_NUMBER 3008006
1129bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown#define SQLITE_SOURCE_ID      "2014-08-15 11:46:33 9491ba7d738528f168657adb43a198238abde19e"
113de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
114de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
115de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Run-Time Library Version Numbers
116de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: sqlite3_version, sqlite3_sourceid
117de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
118de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These interfaces provide the same information as the [SQLITE_VERSION],
119de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
120de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** but are associated with the library instead of the header file.  ^(Cautious
121de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** programmers might include assert() statements in their application to
122de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** verify that values returned by these interfaces match the macros in
123de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the header, and thus insure that the application is
124de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compiled with matching library and header files.
125de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
126de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote><pre>
127de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
128de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
129de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
130de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </pre></blockquote>)^
131de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
132de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
133de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** macro.  ^The sqlite3_libversion() function returns a pointer to the
134de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the sqlite3_version[] string constant.  The sqlite3_libversion()
135de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function is provided for use in DLLs since DLL users usually do not have
136de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** direct access to string constants within the DLL.  ^The
137de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_libversion_number() function returns an integer equal to
138de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_VERSION_NUMBER].  ^The sqlite3_sourceid() function returns
139de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a pointer to a string constant whose value is the same as the
140de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_SOURCE_ID] C preprocessor macro.
141de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
142de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite_version()] and [sqlite_source_id()].
143de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
144de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API SQLITE_EXTERN const char sqlite3_version[];
145de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_libversion(void);
146de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_sourceid(void);
147de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_libversion_number(void);
148de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
149de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
150de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Run-Time Library Compilation Options Diagnostics
151de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
152de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_compileoption_used() function returns 0 or 1
153de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** indicating whether the specified option was defined at
154de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compile time.  ^The SQLITE_ prefix may be omitted from the
155de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** option name passed to sqlite3_compileoption_used().
156de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
157de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_compileoption_get() function allows iterating
158de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** over the list of options that were defined at compile time by
159de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returning the N-th compile time option string.  ^If N is out of range,
160de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_
161de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** prefix is omitted from any strings returned by
162de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_compileoption_get().
163de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
164de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Support for the diagnostic functions sqlite3_compileoption_used()
165de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and sqlite3_compileoption_get() may be omitted by specifying the
166de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
167de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
168de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: SQL functions [sqlite_compileoption_used()] and
169de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite_compileoption_get()] and the [compile_options pragma].
170de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
171de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
172de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_compileoption_used(const char *zOptName);
173de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_compileoption_get(int N);
174de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
175de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
176de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
177de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Test To See If The Library Is Threadsafe
178de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
179de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_threadsafe() function returns zero if and only if
18090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** SQLite was compiled with mutexing code omitted due to the
181de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_THREADSAFE] compile-time option being set to 0.
182de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
183de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite can be compiled with or without mutexes.  When
184de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
185de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are enabled and SQLite is threadsafe.  When the
186de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_THREADSAFE] macro is 0,
187de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the mutexes are omitted.  Without the mutexes, it is not safe
188de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to use SQLite concurrently from more than one thread.
189de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
190de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Enabling mutexes incurs a measurable performance penalty.
191de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** So if speed is of utmost importance, it makes sense to disable
192de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the mutexes.  But for maximum safety, mutexes should be enabled.
193de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The default behavior is for mutexes to be enabled.
194de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
195de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This interface can be used by an application to make sure that the
196de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** version of SQLite that it is linking against was compiled with
197de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the desired setting of the [SQLITE_THREADSAFE] macro.
198de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
199de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This interface only reports on the compile-time mutex setting
200de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
201de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
202de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be fully or partially disabled using a call to [sqlite3_config()]
203de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
204de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [SQLITE_CONFIG_MUTEX].  ^(The return value of the
205de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_threadsafe() function shows only the compile-time setting of
206de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** thread safety, not any run-time changes to that setting made by
207de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
208de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is unchanged by calls to sqlite3_config().)^
209de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
210de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See the [threading mode] documentation for additional information.
211de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
212de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_threadsafe(void);
213de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
214de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
215de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Database Connection Handle
216de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {database connection} {database connections}
217de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
218de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Each open SQLite database is represented by a pointer to an instance of
219de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
220de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
221de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
2228fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** and [sqlite3_close_v2()] are its destructors.  There are many other
2238fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** interfaces (such as
224de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
225de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_busy_timeout()] to name but three) that are methods on an
226de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3 object.
227de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
228de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3 sqlite3;
229de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
230de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
231de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: 64-Bit Integer Types
232de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: sqlite_int64 sqlite_uint64
233de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
234de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Because there is no cross-platform way to specify 64-bit integer types
235de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite includes typedefs for 64-bit signed and unsigned integers.
236de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
237de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
238de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite_int64 and sqlite_uint64 types are supported for backwards
239de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compatibility only.
240de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
241de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_int64 and sqlite_int64 types can store integer values
242de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
243de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_uint64 and sqlite_uint64 types can store integer values
244de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** between 0 and +18446744073709551615 inclusive.
245de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
246de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef SQLITE_INT64_TYPE
247de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  typedef SQLITE_INT64_TYPE sqlite_int64;
248de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
249de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#elif defined(_MSC_VER) || defined(__BORLANDC__)
250de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  typedef __int64 sqlite_int64;
251de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  typedef unsigned __int64 sqlite_uint64;
252de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#else
253de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  typedef long long int sqlite_int64;
254de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  typedef unsigned long long int sqlite_uint64;
255de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
256de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef sqlite_int64 sqlite3_int64;
257de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef sqlite_uint64 sqlite3_uint64;
258de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
259de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
260de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If compiling for a processor that lacks floating point support,
261de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** substitute integer for floating-point.
262de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
263de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef SQLITE_OMIT_FLOATING_POINT
264de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori# define double sqlite3_int64
265de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
266de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
267de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
268de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Closing A Database Connection
269de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2708fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
2718fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** for the [sqlite3] object.
2729bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
2738fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the [sqlite3] object is successfully destroyed and all associated
2748fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** resources are deallocated.
2758fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
2768fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^If the database connection is associated with unfinalized prepared
2778fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** statements or unfinished sqlite3_backup objects then sqlite3_close()
2788fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** will leave the database connection open and return [SQLITE_BUSY].
2798fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^If sqlite3_close_v2() is called with unfinalized prepared statements
2809bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** and/or unfinished sqlite3_backups, then the database connection becomes
2818fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** an unusable "zombie" which will automatically be deallocated when the
2828fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** last prepared statement is finalized or the last sqlite3_backup is
2838fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** finished.  The sqlite3_close_v2() interface is intended for use with
2848fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** host languages that are garbage collected, and where the order in which
2858fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** destructors are called is arbitrary.
2868fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
2878fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** Applications should [sqlite3_finalize | finalize] all [prepared statements],
2888fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [sqlite3_blob_close | close] all [BLOB handles], and
2898fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
2908fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** with the [sqlite3] object prior to attempting to close the object.  ^If
2918fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** sqlite3_close_v2() is called on a [database connection] that still has
2928fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** outstanding [prepared statements], [BLOB handles], and/or
2939bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
2948fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** of resources is deferred until all [prepared statements], [BLOB handles],
2958fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** and [sqlite3_backup] objects are also destroyed.
2968fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
2978fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^If an [sqlite3] object is destroyed while a transaction is open,
298de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the transaction is automatically rolled back.
299de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3008fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
3018fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** must be either a NULL
302de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pointer or an [sqlite3] object pointer obtained
303de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from [sqlite3_open()], [sqlite3_open16()], or
304de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_open_v2()], and not previously closed.
3058fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
3068fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** argument is a harmless no-op.
307de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3088fecf56c625b5691ee3381e107ccbe1ff42398b1Nick KralevichSQLITE_API int sqlite3_close(sqlite3*);
3098fecf56c625b5691ee3381e107ccbe1ff42398b1Nick KralevichSQLITE_API int sqlite3_close_v2(sqlite3*);
310de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
311de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
312de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The type for a callback function.
313de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This is legacy and deprecated.  It is included for historical
314de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compatibility and is not documented.
315de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
316de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef int (*sqlite3_callback)(void*,int,char**, char**);
317de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
318de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
319de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: One-Step Query Execution Interface
320de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
321de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_exec() interface is a convenience wrapper around
322de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
323de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that allows an application to run multiple statements of SQL
324de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** without having to use a lot of C code.
325de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
326de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
327de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** semicolon-separate SQL statements passed into its 2nd argument,
328de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in the context of the [database connection] passed in as its 1st
329de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** argument.  ^If the callback function of the 3rd argument to
330de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_exec() is not NULL, then it is invoked for each result row
331de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** coming out of the evaluated SQL statements.  ^The 4th argument to
33290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** sqlite3_exec() is relayed through to the 1st argument of each
333de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** callback invocation.  ^If the callback pointer to sqlite3_exec()
334de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is NULL, then no callback is ever invoked and result rows are
335de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ignored.
336de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
337de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If an error occurs while evaluating the SQL statements passed into
338de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_exec(), then execution of the current statement stops and
339de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
340de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is not NULL then any error message is written into memory obtained
341de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from [sqlite3_malloc()] and passed back through the 5th parameter.
342de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** To avoid memory leaks, the application should invoke [sqlite3_free()]
343de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on error message strings returned through the 5th parameter of
344de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of sqlite3_exec() after the error message string is no longer needed.
345de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
346de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
347de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** NULL before returning.
348de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
349de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
350de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routine returns SQLITE_ABORT without invoking the callback again and
351de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** without running any subsequent SQL statements.
352de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
353de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The 2nd argument to the sqlite3_exec() callback function is the
354de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
355de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** callback is an array of pointers to strings obtained as if from
356de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_column_text()], one for each column.  ^If an element of a
357de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** result row is NULL then the corresponding string pointer for the
358de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
359de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_exec() callback is an array of pointers to strings where each
360de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** entry represents the name of corresponding result column as obtained
361de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from [sqlite3_column_name()].
362de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
363de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
364de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to an empty string, or a pointer that contains only whitespace and/or
365de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQL comments, then no SQL statements are evaluated and the database
366de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is not changed.
367de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
368de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Restrictions:
369de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
370de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
371de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> The application must insure that the 1st parameter to sqlite3_exec()
372de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      is a valid and open [database connection].
3738fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li> The application must not close the [database connection] specified by
374de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
375de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> The application must not modify the SQL statement text passed into
376de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
377de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>
378de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
379de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_exec(
380de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3*,                                  /* An open database */
381de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *sql,                           /* SQL to be evaluated */
382de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*callback)(void*,int,char**,char**),  /* Callback function */
383de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *,                                    /* 1st argument to callback */
384de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  char **errmsg                              /* Error msg written here */
385de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
386de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
387de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
388de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Result Codes
3899bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** KEYWORDS: {result code definitions}
390de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
391de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Many SQLite functions return an integer result code from the set shown
39290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** here in order to indicate success or failure.
393de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
394de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** New error codes may be added in future versions of SQLite.
395de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3969bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** See also: [extended result code definitions]
397de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
398de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OK           0   /* Successful result */
399de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/* beginning-of-error-codes */
400de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_ERROR        1   /* SQL error or missing database */
401de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
402de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_PERM         3   /* Access permission denied */
403de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_ABORT        4   /* Callback routine requested an abort */
404de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_BUSY         5   /* The database file is locked */
405de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LOCKED       6   /* A table in the database is locked */
406de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_NOMEM        7   /* A malloc() failed */
407de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
408de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
409de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
410de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
41190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
412de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_FULL        13   /* Insertion failed because database is full */
413de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
414de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
415de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_EMPTY       16   /* Database is empty */
416de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SCHEMA      17   /* The database schema changed */
417de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
418de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
419de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_MISMATCH    20   /* Data type mismatch */
420de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_MISUSE      21   /* Library used incorrectly */
421de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
422de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_AUTH        23   /* Authorization denied */
423de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_FORMAT      24   /* Auxiliary database format error */
424de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
425de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_NOTADB      26   /* File opened that is not a database file */
4268fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
4278fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */
428de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
429de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
430de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/* end-of-error-codes */
431de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
432de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
433de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Extended Result Codes
4349bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** KEYWORDS: {extended result code definitions}
435de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4369bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** In its default configuration, SQLite API routines return one of 30 integer
4379bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** [result codes].  However, experience has shown that many of
438de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** these result codes are too coarse-grained.  They do not provide as
439de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** much information about problems as programmers might like.  In an effort to
440de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** address this, newer versions of SQLite (version 3.3.8 and later) include
441de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** support for additional result codes that provide more detailed information
4429bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** about errors. These [extended result codes] are enabled or disabled
443de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on a per database connection basis using the
4449bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** [sqlite3_extended_result_codes()] API.  Or, the extended code for
4459bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** the most recent error can be obtained using
4469bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** [sqlite3_extended_errcode()].
447de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
448de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
449de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
450de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
451de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
452de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
453de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
454de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
455de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
456de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
457de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
458de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
459de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
460de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
461de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
462de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
463de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
464de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
465de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
466de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
467de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
46890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
46990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
4708fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
4718fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
4728fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
4738fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
474de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
475de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
4768fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
477de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
4788fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
4798fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
4808fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))
48190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
48290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
48390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
4848fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
4858fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
486c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
4878fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
4888fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
4898fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
4908fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
4918fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
4928fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))
4938fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONSTRAINT_TRIGGER      (SQLITE_CONSTRAINT | (7<<8))
4948fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONSTRAINT_UNIQUE       (SQLITE_CONSTRAINT | (8<<8))
4958fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
4968fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONSTRAINT_ROWID        (SQLITE_CONSTRAINT |(10<<8))
4978fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
4988fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
4998fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
500de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
501de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
502de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Flags For File Open Operations
503de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
504de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These bit values are intended for use in the
505de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** 3rd parameter to the [sqlite3_open_v2()] interface and
50690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
507de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
508de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
509de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
510de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
511de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
512de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
513de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
51490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
5158fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */
516de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
517de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
518de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
519de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
520de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
521de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
522de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
523de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
524de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
525de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
526de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
527de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
528de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
52990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/* Reserved:                         0x00F00000 */
53090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
531de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
532de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Device Characteristics
533de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
534de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xDeviceCharacteristics method of the [sqlite3_io_methods]
5358fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** object returns an integer which is a vector of these
536de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** bit values expressing I/O characteristics of the mass storage
537de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** device that holds the file that the [sqlite3_io_methods]
538de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** refers to.
539de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
540de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The SQLITE_IOCAP_ATOMIC property means that all writes of
541de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
542de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** mean that writes of blocks that are nnn bytes in size and
543de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are aligned to an address which is an integer multiple of
544de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
545de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that when data is appended to a file, the data is appended
546de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** first then the size of the file is extended, never the other
547de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
548de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** information is written to disk in the same order as calls
54990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** to xWrite().  The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
55090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** after reboot following a crash or power loss, the only bytes in a
55190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** file that were written at the application level might have changed
55290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** and that adjacent bytes, even bytes within the same sector are
5538fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
5541c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** flag indicate that a file cannot be deleted when open.  The
5551c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
5561c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** read-only media and cannot be changed even by processes with
5571c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** elevated privileges.
558de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
559de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_ATOMIC                 0x00000001
560de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_ATOMIC512              0x00000002
561de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_ATOMIC1K               0x00000004
562de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_ATOMIC2K               0x00000008
563de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_ATOMIC4K               0x00000010
564de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_ATOMIC8K               0x00000020
565de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_ATOMIC16K              0x00000040
566de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_ATOMIC32K              0x00000080
567de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_ATOMIC64K              0x00000100
568de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_SAFE_APPEND            0x00000200
569de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_SEQUENTIAL             0x00000400
570de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
57190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000
5721c7cea379348522163370244e8fbbff8a136b7faNick Kralevich#define SQLITE_IOCAP_IMMUTABLE              0x00002000
573de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
574de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
575de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: File Locking Levels
576de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
577de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite uses one of these integer values as the second
578de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** argument to calls it makes to the xLock() and xUnlock() methods
579de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of an [sqlite3_io_methods] object.
580de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
581de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LOCK_NONE          0
582de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LOCK_SHARED        1
583de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LOCK_RESERVED      2
584de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LOCK_PENDING       3
585de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LOCK_EXCLUSIVE     4
586de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
587de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
588de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Synchronization Type Flags
589de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
590de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When SQLite invokes the xSync() method of an
591de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_io_methods] object it uses a combination of
592de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** these integer values as the second argument.
593de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
594de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
595de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sync operation only needs to flush data to mass storage.  Inode
596de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** information need not be flushed. If the lower four bits of the flag
597de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
598de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If the lower four bits equal SQLITE_SYNC_FULL, that means
599de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to use Mac OS X style fullsync instead of fsync().
60095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
60195c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
60295c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
60395c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** settings.  The [synchronous pragma] determines when calls to the
60495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** xSync VFS method occur and applies uniformly across all platforms.
60595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
60695c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** energetic or rigorous or forceful the sync operations are and
60795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** only make a difference on Mac OSX for the default SQLite code.
60895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** (Third-party VFS implementations might also make the distinction
60995c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
61095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** operating systems natively supported by SQLite, only Mac OSX
61195c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** cares about the difference.)
612de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
613de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SYNC_NORMAL        0x00002
614de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SYNC_FULL          0x00003
615de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SYNC_DATAONLY      0x00010
616de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
617de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
618de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: OS Interface Open File Handle
619de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
620de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** An [sqlite3_file] object represents an open file in the
621de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_vfs | OS interface layer].  Individual OS interface
622de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementations will
623de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** want to subclass this object by appending additional fields
624de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for their own use.  The pMethods entry is a pointer to an
625de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_io_methods] object that defines methods for performing
626de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** I/O operations on the open file.
627de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
628de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_file sqlite3_file;
629de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_file {
630de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
631de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
632de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
633de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
634de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: OS Interface File Virtual Methods Object
635de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
63690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** Every file opened by the [sqlite3_vfs.xOpen] method populates an
637de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_file] object (or, more commonly, a subclass of the
638de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_file] object) with a pointer to an instance of this object.
639de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This object defines the methods used to perform various operations
640de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** against the open file represented by the [sqlite3_file] object.
641de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
64290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
643de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
64490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
64590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
64690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
64790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** to NULL.
648de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
649de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
650de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
651de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
652de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** flag may be ORed in to indicate that only the data of the file
653de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and not its inode needs to be synced.
654de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
655de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The integer values to xLock() and xUnlock() are one of
656de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
657de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_LOCK_NONE],
658de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_LOCK_SHARED],
659de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_LOCK_RESERVED],
660de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_LOCK_PENDING], or
661de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_LOCK_EXCLUSIVE].
662de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>
663de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xLock() increases the lock. xUnlock() decreases the lock.
664de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xCheckReservedLock() method checks whether any database connection,
665de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** either in this process or in some other process, is holding a RESERVED,
666de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** PENDING, or EXCLUSIVE lock on the file.  It returns true
667de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if such a lock exists and false otherwise.
668de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
669de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xFileControl() method is a generic interface that allows custom
670de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** VFS implementations to directly control an open file using the
671de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_file_control()] interface.  The second "op" argument is an
672de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** integer opcode.  The third argument is a generic pointer intended to
673de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** point to a structure that may contain arguments or space in which to
674de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** write return values.  Potential uses for xFileControl() might be
675de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** functions to enable blocking locks with timeouts, to change the
676de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** locking strategy (for example to use dot-file locks), to inquire
677de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** about the status of a lock, or to break stale locks.  The SQLite
678de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** core reserves all opcodes less than 100 for its own use.
6799bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** A [file control opcodes | list of opcodes] less than 100 is available.
680de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Applications that define a custom xFileControl method should use opcodes
68190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** greater than 100 to avoid conflicts.  VFS implementations should
68290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** return [SQLITE_NOTFOUND] for file control opcodes that they do not
68390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** recognize.
684de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
685de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xSectorSize() method returns the sector size of the
686de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** device that underlies the file.  The sector size is the
687de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** minimum write that can be performed without disturbing
688de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** other bytes in the file.  The xDeviceCharacteristics()
689de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** method returns a bit vector describing behaviors of the
690de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** underlying device:
691de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
692de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
693de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_ATOMIC]
694de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_ATOMIC512]
695de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_ATOMIC1K]
696de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_ATOMIC2K]
697de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_ATOMIC4K]
698de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_ATOMIC8K]
699de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_ATOMIC16K]
700de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_ATOMIC32K]
701de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_ATOMIC64K]
702de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_SAFE_APPEND]
703de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_IOCAP_SEQUENTIAL]
704de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>
705de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
706de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The SQLITE_IOCAP_ATOMIC property means that all writes of
707de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
708de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** mean that writes of blocks that are nnn bytes in size and
709de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are aligned to an address which is an integer multiple of
710de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
711de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that when data is appended to a file, the data is appended
712de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** first then the size of the file is extended, never the other
713de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
714de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** information is written to disk in the same order as calls
715de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to xWrite().
716de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
717de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
718de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in the unread portions of the buffer with zeros.  A VFS that
719de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** fails to zero-fill short reads might seem to work.  However,
720de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** failure to zero-fill short reads will eventually lead to
721de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database corruption.
722de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
723de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_io_methods sqlite3_io_methods;
724de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_io_methods {
725de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int iVersion;
726de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xClose)(sqlite3_file*);
727de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
728de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
729de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
730de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xSync)(sqlite3_file*, int flags);
731de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
732de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xLock)(sqlite3_file*, int);
733de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xUnlock)(sqlite3_file*, int);
734de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
735de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
736de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xSectorSize)(sqlite3_file*);
737de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xDeviceCharacteristics)(sqlite3_file*);
738de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  /* Methods above are valid for version 1 */
739de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
740de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
741de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xShmBarrier)(sqlite3_file*);
742de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
743de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  /* Methods above are valid for version 2 */
7448fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
7458fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
7468fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  /* Methods above are valid for version 3 */
747de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  /* Additional methods may be added in future releases */
748de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
749de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
750de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
751de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Standard File Control Opcodes
7529bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** KEYWORDS: {file control opcodes} {file control opcode}
753de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
754de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These integer constants are opcodes for the xFileControl method
755de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
756de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface.
757de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
758de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
759de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** opcode causes the xFileControl method to write the current state of
760de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
761de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
762de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** into an integer that the pArg argument points to. This capability
763de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is used during testing and only needs to be supported when SQLITE_TEST
764de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is defined.
765c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <ul>
766c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <li>[[SQLITE_FCNTL_SIZE_HINT]]
767de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
768de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** layer a hint of how large the database file will grow to be during the
769de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** current transaction.  This hint is not guaranteed to be accurate but it
770de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is often close.  The underlying VFS might choose to preallocate database
771de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** file space based on this hint in order to help writes to the database
772de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** file run faster.
773de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
774c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
775de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
776de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** extends and truncates the database file in chunks of a size specified
777de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by the user. The fourth argument to [sqlite3_file_control()] should
778de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** point to an integer (type int) containing the new chunk-size to use
779de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for the nominated database. Allocating database file space in large
780de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** chunks (say 1MB at a time), may reduce file-system fragmentation and
781de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** improve performance on some systems.
78290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
783c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <li>[[SQLITE_FCNTL_FILE_POINTER]]
78490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
78590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** to the [sqlite3_file] object associated with a particular database
78690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** connection.  See the [sqlite3_file_control()] documentation for
78790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** additional information.
78890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
789c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
7908fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** No longer in use.
7918fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
7928fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li>[[SQLITE_FCNTL_SYNC]]
7938fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
7948fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** sent to the VFS immediately before the xSync method is invoked on a
7958fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** database file descriptor. Or, if the xSync method is not invoked
7968fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** because the user has configured SQLite with
7978fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
7988fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** of the xSync method. In most cases, the pointer argument passed with
7998fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** this file-control is NULL. However, if the database file is being synced
8008fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** as part of a multi-database commit, the argument points to a nul-terminated
8018fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** string containing the transactions master-journal file name. VFSes that
8028fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** do not need this signal should silently ignore this opcode. Applications
8038fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** should not call [sqlite3_file_control()] with this opcode as doing so may
8048fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** disrupt the operation of the specialized VFSes that do require it.
8058fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
8068fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
8078fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
8088fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** and sent to the VFS after a transaction has been committed immediately
8098fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** but before the database is unlocked. VFSes that do not need this signal
8108fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** should silently ignore this opcode. Applications should not call
8118fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [sqlite3_file_control()] with this opcode as doing so may disrupt the
8128fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** operation of the specialized VFSes that do require it.
81390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
814c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
81590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
81690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** retry counts and intervals for certain disk I/O operations for the
81790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** windows [VFS] in order to provide robustness in the presence of
81890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** anti-virus programs.  By default, the windows VFS will retry file read,
81990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** file write, and file delete operations up to 10 times, with a delay
82090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** of 25 milliseconds before the first retry and with the delay increasing
82190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** by an additional 25 milliseconds with each subsequent retry.  This
82290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** opcode allows these two values (10 retries and 25 milliseconds of delay)
82390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** to be adjusted.  The values are changed for all database connections
82490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** within the same process.  The argument is a pointer to an array of two
82590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** integers where the first integer i the new retry count and the second
82690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** integer is the delay.  If either integer is negative, then the setting
82790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is not changed but instead the prior value of that setting is written
82890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** into the array entry, allowing the current retry settings to be
82990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** interrogated.  The zDbName parameter is ignored.
83090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
831c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
83290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
8338fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary
83490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** write ahead log and shared memory files used for transaction control
83590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** are automatically deleted when the latest connection to the database
83690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** closes.  Setting persistent WAL mode causes those files to persist after
83790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** close.  Persisting the files is useful when other processes that do not
83890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** have write permission on the directory containing the database file want
83990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** to read the database file, as the WAL and shared memory files must exist
84090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** in order for the database to be readable.  The fourth parameter to
84190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
84290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
84390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** WAL mode.  If the integer is -1, then it is overwritten with the current
84490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** WAL persistence setting.
84590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
846c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
84790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
84890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
84990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
85090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** xDeviceCharacteristics methods. The fourth parameter to
85190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
85290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
85390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** mode.  If the integer is -1, then it is overwritten with the current
85490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** zero-damage mode setting.
85590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
856c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <li>[[SQLITE_FCNTL_OVERWRITE]]
85790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
85890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** a write transaction to indicate that, unless it is rolled back for some
85990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** reason, the entire database file will be overwritten by the current
86090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** transaction. This is used by VACUUM operations.
86190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
862c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <li>[[SQLITE_FCNTL_VFSNAME]]
86390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
86490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
86590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** final bottom-level VFS are written into memory obtained from
86690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_malloc()] and the result is stored in the char* variable
86790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** that the fourth parameter of [sqlite3_file_control()] points to.
86890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The caller is responsible for freeing the memory when done.  As with
86990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** all file-control actions, there is no guarantee that this will actually
87090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** do anything.  Callers should initialize the char* variable to a NULL
87190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** pointer in case this file-control is not implemented.  This file-control
87290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is intended for diagnostic use only.
873c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown**
874c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** <li>[[SQLITE_FCNTL_PRAGMA]]
875c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
876c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** file control is sent to the open [sqlite3_file] object corresponding
877c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** to the database file to which the pragma statement refers. ^The argument
878c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
879c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** pointers to strings (char**) in which the second element of the array
880c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** is the name of the pragma and the third element is the argument to the
881c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** pragma or NULL if the pragma has no argument.  ^The handler for an
882c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
883c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** of the char** argument point to a string obtained from [sqlite3_mprintf()]
884c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** or the equivalent and that string will become the result of the pragma or
885c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** the error message if the pragma fails. ^If the
886c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
887c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
888c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** file control returns [SQLITE_OK], then the parser assumes that the
889c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** VFS has handled the PRAGMA itself and the parser generates a no-op
890c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** prepared statement.  ^If the [SQLITE_FCNTL_PRAGMA] file control returns
891c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
892c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** that the VFS encountered an error while handling the [PRAGMA] and the
893c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
894c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** file control occurs at the beginning of pragma statement analysis and so
895c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** it is able to override built-in [PRAGMA] statements.
8968fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
8978fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
8988fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The [SQLITE_FCNTL_BUSYHANDLER]
8998fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** file-control may be invoked by SQLite on the database file handle
9008fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** shortly after it is opened in order to provide a custom VFS with access
9018fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to the connections busy-handler callback. The argument is of type (void **)
9028fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** - an array of two (void *) values. The first (void *) actually points
9038fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to a function of type (int (*)(void *)). In order to invoke the connections
9048fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** busy-handler, this function should be invoked with the second (void *) in
9058fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the array as the only argument. If it returns non-zero, then the operation
9068fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** should be retried. If it returns zero, the custom VFS should abandon the
9078fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** current operation.
9088fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
9098fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
9108fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
9118fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to have SQLite generate a
9128fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** temporary filename using the same algorithm that is followed to generate
9138fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** temporary filenames for TEMP tables and other internal uses.  The
9148fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** argument should be a char** which will be filled with the filename
9158fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** written into memory obtained from [sqlite3_malloc()].  The caller should
9168fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** invoke [sqlite3_free()] on the result to avoid a memory leak.
9178fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
9188fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
9198fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
9208fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** maximum number of bytes that will be used for memory-mapped I/O.
9218fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The argument is a pointer to a value of type sqlite3_int64 that
9228fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** is an advisory maximum number of bytes in the file to memory map.  The
9238fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** pointer is overwritten with the old value.  The limit is not changed if
9248fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the value originally pointed to is negative, and so the current limit
9258fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** can be queried by passing in a pointer to a negative number.  This
9268fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** file-control is used internally to implement [PRAGMA mmap_size].
9278fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
9288fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li>[[SQLITE_FCNTL_TRACE]]
9298fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The [SQLITE_FCNTL_TRACE] file control provides advisory information
9308fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to the VFS about what the higher layers of the SQLite stack are doing.
9318fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** This file control is used by some VFS activity tracing [shims].
9328fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The argument is a zero-terminated string.  Higher layers in the
9338fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** SQLite stack may generate instances of this file control if
9348fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
9358fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
9368fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li>[[SQLITE_FCNTL_HAS_MOVED]]
9378fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
9388fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** pointer to an integer and it writes a boolean into that integer depending
9398fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** on whether or not the file has been renamed, moved, or deleted since it
9408fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** was first opened.
9418fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
9421c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
9431c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This
9441c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** opcode causes the xFileControl method to swap the file handle with the one
9451c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** pointed to by the pArg argument.  This capability is used during testing
9461c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** and only needs to be supported when SQLITE_TEST is defined.
9471c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**
948c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** </ul>
94990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
95090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FCNTL_LOCKSTATE               1
95190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_GET_LOCKPROXYFILE             2
95290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_SET_LOCKPROXYFILE             3
95390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_LAST_ERRNO                    4
95490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FCNTL_SIZE_HINT               5
95590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FCNTL_CHUNK_SIZE              6
95690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FCNTL_FILE_POINTER            7
95790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FCNTL_SYNC_OMITTED            8
95890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FCNTL_WIN32_AV_RETRY          9
95990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FCNTL_PERSIST_WAL            10
96090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FCNTL_OVERWRITE              11
96190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FCNTL_VFSNAME                12
96290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
963c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown#define SQLITE_FCNTL_PRAGMA                 14
9648fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_FCNTL_BUSYHANDLER            15
9658fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_FCNTL_TEMPFILENAME           16
9668fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_FCNTL_MMAP_SIZE              18
9678fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_FCNTL_TRACE                  19
9688fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_FCNTL_HAS_MOVED              20
9698fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_FCNTL_SYNC                   21
9708fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_FCNTL_COMMIT_PHASETWO        22
9711c7cea379348522163370244e8fbbff8a136b7faNick Kralevich#define SQLITE_FCNTL_WIN32_SET_HANDLE       23
972de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
973de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
974de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Mutex Handle
975de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
976de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The mutex module within SQLite defines [sqlite3_mutex] to be an
977de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** abstract type for a mutex object.  The SQLite core never looks
978de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** at the internal representation of an [sqlite3_mutex].  It only
979de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** deals with pointers to the [sqlite3_mutex] object.
980de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
981de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Mutexes are created using [sqlite3_mutex_alloc()].
982de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
983de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_mutex sqlite3_mutex;
984de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
985de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
986de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: OS Interface Object
987de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
988de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** An instance of the sqlite3_vfs object defines the interface between
989de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the SQLite core and the underlying operating system.  The "vfs"
99090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** in the name of the object stands for "virtual file system".  See
99190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the [VFS | VFS documentation] for further information.
992de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
993de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The value of the iVersion field is initially 1 but may be larger in
994de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** future versions of SQLite.  Additional fields may be appended to this
995de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** object when the iVersion value is increased.  Note that the structure
996de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the sqlite3_vfs object changes in the transaction between
997de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
998de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** modified.
999de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1000de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The szOsFile field is the size of the subclassed [sqlite3_file]
1001de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** structure used by this VFS.  mxPathname is the maximum length of
1002de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a pathname in this VFS.
1003de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1004de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Registered sqlite3_vfs objects are kept on a linked list formed by
1005de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the pNext pointer.  The [sqlite3_vfs_register()]
1006de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and [sqlite3_vfs_unregister()] interfaces manage this list
1007de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in a thread-safe way.  The [sqlite3_vfs_find()] interface
1008de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** searches the list.  Neither the application code nor the VFS
1009de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation should use the pNext pointer.
1010de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1011de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The pNext field is the only field in the sqlite3_vfs
1012de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** structure that SQLite will ever modify.  SQLite will only access
1013de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or modify this field while holding a particular static mutex.
1014de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The application should never modify anything within the sqlite3_vfs
1015de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** object once the object has been registered.
1016de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1017de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The zName field holds the name of the VFS module.  The name must
1018de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be unique across all VFS modules.
1019de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
102090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[sqlite3_vfs.xOpen]]
1021de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite guarantees that the zFilename parameter to xOpen
1022de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is either a NULL pointer or string obtained
1023de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from xFullPathname() with an optional suffix added.
1024de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If a suffix is added to the zFilename parameter, it will
1025de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** consist of a single "-" character followed by no more than
102690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** 11 alphanumeric and/or "-" characters.
1027de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite further guarantees that
1028de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the string will be valid and unchanged until xClose() is
1029de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** called. Because of the previous sentence,
1030de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [sqlite3_file] can safely store a pointer to the
1031de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** filename if it needs to remember the filename for some reason.
1032de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1033de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** must invent its own temporary name for the file.  ^Whenever the
1034de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xFilename parameter is NULL it will also be the case that the
1035de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1036de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1037de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The flags argument to xOpen() includes all bits set in
1038de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
1039de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [sqlite3_open16()] is used, then flags includes at least
1040de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1041de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If xOpen() opens a file read-only then it sets *pOutFlags to
1042de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
1043de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1044de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(SQLite will also add one of the following flags to the xOpen()
1045de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** call, depending on the object being opened:
1046de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1047de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
1048de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  [SQLITE_OPEN_MAIN_DB]
1049de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
1050de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  [SQLITE_OPEN_TEMP_DB]
1051de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
1052de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  [SQLITE_OPEN_TRANSIENT_DB]
1053de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  [SQLITE_OPEN_SUBJOURNAL]
1054de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
1055de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  [SQLITE_OPEN_WAL]
1056de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>)^
1057de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1058de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The file I/O implementation can use the object type flags to
1059de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** change the way it deals with files.  For example, an application
1060de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that does not care about crash recovery or rollback might make
1061de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the open of a journal file a no-op.  Writes to this journal would
1062de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** also be no-ops, and any attempt to read the journal would return
1063de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_IOERR.  Or the implementation might recognize that a database
1064de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** file will be doing page-aligned sector reads and writes in a random
1065de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** order and set up its I/O subsystem accordingly.
1066de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1067de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite might also add one of the following flags to the xOpen method:
1068de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1069de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
1070de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_OPEN_DELETEONCLOSE]
1071de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_OPEN_EXCLUSIVE]
1072de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>
1073de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1074de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1075de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
1076de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will be set for TEMP databases and their journals, transient
1077de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** databases, and subjournals.
1078de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1079de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1080de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1081de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1082de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1083de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_OPEN_CREATE, is used to indicate that file should always
1084de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be created, and that it is an error if it already exists.
1085de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** It is <i>not</i> used to indicate the file should be opened
1086de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for exclusive access.
1087de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1088de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^At least szOsFile bytes of memory are allocated by SQLite
1089de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to hold the  [sqlite3_file] structure passed as the third
1090de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** argument to xOpen.  The xOpen method does not have to
1091de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** allocate the structure; it should just fill it in.  Note that
1092de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the xOpen method must set the sqlite3_file.pMethods to either
1093de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
1094de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
1095de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** element will be valid after xOpen returns regardless of the success
1096de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or failure of the xOpen call.
1097de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
109890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[sqlite3_vfs.xAccess]]
1099de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1100de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1101de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1102de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to test whether a file is at least readable.   The file can be a
1103de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** directory.
1104de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1105de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite will always allocate at least mxPathname+1 bytes for the
1106de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** output buffer xFullPathname.  The exact size of the output buffer
1107de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is also passed as a parameter to both  methods. If the output buffer
1108de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1109de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** handled as a fatal error by SQLite, vfs implementations should endeavor
1110de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to prevent this by setting mxPathname to a sufficiently large value.
1111de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1112de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1113de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interfaces are not strictly a part of the filesystem, but they are
1114de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** included in the VFS structure for completeness.
1115de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xRandomness() function attempts to return nBytes bytes
1116de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of good-quality randomness into zOut.  The return value is
1117de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the actual number of bytes of randomness obtained.
1118de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xSleep() method causes the calling thread to sleep for at
1119de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** least the number of microseconds given.  ^The xCurrentTime()
1120de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** method returns a Julian Day Number for the current date and time as
1121de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a floating point value.
1122de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
112390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** Day Number multiplied by 86400000 (the number of milliseconds in
1124de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a 24-hour day).
1125de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite will use the xCurrentTimeInt64() method to get the current
1126de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** date and time if that method is available (if iVersion is 2 or
1127de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** greater and the function pointer is not NULL) and will fall back
1128de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
112990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
113090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
113190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** are not used by the SQLite core.  These optional interfaces are provided
113290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** by some VFSes to facilitate testing of the VFS code. By overriding
113390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** system calls with functions under its control, a test program can
113490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** simulate faults and error conditions that would otherwise be difficult
113590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** or impossible to induce.  The set of system calls that can be overridden
113690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** varies from one VFS to another, and from one version of the same VFS to the
113790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** next.  Applications that use these interfaces must be prepared for any
113890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** or all of these interfaces to be NULL or for their behavior to change
113990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** from one release to the next.  Applications must not attempt to access
114090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** any of these methods if the iVersion of the VFS is less than 3.
1141de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1142de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_vfs sqlite3_vfs;
114390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Browntypedef void (*sqlite3_syscall_ptr)(void);
1144de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_vfs {
114590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int iVersion;            /* Structure version number (currently 3) */
1146de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int szOsFile;            /* Size of subclassed sqlite3_file */
1147de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int mxPathname;          /* Maximum file pathname length */
1148de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3_vfs *pNext;      /* Next registered VFS */
1149de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zName;       /* Name of this virtual file system */
1150de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pAppData;          /* Pointer to application-specific data */
1151de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1152de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori               int flags, int *pOutFlags);
1153de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1154de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1155de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1156de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1157de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1158de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1159de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xDlClose)(sqlite3_vfs*, void*);
1160de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1161de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xSleep)(sqlite3_vfs*, int microseconds);
1162de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xCurrentTime)(sqlite3_vfs*, double*);
1163de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xGetLastError)(sqlite3_vfs*, int, char *);
1164de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  /*
1165de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  ** The methods above are in version 1 of the sqlite_vfs object
1166de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  ** definition.  Those that follow are added in version 2 or later
1167de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  */
1168de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1169de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  /*
1170de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
117190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  ** Those below are for version 3 and greater.
117290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  */
117390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
117490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
117590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
117690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  /*
117790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1178de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  ** New fields may be appended in figure versions.  The iVersion
1179de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  ** value will increment whenever this happens.
1180de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  */
1181de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
1182de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1183de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1184de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Flags for the xAccess VFS method
1185de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1186de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These integer constants can be used as the third parameter to
1187de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the xAccess method of an [sqlite3_vfs] object.  They determine
1188de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** what kind of permissions the xAccess method is looking for.
1189de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** With SQLITE_ACCESS_EXISTS, the xAccess method
1190de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** simply checks whether the file exists.
1191de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** With SQLITE_ACCESS_READWRITE, the xAccess method
1192de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** checks whether the named directory is both readable and writable
1193de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (in other words, if files can be added, removed, and renamed within
1194de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the directory).
1195de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1196de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [temp_store_directory pragma], though this could change in a future
1197de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** release of SQLite.
1198de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** With SQLITE_ACCESS_READ, the xAccess method
1199de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
1200de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** currently unused, though it might be used in a future release of
1201de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite.
1202de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1203de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_ACCESS_EXISTS    0
1204de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
1205de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_ACCESS_READ      2   /* Unused */
1206de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1207de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1208de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Flags for the xShmLock VFS method
1209de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1210de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These integer constants define the various locking operations
1211de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** allowed by the xShmLock method of [sqlite3_io_methods].  The
1212de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** following are the only legal combinations of flags to the
1213de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xShmLock method:
1214de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1215de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
1216de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1217de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1218de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1219de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1220de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>
1221de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1222de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1223de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** was given no the corresponding lock.
1224de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1225de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xShmLock method can transition between unlocked and SHARED or
1226de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
1227de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and EXCLUSIVE.
1228de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1229de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SHM_UNLOCK       1
1230de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SHM_LOCK         2
1231de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SHM_SHARED       4
1232de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SHM_EXCLUSIVE    8
1233de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1234de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1235de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Maximum xShmLock index
1236de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1237de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xShmLock method on [sqlite3_io_methods] may use values
1238de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** between 0 and this upper bound as its "offset" argument.
1239de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The SQLite core will never attempt to acquire or release a
1240de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** lock outside of this range
1241de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1242de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SHM_NLOCK        8
1243de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1244de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1245de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1246de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Initialize The SQLite Library
1247de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1248de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_initialize() routine initializes the
1249de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite library.  ^The sqlite3_shutdown() routine
1250de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** deallocates any resources that were allocated by sqlite3_initialize().
1251de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines are designed to aid in process initialization and
1252de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** shutdown on embedded systems.  Workstation applications using
1253de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite normally do not need to invoke either of these routines.
1254de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1255de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A call to sqlite3_initialize() is an "effective" call if it is
1256de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the first time sqlite3_initialize() is invoked during the lifetime of
1257de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the process, or if it is the first time sqlite3_initialize() is invoked
1258de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** following a call to sqlite3_shutdown().  ^(Only an effective call
1259de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of sqlite3_initialize() does any initialization.  All other calls
1260de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are harmless no-ops.)^
1261de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1262de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A call to sqlite3_shutdown() is an "effective" call if it is the first
1263de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
1264de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an effective call to sqlite3_shutdown() does any deinitialization.
1265de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1266de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1267de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1268de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is not.  The sqlite3_shutdown() interface must only be called from a
1269de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** single thread.  All open [database connections] must be closed and all
1270de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** other SQLite resources must be deallocated prior to invoking
1271de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_shutdown().
1272de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1273de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Among other things, ^sqlite3_initialize() will invoke
1274de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
1275de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will invoke sqlite3_os_end().
1276de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1277de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1278de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If for some reason, sqlite3_initialize() is unable to initialize
1279de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the library (perhaps it is unable to allocate a needed resource such
1280de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as a mutex) it returns an [error code] other than [SQLITE_OK].
1281de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1282de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_initialize() routine is called internally by many other
1283de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite interfaces so that an application usually does not need to
1284de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
1285de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** calls sqlite3_initialize() so the SQLite library will be automatically
1286de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** initialized when [sqlite3_open()] is called if it has not be initialized
1287de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1288de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compile-time option, then the automatic calls to sqlite3_initialize()
1289de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are omitted and the application must call sqlite3_initialize() directly
1290de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** prior to using any other SQLite interface.  For maximum portability,
1291de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it is recommended that applications always invoke sqlite3_initialize()
1292de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** directly prior to using any other SQLite interface.  Future releases
1293de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of SQLite may require this.  In other words, the behavior exhibited
1294de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1295de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** default behavior in some future release of SQLite.
1296de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1297de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_os_init() routine does operating-system specific
1298de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** initialization of the SQLite library.  The sqlite3_os_end()
1299de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routine undoes the effect of sqlite3_os_init().  Typical tasks
1300de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** performed by these routines include allocation or deallocation
1301de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of static resources, initialization of global variables,
1302de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** setting up a default [sqlite3_vfs] module, or setting up
1303de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a default configuration using [sqlite3_config()].
1304de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1305de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The application should never invoke either sqlite3_os_init()
1306de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or sqlite3_os_end() directly.  The application should only invoke
1307de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
1308de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface is called automatically by sqlite3_initialize() and
1309de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
1310de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementations for sqlite3_os_init() and sqlite3_os_end()
1311de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1312de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When [custom builds | built for other platforms]
1313de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (using the [SQLITE_OS_OTHER=1] compile-time
1314de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** option) the application must supply a suitable implementation for
1315de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
1316de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation of sqlite3_os_init() or sqlite3_os_end()
1317de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** must return [SQLITE_OK] on success and some other [error code] upon
1318de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** failure.
1319de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1320de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_initialize(void);
1321de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_shutdown(void);
1322de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_os_init(void);
1323de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_os_end(void);
1324de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1325de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1326de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Configuring The SQLite Library
1327de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1328de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_config() interface is used to make global configuration
1329de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** changes to SQLite in order to tune SQLite to the specific needs of
1330de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the application.  The default configuration is recommended for most
1331de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** applications and so this routine is usually not necessary.  It is
1332de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** provided to support rare applications with unusual needs.
1333de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1334de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_config() interface is not threadsafe.  The application
1335de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** must insure that no other SQLite interfaces are invoked by other
1336de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()
1337de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** may only be invoked prior to library initialization using
1338de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1339de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1340de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1341de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Note, however, that ^sqlite3_config() can be called as part of the
1342de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation of an application-defined [sqlite3_os_init()].
1343de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1344de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The first argument to sqlite3_config() is an integer
134590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [configuration option] that determines
1346de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** what property of SQLite is to be configured.  Subsequent arguments
134790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** vary depending on the [configuration option]
1348de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in the first argument.
1349de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1350de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1351de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the option is unknown or SQLite is unable to set the option
1352de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then this routine returns a non-zero [error code].
1353de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1354de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_config(int, ...);
1355de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1356de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1357de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Configure database connections
1358de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1359de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_db_config() interface is used to make configuration
1360de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** changes to a [database connection].  The interface is similar to
1361de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_config()] except that the changes apply to a single
136290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [database connection] (specified in the first argument).
1363de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1364de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The second argument to sqlite3_db_config(D,V,...)  is the
136590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
136690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** that indicates what aspect of the [database connection] is being configured.
136790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** Subsequent arguments vary depending on the configuration verb.
1368de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1369de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1370de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the call is considered successful.
1371de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1372de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1373de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1374de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1375de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Memory Allocation Routines
1376de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1377de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** An instance of this object defines the interface between SQLite
1378de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and low-level memory allocation routines.
1379de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1380de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This object is used in only one place in the SQLite interface.
1381de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A pointer to an instance of this object is the argument to
1382de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_config()] when the configuration option is
1383de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1384de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** By creating an instance of this object
1385de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1386de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** during configuration, an application can specify an alternative
1387de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory allocation subsystem for SQLite to use for all of its
1388de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** dynamic memory needs.
1389de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1390de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Note that SQLite comes with several [built-in memory allocators]
1391de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that are perfectly adequate for the overwhelming majority of applications
1392de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and that this object is only useful to a tiny minority of applications
1393de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with specialized memory allocation requirements.  This object is
1394de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** also used during testing of SQLite in order to specify an alternative
1395de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory allocator that simulates memory out-of-memory conditions in
1396de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** order to verify that SQLite recovers gracefully from such
1397de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** conditions.
1398de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
139990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The xMalloc, xRealloc, and xFree methods must work like the
140090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** malloc(), realloc() and free() functions from the standard C library.
140190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^SQLite guarantees that the second argument to
1402de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xRealloc is always a value returned by a prior call to xRoundup.
1403de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1404de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xSize should return the allocated size of a memory allocation
1405de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** previously obtained from xMalloc or xRealloc.  The allocated size
1406de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is always at least as big as the requested size but may be larger.
1407de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1408de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xRoundup method returns what would be the allocated size of
1409de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a memory allocation given a particular requested size.  Most memory
1410de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** allocators round up memory allocations at least to the next multiple
1411de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of 8.  Some allocators round up to a larger multiple or to a power of 2.
1412de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Every memory allocation request coming in through [sqlite3_malloc()]
1413de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0,
1414de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that causes the corresponding memory allocation to fail.
1415de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
14168fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The xInit method initializes the memory allocator.  For example,
1417de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it might allocate any require mutexes or initialize internal data
1418de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** structures.  The xShutdown method is invoked (indirectly) by
1419de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_shutdown()] and should deallocate any resources acquired
1420de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by xInit.  The pAppData pointer is used as the only parameter to
1421de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xInit and xShutdown.
1422de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1423de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1424de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the xInit method, so the xInit method need not be threadsafe.  The
1425de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xShutdown method is only called from [sqlite3_shutdown()] so it does
1426de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not need to be threadsafe either.  For all other methods, SQLite
1427de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1428de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1429de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it is by default) and so the methods are automatically serialized.
1430de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1431de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** methods must be threadsafe or else make their own arrangements for
1432de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** serialization.
1433de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1434de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite will never invoke xInit() more than once without an intervening
1435de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** call to xShutdown().
1436de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1437de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_mem_methods sqlite3_mem_methods;
1438de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_mem_methods {
1439de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *(*xMalloc)(int);         /* Memory allocation function */
1440de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xFree)(void*);          /* Free a prior allocation */
1441de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *(*xRealloc)(void*,int);  /* Resize an allocation */
1442de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xSize)(void*);           /* Return the size of an allocation */
1443de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xRoundup)(int);          /* Round up request size to allocation size */
1444de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xInit)(void*);           /* Initialize the memory allocator */
1445de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
1446de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pAppData;                /* Argument to xInit() and xShutdown() */
1447de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
1448de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1449de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1450de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Configuration Options
145190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** KEYWORDS: {configuration option}
1452de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1453de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These constants are the available integer configuration options that
1454de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be passed as the first argument to the [sqlite3_config()] interface.
1455de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1456de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** New configuration options may be added in future releases of SQLite.
1457de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Existing configuration options might be discontinued.  Applications
1458de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** should check the return code from [sqlite3_config()] to make sure that
1459de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the call worked.  The [sqlite3_config()] interface will return a
1460de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** non-zero [error code] if a discontinued or unsupported configuration option
1461de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is invoked.
1462de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1463de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dl>
146490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1465de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>There are no arguments to this option.  ^This option sets the
1466de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [threading mode] to Single-thread.  In other words, it disables
1467de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** all mutexing and puts SQLite into a mode where it can only be used
1468de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by a single thread.   ^If SQLite is compiled with
1469de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1470de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it is not possible to change the [threading mode] from its default
1471de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value of Single-thread and so [sqlite3_config()] will return
1472de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1473de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** configuration option.</dd>
1474de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
147590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1476de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>There are no arguments to this option.  ^This option sets the
1477de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [threading mode] to Multi-thread.  In other words, it disables
1478de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** mutexing on [database connection] and [prepared statement] objects.
1479de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The application is responsible for serializing access to
1480de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connections] and [prepared statements].  But other mutexes
1481de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are enabled so that SQLite will be safe to use in a multi-threaded
1482de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** environment as long as no two threads attempt to use the same
1483de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection] at the same time.  ^If SQLite is compiled with
1484de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1485de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it is not possible to set the Multi-thread [threading mode] and
1486de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1487de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1488de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
148990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1490de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>There are no arguments to this option.  ^This option sets the
1491de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [threading mode] to Serialized. In other words, this option enables
1492de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** all mutexes including the recursive
1493de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** mutexes on [database connection] and [prepared statement] objects.
1494de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** In this mode (which is the default when SQLite is compiled with
1495de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1496de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to [database connections] and [prepared statements] so that the
1497de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** application is free to use the same [database connection] or the
1498de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** same [prepared statement] in different threads at the same time.
1499de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If SQLite is compiled with
1500de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1501de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it is not possible to set the Serialized [threading mode] and
1502de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1503de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1504de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
150590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1506de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^(This option takes a single argument which is a pointer to an
1507de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** instance of the [sqlite3_mem_methods] structure.  The argument specifies
1508de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** alternative low-level memory allocation routines to be used in place of
1509de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the memory allocation routines built into SQLite.)^ ^SQLite makes
1510de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** its own private copy of the content of the [sqlite3_mem_methods] structure
1511de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** before the [sqlite3_config()] call returns.</dd>
1512de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
151390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1514de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^(This option takes a single argument which is a pointer to an
1515de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]
1516de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** structure is filled with the currently defined memory allocation routines.)^
1517de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This option can be used to overload the default memory allocation
1518de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routines with a wrapper that simulations memory allocation failure or
1519de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** tracks memory usage, for example. </dd>
1520de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
152190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1522de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^This option takes single argument of type int, interpreted as a
1523de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** boolean, which enables or disables the collection of memory allocation
1524de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** statistics. ^(When memory allocation statistics are disabled, the
1525de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** following SQLite interfaces become non-operational:
1526de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <ul>
1527de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li> [sqlite3_memory_used()]
1528de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li> [sqlite3_memory_highwater()]
1529de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li> [sqlite3_soft_heap_limit64()]
1530de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li> [sqlite3_status()]
1531de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   </ul>)^
1532de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Memory allocation statistics are enabled by default unless SQLite is
1533de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1534de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** allocation statistics are disabled by default.
1535de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </dd>
1536de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
153790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1538de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^This option specifies a static memory buffer that SQLite can use for
1539de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** scratch memory.  There are three arguments:  A pointer an 8-byte
154090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** aligned memory buffer from which the scratch allocations will be
1541de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** drawn, the size of each scratch allocation (sz),
1542de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the maximum number of scratch allocations (N).  The sz
1543de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** argument must be a multiple of 16.
1544de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The first argument must be a pointer to an 8-byte aligned buffer
1545de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of at least sz*N bytes of memory.
1546de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite will use no more than two scratch buffers per thread.  So
1547de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** N should be set to twice the expected maximum number of threads.
1548de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite will never require a scratch buffer that is more than 6
1549de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** times the database page size. ^If SQLite needs needs additional
1550de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** scratch memory beyond what is provided by this configuration option, then
1551de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
1552de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
155390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1554de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^This option specifies a static memory buffer that SQLite can use for
155590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the database page cache with the default page cache implementation.
1556de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This configuration should not be used if an application-define page
155790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option.
1558de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** There are three arguments to this option: A pointer to 8-byte aligned
1559de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory, the size of each page buffer (sz), and the number of pages (N).
1560de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sz argument should be the size of the largest database page
1561de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (a power of two between 512 and 32768) plus a little extra for each
1562de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** page header.  ^The page header size is 20 to 40 bytes depending on
1563de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the host architecture.  ^It is harmless, apart from the wasted memory,
1564de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to make sz a little too large.  The first
1565de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** argument should point to an allocation of at least sz*N bytes of memory.
1566de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite will use the memory provided by the first argument to satisfy its
1567de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory needs for the first N pages that it adds to cache.  ^If additional
1568de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** page cache memory is needed beyond what is provided by this option, then
1569de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite goes to [sqlite3_malloc()] for the additional storage space.
1570de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The pointer in the first argument must
1571de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be aligned to an 8-byte boundary or subsequent behavior of SQLite
1572de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will be undefined.</dd>
1573de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
157490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1575de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^This option specifies a static memory buffer that SQLite will use
1576de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for all of its dynamic memory allocation needs beyond those provided
1577de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
1578de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** There are three arguments: An 8-byte aligned pointer to the memory,
1579de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the number of bytes in the memory buffer, and the minimum allocation size.
1580de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1581de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to using its default memory allocator (the system malloc() implementation),
1582de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
1583de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
1584de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
1585de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** allocator is engaged to handle all of SQLites memory allocation needs.
1586de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The first pointer (the memory pointer) must be aligned to an 8-byte
158790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** boundary or subsequent behavior of SQLite will be undefined.
158890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The minimum allocation size is capped at 2**12. Reasonable values
158990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** for the minimum allocation size are 2**5 through 2**8.</dd>
1590de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
159190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1592de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^(This option takes a single argument which is a pointer to an
1593de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** instance of the [sqlite3_mutex_methods] structure.  The argument specifies
1594de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** alternative low-level mutex routines to be used in place
1595de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
1596de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** content of the [sqlite3_mutex_methods] structure before the call to
1597de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_config()] returns. ^If SQLite is compiled with
1598de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1599de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the entire mutexing subsystem is omitted from the build and hence calls to
1600de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1601de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** return [SQLITE_ERROR].</dd>
1602de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
160390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1604de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^(This option takes a single argument which is a pointer to an
1605de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** instance of the [sqlite3_mutex_methods] structure.  The
1606de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_mutex_methods]
1607de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** structure is filled with the currently defined mutex routines.)^
1608de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This option can be used to overload the default mutex allocation
1609de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routines with a wrapper used to track mutex usage for performance
1610de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** profiling or testing, for example.   ^If SQLite is compiled with
1611de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1612de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the entire mutexing subsystem is omitted from the build and hence calls to
1613de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1614de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** return [SQLITE_ERROR].</dd>
1615de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
161690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1617de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^(This option takes two arguments that determine the default
1618de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory allocation for the lookaside memory allocator on each
1619de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection].  The first argument is the
1620de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** size of each lookaside buffer slot and the second is the number of
1621de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** slots allocated to each database connection.)^  ^(This option sets the
1622de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1623de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** verb to [sqlite3_db_config()] can be used to change the lookaside
1624de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** configuration on individual connections.)^ </dd>
1625de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
162690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1627de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^(This option takes a single argument which is a pointer to
162890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** an [sqlite3_pcache_methods2] object.  This object specifies the interface
1629de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to a custom page cache implementation.)^  ^SQLite makes a copy of the
1630de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** object and uses it for page cache memory allocations.</dd>
1631de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
163290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1633de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^(This option takes a single argument which is a pointer to an
163490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_pcache_methods2] object.  SQLite copies of the current
1635de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** page cache implementation into that object.)^ </dd>
1636de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
163790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
16388fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
16398fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** global [error log].
16408fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1641de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function with a call signature of void(*)(void*,int,const char*),
1642de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and a pointer to void. ^If the function pointer is not NULL, it is
1643de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** invoked by [sqlite3_log()] to process each logging event.  ^If the
1644de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1645de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1646de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** passed through as the first parameter to the application-defined logger
1647de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function whenever that function is invoked.  ^The second parameter to
1648de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the logger function is a copy of the first parameter to the corresponding
1649de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_log()] call and is intended to be a [result code] or an
1650de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [extended result code].  ^The third parameter passed to the logger is
1651de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** log message after formatting via [sqlite3_snprintf()].
1652de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The SQLite logging interface is not reentrant; the logger function
1653de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** supplied by the application must not invoke any SQLite interface.
1654de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** In a multi-threaded application, the application-defined logger
1655de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function must be threadsafe. </dd>
1656de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
165790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
16588fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dd>^(This option takes a single argument of type int. If non-zero, then
165990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** URI handling is globally enabled. If the parameter is zero, then URI handling
16608fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** is globally disabled.)^ ^If URI handling is globally enabled, all filenames
166190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
166290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** specified as part of [ATTACH] commands are interpreted as URIs, regardless
166390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
16648fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** connection is opened. ^If it is globally disabled, filenames are
166590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
16668fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** database connection is opened. ^(By default, URI handling is globally
166790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** disabled. The default value may be changed by compiling with the
16688fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [SQLITE_USE_URI] symbol defined.)^
16698fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
16708fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
16718fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dd>^This option takes a single integer argument which is interpreted as
16728fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** a boolean in order to enable or disable the use of covering indices for
16738fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** full table scans in the query optimizer.  ^The default setting is determined
16748fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
16758fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** if that compile-time option is omitted.
16768fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The ability to disable the use of covering indices for full table scans
16778fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** is because some incorrectly coded legacy applications might malfunction
16788fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** when the optimization is enabled.  Providing the ability to
16798fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** disable the optimization allows the older, buggy application code to work
16808fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** without change even with newer versions of SQLite.
168190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
168290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
16838fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
168490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd> These options are obsolete and should not be used by new code.
168590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** They are retained for backwards compatibility but are now no-ops.
16868fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** </dd>
16878fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
16888fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [[SQLITE_CONFIG_SQLLOG]]
16898fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dt>SQLITE_CONFIG_SQLLOG
16908fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dd>This option is only available if sqlite is compiled with the
16918fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
16928fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
16938fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The second should be of type (void*). The callback is invoked by the library
16948fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** in three separate circumstances, identified by the value passed as the
16958fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** fourth parameter. If the fourth parameter is 0, then the database connection
16968fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** passed as the second argument has just been opened. The third argument
16978fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** points to a buffer containing the name of the main database file. If the
16988fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** fourth parameter is 1, then the SQL statement that the third parameter
16998fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** points to has just been executed. Or, if the fourth parameter is 2, then
17008fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the connection being passed as the second parameter is being closed. The
17018fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** third parameter is passed NULL In this case.  An example of using this
17028fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** configuration option can be seen in the "test_sqllog.c" source file in
17038fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the canonical SQLite source tree.</dd>
17048fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
17058fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [[SQLITE_CONFIG_MMAP_SIZE]]
17068fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dt>SQLITE_CONFIG_MMAP_SIZE
17078fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
17088fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** that are the default mmap size limit (the default setting for
17098fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
17108fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The default setting can be overridden by each database connection using
17118fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** either the [PRAGMA mmap_size] command, or by using the
17128fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
17138fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** cannot be changed at run-time.  Nor may the maximum allowed mmap size
17148fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** exceed the compile-time maximum mmap size set by the
17158fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
17168fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^If either argument to this option is negative, then that argument is
17178fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** changed to its compile-time default.
17188fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
17198fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
17208fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
17218fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dd>^This option is only available if SQLite is compiled for Windows
17228fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined.
17238fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
17248fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** that specifies the maximum size of the created heap.
1725de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </dl>
1726de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1727de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
1728de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
1729de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
1730de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
1731de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
1732de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
1733de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
1734de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
1735de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
1736de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
1737de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
1738de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1739de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
174090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_CONFIG_PCACHE       14  /* no-op */
174190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_CONFIG_GETPCACHE    15  /* no-op */
1742de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
174390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_CONFIG_URI          17  /* int */
174490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
174590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
17468fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
17478fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
17488fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
17498fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
1750de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1751de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1752de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Database Connection Configuration Options
1753de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1754de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These constants are the available integer configuration options that
1755de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be passed as the second argument to the [sqlite3_db_config()] interface.
1756de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1757de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** New configuration options may be added in future releases of SQLite.
1758de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Existing configuration options might be discontinued.  Applications
1759de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** should check the return code from [sqlite3_db_config()] to make sure that
1760de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the call worked.  ^The [sqlite3_db_config()] interface will return a
1761de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** non-zero [error code] if a discontinued or unsupported configuration option
1762de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is invoked.
1763de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1764de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dl>
1765de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1766de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd> ^This option takes three additional arguments that determine the
1767de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [lookaside memory allocator] configuration for the [database connection].
1768de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first argument (the third parameter to [sqlite3_db_config()] is a
176990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** pointer to a memory buffer to use for lookaside memory.
1770de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1771de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** may be NULL in which case SQLite will allocate the
1772de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1773de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** size of each lookaside buffer slot.  ^The third argument is the number of
1774de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** slots.  The size of the buffer in the first argument must be greater than
1775de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or equal to the product of the second and third arguments.  The buffer
1776de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** must be aligned to an 8-byte boundary.  ^If the second argument to
1777de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1778de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** rounded down to the next smaller multiple of 8.  ^(The lookaside memory
1779de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** configuration for a database connection can only be changed when that
1780de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** connection is not currently using lookaside memory, or in other words
1781de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** when the "current value" returned by
1782de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1783de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Any attempt to change the lookaside memory configuration when lookaside
1784de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory is in use leaves the configuration unchanged and returns
1785de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_BUSY].)^</dd>
1786de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
178790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
178890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd> ^This option is used to enable or disable the enforcement of
178990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [foreign key constraints].  There should be two additional arguments.
179090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The first argument is an integer which is 0 to disable FK enforcement,
179190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** positive to enable FK enforcement or negative to leave FK enforcement
179290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** unchanged.  The second parameter is a pointer to an integer into which
179390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is written 0 or 1 to indicate whether FK enforcement is off or on
179490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** following this call.  The second parameter may be a NULL pointer, in
179590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** which case the FK enforcement setting is not reported back. </dd>
179690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
179790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
179890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
179990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** There should be two additional arguments.
180090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The first argument is an integer which is 0 to disable triggers,
180190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** positive to enable triggers or negative to leave the setting unchanged.
180290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The second parameter is a pointer to an integer into which
180390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is written 0 or 1 to indicate whether triggers are disabled or enabled
180490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** following this call.  The second parameter may be a NULL pointer, in
180590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** which case the trigger setting is not reported back. </dd>
180690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
1807de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </dl>
1808de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
180990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
181090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
181190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
1812de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1813de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1814de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1815de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Enable Or Disable Extended Result Codes
1816de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1817de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_extended_result_codes() routine enables or disables the
1818de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [extended result codes] feature of SQLite. ^The extended result
1819de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** codes are disabled by default for historical compatibility.
1820de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1821de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
1822de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1823de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1824de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Last Insert Rowid
1825de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
18268fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
18278fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** has a unique 64-bit signed
1828de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** integer key called the [ROWID | "rowid"]. ^The rowid is always available
1829de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
1830de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** names are not also used by explicitly declared columns. ^If
1831de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the table has a column of type [INTEGER PRIMARY KEY] then that column
1832de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is another alias for the rowid.
1833de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
18348fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the
18358fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** most recent successful [INSERT] into a rowid table or [virtual table]
18368fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** on database connection D.
18378fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^Inserts into [WITHOUT ROWID] tables are not recorded.
18388fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^If no successful [INSERT]s into rowid tables
18398fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** have ever occurred on the database connection D,
18408fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** then sqlite3_last_insert_rowid(D) returns zero.
1841de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
184290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
184390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** method, then this routine will return the [rowid] of the inserted
184490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** row as long as the trigger or virtual table method is running.
184590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** But once the trigger or virtual table method ends, the value returned
184690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** by this routine reverts to what it was before the trigger or virtual
184790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** table method began.)^
1848de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1849de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^An [INSERT] that fails due to a constraint violation is not a
1850de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** successful [INSERT] and does not change the value returned by this
1851de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
1852de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and INSERT OR ABORT make no changes to the return value of this
1853de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routine when their insertion fails.  ^(When INSERT OR REPLACE
1854de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** encounters a constraint violation, it does not fail.  The
1855de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** INSERT continues to completion after deleting rows that caused
1856de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the constraint problem so INSERT OR REPLACE will always change
1857de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the return value of this interface.)^
1858de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1859de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^For the purposes of this routine, an [INSERT] is considered to
1860de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be successful even if it is subsequently rolled back.
1861de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1862de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This function is accessible to SQL statements via the
1863de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [last_insert_rowid() SQL function].
1864de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1865de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If a separate thread performs a new [INSERT] on the same
1866de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database connection while the [sqlite3_last_insert_rowid()]
1867de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function is running and thus changes the last insert [rowid],
1868de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the value returned by [sqlite3_last_insert_rowid()] is
1869de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** unpredictable and might not equal either the old or the new
1870de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** last insert [rowid].
1871de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1872de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
1873de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1874de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1875de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Count The Number Of Rows Modified
1876de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1877de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This function returns the number of database rows that were changed
1878de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or inserted or deleted by the most recently completed SQL statement
1879de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on the [database connection] specified by the first parameter.
1880de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
1881de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [DELETE] statement are counted.  Auxiliary changes caused by
1882de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** triggers or [foreign key actions] are not counted.)^ Use the
1883de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_total_changes()] function to find the total number of changes
1884de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** including changes caused by triggers and foreign key actions.
1885de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1886de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
1887de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are not counted.  Only real table changes are counted.
1888de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1889de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(A "row change" is a change to a single row of a single table
1890de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
1891de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are changed as side effects of [REPLACE] constraint resolution,
1892de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** rollback, ABORT processing, [DROP TABLE], or by any other
1893de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** mechanisms do not count as direct row changes.)^
1894de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1895de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A "trigger context" is a scope of execution that begins and
1896de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ends with the script of a [CREATE TRIGGER | trigger].
1897de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Most SQL statements are
1898de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** evaluated outside of any trigger.  This is the "top level"
1899de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** trigger context.  If a trigger fires from the top level, a
1900de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** new trigger context is entered for the duration of that one
1901de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** trigger.  Subtriggers create subcontexts for their duration.
1902de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1903de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
1904de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not create a new trigger context.
1905de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1906de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This function returns the number of direct row changes in the
1907de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** most recent INSERT, UPDATE, or DELETE statement within the same
1908de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** trigger context.
1909de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1910de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Thus, when called from the top level, this function returns the
1911de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** number of changes in the most recent INSERT, UPDATE, or DELETE
1912de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that also occurred at the top level.  ^(Within the body of a trigger,
1913de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the sqlite3_changes() interface can be called to find the number of
1914de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** changes in the most recently completed INSERT, UPDATE, or DELETE
1915de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** statement within the body of the same trigger.
1916de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** However, the number returned does not include changes
1917de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** caused by subtriggers since those have their own context.)^
1918de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1919de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also the [sqlite3_total_changes()] interface, the
1920de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [count_changes pragma], and the [changes() SQL function].
1921de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1922de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If a separate thread makes changes on the same database connection
1923de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** while [sqlite3_changes()] is running then the value returned
1924de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is unpredictable and not meaningful.
1925de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1926de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_changes(sqlite3*);
1927de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1928de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1929de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Total Number Of Rows Modified
1930de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1931de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This function returns the number of row changes caused by [INSERT],
1932de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [UPDATE] or [DELETE] statements since the [database connection] was opened.
1933de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The count returned by sqlite3_total_changes() includes all changes
1934de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from all [CREATE TRIGGER | trigger] contexts and changes made by
1935de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [foreign key actions]. However,
1936de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the count does not include changes used to implement [REPLACE] constraints,
1937de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** do rollbacks or ABORT processing, or [DROP TABLE] processing.  The
1938de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** count does not include rows of views that fire an [INSTEAD OF trigger],
1939de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** though if the INSTEAD OF trigger makes changes of its own, those changes
1940de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are counted.)^
1941de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_total_changes() function counts the changes as soon as
1942de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the statement that makes them is completed (when the statement handle
1943de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
1944de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1945de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also the [sqlite3_changes()] interface, the
1946de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [count_changes pragma], and the [total_changes() SQL function].
1947de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1948de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If a separate thread makes changes on the same database connection
1949de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** while [sqlite3_total_changes()] is running then the value
1950de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returned is unpredictable and not meaningful.
1951de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1952de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_total_changes(sqlite3*);
1953de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1954de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1955de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Interrupt A Long-Running Query
1956de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1957de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This function causes any pending database operation to abort and
1958de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** return at its earliest opportunity. This routine is typically
1959de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** called in response to a user action such as pressing "Cancel"
1960de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or Ctrl-C where the user wants a long query operation to halt
1961de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** immediately.
1962de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1963de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^It is safe to call this routine from a thread different from the
1964de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** thread that is currently running the database operation.  But it
1965de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is not safe to call this routine with a [database connection] that
1966de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is closed or might close before sqlite3_interrupt() returns.
1967de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1968de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If an SQL operation is very nearly finished at the time when
1969de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_interrupt() is called, then it might not have an opportunity
1970de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to be interrupted and might continue to completion.
1971de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1972de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
1973de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
1974de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that is inside an explicit transaction, then the entire transaction
1975de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will be rolled back automatically.
1976de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1977de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_interrupt(D) call is in effect until all currently running
1978de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQL statements on [database connection] D complete.  ^Any new SQL statements
1979de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that are started after the sqlite3_interrupt() call and before the
1980de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** running statements reaches zero are interrupted as if they had been
1981de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** running prior to the sqlite3_interrupt() call.  ^New SQL statements
1982de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that are started after the running statement count reaches zero are
1983de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not effected by the sqlite3_interrupt().
1984de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^A call to sqlite3_interrupt(D) that occurs when there are no running
1985de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQL statements is a no-op and has no effect on SQL statements
1986de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that are started after the sqlite3_interrupt() call returns.
1987de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1988de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If the database connection closes while [sqlite3_interrupt()]
1989de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is running then bad things will likely happen.
1990de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
1991de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_interrupt(sqlite3*);
1992de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
1993de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
1994de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Determine If An SQL Statement Is Complete
1995de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
1996de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines are useful during command-line input to determine if the
1997de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** currently entered text seems to form a complete SQL statement or
1998de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if additional input is needed before sending the text into
1999de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite for parsing.  ^These routines return 1 if the input string
2000de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** appears to be a complete SQL statement.  ^A statement is judged to be
2001de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** complete if it ends with a semicolon token and is not a prefix of a
2002de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
2003de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** string literals or quoted identifier names or comments are not
2004de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** independent tokens (they are part of the token in which they are
2005de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** embedded) and thus do not count as a statement terminator.  ^Whitespace
2006de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and comments that follow the final semicolon are ignored.
2007de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2008de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These routines return 0 if the statement is incomplete.  ^If a
2009de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory allocation fails, then SQLITE_NOMEM is returned.
2010de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2011de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These routines do not parse the SQL statements thus
2012de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will not detect syntactically incorrect SQL.
2013de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2014de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2015de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2016de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** automatically by sqlite3_complete16().  If that initialization fails,
2017de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the return value from sqlite3_complete16() will be non-zero
2018de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** regardless of whether or not the input SQL is complete.)^
2019de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2020de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The input to [sqlite3_complete()] must be a zero-terminated
2021de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** UTF-8 string.
2022de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2023de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The input to [sqlite3_complete16()] must be a zero-terminated
2024de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** UTF-16 string in native byte order.
2025de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2026de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_complete(const char *sql);
2027de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_complete16(const void *sql);
2028de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2029de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2030de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2031de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
20329bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
20339bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** that might be invoked with argument P whenever
20349bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** an attempt is made to access a database table associated with
20359bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** [database connection] D when another thread
20369bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** or process has the table locked.
20379bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** The sqlite3_busy_handler() interface is used to implement
20389bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2039de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
20409bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** ^If the busy callback is NULL, then [SQLITE_BUSY]
2041de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is returned immediately upon encountering the lock.  ^If the busy callback
2042de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is not NULL, then the callback might be invoked with two arguments.
2043de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2044de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first argument to the busy handler is a copy of the void* pointer which
2045de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is the third argument to sqlite3_busy_handler().  ^The second argument to
2046de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the busy handler callback is the number of times that the busy handler has
20479bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** been invoked for the same locking event.  ^If the
2048de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** busy callback returns 0, then no additional attempts are made to
20499bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** access the database and [SQLITE_BUSY] is returned
20509bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** to the application.
2051de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the callback returns non-zero, then another attempt
20529bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** is made to access the database and the cycle repeats.
2053de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2054de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The presence of a busy handler does not guarantee that it will be invoked
2055de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** when there is lock contention. ^If SQLite determines that invoking the busy
2056de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
20579bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** to the application instead of invoking the
20589bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** busy handler.
2059de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Consider a scenario where one process is holding a read lock that
2060de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it is trying to promote to a reserved lock and
2061de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a second process is holding a reserved lock that it is trying
2062de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to promote to an exclusive lock.  The first process cannot proceed
2063de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** because it is blocked by the second and the second process cannot
2064de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** proceed because it is blocked by the first.  If both processes
2065de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** invoke the busy handlers, neither will make any progress.  Therefore,
2066de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2067de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will induce the first process to release its read lock and allow
2068de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the second process to proceed.
2069de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2070de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The default busy callback is NULL.
2071de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2072de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(There can only be a single busy handler defined for each
2073de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection].  Setting a new busy handler clears any
2074de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
20759bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** or evaluating [PRAGMA busy_timeout=N] will change the
20769bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** busy handler and thus clear any previously set busy handler.
2077de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2078de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The busy callback should not take any actions which modify the
20799bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** database connection that invoked the busy handler.  In other words,
20809bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** the busy handler is not reentrant.  Any such actions
2081de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** result in undefined behavior.
2082de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2083de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A busy handler must not close the database connection
2084de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [prepared statement] that invoked the busy handler.
2085de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2086de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
2087de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2088de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2089de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Set A Busy Timeout
2090de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2091de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2092de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for a specified amount of time when a table is locked.  ^The handler
2093de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will sleep multiple times until at least "ms" milliseconds of sleeping
2094de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** have accumulated.  ^After at least "ms" milliseconds of sleeping,
2095de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the handler returns 0 which causes [sqlite3_step()] to return
20969bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** [SQLITE_BUSY].
2097de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2098de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Calling this routine with an argument less than or equal to zero
2099de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** turns off all busy handlers.
2100de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2101de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(There can only be a single busy handler for a particular
2102de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection] any any given moment.  If another busy handler
2103de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** was defined  (using [sqlite3_busy_handler()]) prior to calling
2104de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** this routine, that other busy handler is cleared.)^
21059bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown**
21069bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** See also:  [PRAGMA busy_timeout]
2107de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2108de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2109de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2110de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2111de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Convenience Routines For Running Queries
2112de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
211395c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** This is a legacy interface that is preserved for backwards compatibility.
211495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** Use of this interface is not recommended.
211595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
2116de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Definition: A <b>result table</b> is memory data structure created by the
2117de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_get_table()] interface.  A result table records the
2118de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** complete query results from one or more queries.
2119de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2120de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The table conceptually has a number of rows and columns.  But
2121de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** these numbers are not part of the result table itself.  These
2122de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** numbers are obtained separately.  Let N be the number of rows
2123de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and M be the number of columns.
2124de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2125de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A result table is an array of pointers to zero-terminated UTF-8 strings.
2126de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** There are (N+1)*M elements in the array.  The first M pointers point
2127de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to zero-terminated strings that  contain the names of the columns.
2128de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The remaining entries all point to query results.  NULL values result
2129de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in NULL pointers.  All other values are in their UTF-8 zero-terminated
2130de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** string representation as returned by [sqlite3_column_text()].
2131de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2132de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A result table might consist of one or more memory allocations.
2133de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** It is not safe to pass a result table directly to [sqlite3_free()].
2134de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A result table should be deallocated using [sqlite3_free_table()].
2135de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
213695c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^(As an example of the result table format, suppose a query result
2137de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is as follows:
2138de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2139de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote><pre>
2140de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        Name        | Age
2141de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        -----------------------
2142de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        Alice       | 43
2143de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        Bob         | 28
2144de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        Cindy       | 21
2145de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </pre></blockquote>
2146de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2147de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** There are two column (M==2) and three rows (N==3).  Thus the
2148de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** result table has 8 entries.  Suppose the result table is stored
2149de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in an array names azResult.  Then azResult holds this content:
2150de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2151de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote><pre>
2152de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        azResult&#91;0] = "Name";
2153de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        azResult&#91;1] = "Age";
2154de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        azResult&#91;2] = "Alice";
2155de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        azResult&#91;3] = "43";
2156de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        azResult&#91;4] = "Bob";
2157de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        azResult&#91;5] = "28";
2158de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        azResult&#91;6] = "Cindy";
2159de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**        azResult&#91;7] = "21";
216095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** </pre></blockquote>)^
2161de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2162de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_get_table() function evaluates one or more
2163de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** semicolon-separated SQL statements in the zero-terminated UTF-8
2164de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** string of its 2nd parameter and returns a result table to the
2165de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pointer given in its 3rd parameter.
2166de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2167de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** After the application has finished with the result from sqlite3_get_table(),
216895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** it must pass the result table pointer to sqlite3_free_table() in order to
2169de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** release the memory that was malloced.  Because of the way the
2170de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2171de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function must not try to call [sqlite3_free()] directly.  Only
2172de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_free_table()] is able to release the memory properly and safely.
2173de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
217495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** The sqlite3_get_table() interface is implemented as a wrapper around
2175de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
2176de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to any internal data structures of SQLite.  It uses only the public
2177de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface defined here.  As a consequence, errors that occur in the
2178de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** wrapper layer outside of the internal [sqlite3_exec()] call are not
2179de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** reflected in subsequent calls to [sqlite3_errcode()] or
218095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** [sqlite3_errmsg()].
2181de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2182de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_get_table(
2183de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,          /* An open database */
2184de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zSql,     /* SQL to be evaluated */
2185de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  char ***pazResult,    /* Results of the query */
2186de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int *pnRow,           /* Number of result rows written here */
2187de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int *pnColumn,        /* Number of result columns written here */
2188de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  char **pzErrmsg       /* Error msg written here */
2189de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
2190de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_free_table(char **result);
2191de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2192de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2193de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Formatted String Printing Functions
2194de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2195de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines are work-alikes of the "printf()" family of functions
2196de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from the standard C library.
2197de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2198de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2199de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** results into memory obtained from [sqlite3_malloc()].
2200de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The strings returned by these two routines should be
2201de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** released by [sqlite3_free()].  ^Both routines return a
2202de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
2203de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory to hold the resulting string.
2204de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
220590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2206de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the standard C library.  The result is written into the
2207de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** buffer supplied as the second parameter whose size is given by
2208de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the first parameter. Note that the order of the
2209de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** first two parameters is reversed from snprintf().)^  This is an
2210de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** historical accident that cannot be fixed without breaking
2211de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** backwards compatibility.  ^(Note also that sqlite3_snprintf()
2212de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returns a pointer to its buffer instead of the number of
2213de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** characters actually written into the buffer.)^  We admit that
2214de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the number of characters written would be a more useful return
2215de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value but we cannot change the implementation of sqlite3_snprintf()
2216de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** now without breaking compatibility.
2217de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2218de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2219de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** guarantees that the buffer is always zero-terminated.  ^The first
2220de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameter "n" is the total size of the buffer, including space for
2221de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the zero terminator.  So the longest string that can be completely
2222de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** written will be n-1 characters.
2223de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
222490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
222590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
2226de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines all implement some additional formatting
2227de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** options that are useful for constructing SQL statements.
2228de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** All of the usual printf() formatting options apply.  In addition, there
2229de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is are "%q", "%Q", and "%z" options.
2230de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
223190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^(The %q option works like %s in that it substitutes a nul-terminated
2232de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** string from the argument list.  But %q also doubles every '\'' character.
2233de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** %q is designed for use inside a string literal.)^  By doubling each '\''
2234de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** character it escapes that character and allows it to be inserted into
2235de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the string.
2236de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2237de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** For example, assume the string variable zText contains text as follows:
2238de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2239de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote><pre>
2240de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  char *zText = "It's a happy day!";
2241de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </pre></blockquote>
2242de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2243de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** One can use this text in an SQL statement as follows:
2244de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2245de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote><pre>
2246de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2247de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  sqlite3_exec(db, zSQL, 0, 0, 0);
2248de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  sqlite3_free(zSQL);
2249de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </pre></blockquote>
2250de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2251de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Because the %q format string is used, the '\'' character in zText
2252de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is escaped and the SQL generated is as follows:
2253de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2254de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote><pre>
2255de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  INSERT INTO table1 VALUES('It''s a happy day!')
2256de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </pre></blockquote>
2257de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2258de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This is correct.  Had we used %s instead of %q, the generated SQL
2259de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** would have looked like this:
2260de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2261de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote><pre>
2262de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  INSERT INTO table1 VALUES('It's a happy day!');
2263de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </pre></blockquote>
2264de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2265de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This second example is an SQL syntax error.  As a general rule you should
2266de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** always use %q instead of %s when inserting text into a string literal.
2267de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2268de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The %Q option works like %q except it also adds single quotes around
2269de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the outside of the total string.  Additionally, if the parameter in the
2270de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2271de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** single quotes).)^  So, for example, one could say:
2272de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2273de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote><pre>
2274de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2275de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  sqlite3_exec(db, zSQL, 0, 0, 0);
2276de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  sqlite3_free(zSQL);
2277de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </pre></blockquote>
2278de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2279de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The code above will render a correct SQL statement in the zSQL
2280de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** variable even if the zText variable is a NULL pointer.
2281de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2282de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The "%z" formatting option works like "%s" but with the
2283de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** addition that after the string has been read and copied into
2284de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the result, [sqlite3_free()] is called on the input string.)^
2285de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2286de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API char *sqlite3_mprintf(const char*,...);
2287de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2288de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
228990ed05d921d6ed7f12012d9786d53f57fafee51aJeff BrownSQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2290de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2291de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2292de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Memory Allocation Subsystem
2293de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2294de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The SQLite core uses these three routines for all of its own
2295de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** internal memory allocation needs. "Core" in the previous sentence
2296de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** does not include operating-system specific VFS implementation.  The
2297de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Windows VFS uses native malloc() and free() for some operations.
2298de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2299de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_malloc() routine returns a pointer to a block
2300de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of memory at least N bytes in length, where N is the parameter.
2301de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If sqlite3_malloc() is unable to obtain sufficient free
2302de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory, it returns a NULL pointer.  ^If the parameter N to
2303de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2304de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a NULL pointer.
2305de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2306de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Calling sqlite3_free() with a pointer previously returned
2307de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2308de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that it might be reused.  ^The sqlite3_free() routine is
2309de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a no-op if is called with a NULL pointer.  Passing a NULL pointer
2310de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to sqlite3_free() is harmless.  After being freed, memory
2311de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** should neither be read nor written.  Even reading previously freed
2312de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory might result in a segmentation fault or other severe error.
2313de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Memory corruption, a segmentation fault, or other severe error
2314de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** might result if sqlite3_free() is called with a non-NULL pointer that
2315de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2316de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2317de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The sqlite3_realloc() interface attempts to resize a
2318de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** prior memory allocation to be at least N bytes, where N is the
2319de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** second parameter.  The memory allocation to be resized is the first
2320de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameter.)^ ^ If the first parameter to sqlite3_realloc()
2321de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is a NULL pointer then its behavior is identical to calling
2322de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
2323de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the second parameter to sqlite3_realloc() is zero or
2324de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** negative then the behavior is exactly the same as calling
2325de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
2326de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^sqlite3_realloc() returns a pointer to a memory allocation
2327de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of at least N bytes in size or NULL if sufficient memory is unavailable.
2328de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If M is the size of the prior allocation, then min(N,M) bytes
2329de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the prior allocation are copied into the beginning of buffer returned
2330de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by sqlite3_realloc() and the prior allocation is freed.
2331de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If sqlite3_realloc() returns NULL, then the prior allocation
2332de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is not freed.
2333de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2334de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
2335de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is always aligned to at least an 8 byte boundary, or to a
2336de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2337de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** option is used.
2338de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2339de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2340de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2341de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation of these routines to be omitted.  That capability
2342de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is no longer provided.  Only built-in memory allocators can be used.
2343de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
23448fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2345de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the system malloc() and free() directly when converting
2346de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** filenames between the UTF-8 encoding used by SQLite
2347de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and whatever filename encoding is used by the particular Windows
23488fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** installation.  Memory allocation errors were detected, but
23498fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** they were reported back as [SQLITE_CANTOPEN] or
2350de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2351de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2352de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2353de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** must be either NULL or else pointers obtained from a prior
2354de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2355de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not yet been released.
2356de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2357de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The application must not read or write any part of
2358de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a block of memory after it has been released using
2359de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_free()] or [sqlite3_realloc()].
2360de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2361de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void *sqlite3_malloc(int);
2362de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void *sqlite3_realloc(void*, int);
2363de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_free(void*);
2364de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2365de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2366de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Memory Allocator Statistics
2367de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2368de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite provides these two interfaces for reporting on the status
2369de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2370de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routines, which form the built-in memory allocation subsystem.
2371de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2372de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_memory_used()] routine returns the number of bytes
2373de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of memory currently outstanding (malloced but not freed).
2374de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_memory_highwater()] routine returns the maximum
2375de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value of [sqlite3_memory_used()] since the high-water mark
2376de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** was last reset.  ^The values returned by [sqlite3_memory_used()] and
2377de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_memory_highwater()] include any overhead
2378de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** added by SQLite in its implementation of [sqlite3_malloc()],
2379de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** but not overhead added by the any underlying system library
2380de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routines that [sqlite3_malloc()] may call.
2381de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2382de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The memory high-water mark is reset to the current value of
2383de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_memory_used()] if and only if the parameter to
2384de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_memory_highwater()] is true.  ^The value returned
2385de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by [sqlite3_memory_highwater(1)] is the high-water mark
2386de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** prior to the reset.
2387de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2388de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2389de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2390de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2391de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2392de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Pseudo-Random Number Generator
2393de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2394de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2395de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** select random [ROWID | ROWIDs] when inserting new records into a table that
2396de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** already uses the largest possible [ROWID].  The PRNG is also used for
2397de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the build-in random() and randomblob() SQL functions.  This interface allows
2398de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** applications to access the same PRNG for other purposes.
2399de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2400de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^A call to this routine stores N bytes of randomness into buffer P.
24018fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^If N is less than one, then P can be a NULL pointer.
2402de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
24038fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^If this routine has not been previously called or if the previous
24048fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** call had N less than one, then the PRNG is seeded using randomness
24058fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** obtained from the xRandomness method of the default [sqlite3_vfs] object.
24068fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^If the previous call to this routine had an N of 1 or more then
24078fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the pseudo-randomness is generated
2408de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** internally and without recourse to the [sqlite3_vfs] xRandomness
2409de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** method.
2410de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2411de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_randomness(int N, void *P);
2412de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2413de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2414de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Compile-Time Authorization Callbacks
2415de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
241690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^This routine registers an authorizer callback with a particular
2417de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection], supplied in the first argument.
2418de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The authorizer callback is invoked as SQL statements are being compiled
2419de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2420de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
2421de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** points during the compilation process, as logic is being created
2422de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to perform various actions, the authorizer callback is invoked to
2423de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** see if those actions are allowed.  ^The authorizer callback should
2424de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2425de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** specific action but allow the SQL statement to continue to be
2426de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2427de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** rejected with an error.  ^If the authorizer callback returns
2428de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2429de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2430de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the authorizer will fail with an error message.
2431de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2432de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When the callback returns [SQLITE_OK], that means the operation
2433de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** requested is ok.  ^When the callback returns [SQLITE_DENY], the
2434de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_prepare_v2()] or equivalent call that triggered the
2435de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** authorizer will fail with an error message explaining that
2436de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** access is denied.
2437de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2438de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first parameter to the authorizer callback is a copy of the third
2439de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2440de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the callback is an integer [SQLITE_COPY | action code] that specifies
2441de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the particular action to be authorized. ^The third through sixth parameters
2442de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the callback are zero-terminated strings that contain additional
2443de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** details about the action to be authorized.
2444de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2445de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the action code is [SQLITE_READ]
2446de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the callback returns [SQLITE_IGNORE] then the
2447de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [prepared statement] statement is constructed to substitute
2448de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a NULL value in place of the table column that would have
2449de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
2450de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** return can be used to deny an untrusted user access to individual
2451de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** columns of a table.
2452de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the action code is [SQLITE_DELETE] and the callback returns
2453de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2454de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [truncate optimization] is disabled and all rows are deleted individually.
2455de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2456de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** An authorizer is used when [sqlite3_prepare | preparing]
2457de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQL statements from an untrusted source, to ensure that the SQL statements
2458de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** do not try to access data they are not allowed to see, or that they do not
2459de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** try to execute malicious statements that damage the database.  For
2460de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** example, an application may allow a user to enter arbitrary
2461de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQL queries for evaluation by a database.  But the application does
2462de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not want the user to be able to make arbitrary changes to the
2463de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database.  An authorizer could then be put in place while the
2464de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** user-entered SQL is being [sqlite3_prepare | prepared] that
2465de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** disallows everything except [SELECT] statements.
2466de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2467de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Applications that need to process SQL from untrusted sources
2468de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** might also consider lowering resource limits using [sqlite3_limit()]
2469de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and limiting database size using the [max_page_count] [PRAGMA]
2470de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in addition to using an authorizer.
2471de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2472de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Only a single authorizer can be in place on a database connection
2473de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** at a time.  Each call to sqlite3_set_authorizer overrides the
2474de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** previous call.)^  ^Disable the authorizer by installing a NULL callback.
2475de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The authorizer is disabled by default.
2476de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2477de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The authorizer callback must not do anything that will modify
2478de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the database connection that invoked the authorizer callback.
2479de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2480de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database connections for the meaning of "modify" in this paragraph.
2481de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2482de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2483de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** statement might be re-prepared during [sqlite3_step()] due to a
2484de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** schema change.  Hence, the application should ensure that the
2485de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** correct authorizer callback remains in place during the [sqlite3_step()].
2486de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2487de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Note that the authorizer callback is invoked only during
2488de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_prepare()] or its variants.  Authorization is not
2489de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** performed during statement evaluation in [sqlite3_step()], unless
2490de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as stated in the previous paragraph, sqlite3_step() invokes
2491de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2492de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2493de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_set_authorizer(
2494de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3*,
2495de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2496de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pUserData
2497de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
2498de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2499de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2500de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Authorizer Return Codes
2501de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2502de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [sqlite3_set_authorizer | authorizer callback function] must
2503de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** return either [SQLITE_OK] or one of these two constants in order
2504de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to signal SQLite whether or not the action is permitted.  See the
2505de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_set_authorizer | authorizer documentation] for additional
2506de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** information.
250790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
25089bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
25099bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** returned from the [sqlite3_vtab_on_conflict()] interface.
2510de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2511de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
2512de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
2513de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2514de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2515de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Authorizer Action Codes
2516de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2517de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [sqlite3_set_authorizer()] interface registers a callback function
2518de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that is invoked to authorize certain SQL statement actions.  The
2519de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** second parameter to the callback is an integer code that specifies
2520de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** what action is being authorized.  These are the integer action codes that
2521de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the authorizer callback may be passed.
2522de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2523de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These action code values signify what kind of operation is to be
2524de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** authorized.  The 3rd and 4th parameters to the authorization
2525de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** callback function will be parameters or NULL depending on which of these
2526de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** codes is used as the second parameter.  ^(The 5th parameter to the
2527de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** authorizer callback is the name of the database ("main", "temp",
2528de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
2529de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is the name of the inner-most trigger or view that is responsible for
2530de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the access attempt or NULL if this access attempt is directly from
2531de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** top-level SQL code.
2532de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2533de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/******************************************* 3rd ************ 4th ***********/
2534de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
2535de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
2536de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
2537de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
2538de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
2539de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
2540de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
2541de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
2542de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DELETE                9   /* Table Name      NULL            */
2543de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
2544de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
2545de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
2546de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
2547de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
2548de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
2549de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
2550de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
2551de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_INSERT               18   /* Table Name      NULL            */
2552de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
2553de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_READ                 20   /* Table Name      Column Name     */
2554de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SELECT               21   /* NULL            NULL            */
2555de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TRANSACTION          22   /* Operation       NULL            */
2556de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
2557de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_ATTACH               24   /* Filename        NULL            */
2558de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DETACH               25   /* Database Name   NULL            */
2559de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
2560de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_REINDEX              27   /* Index Name      NULL            */
2561de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
2562de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
2563de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
2564de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_FUNCTION             31   /* NULL            Function Name   */
2565de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
2566de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_COPY                  0   /* No longer used */
25678fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_RECURSIVE            33   /* NULL            NULL            */
2568de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2569de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2570de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Tracing And Profiling Functions
2571de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2572de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines register callback functions that can be used for
2573de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** tracing and profiling the execution of SQL statements.
2574de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2575de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The callback function registered by sqlite3_trace() is invoked at
2576de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** various times when an SQL statement is being run by [sqlite3_step()].
2577de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2578de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQL statement text as the statement first begins executing.
2579de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Additional sqlite3_trace() callbacks might occur
2580de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as each triggered subprogram is entered.  The callbacks for triggers
2581de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** contain a UTF-8 SQL comment that identifies the trigger.)^
2582de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
25838fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
25848fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the length of [bound parameter] expansion in the output of sqlite3_trace().
25858fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
2586de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The callback function registered by sqlite3_profile() is invoked
2587de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as each SQL statement finishes.  ^The profile callback contains
2588de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the original statement text and an estimate of wall-clock time
2589de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of how long that statement took to run.  ^The profile callback
2590de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** time is in units of nanoseconds, however the current implementation
2591de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is only capable of millisecond resolution so the six least significant
2592de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** digits in the time are meaningless.  Future versions of SQLite
2593de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** might provide greater resolution on the profiler callback.  The
2594de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_profile() function is considered experimental and is
2595de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** subject to change in future versions of SQLite.
2596de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2597de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2598de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
2599de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2600de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2601de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2602de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Query Progress Callbacks
2603de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2604de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2605de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function X to be invoked periodically during long running calls to
2606de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2607de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database connection D.  An example use for this
2608de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface is to keep a GUI updated during a large query.
2609de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2610de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The parameter P is passed through as the only parameter to the
26118fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** callback function X.  ^The parameter N is the approximate number of
2612de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [virtual machine instructions] that are evaluated between successive
26138fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** invocations of the callback X.  ^If N is less than one then the progress
26148fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** handler is disabled.
2615de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2616de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Only a single progress handler may be defined at one time per
2617de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection]; setting a new progress handler cancels the
2618de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** old one.  ^Setting parameter X to NULL disables the progress handler.
2619de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The progress handler is also disabled by setting N to a value less
2620de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** than 1.
2621de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2622de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the progress callback returns non-zero, the operation is
2623de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interrupted.  This feature can be used to implement a
2624de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** "Cancel" button on a GUI progress dialog box.
2625de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2626de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The progress handler callback must not do anything that will modify
2627de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the database connection that invoked the progress handler.
2628de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2629de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database connections for the meaning of "modify" in this paragraph.
2630de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2631de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2632de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2633de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2634de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2635de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Opening A New Database Connection
2636de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
263790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^These routines open an SQLite database file as specified by the
2638de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** filename argument. ^The filename argument is interpreted as UTF-8 for
2639de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2640de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** order for sqlite3_open16(). ^(A [database connection] handle is usually
2641de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returned in *ppDb, even if an error occurs.  The only exception is that
2642de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2643de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2644de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** object.)^ ^(If the database is opened (and/or created) successfully, then
2645de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
2646de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2647de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an English language description of the error following a failure of any
2648de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the sqlite3_open() routines.
2649de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2650de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The default encoding for the database will be UTF-8 if
2651de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_open() or sqlite3_open_v2() is called and
2652de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** UTF-16 in the native byte order if sqlite3_open16() is used.
2653de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2654de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Whether or not an error occurs when it is opened, resources
2655de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** associated with the [database connection] handle should be released by
2656de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** passing it to [sqlite3_close()] when it is no longer required.
2657de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2658de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_open_v2() interface works like sqlite3_open()
2659de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** except that it accepts two additional parameters for additional control
2660de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** over the new database connection.  ^(The flags parameter to
2661de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_open_v2() can take one of
2662de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the following three values, optionally combined with the
2663de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
266490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
2665de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2666de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dl>
2667de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
2668de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The database is opened in read-only mode.  If the database does not
2669de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** already exist, an error is returned.</dd>)^
2670de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2671de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
2672de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The database is opened for reading and writing if possible, or reading
2673de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** only if the file is write protected by the operating system.  In either
2674de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** case the database must already exist, otherwise an error is returned.</dd>)^
2675de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2676de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
267790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd>The database is opened for reading and writing, and is created if
2678de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it does not already exist. This is the behavior that is always used for
2679de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_open() and sqlite3_open16().</dd>)^
2680de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </dl>
2681de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2682de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If the 3rd parameter to sqlite3_open_v2() is not one of the
268390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** combinations shown above optionally combined with other
268490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
2685de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the behavior is undefined.
2686de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2687de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
2688de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** opens in the multi-thread [threading mode] as long as the single-thread
2689de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** mode has not been set at compile-time or start-time.  ^If the
2690de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
2691de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in the serialized [threading mode] unless single-thread was
2692de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** previously selected at compile-time or start-time.
2693de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
2694de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** eligible to use [shared cache mode], regardless of whether or not shared
2695de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** cache is enabled using [sqlite3_enable_shared_cache()].  ^The
2696de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
2697de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** participate in [shared cache mode] even if it is enabled.
2698de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
269990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The fourth parameter to sqlite3_open_v2() is the name of the
270090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_vfs] object that defines the operating system interface that
270190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the new database connection should use.  ^If the fourth parameter is
270290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** a NULL pointer then the default [sqlite3_vfs] object is used.
270390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
2704de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the filename is ":memory:", then a private, temporary in-memory database
2705de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is created for the connection.  ^This in-memory database will vanish when
2706de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the database connection is closed.  Future versions of SQLite might
2707de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** make use of additional special filenames that begin with the ":" character.
2708de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** It is recommended that when a database filename actually does begin with
2709de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a ":" character you should prefix the filename with a pathname such as
2710de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** "./" to avoid ambiguity.
2711de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2712de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the filename is an empty string, then a private, temporary
2713de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on-disk database will be created.  ^This private database will be
2714de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** automatically deleted as soon as the database connection is closed.
2715de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
271690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
271790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
271890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^If [URI filename] interpretation is enabled, and the filename argument
271990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** begins with "file:", then the filename is interpreted as a URI. ^URI
272090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
272190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** set in the fourth argument to sqlite3_open_v2(), or if it has
272290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** been enabled globally using the [SQLITE_CONFIG_URI] option with the
272390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
272490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** As of SQLite version 3.7.7, URI filename interpretation is turned off
272590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** by default, but future releases of SQLite might enable URI filename
272690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** interpretation by default.  See "[URI filenames]" for additional
272790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** information.
272890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
272990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** URI filenames are parsed according to RFC 3986. ^If the URI contains an
273090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** authority, then it must be either an empty string or the string
273190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** "localhost". ^If the authority is not an empty string or "localhost", an
273290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** error is returned to the caller. ^The fragment component of a URI, if
273390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** present, is ignored.
273490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
273590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^SQLite uses the path component of the URI as the name of the disk file
273690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** which contains the database. ^If the path begins with a '/' character,
273790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** then it is interpreted as an absolute path. ^If the path does not begin
273890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** with a '/' (meaning that the authority section is omitted from the URI)
273990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** then the path is interpreted as a relative path.
274090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^On windows, the first component of an absolute path
274190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is a drive specification (e.g. "C:").
274290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
274390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[core URI query parameters]]
274490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The query component of a URI may contain parameters that are interpreted
274590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** either by SQLite itself, or by a [VFS | custom VFS implementation].
274690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** SQLite interprets the following three query parameters:
274790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
274890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <ul>
274990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
275090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     a VFS object that provides the operating system interface that should
275190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     be used to access the database file on disk. ^If this option is set to
275290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     an empty string the default VFS object is used. ^Specifying an unknown
275390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
275490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     present, then the VFS specified by the option takes precedence over
275590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     the value passed as the fourth parameter to sqlite3_open_v2().
275690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
27578fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
27588fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**     "rwc", or "memory". Attempting to set it to any other value is
27598fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**     an error)^.
276090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     ^If "ro" is specified, then the database is opened for read-only
276190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
27628fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**     third argument to sqlite3_open_v2(). ^If the mode option is set to
276390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     "rw", then the database is opened for read-write (but not create)
276490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
276590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     been set. ^Value "rwc" is equivalent to setting both
27668fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE.  ^If the mode option is
27678fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**     set to "memory" then a pure [in-memory database] that never reads
27688fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**     or writes from disk is used. ^It is an error to specify a value for
27698fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**     the mode parameter that is less restrictive than that specified by
27708fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**     the flags passed in the third parameter to sqlite3_open_v2().
277190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
277290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
277390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     "private". ^Setting it to "shared" is equivalent to setting the
277490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
277590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     sqlite3_open_v2(). ^Setting the cache parameter to "private" is
277690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
277790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
27788fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**     a URI filename, its value overrides any behavior requested by setting
277990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
27801c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**
27811c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**  <li> <b>psow</b>: ^The psow parameter may be "true" (or "on" or "yes" or
27821c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     "1") or "false" (or "off" or "no" or "0") to indicate that the
27831c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     [powersafe overwrite] property does or does not apply to the
27841c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     storage media on which the database file resides.  ^The psow query
27851c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     parameter only works for the built-in unix and Windows VFSes.
27861c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**
27871c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**  <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
27881c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     which if set disables file locking in rollback journal modes.  This
27891c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     is useful for accessing a database on a filesystem that does not
27901c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     support locking.  Caution:  Database corruption might result if two
27911c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     or more processes write to the same database and any one of those
27921c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     processes uses nolock=1.
27931c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**
27941c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**  <li> <b>immutable</b>: ^The immutable parameter is a boolean query
27951c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     parameter that indicates that the database file is stored on
27961c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     read-only media.  ^When immutable is set, SQLite assumes that the
27971c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     database file cannot be changed, even by a process with higher
27981c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     privilege, and so the database is opened read-only and all locking
27991c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     and change detection is disabled.  Caution: Setting the immutable
28001c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     property on a database file that does in fact change can result
28011c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     in incorrect query results and/or [SQLITE_CORRUPT] errors.
28021c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**     See also: [SQLITE_IOCAP_IMMUTABLE].
28031c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**
280490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** </ul>
280590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
280690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^Specifying an unknown parameter in the query component of a URI is not an
280790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** error.  Future versions of SQLite might understand additional query
280890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** parameters.  See "[query parameters with special meaning to SQLite]" for
280990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** additional information.
281090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
281190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[URI filename examples]] <h3>URI filename examples</h3>
281290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
281390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <table border="1" align=center cellpadding=5>
281490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <tr><th> URI filenames <th> Results
281590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <tr><td> file:data.db <td>
281690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          Open the file "data.db" in the current directory.
281790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <tr><td> file:/home/fred/data.db<br>
281890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          file:///home/fred/data.db <br>
281990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          file://localhost/home/fred/data.db <br> <td>
282090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          Open the database file "/home/fred/data.db".
282190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <tr><td> file://darkstar/home/fred/data.db <td>
282290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          An error. "darkstar" is not a recognized authority.
282390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <tr><td style="white-space:nowrap">
282490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
282590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**     <td> Windows only: Open the file "data.db" on fred's desktop on drive
282690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          C:. Note that the %20 escaping in this example is not strictly
282790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          necessary - space characters can be used literally
282890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          in URI filenames.
282990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <tr><td> file:data.db?mode=ro&cache=private <td>
283090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          Open file "data.db" in the current directory for read-only access.
283190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          Regardless of whether or not shared-cache mode is enabled by
283290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          default, use a private cache.
28331c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
28341c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**          Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
28351c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**          that uses dot-files in place of posix advisory locking.
283690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <tr><td> file:data.db?mode=readonly <td>
283790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**          An error. "readonly" is not a valid option for the "mode" parameter.
283890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** </table>
283990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
284090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^URI hexadecimal escape sequences (%HH) are supported within the path and
284190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** query components of a URI. A hexadecimal escape sequence consists of a
284290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** percent sign - "%" - followed by exactly two hexadecimal digits
284390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** specifying an octet value. ^Before the path or query components of a
284490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** URI filename are interpreted, they are encoded using UTF-8 and all
284590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** hexadecimal escape sequences replaced by a single byte containing the
284690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** corresponding octet. If this process generates an invalid UTF-8 encoding,
284790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the results are undefined.
2848de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2849de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <b>Note to Windows users:</b>  The encoding used for the filename argument
2850de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
2851de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** codepage is currently defined.  Filenames containing international
2852de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** characters must be converted to UTF-8 prior to passing them into
2853de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_open() or sqlite3_open_v2().
28548fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
28558fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
28568fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** prior to calling sqlite3_open() or sqlite3_open_v2().  Otherwise, various
28578fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** features that require the use of temporary files may fail.
28588fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
28598fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** See also: [sqlite3_temp_directory]
2860de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2861de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_open(
2862de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *filename,   /* Database filename (UTF-8) */
2863de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 **ppDb          /* OUT: SQLite db handle */
2864de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
2865de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_open16(
2866de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const void *filename,   /* Database filename (UTF-16) */
2867de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 **ppDb          /* OUT: SQLite db handle */
2868de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
2869de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_open_v2(
2870de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *filename,   /* Database filename (UTF-8) */
2871de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 **ppDb,         /* OUT: SQLite db handle */
2872de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int flags,              /* Flags */
2873de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zVfs        /* Name of VFS module to use */
2874de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
2875de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2876de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
287790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Obtain Values For URI Parameters
287890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
287990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** These are utility routines, useful to VFS implementations, that check
288090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** to see if a database file was a URI that contained a specific query
288190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** parameter, and if so obtains the value of that query parameter.
288290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
288390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If F is the database filename pointer passed into the xOpen() method of
288490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** a VFS implementation when the flags parameter to xOpen() has one or
288590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
288690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** P is the name of the query parameter, then
288790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** sqlite3_uri_parameter(F,P) returns the value of the P
288890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** parameter if it exists or a NULL pointer if P does not appear as a
288990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** query parameter on F.  If P is a query parameter of F
289090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** has no explicit value, then sqlite3_uri_parameter(F,P) returns
289190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** a pointer to an empty string.
289290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
289390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
289490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** parameter and returns true (1) or false (0) according to the value
2895c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** of P.  The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
2896c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** value of query parameter P is one of "yes", "true", or "on" in any
2897c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** case or if the value begins with a non-zero number.  The
2898c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
2899c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** query parameter P is one of "no", "false", or "off" in any case or
2900c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** if the value begins with a numeric zero.  If P is not a query
2901c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** parameter on F or if the value of P is does not match any of the
2902c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
290390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
290490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
290590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** 64-bit signed integer and returns that integer, or D if P does not
290690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** exist.  If the value of P is something other than an integer, then
290790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** zero is returned.
290890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
290990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
291090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and
291190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is not a database file pathname pointer that SQLite passed into the xOpen
291290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** VFS method, then the behavior of this routine is undefined and probably
291390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** undesirable.
291490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
291590ed05d921d6ed7f12012d9786d53f57fafee51aJeff BrownSQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
291690ed05d921d6ed7f12012d9786d53f57fafee51aJeff BrownSQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
291790ed05d921d6ed7f12012d9786d53f57fafee51aJeff BrownSQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
291890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
291990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
292090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
2921de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Error Codes And Messages
2922de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2923de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_errcode() interface returns the numeric [result code] or
2924de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [extended result code] for the most recent failed sqlite3_* API call
2925de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** associated with a [database connection]. If a prior API call failed
2926de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** but the most recent API call succeeded, the return value from
2927de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_errcode() is undefined.  ^The sqlite3_extended_errcode()
2928de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface is the same except that it always returns the
2929de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [extended result code] even when extended result codes are
2930de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** disabled.
2931de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2932de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
2933de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** text that describes the error, as either UTF-8 or UTF-16 respectively.
2934de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Memory to hold the error message string is managed internally.
2935de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The application does not need to worry about freeing the result.
2936de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** However, the error string might be overwritten or deallocated by
2937de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** subsequent calls to other SQLite interface functions.)^
2938de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
29398fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The sqlite3_errstr() interface returns the English-language text
29408fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** that describes the [result code], as UTF-8.
29418fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^(Memory to hold the error message string is managed internally
29428fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** and must not be freed by the application)^.
29438fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
2944de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When the serialized [threading mode] is in use, it might be the
2945de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** case that a second error occurs on a separate thread in between
2946de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the time of the first error and the call to these interfaces.
2947de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When that happens, the second error will be reported since these
2948de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interfaces always report the most recent result.  To avoid
2949de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** this, each thread can obtain exclusive use of the [database connection] D
2950de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
2951de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
2952de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** all calls to the interfaces listed here are completed.
2953de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2954de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If an interface fails with SQLITE_MISUSE, that means the interface
2955de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** was invoked incorrectly by the application.  In that case, the
2956de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** error code and message may or may not be set.
2957de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2958de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_errcode(sqlite3 *db);
2959de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
2960de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_errmsg(sqlite3*);
2961de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_errmsg16(sqlite3*);
29628fecf56c625b5691ee3381e107ccbe1ff42398b1Nick KralevichSQLITE_API const char *sqlite3_errstr(int);
2963de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2964de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2965de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: SQL Statement Object
2966de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {prepared statement} {prepared statements}
2967de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2968de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** An instance of this object represents a single SQL statement.
2969de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This object is variously known as a "prepared statement" or a
2970de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** "compiled SQL statement" or simply as a "statement".
2971de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2972de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The life of a statement object goes something like this:
2973de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2974de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ol>
2975de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> Create the object using [sqlite3_prepare_v2()] or a related
2976de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      function.
2977de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> Bind values to [host parameters] using the sqlite3_bind_*()
2978de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      interfaces.
2979de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> Run the SQL by calling [sqlite3_step()] one or more times.
2980de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> Reset the statement using [sqlite3_reset()] then go back
2981de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      to step 2.  Do this zero or more times.
2982de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> Destroy the object using [sqlite3_finalize()].
2983de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ol>
2984de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2985de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Refer to documentation on individual methods above for additional
2986de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** information.
2987de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
2988de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_stmt sqlite3_stmt;
2989de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
2990de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
2991de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Run-time Limits
2992de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
2993de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(This interface allows the size of various constructs to be limited
2994de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on a connection by connection basis.  The first parameter is the
2995de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection] whose limit is to be set or queried.  The
2996de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** second parameter is one of the [limit categories] that define a
2997de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** class of constructs to be size limited.  The third parameter is the
2998de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** new limit for that construct.)^
2999de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3000de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the new limit is a negative number, the limit is unchanged.
3001de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3002de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [limits | hard upper bound]
3003de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** set at compile-time by a C preprocessor macro called
3004de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [limits | SQLITE_MAX_<i>NAME</i>].
3005de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3006de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Attempts to increase a limit above its hard upper bound are
3007de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** silently truncated to the hard upper bound.
3008de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3009de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Regardless of whether or not the limit was changed, the
3010de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_limit()] interface returns the prior value of the limit.
3011de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Hence, to find the current value of a limit without changing it,
3012de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** simply invoke this interface with the third parameter set to -1.
3013de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3014de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Run-time limits are intended for use in applications that manage
3015de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** both their own internal database and also databases that are controlled
3016de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by untrusted external sources.  An example application might be a
3017de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** web browser that has its own databases for storing history and
3018de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** separate databases controlled by JavaScript applications downloaded
3019de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** off the Internet.  The internal databases can be given the
3020de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** large, default limits.  Databases managed by external sources can
3021de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be given much smaller limits designed to prevent a denial of service
3022de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
3023de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface to further control untrusted SQL.  The size of the database
3024de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** created by an untrusted script can be contained using the
3025de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [max_page_count] [PRAGMA].
3026de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3027de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** New run-time limit categories may be added in future releases.
3028de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3029de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3030de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3031de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3032de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Run-Time Limit Categories
3033de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {limit category} {*limit categories}
3034de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3035de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These constants define various performance limits
3036de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that can be lowered at run-time using [sqlite3_limit()].
3037de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The synopsis of the meanings of the various limits is shown below.
3038de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Additional information is available at [limits | Limits in SQLite].
3039de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3040de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dl>
304190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3042de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3043de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
304490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3045de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3046de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
304790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3048de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum number of columns in a table definition or in the
3049de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** result set of a [SELECT] or the maximum number of columns in an index
3050de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or in an ORDER BY or GROUP BY clause.</dd>)^
3051de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
305290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3053de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3054de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
305590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3056de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3057de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
305890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3059de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum number of instructions in a virtual machine program
3060de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** used to implement an SQL statement.  This limit is not currently
3061de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** enforced, though that might be added in some future release of
3062de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite.</dd>)^
3063de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
306490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3065de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum number of arguments on a function.</dd>)^
3066de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
306790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3068de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3069de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
307090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3071de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3072de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum length of the pattern argument to the [LIKE] or
3073de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [GLOB] operators.</dd>)^
3074de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
307590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3076de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3077de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3078de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
307990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3080de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>The maximum depth of recursion for triggers.</dd>)^
3081de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </dl>
3082de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3083de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_LENGTH                    0
3084de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_SQL_LENGTH                1
3085de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_COLUMN                    2
3086de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_EXPR_DEPTH                3
3087de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_COMPOUND_SELECT           4
3088de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_VDBE_OP                   5
3089de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_FUNCTION_ARG              6
3090de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_ATTACHED                  7
3091de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
3092de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_VARIABLE_NUMBER           9
3093de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_LIMIT_TRIGGER_DEPTH            10
3094de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3095de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3096de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Compiling An SQL Statement
3097de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {SQL statement compiler}
3098de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3099de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** To execute an SQL query, it must first be compiled into a byte-code
3100de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** program using one of these routines.
3101de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3102de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The first argument, "db", is a [database connection] obtained from a
3103de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3104de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_open16()].  The database connection must not have been closed.
3105de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3106de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The second argument, "zSql", is the statement to be compiled, encoded
3107de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
3108de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
3109de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** use UTF-16.
3110de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3111de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the nByte argument is less than zero, then zSql is read up to the
3112de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** first zero terminator. ^If nByte is non-negative, then it is the maximum
3113de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** number of  bytes read from zSql.  ^When nByte is non-negative, the
3114de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** zSql string ends at either the first '\000' or '\u0000' character or
3115de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the nByte-th byte, whichever comes first. If the caller knows
3116de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that the supplied string is nul-terminated, then there is a small
3117de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** performance advantage to be gained by passing an nByte parameter that
3118de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is equal to the number of bytes in the input string <i>including</i>
311990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the nul-terminator bytes as this saves SQLite from having to
312090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** make a copy of the input string.
3121de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3122de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3123de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** past the end of the first SQL statement in zSql.  These routines only
3124de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compile the first statement in zSql, so *pzTail is left pointing to
3125de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** what remains uncompiled.
3126de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3127de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3128de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
3129de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to NULL.  ^If the input text contains no SQL (if the input is an empty
3130de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** string or a comment) then *ppStmt is set to NULL.
3131de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The calling procedure is responsible for deleting the compiled
3132de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQL statement using [sqlite3_finalize()] after it has finished with it.
3133de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ppStmt may not be NULL.
3134de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3135de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3136de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** otherwise an [error code] is returned.
3137de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3138de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
3139de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** recommended for all new programs. The two older interfaces are retained
3140de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for backwards compatibility, but their use is discouraged.
3141de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^In the "v2" interfaces, the prepared statement
3142de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that is returned (the [sqlite3_stmt] object) contains a copy of the
3143de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** original SQL text. This causes the [sqlite3_step()] interface to
3144de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** behave differently in three ways:
3145de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3146de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ol>
3147de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>
3148de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3149de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** always used to do, [sqlite3_step()] will automatically recompile the SQL
31508fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
31518fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** retries will occur before sqlite3_step() gives up and returns an error.
3152de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </li>
3153de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3154de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>
3155de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3156de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [error codes] or [extended error codes].  ^The legacy behavior was that
3157de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3158de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the application would have to make a second call to [sqlite3_reset()]
3159de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in order to find the underlying cause of the problem. With the "v2" prepare
3160de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interfaces, the underlying reason for the error is returned immediately.
3161de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </li>
3162de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3163de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>
3164de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the specific value bound to [parameter | host parameter] in the
3165de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** WHERE clause might influence the choice of query plan for a statement,
3166de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the statement will be automatically recompiled, as if there had been
3167de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a schema change, on the first  [sqlite3_step()] call following any change
3168de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the [sqlite3_bind_text | bindings] of that [parameter].
3169de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The specific value of WHERE-clause [parameter] might influence the
3170de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** choice of query plan if the parameter is the left-hand side of a [LIKE]
3171de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [GLOB] operator or if the parameter is compared to an indexed column
317290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3173de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </li>
3174de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ol>
3175de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3176de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_prepare(
3177de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,            /* Database handle */
3178de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zSql,       /* SQL statement, UTF-8 encoded */
3179de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nByte,              /* Maximum length of zSql in bytes. */
3180de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3181de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
3182de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
3183de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_prepare_v2(
3184de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,            /* Database handle */
3185de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zSql,       /* SQL statement, UTF-8 encoded */
3186de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nByte,              /* Maximum length of zSql in bytes. */
3187de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3188de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
3189de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
3190de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_prepare16(
3191de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,            /* Database handle */
3192de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const void *zSql,       /* SQL statement, UTF-16 encoded */
3193de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nByte,              /* Maximum length of zSql in bytes. */
3194de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3195de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
3196de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
3197de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_prepare16_v2(
3198de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,            /* Database handle */
3199de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const void *zSql,       /* SQL statement, UTF-16 encoded */
3200de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nByte,              /* Maximum length of zSql in bytes. */
3201de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3202de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
3203de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
3204de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3205de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3206de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Retrieving Statement SQL
3207de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3208de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This interface can be used to retrieve a saved copy of the original
3209de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQL text used to create a [prepared statement] if that statement was
3210de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
3211de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3212de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3213de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3214de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
321595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** CAPI3REF: Determine If An SQL Statement Writes The Database
321695c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
321795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
321890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** and only if the [prepared statement] X makes no direct changes to
321990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the content of the database file.
322090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
322190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** Note that [application-defined SQL functions] or
322290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [virtual tables] might change the database indirectly as a side effect.
322390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^(For example, if an application defines a function "eval()" that
322490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** calls [sqlite3_exec()], then the following SQL statement would
322590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** change the database file through side-effects:
322690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
322790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <blockquote><pre>
322890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**    SELECT eval('DELETE FROM t1') FROM t2;
322990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** </pre></blockquote>
323090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
323190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** But because the [SELECT] statement does not change the database file
323290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** directly, sqlite3_stmt_readonly() would still return true.)^
323390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
323490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
323590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
323690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** since the statements themselves do not actually modify the database but
323790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** rather they control the timing of when other statements modify the
323890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** database.  ^The [ATTACH] and [DETACH] statements also cause
323990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** sqlite3_stmt_readonly() to return true since, while those statements
324090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** change the configuration of a database connection, they do not make
324190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** changes to the content of the database files on disk.
324295c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori*/
324395c34edce550d0869113085e0cd1b6b09e8fe38bVasu NoriSQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
324495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori
324595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori/*
324690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Determine If A Prepared Statement Has Been Reset
324790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
324890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
324990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [prepared statement] S has been stepped at least once using
325090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_step(S)] but has not run to completion and/or has not
325190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** been reset using [sqlite3_reset(S)].  ^The sqlite3_stmt_busy(S)
325290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** interface returns false if S is a NULL pointer.  If S is not a
325390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** NULL pointer and is not a pointer to a valid [prepared statement]
325490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** object, then the behavior is undefined and probably undesirable.
325590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
325690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** This interface can be used in combination [sqlite3_next_stmt()]
325790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** to locate all prepared statements associated with a database
325890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** connection that are in need of being reset.  This can be used,
325990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** for example, in diagnostic routines to search for prepared
326090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** statements that are holding a transaction open.
326190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
326290ed05d921d6ed7f12012d9786d53f57fafee51aJeff BrownSQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
326390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
326490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
3265de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Dynamically Typed Value Object
3266de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3267de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3268de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite uses the sqlite3_value object to represent all values
3269de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that can be stored in a database table. SQLite uses dynamic typing
3270de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for the values it stores.  ^Values stored in sqlite3_value objects
3271de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be integers, floating point values, strings, BLOBs, or NULL.
3272de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3273de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** An sqlite3_value object may be either "protected" or "unprotected".
3274de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Some interfaces require a protected sqlite3_value.  Other interfaces
3275de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will accept either a protected or an unprotected sqlite3_value.
3276de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Every interface that accepts sqlite3_value arguments specifies
3277de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** whether or not it requires a protected sqlite3_value.
3278de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3279de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The terms "protected" and "unprotected" refer to whether or not
328090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** a mutex is held.  An internal mutex is held for a protected
3281de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_value object but no mutex is held for an unprotected
3282de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_value object.  If SQLite is compiled to be single-threaded
3283de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3284de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or if SQLite is run in one of reduced mutex modes
3285de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3286de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then there is no distinction between protected and unprotected
3287de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_value objects and they can be used interchangeably.  However,
3288de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for maximum code portability it is recommended that applications
3289de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** still make the distinction between protected and unprotected
3290de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_value objects even when not strictly required.
3291de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3292de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_value objects that are passed as parameters into the
3293de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation of [application-defined SQL functions] are protected.
3294de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_value object returned by
3295de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_column_value()] is unprotected.
3296de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Unprotected sqlite3_value objects may only be used with
3297de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_result_value()] and [sqlite3_bind_value()].
3298de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [sqlite3_value_blob | sqlite3_value_type()] family of
3299de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interfaces require protected sqlite3_value objects.
3300de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3301de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct Mem sqlite3_value;
3302de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3303de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3304de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: SQL Function Context Object
3305de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3306de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The context in which an SQL function executes is stored in an
3307de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_context object.  ^A pointer to an sqlite3_context object
3308de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is always first parameter to [application-defined SQL functions].
3309de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The application-defined SQL function implementation will pass this
3310de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3311de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3312de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3313de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and/or [sqlite3_set_auxdata()].
3314de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3315de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_context sqlite3_context;
3316de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3317de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3318de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Binding Values To Prepared Statements
3319de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3320de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3321de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3322de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3323de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** literals may be replaced by a [parameter] that matches one of following
3324de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** templates:
3325de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3326de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
3327de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  ?
3328de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  ?NNN
3329de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  :VVV
3330de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  @VVV
3331de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  $VVV
3332de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>
3333de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3334de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** In the templates above, NNN represents an integer literal,
3335de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and VVV represents an alphanumeric identifier.)^  ^The values of these
3336de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameters (also called "host parameter names" or "SQL parameters")
3337de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be set using the sqlite3_bind_*() routines defined here.
3338de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3339de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first argument to the sqlite3_bind_*() routines is always
3340de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a pointer to the [sqlite3_stmt] object returned from
3341de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_prepare_v2()] or its variants.
3342de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3343de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The second argument is the index of the SQL parameter to be set.
3344de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The leftmost SQL parameter has an index of 1.  ^When the same named
3345de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQL parameter is used more than once, second and subsequent
3346de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** occurrences have the same index as the first occurrence.
3347de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The index for named parameters can be looked up using the
3348de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_bind_parameter_index()] API if desired.  ^The index
3349de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for "?NNN" parameters is the value of NNN.
3350de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The NNN value must be between 1 and the [sqlite3_limit()]
3351de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3352de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3353de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The third argument is the value to bind to the parameter.
33548fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
33558fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
33568fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** is ignored and the end result is the same as sqlite3_bind_null().
3357de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3358de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(In those routines that have a fourth argument, its value is the
3359de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** number of bytes in the parameter.  To be clear: the value is the
3360de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** number of <u>bytes</u> in the value, not the number of characters.)^
33618fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
33628fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** is negative, then the length of the string is
3363de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the number of bytes up to the first zero terminator.
33648fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** If the fourth parameter to sqlite3_bind_blob() is negative, then
33658fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the behavior is undefined.
336690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If a non-negative fourth parameter is provided to sqlite3_bind_text()
336790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** or sqlite3_bind_text16() then that parameter must be the byte offset
336890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** where the NUL terminator would occur assuming the string were NUL
336990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** terminated.  If any NUL characters occur at byte offsets less than
337090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the value of the fourth parameter then the resulting string value will
337190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** contain embedded NULs.  The result of expressions involving strings
337290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** with embedded NULs is undefined.
3373de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3374de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
3375de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
337695c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** string after SQLite has finished with it.  ^The destructor is called
337795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
337895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
337995c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^If the fifth argument is
3380de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the special value [SQLITE_STATIC], then SQLite assumes that the
3381de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** information is in static, unmanaged space and does not need to be freed.
3382de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3383de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite makes its own private copy of the data immediately, before
3384de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the sqlite3_bind_*() routine returns.
3385de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3386de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3387de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
3388de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (just an integer to hold its size) while it is being processed.
3389de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Zeroblobs are intended to serve as placeholders for BLOBs whose
3390de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** content is later written using
3391de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_blob_open | incremental BLOB I/O] routines.
3392de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^A negative value for the zeroblob results in a zero-length BLOB.
3393de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3394de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3395de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for the [prepared statement] or with a prepared statement for which
3396de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3397de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
3398de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routine is passed a [prepared statement] that has been finalized, the
3399de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** result is undefined and probably harmful.
3400de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3401de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3402de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Unbound parameters are interpreted as NULL.
3403de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3404de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3405de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [error code] if anything goes wrong.
3406de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^[SQLITE_RANGE] is returned if the parameter
3407de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
3408de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3409de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_bind_parameter_count()],
3410de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3411de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3412de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3413de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
3414de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
3415de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3416de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
3417de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
3418de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3419de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3420de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3421de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3422de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3423de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Number Of SQL Parameters
3424de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3425de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This routine can be used to find the number of [SQL parameters]
3426de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in a [prepared statement].  SQL parameters are tokens of the
3427de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3428de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** placeholders for values that are [sqlite3_bind_blob | bound]
3429de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the parameters at a later time.
3430de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3431de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(This routine actually returns the index of the largest (rightmost)
3432de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameter. For all forms except ?NNN, this will correspond to the
3433de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** number of unique parameters.  If parameters of the ?NNN form are used,
3434de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** there may be gaps in the list.)^
3435de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3436de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_bind_blob|sqlite3_bind()],
3437de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_bind_parameter_name()], and
3438de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_bind_parameter_index()].
3439de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3440de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
3441de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3442de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3443de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Name Of A Host Parameter
3444de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3445de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_bind_parameter_name(P,N) interface returns
3446de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the name of the N-th [SQL parameter] in the [prepared statement] P.
3447de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3448de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3449de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** respectively.
3450de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** In other words, the initial ":" or "$" or "@" or "?"
3451de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is included as part of the name.)^
3452de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Parameters of the form "?" without a following integer have no name
3453de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and are referred to as "nameless" or "anonymous parameters".
3454de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3455de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first host parameter has an index of 1, not 0.
3456de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3457de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the value N is out of range or if the N-th parameter is
3458de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** nameless, then NULL is returned.  ^The returned string is
3459de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** always in UTF-8 encoding even if the named parameter was
3460de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** originally specified as UTF-16 in [sqlite3_prepare16()] or
3461de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_prepare16_v2()].
3462de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3463de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_bind_blob|sqlite3_bind()],
3464de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_bind_parameter_count()], and
3465de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_bind_parameter_index()].
3466de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3467de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3468de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3469de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3470de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Index Of A Parameter With A Given Name
3471de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3472de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Return the index of an SQL parameter given its name.  ^The
3473de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** index value returned is suitable for use as the second
3474de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
3475de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is returned if no matching parameter is found.  ^The parameter
3476de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** name must be given in UTF-8 even if the original statement
3477de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3478de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3479de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_bind_blob|sqlite3_bind()],
3480de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_bind_parameter_count()], and
3481de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_bind_parameter_index()].
3482de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3483de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3484de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3485de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3486de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Reset All Bindings On A Prepared Statement
3487de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3488de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3489de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3490de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Use this routine to reset all host parameters to NULL.
3491de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3492de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
3493de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3494de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3495de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Number Of Columns In A Result Set
3496de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3497de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Return the number of columns in the result set returned by the
3498de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
3499de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** statement that does not return data (for example an [UPDATE]).
3500de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3501de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_data_count()]
3502de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3503de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
3504de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3505de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3506de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Column Names In A Result Set
3507de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3508de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These routines return the name assigned to a particular column
3509de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
3510de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface returns a pointer to a zero-terminated UTF-8 string
3511de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and sqlite3_column_name16() returns a pointer to a zero-terminated
3512de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** UTF-16 string.  ^The first parameter is the [prepared statement]
3513de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that implements the [SELECT] statement. ^The second parameter is the
3514de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** column number.  ^The leftmost column is number 0.
3515de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3516de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The returned string pointer is valid until either the [prepared statement]
351790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is destroyed by [sqlite3_finalize()] or until the statement is automatically
351890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** reprepared by the first call to [sqlite3_step()] for a particular run
351990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** or until the next call to
3520de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3521de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3522de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If sqlite3_malloc() fails during the processing of either routine
3523de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (for example during a conversion from UTF-8 to UTF-16) then a
3524de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** NULL pointer is returned.
3525de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3526de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The name of a result column is the value of the "AS" clause for
3527de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that column, if there is an AS clause.  If there is no AS clause
3528de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the name of the column is unspecified and may change from
3529de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** one release of SQLite to the next.
3530de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3531de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
3532de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
3533de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3534de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3535de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Source Of Data In A Query Result
3536de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3537de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These routines provide a means to determine the database, table, and
3538de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** table column that is the origin of a particular result column in
3539de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SELECT] statement.
3540de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The name of the database or table or column can be returned as
3541de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
3542de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the database name, the _table_ routines return the table name, and
3543de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the origin_ routines return the column name.
3544de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The returned string is valid until the [prepared statement] is destroyed
354590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** using [sqlite3_finalize()] or until the statement is automatically
354690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** reprepared by the first call to [sqlite3_step()] for a particular run
354790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** or until the same information is requested
3548de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** again in a different encoding.
3549de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3550de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The names returned are the original un-aliased names of the
3551de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database, table, and column.
3552de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3553de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first argument to these interfaces is a [prepared statement].
3554de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These functions return information about the Nth result column returned by
3555de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the statement, where N is the second function argument.
3556de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The left-most column is column 0 for these routines.
3557de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3558de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the Nth column returned by the statement is an expression or
3559de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** subquery and is not a column value, then all of these functions return
3560de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** NULL.  ^These routine might also return NULL if a memory allocation error
3561de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** occurs.  ^Otherwise, they return the name of the attached database, table,
3562de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or column that query result column was extracted from.
3563de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3564de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^As with all other SQLite APIs, those whose names end with "16" return
3565de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** UTF-16 encoded strings and the other functions return UTF-8.
3566de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3567de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These APIs are only available if the library was compiled with the
3568de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3569de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3570de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If two or more threads call one or more of these routines against the same
3571de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** prepared statement and column at the same time then the results are
3572de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** undefined.
3573de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3574de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If two or more threads call one or more
3575de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_column_database_name | column metadata interfaces]
3576de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for the same [prepared statement] and result column
3577de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** at the same time then the results are undefined.
3578de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3579de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
3580de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
3581de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
3582de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
3583de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
3584de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
3585de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3586de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3587de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Declared Datatype Of A Query Result
3588de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3589de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The first parameter is a [prepared statement].
3590de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If this statement is a [SELECT] statement and the Nth column of the
3591de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returned result set of that [SELECT] is a table column (not an
3592de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** expression or subquery) then the declared type of the table
3593de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** column is returned.)^  ^If the Nth column of the result set is an
3594de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** expression or subquery, then a NULL pointer is returned.
3595de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The returned string is always UTF-8 encoded.
3596de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3597de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(For example, given the database schema:
3598de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3599de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CREATE TABLE t1(c1 VARIANT);
3600de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3601de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the following statement to be compiled:
3602de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3603de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SELECT c1 + 1, c1 FROM t1;
3604de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3605de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** this routine would return the string "VARIANT" for the second result
3606de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** column (i==1), and a NULL pointer for the first result column (i==0).)^
3607de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3608de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite uses dynamic run-time typing.  ^So just because a column
3609de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is declared to contain a particular type does not mean that the
3610de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** data stored in that column is of the declared type.  SQLite is
3611de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** strongly typed, but the typing is dynamic not static.  ^Type
3612de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is associated with individual values, not with the containers
3613de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** used to hold those values.
3614de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3615de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
3616de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
3617de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3618de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3619de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Evaluate An SQL Statement
3620de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3621de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** After a [prepared statement] has been prepared using either
3622de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3623de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3624de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** must be called one or more times to evaluate the statement.
3625de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3626de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The details of the behavior of the sqlite3_step() interface depend
3627de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on whether the statement was prepared using the newer "v2" interface
3628de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
3629de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
3630de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** new "v2" interface is recommended for new applications but the legacy
3631de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface will continue to be supported.
3632de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3633de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
3634de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
3635de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^With the "v2" interface, any of the other [result codes] or
3636de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [extended result codes] might be returned as well.
3637de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3638de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
3639de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database locks it needs to do its job.  ^If the statement is a [COMMIT]
3640de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or occurs outside of an explicit transaction, then you can retry the
364190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** statement.  If the statement is not a [COMMIT] and occurs within an
3642de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** explicit transaction then you should rollback the transaction before
3643de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** continuing.
3644de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3645de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^[SQLITE_DONE] means that the statement has finished executing
3646de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** successfully.  sqlite3_step() should not be called again on this virtual
3647de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** machine without first calling [sqlite3_reset()] to reset the virtual
3648de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** machine back to its initial state.
3649de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3650de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
3651de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is returned each time a new row of data is ready for processing by the
3652de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** caller. The values may be accessed using the [column access functions].
3653de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_step() is called again to retrieve the next row of data.
3654de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3655de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
3656de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** violation) has occurred.  sqlite3_step() should not be called again on
3657de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the VM. More information may be found by calling [sqlite3_errmsg()].
3658de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^With the legacy interface, a more specific error code (for example,
3659de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
3660de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be obtained by calling [sqlite3_reset()] on the
3661de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [prepared statement].  ^In the "v2" interface,
3662de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the more specific error code is returned directly by sqlite3_step().
3663de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3664de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_MISUSE] means that the this routine was called inappropriately.
3665de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Perhaps it was called on a [prepared statement] that has
3666de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** already been [sqlite3_finalize | finalized] or on one that had
3667de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
3668de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be the case that the same database connection is being used by two or
3669de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** more threads at the same moment in time.
3670de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
367190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** For all versions of SQLite up to and including 3.6.23.1, a call to
367290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_reset()] was required after sqlite3_step() returned anything
367390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** other than [SQLITE_ROW] before any subsequent invocation of
367490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** sqlite3_step().  Failure to reset the prepared statement using
367590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
367690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** sqlite3_step().  But after version 3.6.23.1, sqlite3_step() began
367790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** calling [sqlite3_reset()] automatically in this circumstance rather
367890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** than returning [SQLITE_MISUSE].  This is not considered a compatibility
367990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** break because any application that ever receives an SQLITE_MISUSE error
368090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
368190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** can be used to restore the legacy behavior.
3682de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3683de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
3684de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** API always returns a generic error code, [SQLITE_ERROR], following any
3685de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
3686de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
3687de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** specific [error codes] that better describes the error.
3688de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** We admit that this is a goofy design.  The problem has been fixed
3689de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the "v2" interface.  If you prepare all of your SQL statements
3690de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
3691de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
3692de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the more specific [error codes] are returned directly
3693de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by sqlite3_step().  The use of the "v2" interface is recommended.
3694de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3695de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_step(sqlite3_stmt*);
3696de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3697de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3698de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Number of columns in a result set
3699de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3700de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_data_count(P) interface returns the number of columns in the
3701de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** current row of the result set of [prepared statement] P.
3702de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If prepared statement P does not have results ready to return
3703de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
3704de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interfaces) then sqlite3_data_count(P) returns 0.
3705de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
370690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
370790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_step](P) returned [SQLITE_DONE].  ^The sqlite3_data_count(P)
370890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** will return non-zero if previous call to [sqlite3_step](P) returned
370990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
371090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** where it always returns zero since each step of that multi-step
371190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** pragma returns 0 columns of data.
3712de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3713de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_column_count()]
3714de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3715de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
3716de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3717de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3718de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Fundamental Datatypes
3719de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: SQLITE_TEXT
3720de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3721de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Every value in SQLite has one of five fundamental datatypes:
3722de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3723de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
3724de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> 64-bit signed integer
3725de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> 64-bit IEEE floating point number
3726de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> string
3727de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> BLOB
3728de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> NULL
3729de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>)^
3730de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3731de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These constants are codes for each of those types.
3732de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3733de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Note that the SQLITE_TEXT constant was also used in SQLite version 2
3734de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for a completely different meaning.  Software that links against both
3735de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
3736de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_TEXT.
3737de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3738de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_INTEGER  1
3739de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_FLOAT    2
3740de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_BLOB     4
3741de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_NULL     5
3742de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef SQLITE_TEXT
3743de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori# undef SQLITE_TEXT
3744de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#else
3745de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori# define SQLITE_TEXT     3
3746de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
3747de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE3_TEXT     3
3748de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3749de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3750de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Result Values From A Query
3751de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {column access functions}
3752de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3753de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines form the "result set" interface.
3754de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3755de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These routines return information about a single column of the current
3756de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** result row of a query.  ^In every case the first argument is a pointer
3757de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
3758de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that was returned from [sqlite3_prepare_v2()] or one of its variants)
3759de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the second argument is the index of the column for which information
3760de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** should be returned. ^The leftmost column of the result set has the index 0.
3761de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The number of columns in the result can be determined using
3762de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_column_count()].
3763de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3764de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If the SQL statement does not currently point to a valid row, or if the
3765de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** column index is out of range, the result is undefined.
3766de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines may only be called when the most recent call to
3767de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_step()] has returned [SQLITE_ROW] and neither
3768de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
3769de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If any of these routines are called after [sqlite3_reset()] or
3770de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_finalize()] or after [sqlite3_step()] has returned
3771de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** something other than [SQLITE_ROW], the results are undefined.
3772de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
3773de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are called from a different thread while any of these routines
3774de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are pending, then the results are undefined.
3775de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3776de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_column_type() routine returns the
3777de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_INTEGER | datatype code] for the initial data type
3778de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
3779de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
3780de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returned by sqlite3_column_type() is only meaningful if no type
3781de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** conversions have occurred as described below.  After a type conversion,
3782de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the value returned by sqlite3_column_type() is undefined.  Future
3783de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** versions of SQLite may change the behavior of sqlite3_column_type()
3784de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** following a type conversion.
3785de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3786de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
3787de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routine returns the number of bytes in that BLOB or string.
3788de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
3789de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the string to UTF-8 and then returns the number of bytes.
3790de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the result is a numeric value then sqlite3_column_bytes() uses
3791de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
3792de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the number of bytes in that string.
3793de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
3794de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3795de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
3796de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routine returns the number of bytes in that BLOB or string.
3797de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
3798de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the string to UTF-16 and then returns the number of bytes.
3799de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the result is a numeric value then sqlite3_column_bytes16() uses
3800de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
3801de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the number of bytes in that string.
3802de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
3803de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3804de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The values returned by [sqlite3_column_bytes()] and
3805de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_column_bytes16()] do not include the zero terminators at the end
3806de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the string.  ^For clarity: the values returned by
3807de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
3808de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** bytes in the string, not the number of characters.
3809de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3810de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
381190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** even empty strings, are always zero-terminated.  ^The return
3812de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
3813de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3814de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The object returned by [sqlite3_column_value()] is an
3815de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
3816de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
3817de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If the [unprotected sqlite3_value] object returned by
3818de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_column_value()] is used in any other way, including calls
3819de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
3820de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [sqlite3_value_bytes()], then the behavior is undefined.
3821de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3822de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines attempt to convert the value where appropriate.  ^For
3823de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** example, if the internal representation is FLOAT and a text result
3824de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is requested, [sqlite3_snprintf()] is used internally to perform the
3825de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** conversion automatically.  ^(The following table details the conversions
3826de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that are applied:
3827de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3828de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote>
3829de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <table border="1">
3830de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
3831de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3832de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
3833de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
38348fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <tr><td>  NULL    <td>   TEXT    <td> Result is a NULL pointer
38358fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <tr><td>  NULL    <td>   BLOB    <td> Result is a NULL pointer
3836de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
3837de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
3838de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
38398fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <tr><td>  FLOAT   <td> INTEGER   <td> [CAST] to INTEGER
3840de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
38418fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <tr><td>  FLOAT   <td>   BLOB    <td> [CAST] to BLOB
38428fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <tr><td>  TEXT    <td> INTEGER   <td> [CAST] to INTEGER
38438fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <tr><td>  TEXT    <td>  FLOAT    <td> [CAST] to REAL
3844de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td>  TEXT    <td>   BLOB    <td> No change
38458fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <tr><td>  BLOB    <td> INTEGER   <td> [CAST] to INTEGER
38468fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <tr><td>  BLOB    <td>  FLOAT    <td> [CAST] to REAL
3847de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
3848de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </table>
3849de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </blockquote>)^
3850de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3851de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The table above makes reference to standard C library functions atoi()
3852de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and atof().  SQLite does not really use these functions.  It has its
3853de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** own equivalent internal routines.  The atoi() and atof() names are
3854de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** used in the table for brevity and because they are familiar to most
3855de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** C programmers.
3856de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3857de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Note that when type conversions occur, pointers returned by prior
3858de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
3859de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_column_text16() may be invalidated.
3860de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Type conversions and pointer invalidations might occur
3861de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in the following cases:
3862de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3863de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
3864de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> The initial content is a BLOB and sqlite3_column_text() or
3865de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      sqlite3_column_text16() is called.  A zero-terminator might
3866de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      need to be added to the string.</li>
3867de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
3868de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      sqlite3_column_text16() is called.  The content must be converted
3869de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      to UTF-16.</li>
3870de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
3871de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      sqlite3_column_text() is called.  The content must be converted
3872de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      to UTF-8.</li>
3873de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>
3874de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3875de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Conversions between UTF-16be and UTF-16le are always done in place and do
3876de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not invalidate a prior pointer, though of course the content of the buffer
3877de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that the prior pointer references will have been modified.  Other kinds
3878de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of conversion are done in place when it is possible, but sometimes they
3879de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are not possible and in those cases prior pointers are invalidated.
3880de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3881de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The safest and easiest to remember policy is to invoke these routines
3882de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in one of the following ways:
3883de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3884de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
3885de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
3886de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
3887de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
3888de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>
3889de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3890de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** In other words, you should call sqlite3_column_text(),
3891de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
3892de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** into the desired format, then invoke sqlite3_column_bytes() or
3893de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
3894de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to sqlite3_column_text() or sqlite3_column_blob() with calls to
3895de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
3896de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with calls to sqlite3_column_bytes().
3897de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3898de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The pointers returned are valid until a type conversion occurs as
3899de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
3900de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
3901de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned
39028fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
3903de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_free()].
3904de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3905de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(If a memory allocation error occurs during the evaluation of any
3906de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of these routines, a default value is returned.  The default value
3907de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is either the integer 0, the floating point number 0.0, or a NULL
3908de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pointer.  Subsequent calls to [sqlite3_errcode()] will return
3909de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_NOMEM].)^
3910de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3911de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
3912de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
3913de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
3914de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
3915de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
3916de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
3917de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
3918de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
3919de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
3920de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
3921de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3922de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3923de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Destroy A Prepared Statement Object
3924de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3925de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_finalize() function is called to delete a [prepared statement].
392690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^If the most recent evaluation of the statement encountered no errors
392795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** or if the statement is never been evaluated, then sqlite3_finalize() returns
392895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
392995c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** sqlite3_finalize(S) returns the appropriate [error code] or
393095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** [extended error code].
393195c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
393295c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^The sqlite3_finalize(S) routine can be called at any point during
393395c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** the life cycle of [prepared statement] S:
393495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** before statement S is ever evaluated, after
393595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** one or more calls to [sqlite3_reset()], or after any call
393695c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** to [sqlite3_step()] regardless of whether or not the statement has
393795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** completed execution.
393895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
393995c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
394095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
394195c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** The application must finalize every [prepared statement] in order to avoid
394295c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** resource leaks.  It is a grievous error for the application to try to use
394395c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** a prepared statement after it has been finalized.  Any use of a prepared
394495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** statement after it has been finalized can result in undefined and
394595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** undesirable behavior such as segfaults and heap corruption.
3946de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3947de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
3948de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3949de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3950de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Reset A Prepared Statement Object
3951de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3952de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_reset() function is called to reset a [prepared statement]
3953de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** object back to its initial state, ready to be re-executed.
3954de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Any SQL statement variables that had values bound to them using
3955de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
3956de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Use [sqlite3_clear_bindings()] to reset the bindings.
3957de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3958de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
3959de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** back to the beginning of its program.
3960de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3961de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the most recent call to [sqlite3_step(S)] for the
3962de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
3963de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or if [sqlite3_step(S)] has never before been called on S,
3964de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then [sqlite3_reset(S)] returns [SQLITE_OK].
3965de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3966de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the most recent call to [sqlite3_step(S)] for the
3967de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [prepared statement] S indicated an error, then
3968de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_reset(S)] returns an appropriate [error code].
3969de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3970de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_reset(S)] interface does not change the values
3971de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
3972de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
3973de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
3974de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
3975de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
3976de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Create Or Redefine SQL Functions
3977de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {function creation routines}
3978de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {application-defined SQL function}
3979de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {application-defined SQL functions}
3980de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3981de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These functions (collectively known as "function creation routines")
3982de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are used to add SQL functions or aggregates or to redefine the behavior
3983de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of existing SQL functions or aggregates.  The only differences between
3984de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** these routines are the text encoding expected for
398590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the second parameter (the name of the function being created)
3986de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the presence or absence of a destructor callback for
3987de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the application data pointer.
3988de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3989de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first parameter is the [database connection] to which the SQL
3990de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function is to be added.  ^If an application uses more than one database
3991de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** connection then application-defined SQL functions must be added
3992de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to each database connection separately.
3993de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
3994de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The second parameter is the name of the SQL function to be created or
3995de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8
3996de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** representation, exclusive of the zero-terminator.  ^Note that the name
3997de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
3998de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Any attempt to create a function with a longer name
3999de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will result in [SQLITE_MISUSE] being returned.
4000de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4001de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The third parameter (nArg)
4002de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is the number of arguments that the SQL function or
4003de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** aggregate takes. ^If this parameter is -1, then the SQL function or
4004de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** aggregate may take any number of arguments between 0 and the limit
4005de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
4006de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameter is less than -1 or greater than 127 then the behavior is
4007de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** undefined.
4008de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4009de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The fourth parameter, eTextRep, specifies what
4010de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_UTF8 | text encoding] this SQL function prefers for
40118fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** its parameters.  The application should set this parameter to
40128fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [SQLITE_UTF16LE] if the function implementation invokes
40138fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
40148fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** implementation invokes [sqlite3_value_text16be()] on an input, or
40158fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
40168fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** otherwise.  ^The same SQL function may be registered multiple times using
40178fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** different preferred text encodings, with different implementations for
40188fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** each encoding.
4019de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^When multiple implementations of the same function are available, SQLite
4020de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will pick the one that involves the least amount of data conversion.
40218fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
40228fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
40238fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to signal that the function will always return the same result given
40248fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the same inputs within a single SQL statement.  Most SQL functions are
40258fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** deterministic.  The built-in [random()] SQL function is an example of a
40268fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** function that is not deterministic.  The SQLite query planner is able to
40278fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** perform additional optimizations on deterministic functions, so use
40288fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4029de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4030de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
4031de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function can gain access to this pointer using [sqlite3_user_data()].)^
4032de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
403390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
4034de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pointers to C-language functions that implement the SQL function or
4035de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4036de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** callback only; NULL pointers must be passed as the xStep and xFinal
4037de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameters. ^An aggregate SQL function requires an implementation of xStep
4038de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
403990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** SQL function or aggregate, pass NULL pointers for all three function
4040de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** callbacks.
4041de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
404290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
404395c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** then it is destructor for the application data pointer.
404495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** The destructor is invoked when the function is deleted, either by being
404595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** overloaded or when the database connection closes.)^
404695c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^The destructor is also invoked if the call to
404795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** sqlite3_create_function_v2() fails.
404895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^When the destructor callback of the tenth parameter is invoked, it
404995c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** is passed a single argument which is a copy of the application data
405095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** pointer which was the fifth parameter to sqlite3_create_function_v2().
4051de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4052de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^It is permitted to register multiple implementations of the same
4053de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** functions with the same name but with either differing numbers of
4054de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** arguments or differing preferred text encodings.  ^SQLite will use
4055de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the implementation that most closely matches the way in which the
4056de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQL function is used.  ^A function implementation with a non-negative
4057de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** nArg parameter is a better match than a function implementation with
4058de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a negative nArg.  ^A function where the preferred text encoding
4059de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** matches the database encoding is a better
4060de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** match than a function where the encoding is different.
4061de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^A function where the encoding difference is between UTF16le and UTF16be
4062de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is a closer match than a function where the encoding difference is
4063de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** between UTF8 and UTF16.
4064de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4065de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Built-in functions may be overloaded by new application-defined functions.
4066de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4067de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^An application-defined function is permitted to call other
4068de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite interfaces.  However, such calls must not
4069de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** close the database connection nor finalize or reset the prepared
4070de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** statement in which the function is running.
4071de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4072de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_create_function(
4073de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,
4074de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zFunctionName,
4075de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nArg,
4076de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int eTextRep,
4077de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pApp,
4078de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4079de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4080de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xFinal)(sqlite3_context*)
4081de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4082de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_create_function16(
4083de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,
4084de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const void *zFunctionName,
4085de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nArg,
4086de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int eTextRep,
4087de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pApp,
4088de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4089de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4090de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xFinal)(sqlite3_context*)
4091de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4092de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_create_function_v2(
4093de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,
4094de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zFunctionName,
4095de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nArg,
4096de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int eTextRep,
4097de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pApp,
4098de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4099de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4100de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xFinal)(sqlite3_context*),
4101de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void(*xDestroy)(void*)
4102de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4103de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4104de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4105de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Text Encodings
4106de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4107de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These constant define integer codes that represent the various
4108de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** text encodings supported by SQLite.
4109de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4110de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_UTF8           1
4111de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_UTF16LE        2
4112de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_UTF16BE        3
4113de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_UTF16          4    /* Use native byte order */
41148fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_ANY            5    /* Deprecated */
4115de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
4116de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4117de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
41188fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** CAPI3REF: Function Flags
41198fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
41208fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** These constants may be ORed together with the
41218fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
41228fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to [sqlite3_create_function()], [sqlite3_create_function16()], or
41238fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [sqlite3_create_function_v2()].
41248fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich*/
41258fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_DETERMINISTIC    0x800
41268fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich
41278fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich/*
4128de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Deprecated Functions
4129de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** DEPRECATED
4130de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4131de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These functions are [deprecated].  In order to maintain
4132de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** backwards compatibility with older code, these functions continue
4133de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to be supported.  However, new applications should avoid
4134de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the use of these functions.  To help encourage people to avoid
4135de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** using these functions, we are not going to tell you what they do.
4136de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4137de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifndef SQLITE_OMIT_DEPRECATED
4138de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4139de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4140de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4141de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4142de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
41438fecf56c625b5691ee3381e107ccbe1ff42398b1Nick KralevichSQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
41448fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich                      void*,sqlite3_int64);
4145de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
4146de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4147de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4148de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Obtaining SQL Function Parameter Values
4149de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4150de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The C-language implementation of SQL functions and aggregates uses
4151de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** this set of interface routines to access the parameter values on
4152de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the function or aggregate.
4153de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4154de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xFunc (for scalar functions) or xStep (for aggregates) parameters
4155de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to [sqlite3_create_function()] and [sqlite3_create_function16()]
4156de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** define callbacks that implement the SQL functions and aggregates.
415790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The 3rd parameter to these callbacks is an array of pointers to
4158de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
4159de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** each parameter to the SQL function.  These routines are used to
4160de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** extract values from the [sqlite3_value] objects.
4161de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4162de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines work only with [protected sqlite3_value] objects.
4163de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Any attempt to use these routines on an [unprotected sqlite3_value]
4164de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** object results in undefined behavior.
4165de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4166de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These routines work just like the corresponding [column access functions]
4167de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** except that  these routines take a single [protected sqlite3_value] object
4168de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4169de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4170de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4171de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in the native byte-order of the host machine.  ^The
4172de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4173de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** extract UTF-16 strings as big-endian and little-endian respectively.
4174de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4175de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The sqlite3_value_numeric_type() interface attempts to apply
4176de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** numeric affinity to the value.  This means that an attempt is
4177de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** made to convert the value to an integer or floating point.  If
4178de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** such a conversion is possible without loss of information (in other
4179de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** words, if the value is a string that looks like a number)
4180de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the conversion is performed.  Otherwise no conversion occurs.
4181de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4182de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4183de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Please pay particular attention to the fact that the pointer returned
4184de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4185de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4186de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4187de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [sqlite3_value_text16()].
4188de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4189de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines must be called from the same thread as
4190de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the SQL function that supplied the [sqlite3_value*] parameters.
4191de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4192de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
4193de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_value_bytes(sqlite3_value*);
4194de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
4195de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API double sqlite3_value_double(sqlite3_value*);
4196de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_value_int(sqlite3_value*);
4197de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
4198de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
4199de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
4200de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
4201de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
4202de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_value_type(sqlite3_value*);
4203de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
4204de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4205de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4206de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Obtain Aggregate Function Context
4207de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4208de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Implementations of aggregate SQL functions use this
4209de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routine to allocate memory for storing their state.
4210de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4211de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first time the sqlite3_aggregate_context(C,N) routine is called
4212de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for a particular aggregate function, SQLite
4213de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** allocates N of memory, zeroes out that memory, and returns a pointer
4214de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the new memory. ^On second and subsequent calls to
4215de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_aggregate_context() for the same aggregate function instance,
4216de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the same buffer is returned.  Sqlite3_aggregate_context() is normally
4217de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** called once for each invocation of the xStep callback and then one
4218de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** last time when the xFinal callback is invoked.  ^(When no rows match
4219de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an aggregate query, the xStep() callback of the aggregate function
4220de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation is never called and xFinal() is called exactly once.
4221de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** In those cases, sqlite3_aggregate_context() might be called for the
4222de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** first time from within xFinal().)^
4223de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
42248fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
42258fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** when first called if N is less than or equal to zero or if a memory
42268fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** allocate error occurs.
4227de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4228de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4229de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** determined by the N parameter on first successful call.  Changing the
4230de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value of N in subsequent call to sqlite3_aggregate_context() within
4231de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the same aggregate function instance will not resize the memory
42328fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** allocation.)^  Within the xFinal callback, it is customary to set
42338fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
42348fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** pointless memory allocations occur.
4235de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4236de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite automatically frees the memory allocated by
4237de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_aggregate_context() when the aggregate query concludes.
4238de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4239de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The first parameter must be a copy of the
4240de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_context | SQL function context] that is the first parameter
4241de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the xStep or xFinal callback routine that implements the aggregate
4242de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function.
4243de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4244de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This routine must be called from the same thread in which
4245de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the aggregate SQL function is running.
4246de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4247de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4248de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4249de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4250de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: User Data For Functions
4251de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4252de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_user_data() interface returns a copy of
4253de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the pointer that was the pUserData parameter (the 5th parameter)
4254de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the [sqlite3_create_function()]
4255de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and [sqlite3_create_function16()] routines that originally
4256de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** registered the application defined function.
4257de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4258de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This routine must be called from the same thread in which
4259de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the application-defined function is running.
4260de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4261de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void *sqlite3_user_data(sqlite3_context*);
4262de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4263de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4264de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Database Connection For Functions
4265de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4266de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_context_db_handle() interface returns a copy of
4267de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the pointer to the [database connection] (the 1st parameter)
4268de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the [sqlite3_create_function()]
4269de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and [sqlite3_create_function16()] routines that originally
4270de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** registered the application defined function.
4271de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4272de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
4273de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4274de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4275de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Function Auxiliary Data
4276de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
42778fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** These functions may be used by (non-aggregate) SQL functions to
4278de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** associate metadata with argument values. If the same value is passed to
4279de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** multiple invocations of the same SQL function during query execution, under
42808fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** some circumstances the associated metadata may be preserved.  An example
42818fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** of where this might be useful is in a regular-expression matching
42828fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** function. The compiled version of the regular expression can be stored as
42838fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** metadata associated with the pattern string.
42848fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** Then as long as the pattern string remains the same,
42858fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the compiled regular expression can be reused on multiple
42868fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** invocations of the same function.
4287de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4288de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
4289de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** associated by the sqlite3_set_auxdata() function with the Nth argument
42908fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** value to the application-defined function. ^If there is no metadata
42918fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** associated with the function argument, this sqlite3_get_auxdata() interface
42928fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** returns a NULL pointer.
42938fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
42948fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
42958fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** argument of the application-defined function.  ^Subsequent
42968fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** calls to sqlite3_get_auxdata(C,N) return P from the most recent
42978fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
42988fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** NULL if the metadata has been discarded.
42998fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
43008fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** SQLite will invoke the destructor function X with parameter P exactly
43018fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** once, when the metadata is discarded.
43028fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** SQLite is free to discard the metadata at any time, including: <ul>
43038fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li> when the corresponding function parameter changes, or
43048fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
43058fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**      SQL statement, or
43068fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or
43078fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <li> during the original sqlite3_set_auxdata() call when a memory
43088fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**      allocation error occurs. </ul>)^
43098fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
43108fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** Note the last bullet in particular.  The destructor X in
43118fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
43128fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** sqlite3_set_auxdata() interface even returns.  Hence sqlite3_set_auxdata()
43138fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** should be called near the end of the function implementation and the
43148fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** function implementation should not make any use of P after
43158fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** sqlite3_set_auxdata() has been called.
4316de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4317de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(In practice, metadata is preserved between function calls for
43188fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** function parameters that are compile-time constants, including literal
43198fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** values and [parameters] and expressions composed from the same.)^
4320de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4321de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines must be called from the same thread in which
4322de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the SQL function is running.
4323de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4324de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
4325de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4326de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4327de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4328de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4329de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Constants Defining Special Destructor Behavior
4330de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4331de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These are special values for the destructor that is passed in as the
4332de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
4333de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** argument is SQLITE_STATIC, it means that the content pointer is constant
4334de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and will never change.  It does not need to be destroyed.  ^The
4335de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_TRANSIENT value means that the content will likely change in
4336de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the near future and that SQLite should make its own private copy of
4337de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the content before returning.
4338de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4339de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The typedef is necessary to work around problems in certain
43408fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** C++ compilers.
4341de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4342de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef void (*sqlite3_destructor_type)(void*);
4343de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
4344de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
4345de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4346de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4347de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Setting The Result Of An SQL Function
4348de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4349de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These routines are used by the xFunc or xFinal callbacks that
4350de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implement SQL functions and aggregates.  See
4351de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_create_function()] and [sqlite3_create_function16()]
4352de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for additional information.
4353de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4354de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These functions work very much like the [parameter binding] family of
4355de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** functions used to bind values to host parameters in prepared statements.
4356de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Refer to the [SQL parameter] documentation for additional information.
4357de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4358de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_blob() interface sets the result from
4359de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an application-defined function to be the BLOB whose content is pointed
4360de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to by the second parameter and which is N bytes long where N is the
4361de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** third parameter.
4362de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4363de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_zeroblob() interfaces set the result of
4364de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the application-defined function to be a BLOB containing all zero
4365de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** bytes and N bytes in size, where N is the value of the 2nd parameter.
4366de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4367de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_double() interface sets the result from
4368de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an application-defined function to be a floating point value specified
4369de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by its 2nd argument.
4370de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4371de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4372de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** cause the implemented SQL function to throw an exception.
4373de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite uses the string pointed to by the
4374de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4375de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as the text of an error message.  ^SQLite interprets the error
4376de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** message string from sqlite3_result_error() as UTF-8. ^SQLite
4377de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interprets the string from sqlite3_result_error16() as UTF-16 in native
4378de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** byte order.  ^If the third parameter to sqlite3_result_error()
4379de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or sqlite3_result_error16() is negative then SQLite takes as the error
4380de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** message all text up through the first zero character.
4381de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the third parameter to sqlite3_result_error() or
4382de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_result_error16() is non-negative then SQLite takes that many
4383de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** bytes (not characters) from the 2nd parameter as the error message.
4384de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_error() and sqlite3_result_error16()
4385de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routines make a private copy of the error message text before
4386de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** they return.  Hence, the calling function can deallocate or
4387de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** modify the text after they return without harm.
4388de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_error_code() function changes the error code
4389de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returned by SQLite as a result of an error in a function.  ^By default,
4390de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
4391de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4392de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
43938fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
43948fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** error indicating that a string or BLOB is too long to represent.
4395de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
43968fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
43978fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** error indicating that a memory allocation failed.
4398de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4399de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_int() interface sets the return value
4400de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the application-defined function to be the 32-bit signed integer
4401de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value given in the 2nd argument.
4402de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_int64() interface sets the return value
4403de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the application-defined function to be the 64-bit signed integer
4404de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value given in the 2nd argument.
4405de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4406de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_null() interface sets the return value
4407de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the application-defined function to be NULL.
4408de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4409de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_text(), sqlite3_result_text16(),
4410de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4411de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** set the return value of the application-defined function to be
4412de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a text string which is represented as UTF-8, UTF-16 native byte order,
4413de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** UTF-16 little endian, or UTF-16 big endian, respectively.
4414de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite takes the text result from the application from
4415de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the 2nd parameter of the sqlite3_result_text* interfaces.
4416de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4417de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is negative, then SQLite takes result text from the 2nd parameter
4418de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** through the first zero character.
4419de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4420de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is non-negative, then as many bytes (not characters) of the text
4421de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pointed to by the 2nd parameter are taken as the application-defined
442290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** function result.  If the 3rd parameter is non-negative, then it
442390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** must be the byte offset into the string where the NUL terminator would
442490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** appear if the string where NUL terminated.  If any NUL characters occur
442590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** in the string at a byte offset that is less than the value of the 3rd
442690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** parameter, then the resulting string will contain embedded NULs and the
442790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** result of expressions operating on strings with embedded NULs is undefined.
4428de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the 4th parameter to the sqlite3_result_text* interfaces
4429de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4430de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function as the destructor on the text or BLOB result when it has
4431de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** finished using that result.
4432de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4433de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4434de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** assumes that the text or BLOB result is in constant space and does not
4435de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** copy the content of the parameter nor call a destructor on the content
4436de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** when it has finished using that result.
4437de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the 4th parameter to the sqlite3_result_text* interfaces
4438de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4439de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then SQLite makes a copy of the result into space obtained from
4440de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from [sqlite3_malloc()] before it returns.
4441de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4442de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_result_value() interface sets the result of
4443de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the application-defined function to be a copy the
4444de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
4445de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4446de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** so that the [sqlite3_value] specified in the parameter may change or
4447de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be deallocated after sqlite3_result_value() returns without harm.
4448de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^A [protected sqlite3_value] object may always be used where an
4449de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [unprotected sqlite3_value] object is required, so either
4450de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** kind of [sqlite3_value] object can be used with this interface.
4451de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4452de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If these routines are called from within the different thread
4453de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** than the one containing the application-defined function that received
4454de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [sqlite3_context] pointer, the results are undefined.
4455de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4456de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4457de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_double(sqlite3_context*, double);
4458de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
4459de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
4460de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
4461de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
4462de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
4463de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_int(sqlite3_context*, int);
4464de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4465de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_null(sqlite3_context*);
4466de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4467de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4468de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4469de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4470de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4471de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
4472de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4473de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4474de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Define New Collating Sequences
4475de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4476de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These functions add, remove, or modify a [collation] associated
4477de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the [database connection] specified as the first argument.
4478de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4479de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The name of the collation is a UTF-8 string
4480de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4481de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4482de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4483de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** considered to be the same name.
4484de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4485de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The third argument (eTextRep) must be one of the constants:
4486de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
4487de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_UTF8],
4488de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_UTF16LE],
4489de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_UTF16BE],
4490de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_UTF16], or
4491de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> [SQLITE_UTF16_ALIGNED].
4492de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>)^
4493de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The eTextRep argument determines the encoding of strings passed
4494de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the collating function callback, xCallback.
4495de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4496de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** force strings to be UTF16 with native byte order.
4497de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4498de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on an even byte address.
4499de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
450090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The fourth argument, pArg, is an application data pointer that is passed
4501de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** through as the first argument to the collating function callback.
4502de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4503de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The fifth argument, xCallback, is a pointer to the collating function.
4504de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Multiple collating functions can be registered using the same name but
4505de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with different eTextRep parameters and SQLite will use whichever
4506de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function requires the least amount of data transformation.
4507de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the xCallback argument is NULL then the collating function is
4508de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** deleted.  ^When all collating functions having the same name are deleted,
4509de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that collation is no longer usable.
4510de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4511de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The collating function callback is invoked with a copy of the pArg
4512de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** application data pointer and with two strings in the encoding specified
4513de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by the eTextRep argument.  The collating function must return an
4514de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** integer that is negative, zero, or positive
4515de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if the first string is less than, equal to, or greater than the second,
451690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** respectively.  A collating function must always return the same answer
4517de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** given the same inputs.  If two or more collating functions are registered
4518de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the same collation name (using different eTextRep values) then all
4519de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** must give an equivalent answer when invoked with equivalent strings.
4520de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The collating function must obey the following properties for all
4521de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** strings A, B, and C:
4522de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4523de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ol>
4524de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> If A==B then B==A.
4525de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> If A==B and B==C then A==C.
4526de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> If A&lt;B THEN B&gt;A.
4527de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> If A&lt;B and B&lt;C then A&lt;C.
4528de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ol>
4529de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4530de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If a collating function fails any of the above constraints and that
4531de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** collating function is  registered and used, then the behavior of SQLite
4532de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is undefined.
4533de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4534de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4535de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the addition that the xDestroy callback is invoked on pArg when
4536de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the collating function is deleted.
4537de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Collating functions are deleted when they are overridden by later
4538de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** calls to the collation creation functions or when the
4539de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection] is closed using [sqlite3_close()].
4540de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
454195c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^The xDestroy callback is <u>not</u> called if the
454295c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** sqlite3_create_collation_v2() function fails.  Applications that invoke
454395c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
454495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** check the return code and dispose of the application data pointer
454595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** themselves rather than expecting SQLite to deal with it for them.
454695c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** This is different from every other SQLite interface.  The inconsistency
454795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** is unfortunate but cannot be changed without breaking backwards
454895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** compatibility.
454995c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
4550de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
4551de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4552de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_create_collation(
4553de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3*,
4554de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zName,
4555de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int eTextRep,
4556de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pArg,
4557de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int(*xCompare)(void*,int,const void*,int,const void*)
4558de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4559de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_create_collation_v2(
4560de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3*,
4561de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zName,
4562de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int eTextRep,
4563de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pArg,
4564de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int(*xCompare)(void*,int,const void*,int,const void*),
4565de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void(*xDestroy)(void*)
4566de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4567de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_create_collation16(
4568de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3*,
4569de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const void *zName,
4570de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int eTextRep,
4571de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pArg,
4572de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int(*xCompare)(void*,int,const void*,int,const void*)
4573de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4574de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4575de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4576de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Collation Needed Callbacks
4577de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4578de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^To avoid having to register all collation sequences before a database
4579de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be used, a single callback function may be registered with the
4580de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection] to be invoked whenever an undefined collation
4581de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sequence is required.
4582de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4583de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the function is registered using the sqlite3_collation_needed() API,
4584de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then it is passed the names of undefined collation sequences as strings
4585de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
4586de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the names are passed as UTF-16 in machine native byte order.
4587de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^A call to either function replaces the existing collation-needed callback.
4588de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4589de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(When the callback is invoked, the first argument passed is a copy
4590de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the second argument to sqlite3_collation_needed() or
4591de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_collation_needed16().  The second argument is the database
4592de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
4593de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
4594de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sequence function required.  The fourth parameter is the name of the
4595de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** required collation sequence.)^
4596de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4597de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The callback function should register the desired collation using
4598de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
4599de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_create_collation_v2()].
4600de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4601de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_collation_needed(
4602de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3*,
4603de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void*,
4604de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void(*)(void*,sqlite3*,int eTextRep,const char*)
4605de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4606de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_collation_needed16(
4607de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3*,
4608de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void*,
4609de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void(*)(void*,sqlite3*,int eTextRep,const void*)
4610de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4611de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4612de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef SQLITE_HAS_CODEC
4613de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4614de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Specify the key for an encrypted database.  This routine should be
4615de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** called right after sqlite3_open().
4616de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4617de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The code to implement this API is not available in the public release
4618de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of SQLite.
4619de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4620de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_key(
4621de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,                   /* Database to be rekeyed */
4622de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const void *pKey, int nKey     /* The key */
4623de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
46248fecf56c625b5691ee3381e107ccbe1ff42398b1Nick KralevichSQLITE_API int sqlite3_key_v2(
46258fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  sqlite3 *db,                   /* Database to be rekeyed */
46268fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  const char *zDbName,           /* Name of the database */
46278fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  const void *pKey, int nKey     /* The key */
46288fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich);
4629de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4630de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4631de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Change the key on an open database.  If the current database is not
4632de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
4633de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database is decrypted.
4634de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4635de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The code to implement this API is not available in the public release
4636de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of SQLite.
4637de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4638de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_rekey(
4639de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,                   /* Database to be rekeyed */
4640de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const void *pKey, int nKey     /* The new key */
4641de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
46428fecf56c625b5691ee3381e107ccbe1ff42398b1Nick KralevichSQLITE_API int sqlite3_rekey_v2(
46438fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  sqlite3 *db,                   /* Database to be rekeyed */
46448fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  const char *zDbName,           /* Name of the database */
46458fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  const void *pKey, int nKey     /* The new key */
46468fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich);
4647de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4648de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4649de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Specify the activation key for a SEE database.  Unless
4650de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** activated, none of the SEE routines will work.
4651de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4652de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_activate_see(
4653de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zPassPhrase        /* Activation phrase */
4654de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4655de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
4656de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4657de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef SQLITE_ENABLE_CEROD
4658de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4659de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Specify the activation key for a CEROD database.  Unless
4660de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** activated, none of the CEROD routines will work.
4661de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4662de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_activate_cerod(
4663de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zPassPhrase        /* Activation phrase */
4664de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4665de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
4666de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4667de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4668de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Suspend Execution For A Short Time
4669de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4670de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_sleep() function causes the current thread to suspend execution
4671de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for at least a number of milliseconds specified in its parameter.
4672de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4673de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If the operating system does not support sleep requests with
4674de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** millisecond time resolution, then the time will be rounded up to
4675de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the nearest second. The number of milliseconds of sleep actually
4676de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** requested from the operating system is returned.
4677de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4678de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite implements this interface by calling the xSleep()
4679de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** method of the default [sqlite3_vfs] object.  If the xSleep() method
4680de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the default VFS is not implemented correctly, or not implemented at
4681de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** all, then the behavior of sqlite3_sleep() may deviate from the description
4682de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in the previous paragraphs.
4683de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4684de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_sleep(int);
4685de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4686de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4687de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Name Of The Folder Holding Temporary Files
4688de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4689de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(If this global variable is made to point to a string which is
4690de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the name of a folder (a.k.a. directory), then all temporary files
4691de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** created by SQLite when using a built-in [sqlite3_vfs | VFS]
4692de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will be placed in that directory.)^  ^If this variable
4693de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is a NULL pointer, then SQLite performs a search for an appropriate
4694de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** temporary file directory.
4695de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
46969bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** Applications are strongly discouraged from using this global variable.
46979bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** It is required to set a temporary folder on Windows Runtime (WinRT).
46989bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** But for all other platforms, it is highly recommended that applications
46999bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** neither read nor write this variable.  This global variable is a relic
47009bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** that exists for backwards compatibility of legacy applications and should
47019bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** be avoided in new projects.
47029bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown**
4703de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** It is not safe to read or modify this variable in more than one
4704de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** thread at a time.  It is not safe to read or modify this variable
4705de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if a [database connection] is being used at the same time in a separate
4706de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** thread.
4707de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** It is intended that this variable be set once
4708de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as part of process initialization and before any SQLite interface
4709de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routines have been called and that this variable remain unchanged
4710de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** thereafter.
4711de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4712de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [temp_store_directory pragma] may modify this variable and cause
4713de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
4714de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [temp_store_directory pragma] always assumes that any string
4715de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that this variable points to is held in memory obtained from
4716de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_malloc] and the pragma may attempt to free that memory
4717de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** using [sqlite3_free].
4718de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Hence, if this variable is modified directly, either it should be
4719de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** made NULL or made to point to memory obtained from [sqlite3_malloc]
4720de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or else the use of the [temp_store_directory pragma] should be avoided.
47219bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** Except when requested by the [temp_store_directory pragma], SQLite
47229bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** does not free the memory that sqlite3_temp_directory points to.  If
47239bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** the application wants that memory to be freed, it must do
47249bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** so itself, taking care to only do so after all [database connection]
47259bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** objects have been destroyed.
47268fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
47278fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
47288fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** prior to calling [sqlite3_open] or [sqlite3_open_v2].  Otherwise, various
47298fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** features that require the use of temporary files may fail.  Here is an
47308fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** example of how to do this using C++ with the Windows Runtime:
47318fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
47328fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <blockquote><pre>
47338fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
47348fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** &nbsp;     TemporaryFolder->Path->Data();
47358fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** char zPathBuf&#91;MAX_PATH + 1&#93;;
47368fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** memset(zPathBuf, 0, sizeof(zPathBuf));
47378fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
47388fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** &nbsp;     NULL, NULL);
47398fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
47408fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** </pre></blockquote>
4741de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4742de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
4743de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4744de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
47458fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** CAPI3REF: Name Of The Folder Holding Database Files
47468fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
47478fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^(If this global variable is made to point to a string which is
47488fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the name of a folder (a.k.a. directory), then all database files
47498fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** specified with a relative pathname and created or accessed by
47508fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
47518fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to be relative to that directory.)^ ^If this variable is a NULL
47528fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** pointer, then SQLite assumes that all database files specified
47538fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** with a relative pathname are relative to the current directory
47548fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** for the process.  Only the windows VFS makes use of this global
47558fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** variable; it is ignored by the unix VFS.
47568fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
47578fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** Changing the value of this variable while a database connection is
47588fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** open can result in a corrupt database.
47598fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
47608fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** It is not safe to read or modify this variable in more than one
47618fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** thread at a time.  It is not safe to read or modify this variable
47628fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** if a [database connection] is being used at the same time in a separate
47638fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** thread.
47648fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** It is intended that this variable be set once
47658fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** as part of process initialization and before any SQLite interface
47668fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** routines have been called and that this variable remain unchanged
47678fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** thereafter.
47688fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
47698fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The [data_store_directory pragma] may modify this variable and cause
47708fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
47718fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the [data_store_directory pragma] always assumes that any string
47728fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** that this variable points to is held in memory obtained from
47738fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [sqlite3_malloc] and the pragma may attempt to free that memory
47748fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** using [sqlite3_free].
47758fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** Hence, if this variable is modified directly, either it should be
47768fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** made NULL or made to point to memory obtained from [sqlite3_malloc]
47778fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** or else the use of the [data_store_directory pragma] should be avoided.
47788fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich*/
47798fecf56c625b5691ee3381e107ccbe1ff42398b1Nick KralevichSQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
47808fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich
47818fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich/*
4782de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Test For Auto-Commit Mode
4783de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {autocommit mode}
4784de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4785de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_get_autocommit() interface returns non-zero or
4786de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** zero if the given database connection is or is not in autocommit mode,
4787de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** respectively.  ^Autocommit mode is on by default.
4788de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Autocommit mode is disabled by a [BEGIN] statement.
4789de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
4790de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4791de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If certain kinds of errors occur on a statement within a multi-statement
4792de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
4793de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
4794de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** transaction might be rolled back automatically.  The only way to
4795de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** find out whether SQLite automatically rolled back the transaction after
4796de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an error is to use this function.
4797de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4798de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If another thread changes the autocommit status of the database
4799de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** connection while this routine is running, then the return value
4800de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is undefined.
4801de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4802de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_get_autocommit(sqlite3*);
4803de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4804de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4805de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Find The Database Handle Of A Prepared Statement
4806de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4807de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_db_handle interface returns the [database connection] handle
4808de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to which a [prepared statement] belongs.  ^The [database connection]
4809de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returned by sqlite3_db_handle is the same [database connection]
4810de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that was the first argument
4811de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
4812de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** create the statement in the first place.
4813de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4814de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
4815de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4816de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
481790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Return The Filename For A Database Connection
481890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
481990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
482090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** associated with database N of connection D.  ^The main database file
482190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** has the name "main".  If there is no attached database N on the database
482290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** connection D, or if database N is a temporary or in-memory database, then
482390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** a NULL pointer is returned.
482490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
482590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The filename returned by this function is the output of the
482690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** xFullPathname method of the [VFS].  ^In other words, the filename
482790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** will be an absolute pathname, even if the filename used
482890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** to open the database originally was a URI or relative pathname.
482990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
483090ed05d921d6ed7f12012d9786d53f57fafee51aJeff BrownSQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
483190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
483290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
4833c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** CAPI3REF: Determine if a database is read-only
4834c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown**
4835c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
4836c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** of connection D is read-only, 0 if it is read/write, or -1 if N is not
4837c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** the name of a database on connection D.
4838c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown*/
4839c82acac4e67711e8d9289b572d334298aeb5d806Jeff BrownSQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
4840c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown
4841c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown/*
4842de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Find the next prepared statement
4843de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4844de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This interface returns a pointer to the next [prepared statement] after
4845de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
4846de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then this interface returns a pointer to the first prepared statement
4847de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** associated with the database connection pDb.  ^If no prepared statement
4848de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** satisfies the conditions of this routine, it returns NULL.
4849de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4850de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [database connection] pointer D in a call to
4851de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_next_stmt(D,S)] must refer to an open database
4852de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** connection and in particular must not be a NULL pointer.
4853de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4854de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
4855de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4856de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4857de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Commit And Rollback Notification Callbacks
4858de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4859de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_commit_hook() interface registers a callback
4860de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function to be invoked whenever a transaction is [COMMIT | committed].
4861de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Any callback set by a previous call to sqlite3_commit_hook()
4862de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for the same database connection is overridden.
4863de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_rollback_hook() interface registers a callback
4864de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
4865de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Any callback set by a previous call to sqlite3_rollback_hook()
4866de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for the same database connection is overridden.
4867de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The pArg argument is passed through to the callback.
4868de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the callback on a commit hook function returns non-zero,
4869de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the commit is converted into a rollback.
4870de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4871de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
4872de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** return the P argument from the previous call of the same function
4873de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on the same [database connection] D, or NULL for
4874de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the first call for each function on D.
4875de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
487690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The commit and rollback hook callbacks are not reentrant.
4877de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The callback implementation must not do anything that will modify
4878de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the database connection that invoked the callback.  Any actions
4879de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to modify the database connection must be deferred until after the
4880de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** completion of the [sqlite3_step()] call that triggered the commit
4881de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or rollback hook in the first place.
488290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** Note that running any other SQL statements, including SELECT statements,
488390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
488490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the database connections for the meaning of "modify" in this paragraph.
4885de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4886de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Registering a NULL function disables the callback.
4887de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4888de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^When the commit hook callback routine returns zero, the [COMMIT]
4889de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** operation is allowed to continue normally.  ^If the commit hook
4890de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
4891de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The rollback hook is invoked on a rollback that results from a commit
4892de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** hook returning non-zero, just as it would be with any other rollback.
4893de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4894de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^For the purposes of this API, a transaction is said to have been
4895de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** rolled back if an explicit "ROLLBACK" statement is executed, or
4896de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an error or constraint causes an implicit rollback to occur.
4897de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The rollback callback is not invoked if a transaction is
4898de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** automatically rolled back because the database connection is closed.
4899de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4900de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also the [sqlite3_update_hook()] interface.
4901de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4902de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
4903de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
4904de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4905de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4906de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Data Change Notification Callbacks
4907de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4908de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_update_hook() interface registers a callback function
4909de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the [database connection] identified by the first argument
49108fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to be invoked whenever a row is updated, inserted or deleted in
49118fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** a rowid table.
4912de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Any callback set by a previous call to this function
4913de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for the same database connection is overridden.
4914de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4915de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The second argument is a pointer to the function to invoke when a
49168fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** row is updated, inserted or deleted in a rowid table.
4917de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first argument to the callback is a copy of the third argument
4918de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to sqlite3_update_hook().
4919de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
4920de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [SQLITE_UPDATE], depending on the operation that caused the callback
4921de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to be invoked.
4922de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The third and fourth arguments to the callback contain pointers to the
4923de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database and table name containing the affected row.
4924de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The final callback parameter is the [rowid] of the row.
4925de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^In the case of an update, this is the [rowid] after the update takes place.
4926de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4927de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The update hook is not invoked when internal system tables are
4928de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** modified (i.e. sqlite_master and sqlite_sequence).)^
49298fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
4930de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4931de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^In the current implementation, the update hook
4932de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is not invoked when duplication rows are deleted because of an
4933de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
4934de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** invoked when rows are deleted using the [truncate optimization].
4935de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The exceptions defined in this paragraph might change in a future
4936de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** release of SQLite.
4937de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4938de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The update hook implementation must not do anything that will modify
4939de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the database connection that invoked the update hook.  Any actions
4940de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to modify the database connection must be deferred until after the
4941de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** completion of the [sqlite3_step()] call that triggered the update hook.
4942de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
4943de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database connections for the meaning of "modify" in this paragraph.
4944de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4945de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_update_hook(D,C,P) function
4946de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returns the P argument from the previous call
4947de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on the same [database connection] D, or NULL for
4948de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the first call on D.
4949de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4950de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
4951de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interfaces.
4952de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4953de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void *sqlite3_update_hook(
4954de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3*,
4955de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
4956de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void*
4957de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
4958de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4959de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4960de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Enable Or Disable Shared Pager Cache
4961de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4962de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(This routine enables or disables the sharing of the database cache
4963de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and schema data structures between [database connection | connections]
4964de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the same database. Sharing is enabled if the argument is true
4965de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and disabled if the argument is false.)^
4966de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4967de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Cache sharing is enabled and disabled for an entire process.
4968de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
4969de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sharing was enabled or disabled for each thread separately.
4970de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4971de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The cache sharing mode set by this interface effects all subsequent
4972de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
4973de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Existing database connections continue use the sharing mode
4974de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that was in effect at the time they were opened.)^
4975de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4976de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
4977de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** successfully.  An [error code] is returned otherwise.)^
4978de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4979de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Shared cache is disabled by default. But this might change in
4980de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** future releases of SQLite.  Applications that care about shared
4981de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** cache setting should set it explicitly.
4982de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
49838fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** This interface is threadsafe on processors where writing a
49848fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** 32-bit integer is atomic.
49858fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
4986de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See Also:  [SQLite Shared-Cache Mode]
4987de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
4988de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_enable_shared_cache(int);
4989de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
4990de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
4991de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Attempt To Free Heap Memory
4992de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
4993de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_release_memory() interface attempts to free N bytes
4994de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of heap memory by deallocating non-essential memory allocations
4995de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** held by the database library.   Memory used to cache database
4996de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pages to improve performance is an example of non-essential memory.
4997de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^sqlite3_release_memory() returns the number of bytes actually freed,
4998de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** which might be more or less than the amount requested.
4999de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_release_memory() routine is a no-op returning zero
5000de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
500190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
500290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** See also: [sqlite3_db_release_memory()]
5003de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5004de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_release_memory(int);
5005de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5006de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
500790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Free Memory Used By A Database Connection
500890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
500990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
501090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** memory as possible from database connection D. Unlike the
50118fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [sqlite3_release_memory()] interface, this interface is in effect even
50128fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
501390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** omitted.
501490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
501590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** See also: [sqlite3_release_memory()]
501690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
501790ed05d921d6ed7f12012d9786d53f57fafee51aJeff BrownSQLITE_API int sqlite3_db_release_memory(sqlite3*);
501890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
501990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
5020de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Impose A Limit On Heap Size
5021de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5022de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
5023de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** soft limit on the amount of heap memory that may be allocated by SQLite.
5024de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite strives to keep heap memory utilization below the soft heap
5025de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** limit by reducing the number of pages held in the page cache
5026de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as heap memory usages approaches the limit.
5027de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The soft heap limit is "soft" because even though SQLite strives to stay
5028de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** below the limit, it will exceed the limit rather than generate
5029de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an [SQLITE_NOMEM] error.  In other words, the soft heap limit
5030de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is advisory only.
5031de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5032de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The return value from sqlite3_soft_heap_limit64() is the size of
503390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the soft heap limit prior to the call, or negative in the case of an
503490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** error.  ^If the argument N is negative
5035de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then no change is made to the soft heap limit.  Hence, the current
5036de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** size of the soft heap limit can be determined by invoking
5037de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_soft_heap_limit64() with a negative argument.
5038de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5039de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the argument N is zero then the soft heap limit is disabled.
5040de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5041de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The soft heap limit is not enforced in the current implementation
5042de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if one or more of following conditions are true:
5043de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5044de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
5045de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> The soft heap limit is set to zero.
5046de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> Memory accounting is disabled using a combination of the
5047de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
5048de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
504990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <li> An alternative page cache implementation is specified using
505090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**      [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
5051de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> The page cache allocates from its own memory pool supplied
5052de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
5053de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**      from the heap.
5054de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>)^
5055de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5056de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
5057de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
5058de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** compile-time option is invoked.  With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
5059de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the soft heap limit is enforced on every memory allocation.  Without
5060de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
5061de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** when memory is allocated by the page cache.  Testing suggests that because
5062de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the page cache is the predominate memory user in SQLite, most
5063de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** applications will achieve adequate soft heap limit enforcement without
5064de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5065de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5066de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The circumstances under which SQLite will enforce the soft heap limit may
5067de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** changes in future releases of SQLite.
5068de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5069de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
5070de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5071de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5072de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Deprecated Soft Heap Limit Interface
5073de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** DEPRECATED
5074de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5075de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
5076de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface.  This routine is provided for historical compatibility
5077de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** only.  All new applications should use the
5078de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_soft_heap_limit64()] interface rather than this one.
5079de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5080de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
5081de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5082de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5083de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5084de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Extract Metadata About A Column Of A Table
5085de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5086de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This routine returns metadata about a specific column of a specific
5087de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database table accessible using the [database connection] handle
5088de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** passed as the first function argument.
5089de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5090de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The column is identified by the second, third and fourth parameters to
5091de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** this function. ^The second parameter is either the name of the database
5092de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (i.e. "main", "temp", or an attached database) containing the specified
5093de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** table or NULL. ^If it is NULL, then all attached databases are searched
5094de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for the table using the same algorithm used by the database engine to
5095de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** resolve unqualified table references.
5096de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5097de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The third and fourth parameters to this function are the table and column
5098de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** name of the desired column, respectively. Neither of these parameters
5099de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** may be NULL.
5100de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5101de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Metadata is returned by writing to the memory locations passed as the 5th
5102de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and subsequent parameters to this function. ^Any of these arguments may be
5103de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** NULL, in which case the corresponding element of metadata is omitted.
5104de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5105de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(<blockquote>
5106de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <table border="1">
5107de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><th> Parameter <th> Output<br>Type <th>  Description
5108de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5109de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> 5th <td> const char* <td> Data type
5110de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5111de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
5112de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
5113de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
5114de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </table>
5115de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </blockquote>)^
5116de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5117de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The memory pointed to by the character pointers returned for the
5118de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** declaration type and collation sequence is valid only until the next
5119de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** call to any SQLite API function.
5120de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5121de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the specified table is actually a view, an [error code] is returned.
5122de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5123de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the specified column is "rowid", "oid" or "_rowid_" and an
5124de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
5125de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameters are set for the explicitly declared column. ^(If there is no
5126de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** explicitly declared [INTEGER PRIMARY KEY] column, then the output
5127de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameters are set as follows:
5128de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5129de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <pre>
5130de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**     data type: "INTEGER"
5131de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**     collation sequence: "BINARY"
5132de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**     not null: 0
5133de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**     primary key: 1
5134de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**     auto increment: 0
5135de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </pre>)^
5136de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5137de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(This function may load one or more schemas from database files. If an
5138de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** error occurs during this process, or if the requested table or column
5139de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** cannot be found, an [error code] is returned and an error message left
5140de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
5141de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5142de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This API is only available if the library was compiled with the
5143de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
5144de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5145de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_table_column_metadata(
5146de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,                /* Connection handle */
5147de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zDbName,        /* Database name or NULL */
5148de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zTableName,     /* Table name */
5149de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zColumnName,    /* Column name */
5150de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  char const **pzDataType,    /* OUTPUT: Declared data type */
5151de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
5152de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
5153de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
5154de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
5155de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
5156de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5157de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5158de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Load An Extension
5159de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5160de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This interface loads an SQLite extension library from the named file.
5161de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5162de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_load_extension() interface attempts to load an
51638fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [SQLite extension] library contained in the file zFile.  If
51648fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the file cannot be loaded directly, attempts are made to load
51658fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** with various operating-system specific extensions added.
51668fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** So for example, if "samplelib" cannot be loaded, then names like
51678fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
51688fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** be tried also.
5169de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5170de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The entry point is zProc.
51718fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^(zProc may be 0, in which case SQLite will try to come up with an
51728fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** entry point name on its own.  It first tries "sqlite3_extension_init".
51738fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** If that does not work, it constructs a name "sqlite3_X_init" where the
51748fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** X is consists of the lower-case equivalent of all ASCII alphabetic
51758fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** characters in the filename from the last "/" to the first following
51768fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** "." and omitting any initial "lib".)^
5177de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_load_extension() interface returns
5178de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5179de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If an error occurs and pzErrMsg is not 0, then the
5180de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_load_extension()] interface shall attempt to
5181de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** fill *pzErrMsg with error message text stored in memory
5182de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** obtained from [sqlite3_malloc()]. The calling function
5183de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** should free this memory by calling [sqlite3_free()].
5184de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5185de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Extension loading must be enabled using
5186de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_enable_load_extension()] prior to calling this API,
5187de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** otherwise an error will be returned.
5188de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5189de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also the [load_extension() SQL function].
5190de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5191de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_load_extension(
5192de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,          /* Load the extension into this database connection */
5193de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zFile,    /* Name of the shared library containing extension */
5194de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
5195de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  char **pzErrMsg       /* Put error message here if not 0 */
5196de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
5197de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5198de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5199de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Enable Or Disable Extension Loading
5200de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5201de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^So as not to open security holes in older applications that are
52028fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** unprepared to deal with [extension loading], and as a means of disabling
52038fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [extension loading] while evaluating user-entered SQL, the following API
5204de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5205de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
52068fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^Extension loading is off by default.
5207de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Call the sqlite3_enable_load_extension() routine with onoff==1
5208de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to turn extension loading on and call it with onoff==0 to turn
5209de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it back off again.
5210de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5211de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
5212de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5213de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5214de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Automatically Load Statically Linked Extensions
5215de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5216de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This interface causes the xEntryPoint() function to be invoked for
5217de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** each new [database connection] that is created.  The idea here is that
52188fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** xEntryPoint() is the entry point for a statically linked [SQLite extension]
5219de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that is to be automatically loaded into all new database connections.
5220de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5221de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Even though the function prototype shows that xEntryPoint() takes
5222de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** no arguments and returns void, SQLite invokes xEntryPoint() with three
5223de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** arguments and expects and integer result as if the signature of the
5224de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** entry point where as follows:
5225de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5226de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote><pre>
5227de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** &nbsp;  int xEntryPoint(
5228de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** &nbsp;    sqlite3 *db,
5229de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** &nbsp;    const char **pzErrMsg,
5230de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** &nbsp;    const struct sqlite3_api_routines *pThunk
5231de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** &nbsp;  );
5232de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </pre></blockquote>)^
5233de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5234de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5235de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5236de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg
5237de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is NULL before calling the xEntryPoint().  ^SQLite will invoke
5238de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any
5239de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5240de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
5241de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5242de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
5243de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on the list of automatic extensions is a harmless no-op. ^No entry point
5244de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will be called more than once for each database connection that is opened.
5245de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
52468fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** See also: [sqlite3_reset_auto_extension()]
52478fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** and [sqlite3_cancel_auto_extension()]
5248de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5249de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
5250de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5251de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
52528fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** CAPI3REF: Cancel Automatic Extension Loading
52538fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
52548fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
52558fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** initialization routine X that was registered using a prior call to
52568fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [sqlite3_auto_extension(X)].  ^The [sqlite3_cancel_auto_extension(X)]
52578fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** routine returns 1 if initialization routine X was successfully
52588fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** unregistered and it returns 0 if X was not on the list of initialization
52598fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** routines.
52608fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich*/
52618fecf56c625b5691ee3381e107ccbe1ff42398b1Nick KralevichSQLITE_API int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void));
52628fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich
52638fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich/*
5264de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Reset Automatic Extension Loading
5265de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5266de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This interface disables all automatic extensions previously
5267de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** registered using [sqlite3_auto_extension()].
5268de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5269de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_reset_auto_extension(void);
5270de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5271de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5272de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The interface to the virtual-table mechanism is currently considered
5273de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to be experimental.  The interface might change in incompatible ways.
5274de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If this is a problem for you, do not use the interface at this time.
5275de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5276de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When the virtual-table mechanism stabilizes, we will declare the
5277de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface fixed, support it indefinitely, and remove this comment.
5278de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5279de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5280de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5281de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Structures used by the virtual table interface
5282de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5283de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_vtab sqlite3_vtab;
5284de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_index_info sqlite3_index_info;
5285de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
5286de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_module sqlite3_module;
5287de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5288de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5289de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Virtual Table Object
5290de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: sqlite3_module {virtual table module}
5291de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
529290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** This structure, sometimes called a "virtual table module",
5293de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** defines the implementation of a [virtual tables].
5294de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This structure consists mostly of methods for the module.
5295de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5296de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^A virtual table module is created by filling in a persistent
5297de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** instance of this structure and passing a pointer to that instance
5298de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
5299de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The registration remains valid until it is replaced by a different
5300de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** module or until the [database connection] closes.  The content
5301de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of this structure must not change while it is registered with
5302de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** any database connection.
5303de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5304de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_module {
5305de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int iVersion;
5306de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xCreate)(sqlite3*, void *pAux,
5307de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori               int argc, const char *const*argv,
5308de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori               sqlite3_vtab **ppVTab, char**);
5309de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xConnect)(sqlite3*, void *pAux,
5310de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori               int argc, const char *const*argv,
5311de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori               sqlite3_vtab **ppVTab, char**);
5312de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5313de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xDisconnect)(sqlite3_vtab *pVTab);
5314de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xDestroy)(sqlite3_vtab *pVTab);
5315de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5316de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xClose)(sqlite3_vtab_cursor*);
5317de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5318de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori                int argc, sqlite3_value **argv);
5319de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xNext)(sqlite3_vtab_cursor*);
5320de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xEof)(sqlite3_vtab_cursor*);
5321de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5322de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5323de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5324de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xBegin)(sqlite3_vtab *pVTab);
5325de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xSync)(sqlite3_vtab *pVTab);
5326de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xCommit)(sqlite3_vtab *pVTab);
5327de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xRollback)(sqlite3_vtab *pVTab);
5328de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5329de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5330de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori                       void **ppArg);
5331de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
533290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  /* The methods above are in version 1 of the sqlite_module object. Those
533390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  ** below are for version 2 and greater. */
533490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int (*xSavepoint)(sqlite3_vtab *pVTab, int);
533590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int (*xRelease)(sqlite3_vtab *pVTab, int);
533690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
5337de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
5338de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5339de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5340de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Virtual Table Indexing Information
5341de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: sqlite3_index_info
5342de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5343de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_index_info structure and its substructures is used as part
5344de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the [virtual table] interface to
5345de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pass information into and receive the reply from the [xBestIndex]
5346de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** method of a [virtual table module].  The fields under **Inputs** are the
5347de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** inputs to xBestIndex and are read-only.  xBestIndex inserts its
5348de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** results into the **Outputs** fields.
5349de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5350de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The aConstraint[] array records WHERE clause constraints of the form:
5351de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5352de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <blockquote>column OP expr</blockquote>
5353de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5354de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
5355de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** stored in aConstraint[].op using one of the
5356de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
5357de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The index of the column is stored in
5358de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
5359de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** expr on the right-hand side can be evaluated (and thus the constraint
5360de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is usable) and false if it cannot.)^
5361de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5362de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The optimizer automatically inverts terms of the form "expr OP column"
5363de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and makes other simplifications to the WHERE clause in an attempt to
5364de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** get as many WHERE clause terms into the form shown above as possible.
5365de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The aConstraint[] array only reports WHERE clause terms that are
5366de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** relevant to the particular virtual table being queried.
5367de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5368de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Information about the ORDER BY clause is stored in aOrderBy[].
5369de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Each term of aOrderBy records a column of the ORDER BY clause.
5370de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5371de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [xBestIndex] method must fill aConstraintUsage[] with information
5372de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** about what parameters to pass to xFilter.  ^If argvIndex>0 then
5373de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the right-hand side of the corresponding aConstraint[] is evaluated
5374de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
5375de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is true, then the constraint is assumed to be fully handled by the
5376de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** virtual table and is not checked again by SQLite.)^
5377de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5378de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The idxNum and idxPtr values are recorded and passed into the
5379de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [xFilter] method.
5380de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^[sqlite3_free()] is used to free idxPtr if and only if
5381de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** needToFreeIdxPtr is true.
5382de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5383de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
5384de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the correct order to satisfy the ORDER BY clause so that no separate
5385de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sorting step is required.
5386de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
53878fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The estimatedCost value is an estimate of the cost of a particular
53888fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** strategy. A cost of N indicates that the cost of the strategy is similar
53898fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to a linear scan of an SQLite table with N rows. A cost of log(N)
53908fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** indicates that the expense of the operation is similar to that of a
53918fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** binary search on a unique indexed field of an SQLite table with N rows.
53928fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
53938fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The estimatedRows value is an estimate of the number of rows that
53948fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** will be returned by the strategy.
53958fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
53968fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
53978fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** structure for SQLite version 3.8.2. If a virtual table extension is
53988fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** used with an SQLite version earlier than 3.8.2, the results of attempting
53998fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to read or write the estimatedRows field are undefined (but are likely
54008fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to included crashing the application). The estimatedRows field should
54018fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** therefore only be used if [sqlite3_libversion_number()] returns a
54028fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** value greater than or equal to 3008002.
5403de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5404de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_index_info {
5405de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  /* Inputs */
5406de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nConstraint;           /* Number of entries in aConstraint */
5407de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  struct sqlite3_index_constraint {
5408de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori     int iColumn;              /* Column on left-hand side of constraint */
5409de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori     unsigned char op;         /* Constraint operator */
5410de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori     unsigned char usable;     /* True if this constraint is usable */
5411de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori     int iTermOffset;          /* Used internally - xBestIndex should ignore */
5412de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  } *aConstraint;            /* Table of WHERE clause constraints */
5413de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nOrderBy;              /* Number of terms in the ORDER BY clause */
5414de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  struct sqlite3_index_orderby {
5415de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori     int iColumn;              /* Column number */
5416de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori     unsigned char desc;       /* True for DESC.  False for ASC. */
5417de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  } *aOrderBy;               /* The ORDER BY clause */
5418de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  /* Outputs */
5419de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  struct sqlite3_index_constraint_usage {
5420de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori    int argvIndex;           /* if >0, constraint is part of argv to xFilter */
5421de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori    unsigned char omit;      /* Do not code a test for this constraint */
5422de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  } *aConstraintUsage;
5423de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int idxNum;                /* Number used to identify the index */
5424de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
5425de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
5426de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int orderByConsumed;       /* True if output is already ordered */
54278fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  double estimatedCost;           /* Estimated cost of using this index */
54288fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  /* Fields below are only available in SQLite 3.8.2 and later */
54298fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
5430de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
5431de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5432de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5433de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Virtual Table Constraint Operator Codes
5434de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5435de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These macros defined the allowed values for the
5436de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_index_info].aConstraint[].op field.  Each value represents
5437de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an operator that is part of a constraint term in the wHERE clause of
5438de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a query that uses a [virtual table].
5439de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5440de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_INDEX_CONSTRAINT_EQ    2
5441de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_INDEX_CONSTRAINT_GT    4
5442de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_INDEX_CONSTRAINT_LE    8
5443de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_INDEX_CONSTRAINT_LT    16
5444de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_INDEX_CONSTRAINT_GE    32
5445de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_INDEX_CONSTRAINT_MATCH 64
5446de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5447de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5448de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Register A Virtual Table Implementation
5449de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5450de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These routines are used to register a new [virtual table module] name.
5451de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Module names must be registered before
5452de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** creating a new [virtual table] using the module and before using a
5453de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** preexisting [virtual table] for the module.
5454de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5455de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The module name is registered on the [database connection] specified
5456de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by the first parameter.  ^The name of the module is given by the
5457de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** second parameter.  ^The third parameter is a pointer to
5458de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the implementation of the [virtual table module].   ^The fourth
5459de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameter is an arbitrary client data pointer that is passed through
5460de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** into the [xCreate] and [xConnect] methods of the virtual table module
5461de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** when a new virtual table is be being created or reinitialized.
5462de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5463de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_create_module_v2() interface has a fifth parameter which
5464de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is a pointer to a destructor for the pClientData.  ^SQLite will
5465de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** invoke the destructor function (if it is not NULL) when SQLite
546695c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** no longer needs the pClientData pointer.  ^The destructor will also
546795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** be invoked if the call to sqlite3_create_module_v2() fails.
546895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^The sqlite3_create_module()
5469de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface is equivalent to sqlite3_create_module_v2() with a NULL
5470de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** destructor.
5471de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5472de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_create_module(
5473de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,               /* SQLite connection to register module with */
5474de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zName,         /* Name of the module */
5475de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const sqlite3_module *p,   /* Methods for the module */
5476de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pClientData          /* Client data for xCreate/xConnect */
5477de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
5478de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_create_module_v2(
5479de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,               /* SQLite connection to register module with */
5480de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zName,         /* Name of the module */
5481de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const sqlite3_module *p,   /* Methods for the module */
5482de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pClientData,         /* Client data for xCreate/xConnect */
5483de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void(*xDestroy)(void*)     /* Module destructor function */
5484de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
5485de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5486de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5487de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Virtual Table Instance Object
5488de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: sqlite3_vtab
5489de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5490de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Every [virtual table module] implementation uses a subclass
5491de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of this object to describe a particular instance
5492de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the [virtual table].  Each subclass will
5493de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be tailored to the specific needs of the module implementation.
5494de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The purpose of this superclass is to define certain fields that are
5495de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** common to all module implementations.
5496de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5497de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Virtual tables methods can set an error message by assigning a
5498de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
5499de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** take care that any prior string is freed by a call to [sqlite3_free()]
5500de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** prior to assigning a new string to zErrMsg.  ^After the error message
5501de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is delivered up to the client application, the string will be automatically
5502de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** freed by sqlite3_free() and the zErrMsg field will be zeroed.
5503de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5504de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_vtab {
5505de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const sqlite3_module *pModule;  /* The module for this virtual table */
5506de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nRef;                       /* NO LONGER USED */
5507de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
5508de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  /* Virtual table implementations will typically add additional fields */
5509de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
5510de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5511de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5512de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Virtual Table Cursor Object
5513de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
5514de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5515de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Every [virtual table module] implementation uses a subclass of the
5516de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** following structure to describe cursors that point into the
5517de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [virtual table] and are used
5518de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to loop through the virtual table.  Cursors are created using the
5519de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
5520de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
5521de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
5522de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the module.  Each module implementation will define
5523de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the content of a cursor structure to suit its own needs.
5524de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5525de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This superclass exists in order to define fields of the cursor that
5526de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are common to all implementations.
5527de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5528de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_vtab_cursor {
5529de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
5530de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  /* Virtual table implementations will typically add additional fields */
5531de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
5532de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5533de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5534de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Declare The Schema Of A Virtual Table
5535de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5536de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [xCreate] and [xConnect] methods of a
5537de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [virtual table module] call this interface
5538de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to declare the format (the names and datatypes of the columns) of
5539de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the virtual tables they implement.
5540de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5541de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
5542de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5543de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5544de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Overload A Function For A Virtual Table
5545de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5546de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Virtual tables can provide alternative implementations of functions
5547de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** using the [xFindFunction] method of the [virtual table module].
5548de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** But global versions of those functions
5549de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** must exist in order to be overloaded.)^
5550de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5551de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(This API makes sure a global version of a function with a particular
5552de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** name and number of parameters exists.  If no such function exists
5553de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** before this API is called, a new function is created.)^  ^The implementation
5554de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of the new function always causes an exception to be thrown.  So
5555de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the new function is not good for anything by itself.  Its only
5556de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** purpose is to be a placeholder function that can be overloaded
5557de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by a [virtual table].
5558de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5559de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
5560de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5561de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5562de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The interface to the virtual-table mechanism defined above (back up
5563de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to a comment remarkably similar to this one) is currently considered
5564de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to be experimental.  The interface might change in incompatible ways.
5565de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If this is a problem for you, do not use the interface at this time.
5566de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5567de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When the virtual-table mechanism stabilizes, we will declare the
5568de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface fixed, support it indefinitely, and remove this comment.
5569de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5570de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5571de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5572de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: A Handle To An Open BLOB
5573de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {BLOB handle} {BLOB handles}
5574de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5575de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** An instance of this object represents an open BLOB on which
5576de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
5577de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Objects of this type are created by [sqlite3_blob_open()]
5578de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and destroyed by [sqlite3_blob_close()].
5579de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
5580de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be used to read or write small subsections of the BLOB.
5581de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
5582de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5583de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_blob sqlite3_blob;
5584de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5585de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5586de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Open A BLOB For Incremental I/O
5587de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5588de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
5589de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in row iRow, column zColumn, table zTable in database zDb;
5590de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in other words, the same BLOB that would be selected by:
5591de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5592de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <pre>
5593de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
5594de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </pre>)^
5595de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5596de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the flags parameter is non-zero, then the BLOB is opened for read
5597de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and write access. ^If it is zero, the BLOB is opened for read access.
5598de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^It is not possible to open a column that is part of an index or primary
5599de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** key for writing. ^If [foreign key constraints] are enabled, it is
5600de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not possible to open a column that is part of a [child key] for writing.
5601de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5602de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Note that the database name is not the filename that contains
5603de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the database but rather the symbolic name of the database that
5604de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** appears after the AS keyword when the database is connected using [ATTACH].
5605de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^For the main database file, the database name is "main".
5606de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^For TEMP tables, the database name is "temp".
5607de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5608de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
5609de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
5610de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to be a null pointer.)^
5611de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This function sets the [database connection] error code and message
5612de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
5613de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** functions. ^Note that the *ppBlob variable is always initialized in a
5614de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
5615de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** regardless of the success or failure of this routine.
5616de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5617de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(If the row that a BLOB handle points to is modified by an
5618de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
5619de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the BLOB handle is marked as "expired".
5620de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This is true if any column of the row is changed, even a column
5621de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** other than the one the BLOB handle is open on.)^
5622de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
562390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
5624de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Changes written into a BLOB prior to the BLOB expiring are not
5625de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** rolled back by the expiration of the BLOB.  Such changes will eventually
5626de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** commit if the transaction continues to completion.)^
5627de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5628de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
5629de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the opened blob.  ^The size of a blob may not be changed by this
5630de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface.  Use the [UPDATE] SQL command to change the size of a
5631de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** blob.
5632de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
56338fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID]
56348fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** table.  Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables.
56358fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
5636de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
5637de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the built-in [zeroblob] SQL function can be used, if desired,
5638de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to create an empty, zero-filled blob in which to read or write using
5639de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** this interface.
5640de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5641de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** To avoid a resource leak, every open [BLOB handle] should eventually
5642de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be released by a call to [sqlite3_blob_close()].
5643de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5644de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_blob_open(
5645de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3*,
5646de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zDb,
5647de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zTable,
5648de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zColumn,
5649de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3_int64 iRow,
5650de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int flags,
5651de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3_blob **ppBlob
5652de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
5653de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5654de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
565595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** CAPI3REF: Move a BLOB Handle to a New Row
565695c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
565795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^This function is used to move an existing blob handle so that it points
565895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** to a different row of the same database table. ^The new row is identified
565995c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** by the rowid value passed as the second argument. Only the row can be
566095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** changed. ^The database, table and column on which the blob handle is open
566195c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** remain the same. Moving an existing blob handle to a new row can be
566295c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** faster than closing the existing handle and opening a new one.
566395c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
566495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
566595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** it must exist and there must be either a blob or text value stored in
566695c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** the nominated column.)^ ^If the new row is not present in the table, or if
566795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** it does not contain a blob or text value, or if another error occurs, an
566895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** SQLite error code is returned and the blob handle is considered aborted.
566995c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
567095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
567195c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
567295c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** always returns zero.
567395c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
567495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^This function sets the database handle error code and message.
567595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori*/
567695c34edce550d0869113085e0cd1b6b09e8fe38bVasu NoriSQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
567795c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori
567895c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori/*
5679de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Close A BLOB Handle
5680de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5681de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Closes an open [BLOB handle].
5682de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5683de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Closing a BLOB shall cause the current transaction to commit
5684de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if there are no other BLOBs, no pending prepared statements, and the
5685de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database connection is in [autocommit mode].
5686de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If any writes were made to the BLOB, they might be held in cache
5687de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** until the close operation if they will fit.
5688de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5689de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Closing the BLOB often forces the changes
5690de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** out to disk and so if any I/O errors occur, they will likely occur
5691de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** at the time when the BLOB is closed.  Any errors that occur during
5692de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** closing are reported as a non-zero return value.)^
5693de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5694de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The BLOB is closed unconditionally.  Even if this routine returns
5695de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an error code, the BLOB is still closed.)^
5696de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5697de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Calling this routine with a null pointer (such as would be returned
5698de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
5699de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5700de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_blob_close(sqlite3_blob *);
5701de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5702de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5703de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Return The Size Of An Open BLOB
5704de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5705de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Returns the size in bytes of the BLOB accessible via the
5706de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** successfully opened [BLOB handle] in its only argument.  ^The
5707de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** incremental blob I/O routines can only read or overwriting existing
5708de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** blob content; they cannot change the size of a blob.
5709de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5710de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This routine only works on a [BLOB handle] which has been created
5711de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by a prior successful call to [sqlite3_blob_open()] and which has not
5712de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5713de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to this routine results in undefined and probably undesirable behavior.
5714de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5715de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
5716de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5717de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5718de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Read Data From A BLOB Incrementally
5719de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5720de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(This function is used to read data from an open [BLOB handle] into a
5721de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** caller-supplied buffer. N bytes of data are copied into buffer Z
5722de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from the open BLOB, starting at offset iOffset.)^
5723de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5724de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If offset iOffset is less than N bytes from the end of the BLOB,
5725de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
5726de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** less than zero, [SQLITE_ERROR] is returned and no data is read.
5727de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The size of the blob (and hence the maximum value of N+iOffset)
5728de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be determined using the [sqlite3_blob_bytes()] interface.
5729de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5730de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^An attempt to read from an expired [BLOB handle] fails with an
5731de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** error code of [SQLITE_ABORT].
5732de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5733de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
5734de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Otherwise, an [error code] or an [extended error code] is returned.)^
5735de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5736de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This routine only works on a [BLOB handle] which has been created
5737de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by a prior successful call to [sqlite3_blob_open()] and which has not
5738de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5739de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to this routine results in undefined and probably undesirable behavior.
5740de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5741de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_blob_write()].
5742de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5743de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
5744de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5745de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5746de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Write Data Into A BLOB Incrementally
5747de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5748de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This function is used to write data into an open [BLOB handle] from a
5749de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
5750de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** into the open BLOB, starting at offset iOffset.
5751de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5752de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the [BLOB handle] passed as the first argument was not opened for
5753de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** writing (the flags parameter to [sqlite3_blob_open()] was zero),
5754de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** this function returns [SQLITE_READONLY].
5755de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5756de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This function may only modify the contents of the BLOB; it is
5757de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not possible to increase the size of a BLOB using this API.
5758de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If offset iOffset is less than N bytes from the end of the BLOB,
5759de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_ERROR] is returned and no data is written.  ^If N is
5760de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** less than zero [SQLITE_ERROR] is returned and no data is written.
5761de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The size of the BLOB (and hence the maximum value of N+iOffset)
5762de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be determined using the [sqlite3_blob_bytes()] interface.
5763de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5764de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^An attempt to write to an expired [BLOB handle] fails with an
5765de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
5766de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** before the [BLOB handle] expired are not rolled back by the
5767de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** expiration of the handle, though of course those changes might
5768de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** have been overwritten by the statement that expired the BLOB handle
5769de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or by other independent statements.
5770de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5771de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
5772de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Otherwise, an  [error code] or an [extended error code] is returned.)^
5773de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5774de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This routine only works on a [BLOB handle] which has been created
5775de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by a prior successful call to [sqlite3_blob_open()] and which has not
5776de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5777de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to this routine results in undefined and probably undesirable behavior.
5778de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5779de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_blob_read()].
5780de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5781de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
5782de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5783de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5784de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Virtual File System Objects
5785de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5786de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A virtual filesystem (VFS) is an [sqlite3_vfs] object
5787de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that SQLite uses to interact
5788de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the underlying operating system.  Most SQLite builds come with a
5789de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** single default VFS that is appropriate for the host computer.
5790de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** New VFSes can be registered and existing VFSes can be unregistered.
5791de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The following interfaces are provided.
5792de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5793de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
5794de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Names are case sensitive.
5795de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Names are zero-terminated UTF-8 strings.
5796de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If there is no match, a NULL pointer is returned.
5797de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If zVfsName is NULL then the default VFS is returned.
5798de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5799de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^New VFSes are registered with sqlite3_vfs_register().
5800de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
5801de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The same VFS can be registered multiple times without injury.
5802de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^To make an existing VFS into the default VFS, register it again
5803de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the makeDflt flag set.  If two different VFSes with the
5804de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** same name are registered, the behavior is undefined.  If a
5805de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** VFS is registered with a name that is NULL or an empty string,
5806de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the behavior is undefined.
5807de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5808de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
5809de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(If the default VFS is unregistered, another VFS is chosen as
5810de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the default.  The choice for the new VFS is arbitrary.)^
5811de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5812de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
5813de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
5814de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
5815de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5816de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5817de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Mutexes
5818de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5819de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The SQLite core uses these routines for thread
5820de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** synchronization. Though they are intended for internal
5821de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** use by SQLite, code that links against SQLite is
5822de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** permitted to use any of these routines.
5823de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5824de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The SQLite source code contains multiple implementations
5825de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of these mutex routines.  An appropriate implementation
5826de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is selected automatically at compile-time.  ^(The following
5827de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementations are available in the SQLite core:
5828de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5829de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
583090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <li>   SQLITE_MUTEX_PTHREADS
5831de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>   SQLITE_MUTEX_W32
5832de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>   SQLITE_MUTEX_NOOP
5833de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>)^
5834de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5835de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
5836de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that does no real locking and is appropriate for use in
58378fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** a single-threaded application.  ^The SQLITE_MUTEX_PTHREADS and
58388fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
58398fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** and Windows.
5840de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5841de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
5842de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
5843de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation is included with the library. In this case the
5844de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** application must supply a custom mutex implementation using the
5845de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
5846de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** before calling sqlite3_initialize() or any other public sqlite3_
5847de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** function that calls sqlite3_initialize().)^
5848de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5849de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_mutex_alloc() routine allocates a new
5850de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** mutex and returns a pointer to it. ^If it returns NULL
5851de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that means that a mutex could not be allocated.  ^SQLite
5852de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will unwind its stack and return an error.  ^(The argument
5853de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to sqlite3_mutex_alloc() is one of these integer constants:
5854de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5855de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
5856de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  SQLITE_MUTEX_FAST
5857de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  SQLITE_MUTEX_RECURSIVE
5858de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  SQLITE_MUTEX_STATIC_MASTER
5859de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  SQLITE_MUTEX_STATIC_MEM
58609bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** <li>  SQLITE_MUTEX_STATIC_OPEN
5861de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  SQLITE_MUTEX_STATIC_PRNG
5862de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li>  SQLITE_MUTEX_STATIC_LRU
58639bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** <li>  SQLITE_MUTEX_STATIC_PMEM
58649bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** <li>  SQLITE_MUTEX_STATIC_APP1
58659bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** <li>  SQLITE_MUTEX_STATIC_APP2
5866de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>)^
5867de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5868de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
5869de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** cause sqlite3_mutex_alloc() to create
5870de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
5871de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
5872de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The mutex implementation does not need to make a distinction
5873de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
5874de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not want to.  ^SQLite will only request a recursive mutex in
5875de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** cases where it really needs one.  ^If a faster non-recursive mutex
5876de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation is available on the host platform, the mutex subsystem
5877de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** might return such a mutex in response to SQLITE_MUTEX_FAST.
5878de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5879de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
5880de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
5881de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a pointer to a static preexisting mutex.  ^Six static mutexes are
5882de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** used by the current version of SQLite.  Future versions of SQLite
5883de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** may add additional static mutexes.  Static mutexes are for internal
5884de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** use by SQLite only.  Applications that use SQLite mutexes should
5885de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
5886de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_MUTEX_RECURSIVE.
5887de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5888de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
5889de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
5890de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returns a different mutex on every call.  ^But for the static
5891de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** mutex types, the same mutex is returned on every call that has
5892de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the same type number.
5893de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5894de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_mutex_free() routine deallocates a previously
5895de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** allocated dynamic mutex.  ^SQLite is careful to deallocate every
5896de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** dynamic mutex that it allocates.  The dynamic mutexes must not be in
5897de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** use when they are deallocated.  Attempting to deallocate a static
5898de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** mutex results in undefined behavior.  ^SQLite never deallocates
5899de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a static mutex.
5900de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5901de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
5902de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to enter a mutex.  ^If another thread is already within the mutex,
5903de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
5904de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
5905de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** upon successful entry.  ^(Mutexes created using
5906de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
5907de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** In such cases the,
5908de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** mutex must be exited an equal number of times before another thread
5909de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can enter.)^  ^(If the same thread tries to enter any other
5910de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** kind of mutex more than once, the behavior is undefined.
5911de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite will never exhibit
5912de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** such behavior in its own use of mutexes.)^
5913de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5914de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Some systems (for example, Windows 95) do not support the operation
5915de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
5916de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will always return SQLITE_BUSY.  The SQLite core only ever uses
5917de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
5918de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5919de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_mutex_leave() routine exits a mutex that was
5920de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** previously entered by the same thread.   ^(The behavior
5921de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is undefined if the mutex is not currently entered by the
5922de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** calling thread or is not currently allocated.  SQLite will
5923de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** never do either.)^
5924de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5925de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
5926de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_mutex_leave() is a NULL pointer, then all three routines
5927de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** behave as no-ops.
5928de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5929de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
5930de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
5931de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
5932de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
5933de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
5934de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
5935de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
5936de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
5937de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
5938de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Mutex Methods Object
5939de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5940de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** An instance of this structure defines the low-level routines
5941de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** used to allocate and use mutexes.
5942de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5943de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Usually, the default mutex implementations provided by SQLite are
5944de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sufficient, however the user has the option of substituting a custom
5945de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation for specialized deployments or systems for which SQLite
5946de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** does not provide a suitable implementation. In this case, the user
5947de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** creates and populates an instance of this structure to pass
5948de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
5949de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Additionally, an instance of this structure can be used as an
5950de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** output variable when querying the system for the current mutex
5951de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
5952de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5953de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The xMutexInit method defined by this structure is invoked as
5954de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** part of system initialization by the sqlite3_initialize() function.
5955de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The xMutexInit routine is called by SQLite exactly once for each
5956de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** effective call to [sqlite3_initialize()].
5957de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5958de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The xMutexEnd method defined by this structure is invoked as
5959de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** part of system shutdown by the sqlite3_shutdown() function. The
5960de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation of this method is expected to release all outstanding
5961de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** resources obtained by the mutex methods implementation, especially
5962de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** those obtained by the xMutexInit method.  ^The xMutexEnd()
5963de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface is invoked exactly once for each call to [sqlite3_shutdown()].
5964de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5965de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The remaining seven methods defined by this structure (xMutexAlloc,
5966de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
5967de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xMutexNotheld) implement the following interfaces (respectively):
5968de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5969de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ul>
5970de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li>  [sqlite3_mutex_alloc()] </li>
5971de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li>  [sqlite3_mutex_free()] </li>
5972de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li>  [sqlite3_mutex_enter()] </li>
5973de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li>  [sqlite3_mutex_try()] </li>
5974de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li>  [sqlite3_mutex_leave()] </li>
5975de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li>  [sqlite3_mutex_held()] </li>
5976de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <li>  [sqlite3_mutex_notheld()] </li>
5977de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ul>)^
5978de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5979de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The only difference is that the public sqlite3_XXX functions enumerated
5980de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** above silently ignore any invocations that pass a NULL pointer instead
5981de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of a valid mutex handle. The implementations of the methods defined
5982de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by this structure are not required to handle this case, the results
5983de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of passing a NULL pointer instead of a valid mutex handle are undefined
5984de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (i.e. it is acceptable to provide an implementation that segfaults if
5985de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it is passed a NULL pointer).
5986de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5987de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xMutexInit() method must be threadsafe.  ^It must be harmless to
5988de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** invoke xMutexInit() multiple times within the same process and without
5989de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** intervening calls to xMutexEnd().  Second and subsequent calls to
5990de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xMutexInit() must be no-ops.
5991de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5992de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
5993de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and its associates).  ^Similarly, xMutexAlloc() must not use SQLite memory
5994de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
5995de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory allocation for a fast or recursive mutex.
5996de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
5997de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
5998de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** called, but only if the prior call to xMutexInit returned SQLITE_OK.
5999de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If xMutexInit fails in any way, it is expected to clean up after itself
6000de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** prior to returning.
6001de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6002de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
6003de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_mutex_methods {
6004de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xMutexInit)(void);
6005de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xMutexEnd)(void);
6006de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3_mutex *(*xMutexAlloc)(int);
6007de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xMutexFree)(sqlite3_mutex *);
6008de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xMutexEnter)(sqlite3_mutex *);
6009de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xMutexTry)(sqlite3_mutex *);
6010de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xMutexLeave)(sqlite3_mutex *);
6011de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xMutexHeld)(sqlite3_mutex *);
6012de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xMutexNotheld)(sqlite3_mutex *);
6013de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
6014de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6015de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6016de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Mutex Verification Routines
6017de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6018de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
6019de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are intended for use inside assert() statements.  ^The SQLite core
6020de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** never uses these routines except inside an assert() and applications
6021de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are advised to follow the lead of the core.  ^The SQLite core only
6022de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** provides implementations for these routines when it is compiled
6023de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the SQLITE_DEBUG flag.  ^External mutex implementations
6024de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are only required to provide these routines if SQLITE_DEBUG is
6025de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** defined and if NDEBUG is not defined.
6026de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6027de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^These routines should return true if the mutex in their argument
6028de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is held or not held, respectively, by the calling thread.
6029de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
603090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The implementation is not required to provide versions of these
6031de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routines that actually work. If the implementation does not provide working
6032de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** versions of these routines, it should at least provide stubs that always
6033de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** return true so that one does not get spurious assertion failures.
6034de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6035de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
6036de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the routine should return 1.   This seems counter-intuitive since
603790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** clearly the mutex cannot be held if it does not exist.  But
6038de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the reason the mutex does not exist is because the build is not
6039de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** using mutexes.  And we do not want the assert() containing the
6040de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** call to sqlite3_mutex_held() to fail, so a non-zero return is
6041de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the appropriate thing to do.  ^The sqlite3_mutex_notheld()
6042de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface should also return 1 when given a NULL pointer.
6043de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6044de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifndef NDEBUG
6045de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
6046de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
6047de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
6048de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6049de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6050de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Mutex Types
6051de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6052de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [sqlite3_mutex_alloc()] interface takes a single argument
6053de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** which is one of these integer constants.
6054de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6055de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The set of static mutexes may change from one SQLite release to the
6056de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** next.  Applications that override the built-in mutex logic must be
6057de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** prepared to accommodate additional static mutexes.
6058de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6059de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_MUTEX_FAST             0
6060de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_MUTEX_RECURSIVE        1
6061de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_MUTEX_STATIC_MASTER    2
6062de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
6063de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
6064de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
6065de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
6066de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
606790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
606890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
60699bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown#define SQLITE_MUTEX_STATIC_APP1      8  /* For use by application */
60709bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown#define SQLITE_MUTEX_STATIC_APP2      9  /* For use by application */
60719bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown#define SQLITE_MUTEX_STATIC_APP3     10  /* For use by application */
6072de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6073de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6074de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Retrieve the mutex for a database connection
6075de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6076de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This interface returns a pointer the [sqlite3_mutex] object that
6077de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** serializes access to the [database connection] given in the argument
6078de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** when the [threading mode] is Serialized.
6079de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the [threading mode] is Single-thread or Multi-thread then this
6080de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** routine returns a NULL pointer.
6081de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6082de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
6083de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6084de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6085de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Low-Level Control Of Database Files
6086de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6087de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_file_control()] interface makes a direct call to the
6088de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xFileControl method for the [sqlite3_io_methods] object associated
6089de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with a particular database identified by the second argument. ^The
609095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** name of the database is "main" for the main database or "temp" for the
6091de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** TEMP database, or the name that appears after the AS keyword for
6092de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** databases that are added using the [ATTACH] SQL command.
6093de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^A NULL pointer can be used in place of "main" to refer to the
6094de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** main database file.
6095de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The third and fourth parameters to this routine
6096de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are passed directly through to the second and third parameters of
6097de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the xFileControl method.  ^The return value of the xFileControl
6098de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** method becomes the return value of this routine.
6099de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
610095c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
610195c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** a pointer to the underlying [sqlite3_file] object to be written into
610295c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** the space pointed to by the 4th parameter.  ^The SQLITE_FCNTL_FILE_POINTER
610395c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** case is a short-circuit path which does not actually invoke the
610495c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori** underlying sqlite3_io_methods.xFileControl method.
610595c34edce550d0869113085e0cd1b6b09e8fe38bVasu Nori**
6106de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the second parameter (zDbName) does not match the name of any
6107de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** open database file, then SQLITE_ERROR is returned.  ^This error
6108de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** code is not remembered and will not be recalled by [sqlite3_errcode()]
6109de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or [sqlite3_errmsg()].  The underlying xFileControl method might
6110de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** also return SQLITE_ERROR.  There is no way to distinguish between
6111de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6112de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xFileControl method.
6113de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6114de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [SQLITE_FCNTL_LOCKSTATE]
6115de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6116de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6117de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6118de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6119de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Testing Interface
6120de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6121de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_test_control() interface is used to read out internal
6122de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** state of SQLite and to inject faults into SQLite for testing
6123de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** purposes.  ^The first parameter is an operation code that determines
6124de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the number, meaning, and operation of all subsequent parameters.
6125de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6126de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This interface is not for use by applications.  It exists solely
6127de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for verifying the correct operation of the SQLite library.  Depending
6128de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on how the SQLite library is compiled, this interface might not exist.
6129de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6130de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The details of the operation codes, their meanings, the parameters
6131de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** they take, and what they do are all subject to change without notice.
6132de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Unlike most of the SQLite API, this function is not guaranteed to
6133de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** operate consistently from one release to the next.
6134de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6135de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_test_control(int op, ...);
6136de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6137de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6138de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Testing Interface Operation Codes
6139de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6140de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These constants are the valid operation code parameters used
6141de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as the first argument to [sqlite3_test_control()].
6142de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6143de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These parameters and their meanings are subject to change
6144de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** without notice.  These values are for testing purposes only.
6145de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Applications should not use any of these parameters or the
6146de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_test_control()] interface.
6147de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6148de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_FIRST                    5
6149de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_PRNG_SAVE                5
6150de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_PRNG_RESTORE             6
6151de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_PRNG_RESET               7
6152de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_BITVEC_TEST              8
6153de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_FAULT_INSTALL            9
6154de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10
6155de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_PENDING_BYTE            11
6156de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_ASSERT                  12
6157de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_ALWAYS                  13
6158de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_RESERVE                 14
6159de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_OPTIMIZATIONS           15
6160de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_TESTCTRL_ISKEYWORD               16
616190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_TESTCTRL_SCRATCHMALLOC           17
616290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_TESTCTRL_LOCALTIME_FAULT         18
616390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_TESTCTRL_EXPLAIN_STMT            19
61648fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_TESTCTRL_NEVER_CORRUPT           20
61658fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_TESTCTRL_VDBE_COVERAGE           21
61661c7cea379348522163370244e8fbbff8a136b7faNick Kralevich#define SQLITE_TESTCTRL_BYTEORDER               22
61679bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown#define SQLITE_TESTCTRL_ISINIT                  23
61689bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown#define SQLITE_TESTCTRL_LAST                    23
6169de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6170de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6171de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: SQLite Runtime Status
6172de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6173de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This interface is used to retrieve runtime status information
6174de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** about the performance of SQLite, and optionally to reset various
6175de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** highwater marks.  ^The first argument is an integer code for
6176de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the specific parameter to measure.  ^(Recognized integer codes
617790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** are of the form [status parameters | SQLITE_STATUS_...].)^
6178de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The current value of the parameter is returned into *pCurrent.
6179de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The highest recorded value is returned in *pHighwater.  ^If the
6180de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** resetFlag is true, then the highest record value is reset after
6181de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** *pHighwater is written.  ^(Some parameters do not record the highest
6182de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value.  For those parameters
6183de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** nothing is written into *pHighwater and the resetFlag is ignored.)^
6184de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Other parameters record only the highwater mark and not the current
6185de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value.  For these latter parameters nothing is written into *pCurrent.)^
6186de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6187de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_status() routine returns SQLITE_OK on success and a
6188de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** non-zero [error code] on failure.
6189de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6190de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This routine is threadsafe but is not atomic.  This routine can be
6191de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** called while other threads are running the same or different SQLite
6192de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interfaces.  However the values returned in *pCurrent and
6193de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** *pHighwater reflect the status of SQLite at different points in time
6194de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and it is possible that another thread might change the parameter
6195de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in between the times when *pCurrent and *pHighwater are written.
6196de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6197de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_db_status()]
6198de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6199de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
6200de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6201de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6202de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6203de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Status Parameters
620490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** KEYWORDS: {status parameters}
6205de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6206de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These integer constants designate various run-time status parameters
6207de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that can be returned by [sqlite3_status()].
6208de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6209de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dl>
621090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
6211de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter is the current amount of memory checked out
6212de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** using [sqlite3_malloc()], either directly or indirectly.  The
6213de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** figure includes calls made to [sqlite3_malloc()] by the application
6214de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and internal memory usage by the SQLite library.  Scratch memory
6215de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
6216de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
6217de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** this parameter.  The amount returned is the sum of the allocation
6218de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
6219de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
622090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
6221de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter records the largest memory allocation request
6222de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
6223de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** internal equivalents).  Only the value returned in the
6224de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** *pHighwater parameter to [sqlite3_status()] is of interest.
6225de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The value written into the *pCurrent parameter is undefined.</dd>)^
6226de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
622790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
622890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd>This parameter records the number of separate memory allocations
622990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** currently checked out.</dd>)^
6230de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
623190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
6232de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter returns the number of pages used out of the
6233de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [pagecache memory allocator] that was configured using
6234de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_CONFIG_PAGECACHE].  The
6235de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value returned is in pages, not in bytes.</dd>)^
6236de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
623790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
6238de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
6239de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter returns the number of bytes of page cache
6240de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
6241de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** buffer and where forced to overflow to [sqlite3_malloc()].  The
6242de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returned value includes allocations that overflowed because they
6243de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** where too large (they were larger than the "sz" parameter to
6244de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
6245de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** no space was left in the page cache.</dd>)^
6246de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
624790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
6248de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter records the largest memory allocation request
6249de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** handed to [pagecache memory allocator].  Only the value returned in the
6250de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** *pHighwater parameter to [sqlite3_status()] is of interest.
6251de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The value written into the *pCurrent parameter is undefined.</dd>)^
6252de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
625390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
6254de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter returns the number of allocations used out of the
6255de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [scratch memory allocator] configured using
6256de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not
6257de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in bytes.  Since a single thread may only have one scratch allocation
6258de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** outstanding at time, this parameter also reports the number of threads
6259de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** using scratch memory at the same time.</dd>)^
6260de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
626190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
6262de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter returns the number of bytes of scratch memory
6263de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
6264de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** buffer and where forced to overflow to [sqlite3_malloc()].  The values
6265de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returned include overflows because the requested allocation was too
6266de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** larger (that is, because the requested allocation was larger than the
6267de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6268de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** slots were available.
6269de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </dd>)^
6270de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
627190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
6272de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter records the largest memory allocation request
6273de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** handed to [scratch memory allocator].  Only the value returned in the
6274de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** *pHighwater parameter to [sqlite3_status()] is of interest.
6275de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The value written into the *pCurrent parameter is undefined.</dd>)^
6276de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
627790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
6278de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter records the deepest parser stack.  It is only
6279de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
6280de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </dl>
6281de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6282de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** New status parameters may be added from time to time.
6283de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6284de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATUS_MEMORY_USED          0
6285de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATUS_PAGECACHE_USED       1
6286de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
6287de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATUS_SCRATCH_USED         3
6288de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATUS_SCRATCH_OVERFLOW     4
6289de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATUS_MALLOC_SIZE          5
6290de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATUS_PARSER_STACK         6
6291de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATUS_PAGECACHE_SIZE       7
6292de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATUS_SCRATCH_SIZE         8
6293de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STATUS_MALLOC_COUNT         9
6294de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6295de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6296de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Database Connection Status
6297de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6298de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This interface is used to retrieve runtime status information
6299de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** about a single [database connection].  ^The first argument is the
6300de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database connection object to be interrogated.  ^The second argument
6301de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is an integer constant, taken from the set of
630290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SQLITE_DBSTATUS options], that
6303de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** determines the parameter to interrogate.  The set of
630490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SQLITE_DBSTATUS options] is likely
6305de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to grow in future releases of SQLite.
6306de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6307de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The current value of the requested parameter is written into *pCur
6308de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the highest instantaneous value is written into *pHiwtr.  ^If
6309de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the resetFlg is true, then the highest instantaneous value is
6310de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** reset back down to the current value.
6311de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6312de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
6313de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** non-zero [error code] on failure.
6314de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6315de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
6316de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6317de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6318de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6319de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6320de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Status Parameters for database connections
632190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** KEYWORDS: {SQLITE_DBSTATUS options}
6322de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6323de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These constants are the available integer "verbs" that can be passed as
6324de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the second argument to the [sqlite3_db_status()] interface.
6325de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6326de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** New verbs may be added in future releases of SQLite. Existing verbs
6327de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** might be discontinued. Applications should check the return code from
6328de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_db_status()] to make sure that the call worked.
6329de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [sqlite3_db_status()] interface will return a non-zero error code
6330de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if a discontinued or unsupported verb is invoked.
6331de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6332de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dl>
633390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
6334de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter returns the number of lookaside memory slots currently
6335de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** checked out.</dd>)^
6336de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
633790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
633890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd>This parameter returns the number malloc attempts that were
633990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** satisfied using lookaside memory. Only the high-water value is meaningful;
634090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the current value is always zero.)^
634190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
634290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
634390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
634490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd>This parameter returns the number malloc attempts that might have
634590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** been satisfied using lookaside memory but failed due to the amount of
634690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** memory requested being larger than the lookaside slot size.
634790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** Only the high-water value is meaningful;
634890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the current value is always zero.)^
634990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
635090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
635190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
635290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd>This parameter returns the number malloc attempts that might have
635390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** been satisfied using lookaside memory but failed due to all lookaside
635490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** memory already being in use.
635590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** Only the high-water value is meaningful;
635690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the current value is always zero.)^
635790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
635890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
6359de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter returns the approximate number of of bytes of heap
6360de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory used by all pager caches associated with the database connection.)^
6361de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
6362de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
636390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
6364de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter returns the approximate number of of bytes of heap
6365de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** memory used to store the schema for all databases associated
6366de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** with the connection - main, temp, and any [ATTACH]-ed databases.)^
6367de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The full amount of memory used by the schemas is reported, even if the
6368de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** schema memory is shared with other database connections due to
6369de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [shared cache mode] being enabled.
6370de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
6371de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
637290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
6373de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>This parameter returns the approximate number of of bytes of heap
6374de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and lookaside memory used by all prepared statements associated with
6375de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the database connection.)^
6376de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
6377de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </dd>
637890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
637990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
638090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd>This parameter returns the number of pager cache hits that have
638190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
638290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is always 0.
638390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** </dd>
638490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
638590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
638690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd>This parameter returns the number of pager cache misses that have
638790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
638890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is always 0.
638990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** </dd>
63908fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
63918fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
63928fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dd>This parameter returns the number of dirty cache entries that have
63938fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** been written to disk. Specifically, the number of pages written to the
63948fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** wal file in wal mode databases, or the number of pages written to the
63958fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** database file in rollback mode databases. Any pages written as part of
63968fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** transaction rollback or database recovery operations are not included.
63978fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** If an IO or other error occurs while writing a page to disk, the effect
63988fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
63998fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
64008fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** </dd>
64018fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
64028fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
64038fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dd>This parameter returns zero for the current value if and only if
64048fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** all foreign key constraints (deferred or immediate) have been
64058fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** resolved.)^  ^The highwater mark is always 0.
64068fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** </dd>
6407de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </dl>
6408de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
640990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBSTATUS_LOOKASIDE_USED       0
641090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBSTATUS_CACHE_USED           1
641190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBSTATUS_SCHEMA_USED          2
641290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBSTATUS_STMT_USED            3
641390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBSTATUS_LOOKASIDE_HIT        4
641490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE  5
641590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6
641690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBSTATUS_CACHE_HIT            7
641790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_DBSTATUS_CACHE_MISS           8
64188fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_DBSTATUS_CACHE_WRITE          9
64198fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_DBSTATUS_DEFERRED_FKS        10
64208fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_DBSTATUS_MAX                 10   /* Largest defined DBSTATUS */
6421de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6422de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6423de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6424de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Prepared Statement Status
6425de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6426de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(Each prepared statement maintains various
642790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SQLITE_STMTSTATUS counters] that measure the number
6428de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of times it has performed specific operations.)^  These counters can
6429de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** be used to monitor the performance characteristics of the prepared
6430de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** statements.  For example, if the number of table steps greatly exceeds
6431de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the number of table searches or result rows, that would tend to indicate
6432de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that the prepared statement is using a full table scan rather than
6433de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an index.
6434de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6435de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(This interface is used to retrieve and reset counter values from
6436de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a [prepared statement].  The first argument is the prepared statement
6437de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** object to be interrogated.  The second argument
643890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is an integer code for a specific [SQLITE_STMTSTATUS counter]
6439de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to be interrogated.)^
6440de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The current value of the requested counter is returned.
6441de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the resetFlg is true, then the counter is reset to zero after this
6442de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** interface call returns.
6443de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6444de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See also: [sqlite3_status()] and [sqlite3_db_status()].
6445de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6446de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
6447de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6448de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6449de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Status Parameters for prepared statements
645090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
6451de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6452de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** These preprocessor macros define integer codes that name counter
6453de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** values associated with the [sqlite3_stmt_status()] interface.
6454de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The meanings of the various counters are as follows:
6455de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6456de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dl>
645790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
6458de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>^This is the number of times that SQLite has stepped forward in
6459de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a table as part of a full table scan.  Large numbers for this counter
6460de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** may indicate opportunities for performance improvement through
6461de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** careful use of indices.</dd>
6462de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
646390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
6464de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>^This is the number of sort operations that have occurred.
6465de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A non-zero value in this counter may indicate an opportunity to
6466de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** improvement performance through careful use of indices.</dd>
6467de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
646890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
6469de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <dd>^This is the number of rows inserted into transient indices that
6470de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** were created automatically in order to help joins run faster.
6471de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A non-zero value in this counter may indicate an opportunity to
6472de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** improvement performance by adding permanent indices that do not
6473de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** need to be reinitialized each time the statement is run.</dd>
64748fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
64758fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
64768fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <dd>^This is the number of virtual machine operations executed
64778fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** by the prepared statement if that number is less than or equal
64788fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** to 2147483647.  The number of virtual machine operations can be
64798fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** used as a proxy for the total work done by the prepared statement.
64808fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** If the number of virtual machine operations exceeds 2147483647
64818fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** then the value returned by this statement status code is undefined.
64828fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** </dd>
6483de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </dl>
6484de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6485de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
6486de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STMTSTATUS_SORT              2
6487de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define SQLITE_STMTSTATUS_AUTOINDEX         3
64888fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#define SQLITE_STMTSTATUS_VM_STEP           4
6489de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6490de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6491de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Custom Page Cache Object
6492de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6493de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_pcache type is opaque.  It is implemented by
6494de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the pluggable module.  The SQLite core has no knowledge of
6495de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** its size or internal structure and never deals with the
6496de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_pcache object except by holding and passing pointers
6497de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the object.
6498de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
649990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** See [sqlite3_pcache_methods2] for additional information.
6500de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6501de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_pcache sqlite3_pcache;
6502de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6503de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
650490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Custom Page Cache Object
650590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
650690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The sqlite3_pcache_page object represents a single page in the
650790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** page cache.  The page cache will allocate instances of this
650890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** object.  Various methods of the page cache use pointers to instances
650990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** of this object as parameters or as their return value.
651090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
651190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** See [sqlite3_pcache_methods2] for additional information.
651290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
651390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Browntypedef struct sqlite3_pcache_page sqlite3_pcache_page;
651490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brownstruct sqlite3_pcache_page {
651590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  void *pBuf;        /* The content of the page */
651690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  void *pExtra;      /* Extra information associated with the page */
651790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown};
651890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
651990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
6520de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Application Defined Page Cache.
6521de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** KEYWORDS: {page cache}
6522de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
652390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
6524de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** register an alternative page cache implementation by passing in an
652590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** instance of the sqlite3_pcache_methods2 structure.)^
6526de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** In many applications, most of the heap memory allocated by
6527de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite is used for the page cache.
6528de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** By implementing a
6529de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** custom page cache using this API, an application can better control
6530de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the amount of memory consumed by SQLite, the way in which
6531de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that memory is allocated and released, and the policies used to
6532de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** determine exactly which parts of a database file are cached and for
6533de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** how long.
6534de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6535de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The alternative page cache mechanism is an
6536de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** extreme measure that is only needed by the most demanding applications.
6537de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The built-in page cache is recommended for most uses.
6538de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
653990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
6540de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** internal buffer by SQLite within the call to [sqlite3_config].  Hence
6541de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the application may discard the parameter after the call to
6542de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_config()] returns.)^
6543de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
654490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[the xInit() page cache method]]
6545de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The xInit() method is called once for each effective
6546de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** call to [sqlite3_initialize()])^
6547de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** (usually only once during the lifetime of the process). ^(The xInit()
654890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
6549de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The intent of the xInit() method is to set up global data structures
6550de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** required by the custom page cache implementation.
6551de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(If the xInit() method is NULL, then the
6552de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** built-in default page cache is used instead of the application defined
6553de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** page cache.)^
6554de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
655590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[the xShutdown() page cache method]]
6556de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The xShutdown() method is called by [sqlite3_shutdown()].
6557de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** It can be used to clean up
6558de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** any outstanding resources before process shutdown, if required.
6559de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The xShutdown() method may be NULL.
6560de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6561de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite automatically serializes calls to the xInit method,
6562de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** so the xInit method need not be threadsafe.  ^The
6563de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** xShutdown method is only called from [sqlite3_shutdown()] so it does
6564de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not need to be threadsafe either.  All other methods must be threadsafe
6565de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** in multithreaded applications.
6566de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6567de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite will never invoke xInit() more than once without an intervening
6568de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** call to xShutdown().
6569de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
657090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[the xCreate() page cache methods]]
6571de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^SQLite invokes the xCreate() method to construct a new cache instance.
6572de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite will typically create one cache instance for each open database file,
6573de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** though this is not guaranteed. ^The
6574de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** first parameter, szPage, is the size in bytes of the pages that must
657590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** be allocated by the cache.  ^szPage will always a power of two.  ^The
657690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** second parameter szExtra is a number of bytes of extra storage
657790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** associated with each page cache entry.  ^The szExtra parameter will
657890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** a number less than 250.  SQLite will use the
657990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** extra szExtra bytes on each page to store metadata about the underlying
658090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** database page on disk.  The value passed into szExtra depends
6581de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on the SQLite version, the target platform, and how SQLite was compiled.
658290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The third argument to xCreate(), bPurgeable, is true if the cache being
658390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** created will be used to cache database pages of a file stored on disk, or
6584de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** false if it is used for an in-memory database. The cache implementation
6585de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** does not have to do anything special based with the value of bPurgeable;
6586de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
6587de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** never invoke xUnpin() except to deliberately delete a page.
6588de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
6589de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** false will always have the "discard" flag set to true.
6590de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Hence, a cache created with bPurgeable false will
6591de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** never contain any unpinned pages.
6592de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
659390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[the xCachesize() page cache method]]
6594de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The xCachesize() method may be called at any time by SQLite to set the
6595de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** suggested maximum cache-size (number of pages stored by) the cache
6596de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** instance passed as the first argument. This is the value configured using
6597de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable
6598de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameter, the implementation is not required to do anything with this
6599de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** value; it is advisory only.
6600de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
660190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[the xPagecount() page cache methods]]
6602de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xPagecount() method must return the number of pages currently
6603de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** stored in the cache, both pinned and unpinned.
6604de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
660590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[the xFetch() page cache methods]]
6606de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xFetch() method locates a page in the cache and returns a pointer to
660790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
660890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The pBuf element of the returned sqlite3_pcache_page object will be a
660990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** pointer to a buffer of szPage bytes used to store the content of a
661090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** single database page.  The pExtra element of sqlite3_pcache_page will be
661190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** a pointer to the szExtra bytes of extra storage that SQLite has requested
661290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** for each entry in the page cache.
661390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
661490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The page to be fetched is determined by the key. ^The minimum key value
661590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is 1.  After it has been retrieved using xFetch, the page is considered
661690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** to be "pinned".
6617de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6618de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If the requested page is already in the page cache, then the page cache
6619de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** implementation must return a pointer to the page buffer with its content
6620de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** intact.  If the requested page is not already in the cache, then the
662190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** cache implementation should use the value of the createFlag
6622de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** parameter to help it determined what action to take:
6623de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6624de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <table border=1 width=85% align=center>
66258fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** <tr><th> createFlag <th> Behavior when page is not already in cache
6626de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
6627de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
6628de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**                 Otherwise return NULL.
6629de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
6630de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**                 NULL if allocating a new page is effectively impossible.
6631de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </table>
6632de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6633de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite
6634de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will only use a createFlag of 2 after a prior call with a createFlag of 1
6635de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** failed.)^  In between the to xFetch() calls, SQLite may
6636de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** attempt to unpin one or more cache pages by spilling the content of
6637de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pinned pages to disk and synching the operating system disk cache.
6638de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
663990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[the xUnpin() page cache method]]
6640de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
6641de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** as its second argument.  If the third parameter, discard, is non-zero,
6642de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the page must be evicted from the cache.
6643de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the discard parameter is
6644de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** zero, then the page may be discarded or retained at the discretion of
6645de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** page cache implementation. ^The page cache implementation
6646de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** may choose to evict unpinned pages at any time.
6647de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6648de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The cache must not perform any reference counting. A single
6649de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** call to xUnpin() unpins the page regardless of the number of prior calls
6650de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to xFetch().
6651de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
665290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[the xRekey() page cache methods]]
6653de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The xRekey() method is used to change the key value associated with the
6654de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** page passed as the second argument. If the cache
6655de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** previously contains an entry associated with newKey, it must be
6656de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** discarded. ^Any prior cache entry associated with newKey is guaranteed not
6657de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to be pinned.
6658de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6659de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When SQLite calls the xTruncate() method, the cache must discard all
6660de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** existing cache entries with page numbers (keys) greater than or equal
6661de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the value of the iLimit parameter passed to xTruncate(). If any
6662de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** of these pages are pinned, they are implicitly unpinned, meaning that
6663de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** they can be safely discarded.
6664de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
666590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[the xDestroy() page cache method]]
6666de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The xDestroy() method is used to delete a cache allocated by xCreate().
6667de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** All resources associated with the specified cache should be freed. ^After
6668de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
666990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** handle invalid, and will not use it with any other sqlite3_pcache_methods2
6670de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** functions.
667190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
667290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[the xShrink() page cache method]]
667390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^SQLite invokes the xShrink() method when it wants the page cache to
667490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** free up as much of heap memory as possible.  The page cache implementation
667590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is not obligated to free any memory, but well-behaved implementations should
667690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** do their best.
667790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
667890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Browntypedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
667990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brownstruct sqlite3_pcache_methods2 {
668090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int iVersion;
668190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  void *pArg;
668290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int (*xInit)(void*);
668390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  void (*xShutdown)(void*);
668490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
668590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
668690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int (*xPagecount)(sqlite3_pcache*);
668790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
668890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
668990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
669090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown      unsigned oldKey, unsigned newKey);
669190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
669290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  void (*xDestroy)(sqlite3_pcache*);
669390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  void (*xShrink)(sqlite3_pcache*);
669490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown};
669590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
669690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
669790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** This is the obsolete pcache_methods object that has now been replaced
669890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** by sqlite3_pcache_methods2.  This object is not used by SQLite.  It is
669990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** retained in the header file for backwards compatibility only.
6700de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6701de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
6702de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_pcache_methods {
6703de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pArg;
6704de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xInit)(void*);
6705de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xShutdown)(void*);
6706de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
6707de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
6708de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int (*xPagecount)(sqlite3_pcache*);
6709de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
6710de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xUnpin)(sqlite3_pcache*, void*, int discard);
6711de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
6712de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
6713de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xDestroy)(sqlite3_pcache*);
6714de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
6715de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
671690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
6717de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6718de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Online Backup Object
6719de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6720de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_backup object records state information about an ongoing
6721de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** online backup operation.  ^The sqlite3_backup object is created by
6722de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a call to [sqlite3_backup_init()] and is destroyed by a call to
6723de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_backup_finish()].
6724de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6725de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See Also: [Using the SQLite Online Backup API]
6726de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6727de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_backup sqlite3_backup;
6728de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6729de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6730de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Online Backup API.
6731de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6732de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The backup API copies the content of one database into another.
6733de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** It is useful either for creating backups of databases or
6734de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for copying in-memory databases to or from persistent files.
6735de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6736de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See Also: [Using the SQLite Online Backup API]
6737de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
673890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^SQLite holds a write transaction open on the destination database file
673990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** for the duration of the backup operation.
674090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^The source database is read-locked only while it is being read;
674190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** it is not locked continuously for the entire backup operation.
674290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ^Thus, the backup may be performed on a live source database without
674390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** preventing other database connections from
6744de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** reading or writing to the source database while the backup is underway.
6745de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6746de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(To perform a backup operation:
6747de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   <ol>
6748de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**     <li><b>sqlite3_backup_init()</b> is called once to initialize the
6749de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**         backup,
6750de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
6751de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**         the data between the two databases, and finally
6752de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**     <li><b>sqlite3_backup_finish()</b> is called to release all resources
6753de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**         associated with the backup operation.
6754de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   </ol>)^
6755de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** There should be exactly one call to sqlite3_backup_finish() for each
6756de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** successful call to sqlite3_backup_init().
6757de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
675890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
6759de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6760de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
6761de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection] associated with the destination database
6762de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the database name, respectively.
6763de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The database name is "main" for the main database, "temp" for the
6764de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** temporary database, or the name specified after the AS keyword in
6765de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an [ATTACH] statement for an attached database.
6766de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The S and M arguments passed to
6767de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_init(D,N,S,M) identify the [database connection]
6768de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and database name of the source database, respectively.
6769de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The source and destination [database connections] (parameters S and D)
677090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
6771de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an error.
6772de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6773de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
677490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** returned and an error code and error message are stored in the
6775de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** destination [database connection] D.
6776de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The error code and message for the failed call to sqlite3_backup_init()
6777de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
6778de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_errmsg16()] functions.
6779de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^A successful call to sqlite3_backup_init() returns a pointer to an
6780de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_backup] object.
6781de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
6782de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_finish() functions to perform the specified backup
6783de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** operation.
6784de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
678590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
6786de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6787de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
6788de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the source and destination databases specified by [sqlite3_backup] object B.
6789de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If N is negative, all remaining source pages are copied.
6790de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
679190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** are still more pages to be copied, then the function returns [SQLITE_OK].
6792de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
6793de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from source to destination, then it returns [SQLITE_DONE].
6794de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If an error occurs while running sqlite3_backup_step(B,N),
6795de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then an [error code] is returned. ^As well as [SQLITE_OK] and
6796de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
6797de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
6798de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
6799de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6800de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
6801de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <ol>
6802de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> the destination database was opened read-only, or
6803de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <li> the destination database is using write-ahead-log journaling
6804de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the destination and source page sizes differ, or
680590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <li> the destination database is an in-memory database and the
6806de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** destination and source page sizes differ.
6807de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** </ol>)^
6808de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6809de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
6810de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [sqlite3_busy_handler | busy-handler function]
6811de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is invoked (if one is specified). ^If the
6812de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** busy-handler returns non-zero before the lock is available, then
6813de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
6814de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_step() can be retried later. ^If the source
6815de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection]
6816de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is being used to write to the source database when sqlite3_backup_step()
6817de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
6818de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** case the call to sqlite3_backup_step() can be retried later on. ^(If
6819de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
6820de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_READONLY] is returned, then
6821de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** there is no point in retrying the call to sqlite3_backup_step(). These
6822de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** errors are considered fatal.)^  The application must accept
6823de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that the backup operation has failed and pass the backup operation handle
6824de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to the sqlite3_backup_finish() to release associated resources.
6825de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6826de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first call to sqlite3_backup_step() obtains an exclusive lock
6827de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on the destination file. ^The exclusive lock is not released until either
6828de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_finish() is called or the backup operation is complete
6829de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
6830de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_step() obtains a [shared lock] on the source database that
6831de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** lasts for the duration of the sqlite3_backup_step() call.
6832de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Because the source database is not locked between calls to
6833de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_step(), the source database may be modified mid-way
6834de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** through the backup process.  ^If the source database is modified by an
6835de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** external process or via a database connection other than the one being
6836de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** used by the backup operation, then the backup will be automatically
6837de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** restarted by the next call to sqlite3_backup_step(). ^If the source
6838de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database is modified by the using the same database connection as is used
6839de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by the backup operation, then the backup database is automatically
6840de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** updated at the same time.
6841de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
684290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
6843de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6844de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
6845de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** application wishes to abandon the backup operation, the application
6846de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
6847de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The sqlite3_backup_finish() interfaces releases all
6848de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** resources associated with the [sqlite3_backup] object.
6849de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
6850de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** active write-transaction on the destination database is rolled back.
6851de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [sqlite3_backup] object is invalid
6852de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and may not be used following a call to sqlite3_backup_finish().
6853de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6854de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
6855de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_step() errors occurred, regardless or whether or not
6856de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_step() completed.
6857de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If an out-of-memory condition or IO error occurred during any prior
6858de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
6859de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_finish() returns the corresponding [error code].
6860de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6861de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
6862de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is not a permanent error and does not affect the return value of
6863de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_finish().
6864de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
686590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
686690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
6867de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6868de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Each call to sqlite3_backup_step() sets two values inside
6869de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the [sqlite3_backup] object: the number of pages still to be backed
6870de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** up and the total number of pages in the source database file.
6871de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
6872de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** retrieve these two values, respectively.
6873de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6874de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The values returned by these functions are only updated by
6875de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_step(). ^If the source database is modified during a backup
6876de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** operation, then the values are not updated to account for any extra
6877de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** pages that need to be updated or the size of the source database file
6878de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** changing.
6879de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6880de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <b>Concurrent Usage of Database Handles</b>
6881de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6882de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The source [database connection] may be used by the application for other
6883de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** purposes while a backup operation is underway or being initialized.
6884de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If SQLite is compiled and configured to support threadsafe database
6885de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** connections, then the source database connection may be used concurrently
6886de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from within other threads.
6887de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6888de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** However, the application must guarantee that the destination
6889de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [database connection] is not passed to any other API (by any thread) after
6890de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_init() is called and before the corresponding call to
6891de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_backup_finish().  SQLite does not currently check to see
6892de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** if the application incorrectly accesses the destination [database connection]
6893de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and so no error code is reported, but the operations may malfunction
6894de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** nevertheless.  Use of the destination database connection while a
6895de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** backup is in progress might also also cause a mutex deadlock.
6896de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6897de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If running in [shared cache mode], the application must
6898de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** guarantee that the shared cache used by the destination database
6899de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is not accessed while the backup is running. In practice this means
6900de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that the application must guarantee that the disk file being
6901de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** backed up to is not accessed by any connection within the process,
6902de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** not just the specific connection that was passed to sqlite3_backup_init().
6903de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6904de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The [sqlite3_backup] object itself is partially threadsafe. Multiple
6905de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** threads may safely make multiple concurrent calls to sqlite3_backup_step().
6906de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
6907de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** APIs are not strictly speaking threadsafe. If they are invoked at the
6908de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** same time as another thread is invoking sqlite3_backup_step() it is
6909de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** possible that they return invalid values.
6910de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
6911de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API sqlite3_backup *sqlite3_backup_init(
6912de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *pDest,                        /* Destination database handle */
6913de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zDestName,                 /* Destination database name */
6914de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *pSource,                      /* Source database handle */
6915de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zSourceName                /* Source database name */
6916de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
6917de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
6918de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
6919de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
6920de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
6921de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
6922de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
6923de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Unlock Notification
6924de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6925de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^When running in shared-cache mode, a database operation may fail with
6926de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
6927de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** individual tables within the shared-cache cannot be obtained. See
6928de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
6929de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This API may be used to register a callback that SQLite will invoke
6930de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** when the connection currently holding the required lock relinquishes it.
6931de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^This API is only available if the library was compiled with the
6932de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
6933de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6934de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** See Also: [Using the SQLite Unlock Notification Feature].
6935de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6936de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Shared-cache locks are released when a database connection concludes
6937de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** its current transaction, either by committing it or rolling it back.
6938de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6939de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^When a connection (known as the blocked connection) fails to obtain a
6940de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
6941de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** identity of the database connection (the blocking connection) that
6942de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** has locked the required resource is stored internally. ^After an
6943de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** application receives an SQLITE_LOCKED error, it may call the
6944de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_unlock_notify() method with the blocked connection handle as
6945de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the first argument to register for a callback that will be invoked
6946de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** when the blocking connections current transaction is concluded. ^The
6947de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
6948de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** call that concludes the blocking connections transaction.
6949de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6950de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
6951de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** there is a chance that the blocking connection will have already
6952de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
6953de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** If this happens, then the specified callback is invoked immediately,
6954de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from within the call to sqlite3_unlock_notify().)^
6955de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6956de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If the blocked connection is attempting to obtain a write-lock on a
6957de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** shared-cache table, and more than one other connection currently holds
6958de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a read-lock on the same table, then SQLite arbitrarily selects one of
6959de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the other connections to use as the blocking connection.
6960de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6961de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^(There may be at most one unlock-notify callback registered by a
6962de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** blocked connection. If sqlite3_unlock_notify() is called when the
6963de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** blocked connection already has a registered unlock-notify callback,
6964de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
6965de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** called with a NULL pointer as its second argument, then any existing
6966de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** unlock-notify callback is canceled. ^The blocked connections
6967de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** unlock-notify callback may also be canceled by closing the blocked
6968de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** connection using [sqlite3_close()].
6969de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6970de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The unlock-notify callback is not reentrant. If an application invokes
6971de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** any sqlite3_xxx API functions from within an unlock-notify callback, a
6972de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** crash or deadlock may be the result.
6973de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6974de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
6975de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returns SQLITE_OK.
6976de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6977de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <b>Callback Invocation Details</b>
6978de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6979de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When an unlock-notify callback is registered, the application provides a
6980de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** single void* pointer that is passed to the callback when it is invoked.
6981de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** However, the signature of the callback function allows SQLite to pass
6982de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** it an array of void* context pointers. The first argument passed to
6983de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** an unlock-notify callback is a pointer to an array of void* pointers,
6984de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** and the second is the number of entries in the array.
6985de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6986de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When a blocking connections transaction is concluded, there may be
6987de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** more than one blocked connection that has registered for an unlock-notify
6988de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** callback. ^If two or more such blocked connections have specified the
6989de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** same callback function, then instead of invoking the callback function
6990de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** multiple times, it is invoked once with the set of void* context pointers
6991de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** specified by the blocked connections bundled together into an array.
6992de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** This gives the application an opportunity to prioritize any actions
6993de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** related to the set of unblocked database connections.
6994de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6995de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <b>Deadlock Detection</b>
6996de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
6997de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Assuming that after registering for an unlock-notify callback a
6998de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** database waits for the callback to be issued before taking any further
6999de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** action (a reasonable assumption), then using this API may cause the
7000de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** application to deadlock. For example, if connection X is waiting for
7001de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** connection Y's transaction to be concluded, and similarly connection
7002de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Y is waiting on connection X's transaction, then neither connection
7003de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will proceed and the system may remain deadlocked indefinitely.
7004de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7005de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
7006de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** detection. ^If a given call to sqlite3_unlock_notify() would put the
7007de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** system in a deadlocked state, then SQLITE_LOCKED is returned and no
7008de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** unlock-notify callback is registered. The system is said to be in
7009de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a deadlocked state if connection A has registered for an unlock-notify
7010de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** callback on the conclusion of connection B's transaction, and connection
7011de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** B has itself registered for an unlock-notify callback when connection
7012de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A's transaction is concluded. ^Indirect deadlock is also detected, so
7013de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the system is also considered to be deadlocked if connection B has
7014de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** registered for an unlock-notify callback on the conclusion of connection
7015de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** C's transaction, where connection C is waiting on connection A. ^Any
7016de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** number of levels of indirection are allowed.
7017de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7018de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** <b>The "DROP TABLE" Exception</b>
7019de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7020de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
7021de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** always appropriate to call sqlite3_unlock_notify(). There is however,
7022de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
7023de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite checks if there are any currently executing SELECT statements
7024de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that belong to the same connection. If there are, SQLITE_LOCKED is
7025de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** returned. In this case there is no "blocking connection", so invoking
7026de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** sqlite3_unlock_notify() results in the unlock-notify callback being
7027de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** invoked immediately. If the application then re-attempts the "DROP TABLE"
7028de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** or "DROP INDEX" query, an infinite loop might be the result.
7029de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7030de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** One way around this problem is to check the extended error code returned
7031de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** by an sqlite3_step() call. ^(If there is a blocking connection, then the
7032de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
7033de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the special "DROP TABLE/INDEX" case, the extended error code is just
7034de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLITE_LOCKED.)^
7035de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
7036de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_unlock_notify(
7037de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *pBlocked,                          /* Waiting connection */
7038de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
7039de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pNotifyArg                            /* Argument to pass to xNotify */
7040de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
7041de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7042de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7043de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
7044de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: String Comparison
7045de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7046c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
7047c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** and extensions to compare the contents of two buffers containing UTF-8
7048c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** strings in a case-independent fashion, using the same definition of "case
7049c82acac4e67711e8d9289b572d334298aeb5d806Jeff Brown** independence" that SQLite uses internally when comparing identifiers.
7050de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
7051c82acac4e67711e8d9289b572d334298aeb5d806Jeff BrownSQLITE_API int sqlite3_stricmp(const char *, const char *);
7052de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
7053de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7054de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
70558fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** CAPI3REF: String Globbing
70568fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich*
70578fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches
70588fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the glob pattern P, and it returns non-zero if string X does not match
70598fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** the glob pattern P.  ^The definition of glob pattern matching used in
70608fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
70618fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** SQL dialect used by SQLite.  ^The sqlite3_strglob(P,X) function is case
70628fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** sensitive.
70638fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich**
70648fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** Note that this routine returns zero on a match and non-zero if the strings
70658fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
70668fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich*/
70678fecf56c625b5691ee3381e107ccbe1ff42398b1Nick KralevichSQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
70688fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich
70698fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich/*
7070de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Error Logging Interface
7071de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
70728fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich** ^The [sqlite3_log()] interface writes a message into the [error log]
7073de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
7074de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^If logging is enabled, the zFormat string and subsequent arguments are
7075de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** used with [sqlite3_snprintf()] to generate the final output string.
7076de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7077de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The sqlite3_log() interface is intended for use by extensions such as
7078de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** virtual tables, collating functions, and SQL functions.  While there is
7079de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** nothing to prevent an application from calling sqlite3_log(), doing so
7080de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is considered bad form.
7081de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7082de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The zFormat string must not be NULL.
7083de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7084de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** To avoid deadlocks and other threading problems, the sqlite3_log() routine
7085de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will not use dynamically allocated memory.  The log message is stored in
7086de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a fixed-length buffer on the stack.  If the log message is longer than
7087de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a few hundred characters, it will be truncated to the length of the
7088de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** buffer.
7089de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
7090de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
7091de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7092de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
7093de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Write-Ahead Log Commit Hook
7094de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7095de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_wal_hook()] function is used to register a callback that
7096de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** will be invoked each time a database connection commits data to a
7097de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [write-ahead log] (i.e. whenever a transaction is committed in
7098de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [journal_mode | journal_mode=WAL mode]).
7099de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7100de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The callback is invoked by SQLite after the commit has taken place and
7101de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** the associated write-lock on the database released, so the implementation
7102de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** may read, write or [checkpoint] the database as required.
7103de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7104de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The first parameter passed to the callback function when it is invoked
7105de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is a copy of the third parameter passed to sqlite3_wal_hook() when
7106de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** registering the callback. ^The second is a copy of the database handle.
7107de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The third parameter is the name of the database that was written to -
7108de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
7109de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is the number of pages currently in the write-ahead log file,
7110de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** including those that were just committed.
7111de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7112de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The callback function should normally return [SQLITE_OK].  ^If an error
7113de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** code is returned, that error will propagate back up through the
7114de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** SQLite code base to cause the statement that provoked the callback
7115de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to report an error, though the commit will have still occurred. If the
7116de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
7117de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** that does not correspond to any valid SQLite error code, the results
7118de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** are undefined.
7119de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7120de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A single database handle may have at most a single write-ahead log callback
7121de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
7122de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** previously registered write-ahead log callback. ^Note that the
7123de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_wal_autocheckpoint()] interface and the
7124de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
7125de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** those overwrite any prior [sqlite3_wal_hook()] settings.
7126de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
7127de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API void *sqlite3_wal_hook(
7128de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3*,
7129de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int(*)(void *,sqlite3*,const char*,int),
7130de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void*
7131de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
7132de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7133de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
7134de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Configure an auto-checkpoint
7135de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7136de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
7137de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [sqlite3_wal_hook()] that causes any database on [database connection] D
7138de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** to automatically [checkpoint]
7139de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** after committing a transaction if there are N or
7140de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** more frames in the [write-ahead log] file.  ^Passing zero or
7141de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a negative value as the nFrame parameter disables automatic
7142de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** checkpoints entirely.
7143de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7144de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The callback registered by this function replaces any existing callback
7145de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback
7146de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
7147de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** configured by this function.
7148de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7149de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
7150de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from SQL.
7151de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
71529bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** ^Checkpoints initiated by this mechanism are
71539bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** [sqlite3_wal_checkpoint_v2|PASSIVE].
71549bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown**
7155de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^Every new [database connection] defaults to having the auto-checkpoint
715690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
715790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** pages.  The use of this interface
7158de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** is only necessary if the default setting is found to be suboptimal
7159de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** for a particular application.
7160de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
7161de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
7162de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7163de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
7164de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** CAPI3REF: Checkpoint a database
7165de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7166de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
7167de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** on [database connection] D to be [checkpointed].  ^If X is NULL or an
7168de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** empty string, then a checkpoint is run on all databases of
7169de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** connection D.  ^If the database connection D is not in
7170de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [WAL | write-ahead log mode] then this interface is a harmless no-op.
71719bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** ^The [sqlite3_wal_checkpoint(D,X)] interface initiates a
71729bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** [sqlite3_wal_checkpoint_v2|PASSIVE] checkpoint.
71739bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** Use the [sqlite3_wal_checkpoint_v2()] interface to get a FULL
71749bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** or RESET checkpoint.
7175de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7176de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** ^The [wal_checkpoint pragma] can be used to invoke this interface
7177de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** from SQL.  ^The [sqlite3_wal_autocheckpoint()] interface and the
7178de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** [wal_autocheckpoint pragma] can be used to cause this interface to be
7179de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** run whenever the WAL reaches a certain size threshold.
718090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
718190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** See also: [sqlite3_wal_checkpoint_v2()]
7182de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
7183de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
7184de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7185de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
718690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Checkpoint a database
718790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
718890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** Run a checkpoint operation on WAL database zDb attached to database
718990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** handle db. The specific operation is determined by the value of the
719090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** eMode parameter:
719190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
719290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dl>
719390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
719490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   Checkpoint as many frames as possible without waiting for any database
719590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   readers or writers to finish. Sync the db file if all frames in the log
719690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   are checkpointed. This mode is the same as calling
71979bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown**   sqlite3_wal_checkpoint(). The [sqlite3_busy_handler|busy-handler callback]
71989bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown**   is never invoked.
719990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
720090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dt>SQLITE_CHECKPOINT_FULL<dd>
72019bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown**   This mode blocks (it invokes the
72029bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown**   [sqlite3_busy_handler|busy-handler callback]) until there is no
720390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   database writer and all readers are reading from the most recent database
720490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   snapshot. It then checkpoints all frames in the log file and syncs the
720590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   database file. This call blocks database writers while it is running,
720690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   but not database readers.
720790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
720890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dt>SQLITE_CHECKPOINT_RESTART<dd>
720990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   This mode works the same way as SQLITE_CHECKPOINT_FULL, except after
72109bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown**   checkpointing the log file it blocks (calls the
72119bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown**   [sqlite3_busy_handler|busy-handler callback])
721290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   until all readers are reading from the database file only. This ensures
721390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   that the next client to write to the database file restarts the log file
721490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   from the beginning. This call blocks database writers while it is running,
721590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**   but not database readers.
721690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** </dl>
721790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
721890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If pnLog is not NULL, then *pnLog is set to the total number of frames in
721990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
722090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the total number of checkpointed frames (including any that were already
722190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** checkpointed when this function is called). *pnLog and *pnCkpt may be
722290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
722390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If no values are available because of an error, they are both set to -1
722490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** before returning to communicate this to the caller.
722590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
722690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** All calls obtain an exclusive "checkpoint" lock on the database file. If
722790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** any other process is running a checkpoint operation at the same time, the
722890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a
722990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** busy-handler configured, it will not be invoked in this case.
723090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
723190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive
723290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** "writer" lock on the database file. If the writer lock cannot be obtained
723390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** immediately, and a busy-handler is configured, it is invoked and the writer
723490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** lock retried until either the busy-handler returns 0 or the lock is
723590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** successfully obtained. The busy-handler is also invoked while waiting for
723690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** database readers as described above. If the busy-handler returns 0 before
723790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** the writer lock is obtained or while waiting for database readers, the
723890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** checkpoint operation proceeds from that point in the same way as
723990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
724090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** without blocking any further. SQLITE_BUSY is returned in this case.
724190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
724290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If parameter zDb is NULL or points to a zero length string, then the
724390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** specified operation is attempted on all WAL databases. In this case the
724490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** values written to output parameters *pnLog and *pnCkpt are undefined. If
724590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** an SQLITE_BUSY error is encountered when processing one or more of the
724690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** attached WAL databases, the operation is still attempted on any remaining
724790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** attached databases and SQLITE_BUSY is returned to the caller. If any other
724890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** error occurs while processing an attached database, processing is abandoned
724990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** and the error code returned to the caller immediately. If no error
725090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** (SQLITE_BUSY or otherwise) is encountered while processing the attached
725190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** databases, SQLITE_OK is returned.
725290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
725390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If database zDb is the name of an attached database that is not in WAL
725490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
725590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** zDb is not NULL (or a zero length string) and is not the name of any
725690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** attached database, SQLITE_ERROR is returned to the caller.
725790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
725890ed05d921d6ed7f12012d9786d53f57fafee51aJeff BrownSQLITE_API int sqlite3_wal_checkpoint_v2(
725990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  sqlite3 *db,                    /* Database handle */
726090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  const char *zDb,                /* Name of attached database (or NULL) */
726190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int eMode,                      /* SQLITE_CHECKPOINT_* value */
726290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int *pnLog,                     /* OUT: Size of WAL log in frames */
726390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
726490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown);
726590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
726690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
726790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Checkpoint operation parameters
726890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
726990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** These constants can be used as the 3rd parameter to
727090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_wal_checkpoint_v2()].  See the [sqlite3_wal_checkpoint_v2()]
727190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** documentation for additional information about the meaning and use of
727290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** each of these values.
727390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
727490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_CHECKPOINT_PASSIVE 0
727590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_CHECKPOINT_FULL    1
727690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_CHECKPOINT_RESTART 2
727790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
727890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
727990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Virtual Table Interface Configuration
728090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
728190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** This function may be called by either the [xConnect] or [xCreate] method
728290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** of a [virtual table] implementation to configure
728390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** various facets of the virtual table interface.
728490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
728590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If this interface is invoked outside the context of an xConnect or
728690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** xCreate virtual table method then the behavior is undefined.
728790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
728890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** At present, there is only one option that may be configured using
728990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].)  Further options
729090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** may be added in the future.
729190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
729290ed05d921d6ed7f12012d9786d53f57fafee51aJeff BrownSQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
729390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
729490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
729590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Virtual Table Configuration Options
729690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
729790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** These macros define the various options to the
729890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_vtab_config()] interface that [virtual table] implementations
729990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** can use to customize and optimize their behavior.
730090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
730190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dl>
730290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
730390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** <dd>Calls of the form
730490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
730590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** where X is an integer.  If X is zero, then the [virtual table] whose
730690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
730790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** support constraints.  In this configuration (which is the default) if
730890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
730990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
731090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** specified as part of the users SQL statement, regardless of the actual
731190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** ON CONFLICT mode specified.
731290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
731390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If X is non-zero, then the virtual table implementation guarantees
731490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
731590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** any modifications to internal or persistent data structures have been made.
731690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
731790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is able to roll back a statement or database transaction, and abandon
731890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** or continue processing the current SQL statement as appropriate.
731990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
732090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
732190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** had been ABORT.
732290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
732390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** Virtual table implementations that are required to handle OR REPLACE
732490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** must do so within the [xUpdate] method. If a call to the
732590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [sqlite3_vtab_on_conflict()] function indicates that the current ON
732690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CONFLICT policy is REPLACE, the virtual table implementation should
732790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** silently replace the appropriate rows within the xUpdate callback and
732890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** return SQLITE_OK. Or, if this is not possible, it may return
732990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
733090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** constraint handling.
733190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** </dl>
733290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
733390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
733490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
733590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
733690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Determine The Virtual Table Conflict Policy
733790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
733890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** This function may only be called from within a call to the [xUpdate] method
733990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
734090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
734190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
734290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** of the SQL statement that triggered the call to the [xUpdate] method of the
734390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [virtual table].
734490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
734590ed05d921d6ed7f12012d9786d53f57fafee51aJeff BrownSQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
734690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
734790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
734890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** CAPI3REF: Conflict resolution modes
73499bee60b0fc0b60d4ae9e7533e0e6b7beca5f37fcJeff Brown** KEYWORDS: {conflict resolution mode}
735090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
735190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** These constants are returned by [sqlite3_vtab_on_conflict()] to
735290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** inform a [virtual table] implementation what the [ON CONFLICT] mode
735390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** is for the SQL statement being evaluated.
735490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown**
735590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** Note that the [SQLITE_IGNORE] constant is also used as a potential
735690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** return value from the [sqlite3_set_authorizer()] callback and that
735790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown** [SQLITE_ABORT] is also a [result code].
735890ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown*/
735990ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_ROLLBACK 1
736090ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
736190ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_FAIL     3
736290ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/* #define SQLITE_ABORT 4  // Also an error code */
736390ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown#define SQLITE_REPLACE  5
736490ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
736590ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
736690ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown
736790ed05d921d6ed7f12012d9786d53f57fafee51aJeff Brown/*
7368de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Undo the hack that converts floating point types to integer for
7369de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** builds on processors without floating point support.
7370de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
7371de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef SQLITE_OMIT_FLOATING_POINT
7372de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori# undef double
7373de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
7374de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7375de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef __cplusplus
7376de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori}  /* End of the 'extern "C"' block */
7377de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
73788fecf56c625b5691ee3381e107ccbe1ff42398b1Nick Kralevich#endif /* _SQLITE3_H_ */
7379de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7380de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
7381de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** 2010 August 30
7382de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7383de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** The author disclaims copyright to this source code.  In place of
7384de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** a legal notice, here is a blessing:
7385de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7386de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**    May you do good and not evil.
7387de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**    May you find forgiveness for yourself and forgive others.
7388de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**    May you share freely, never taking more than you give.
7389de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7390de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*************************************************************************
7391de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
7392de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7393de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifndef _SQLITE3RTREE_H_
7394de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#define _SQLITE3RTREE_H_
7395de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7396de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7397de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef __cplusplus
7398de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noriextern "C" {
7399de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
7400de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7401de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noritypedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
74021c7cea379348522163370244e8fbbff8a136b7faNick Kralevichtypedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
74031c7cea379348522163370244e8fbbff8a136b7faNick Kralevich
74041c7cea379348522163370244e8fbbff8a136b7faNick Kralevich/* The double-precision datatype used by RTree depends on the
74051c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** SQLITE_RTREE_INT_ONLY compile-time option.
74061c7cea379348522163370244e8fbbff8a136b7faNick Kralevich*/
74071c7cea379348522163370244e8fbbff8a136b7faNick Kralevich#ifdef SQLITE_RTREE_INT_ONLY
74081c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  typedef sqlite3_int64 sqlite3_rtree_dbl;
74091c7cea379348522163370244e8fbbff8a136b7faNick Kralevich#else
74101c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  typedef double sqlite3_rtree_dbl;
74111c7cea379348522163370244e8fbbff8a136b7faNick Kralevich#endif
7412de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7413de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
7414de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** Register a geometry callback named zGeom that can be used as part of an
7415de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** R-Tree geometry query as follows:
7416de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**
7417de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
7418de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
7419de2b3240539802d409a25760d5cec9d4ebfd6686Vasu NoriSQLITE_API int sqlite3_rtree_geometry_callback(
7420de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  sqlite3 *db,
7421de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  const char *zGeom,
74221c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
7423de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pContext
7424de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori);
7425de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7426de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7427de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori/*
7428de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** A pointer to a structure of the following type is passed as the first
7429de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori** argument to callbacks registered using rtree_geometry_callback().
7430de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori*/
7431de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Noristruct sqlite3_rtree_geometry {
7432de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
7433de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  int nParam;                     /* Size of array aParam[] */
74341c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  sqlite3_rtree_dbl *aParam;      /* Parameters passed to SQL geom function */
7435de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void *pUser;                    /* Callback implementation user data */
7436de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori  void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
7437de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori};
7438de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
74391c7cea379348522163370244e8fbbff8a136b7faNick Kralevich/*
74401c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** Register a 2nd-generation geometry callback named zScore that can be
74411c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** used as part of an R-Tree geometry query as follows:
74421c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**
74431c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
74441c7cea379348522163370244e8fbbff8a136b7faNick Kralevich*/
74451c7cea379348522163370244e8fbbff8a136b7faNick KralevichSQLITE_API int sqlite3_rtree_query_callback(
74461c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  sqlite3 *db,
74471c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  const char *zQueryFunc,
74481c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  int (*xQueryFunc)(sqlite3_rtree_query_info*),
74491c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  void *pContext,
74501c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  void (*xDestructor)(void*)
74511c7cea379348522163370244e8fbbff8a136b7faNick Kralevich);
74521c7cea379348522163370244e8fbbff8a136b7faNick Kralevich
74531c7cea379348522163370244e8fbbff8a136b7faNick Kralevich
74541c7cea379348522163370244e8fbbff8a136b7faNick Kralevich/*
74551c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** A pointer to a structure of the following type is passed as the
74561c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** argument to scored geometry callback registered using
74571c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** sqlite3_rtree_query_callback().
74581c7cea379348522163370244e8fbbff8a136b7faNick Kralevich**
74591c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** Note that the first 5 fields of this structure are identical to
74601c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** sqlite3_rtree_geometry.  This structure is a subclass of
74611c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** sqlite3_rtree_geometry.
74621c7cea379348522163370244e8fbbff8a136b7faNick Kralevich*/
74631c7cea379348522163370244e8fbbff8a136b7faNick Kralevichstruct sqlite3_rtree_query_info {
74641c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  void *pContext;                   /* pContext from when function registered */
74651c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  int nParam;                       /* Number of function parameters */
74661c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  sqlite3_rtree_dbl *aParam;        /* value of function parameters */
74671c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  void *pUser;                      /* callback can use this, if desired */
74681c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  void (*xDelUser)(void*);          /* function to free pUser */
74691c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  sqlite3_rtree_dbl *aCoord;        /* Coordinates of node or entry to check */
74701c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  unsigned int *anQueue;            /* Number of pending entries in the queue */
74711c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  int nCoord;                       /* Number of coordinates */
74721c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  int iLevel;                       /* Level of current node or entry */
74731c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  int mxLevel;                      /* The largest iLevel value in the tree */
74741c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  sqlite3_int64 iRowid;             /* Rowid for current entry */
74751c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  sqlite3_rtree_dbl rParentScore;   /* Score of parent node */
74761c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  int eParentWithin;                /* Visibility of parent node */
74771c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  int eWithin;                      /* OUT: Visiblity */
74781c7cea379348522163370244e8fbbff8a136b7faNick Kralevich  sqlite3_rtree_dbl rScore;         /* OUT: Write the score here */
74791c7cea379348522163370244e8fbbff8a136b7faNick Kralevich};
74801c7cea379348522163370244e8fbbff8a136b7faNick Kralevich
74811c7cea379348522163370244e8fbbff8a136b7faNick Kralevich/*
74821c7cea379348522163370244e8fbbff8a136b7faNick Kralevich** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
74831c7cea379348522163370244e8fbbff8a136b7faNick Kralevich*/
74841c7cea379348522163370244e8fbbff8a136b7faNick Kralevich#define NOT_WITHIN       0   /* Object completely outside of query region */
74851c7cea379348522163370244e8fbbff8a136b7faNick Kralevich#define PARTLY_WITHIN    1   /* Object partially overlaps query region */
74861c7cea379348522163370244e8fbbff8a136b7faNick Kralevich#define FULLY_WITHIN     2   /* Object fully contained within query region */
74871c7cea379348522163370244e8fbbff8a136b7faNick Kralevich
7488de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7489de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#ifdef __cplusplus
7490de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori}  /* end of the 'extern "C"' block */
7491de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif
7492de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7493de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori#endif  /* ifndef _SQLITE3RTREE_H_ */
7494de2b3240539802d409a25760d5cec9d4ebfd6686Vasu Nori
7495