1/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2/*
3 * The contents of this file are subject to the Mozilla Public
4 * License Version 1.1 (the "License"); you may not use this file
5 * except in compliance with the License. You may obtain a copy of
6 * the License at http://www.mozilla.org/MPL/
7 *
8 * Software distributed under the License is distributed on an "AS
9 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
10 * implied. See the License for the specific language governing
11 * rights and limitations under the License.
12 *
13 * The Original Code is the Netscape Portable Runtime (NSPR).
14 *
15 * The Initial Developer of the Original Code is Netscape
16 * Communications Corporation.  Portions created by Netscape are
17 * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
18 * Rights Reserved.
19 *
20 * Contributor(s):
21 *
22 * Alternatively, the contents of this file may be used under the
23 * terms of the GNU General Public License Version 2 or later (the
24 * "GPL"), in which case the provisions of the GPL are applicable
25 * instead of those above.  If you wish to allow use of your
26 * version of this file only under the terms of the GPL and not to
27 * allow others to use your version of this file under the MPL,
28 * indicate your decision by deleting the provisions above and
29 * replace them with the notice and other provisions required by
30 * the GPL.  If you do not delete the provisions above, a recipient
31 * may use your version of this file under either the MPL or the
32 * GPL.
33 */
34
35#ifndef prerror_h___
36#define prerror_h___
37
38#include "prtypes.h"
39
40PR_BEGIN_EXTERN_C
41
42typedef PRInt32 PRErrorCode;
43
44#define PR_NSPR_ERROR_BASE -6000
45
46#include "prerr.h"
47
48/*
49** Set error will preserve an error condition within a thread context.
50** The values stored are the NSPR (platform independent) translation of
51** the error. Also, if available, the platform specific oserror is stored.
52** If there is no appropriate OS error number, a zero my be supplied.
53*/
54NSPR_API(void) PR_SetError(PRErrorCode errorCode, PRInt32 oserr);
55
56/*
57** The text value specified may be NULL. If it is not NULL and the text length
58** is zero, the string is assumed to be a null terminated C string. Otherwise
59** the text is assumed to be the length specified and possibly include NULL
60** characters (e.g., a multi-national string).
61**
62** The text will be copied into to thread structure and remain there
63** until the next call to PR_SetError.
64*/
65NSPR_API(void) PR_SetErrorText(
66    PRIntn textLength, const char *text);
67
68/*
69** Return the current threads last set error code.
70*/
71NSPR_API(PRErrorCode) PR_GetError(void);
72
73/*
74** Return the current threads last set os error code. This is used for
75** machine specific code that desires the underlying os error.
76*/
77NSPR_API(PRInt32) PR_GetOSError(void);
78
79/*
80** Get the length of the error text. If a zero is returned, then there
81** is no text. Otherwise, the value returned is sufficient to contain
82** the error text currently available.
83*/
84NSPR_API(PRInt32) PR_GetErrorTextLength(void);
85
86/*
87** Copy the current threads current error text. Then actual number of bytes
88** copied is returned as the result. If the result is zero, the 'text' area
89** is unaffected.
90*/
91NSPR_API(PRInt32) PR_GetErrorText(char *text);
92
93
94/*
95Copyright (C) 1987, 1988 Student Information Processing Board of the
96Massachusetts Institute of Technology.
97
98Permission to use, copy, modify, and distribute this software and its
99documentation for any purpose and without fee is hereby granted, provided
100that the above copyright notice appear in all copies and that both that
101copyright notice and this permission notice appear in supporting
102documentation, and that the names of M.I.T. and the M.I.T. S.I.P.B. not be
103used in advertising or publicity pertaining to distribution of the software
104without specific, written prior permission.  M.I.T. and the M.I.T. S.I.P.B.
105make no representations about the suitability of this software for any
106purpose.  It is provided "as is" without express or implied warranty.
107*/
108
109
110/*
111 * NOTE:
112 *		The interfaces for error-code-translation described in the rest of
113 *		this file are preliminary in the 3.1 release of nspr and are subject
114 *		to change in future releases.
115 */
116
117/*
118** Description:	Localizable error code to string function.
119**
120**
121** NSPR provides a mechanism for converting an error code to a
122** descriptive string, in a caller-specified language.
123**
124** Error codes themselves are 32 bit (signed) integers.  Typically,
125** the high order 24 bits are an identifier of which error table the
126** error code is from, and the low order 8 bits are a sequential error
127** number within the table.  NSPR supports error tables whose first
128** error code is not a multiple of 256, such error code assignments
129** should be avoided when possible.
130**
131** Error table 0 is defined to match the UNIX system call error table
132** (sys_errlist); this allows errno values to be used directly in the
133** library.  Other error table numbers are typically formed by
134** compacting together the first four characters of the error table
135** name.  The mapping between characters in the name and numeric
136** values in the error code are defined in a system-independent
137** fashion, so that two systems that can pass integral values between
138** them can reliably pass error codes without loss of meaning; this
139** should work even if the character sets used are not the
140** same. (However, if this is to be done, error table 0 should be
141** avoided, since the local system call error tables may differ.)
142**
143** Libraries defining error codes need only provide a table mapping
144** error code numbers to names and default English descriptions,
145** calling a routine to install the table, making it ``known'' to NSPR
146** library.  Once installed, a table may not be removed.  Any error
147** code the library generates can be converted to the corresponding
148** error message.  There is also a default format for error codes
149** accidentally returned before making the table known, which is of
150** the form "unknown code foo 32", where "foo" would be the name of
151** the table.
152**
153** Normally, the error code conversion routine only supports the
154** languages "i-default" and "en", returning the error-table-provided
155** English description for both languages.  The application may
156** provide a localization plugin, allowing support for additional
157** languages.
158**
159**/
160
161/**********************************************************************/
162/************************* TYPES AND CONSTANTS ************************/
163/**********************************************************************/
164
165/*
166 * PRLanguageCode --
167 *
168 *    NSPR represents a language code as a non-negative integer.
169 *    Languages 0 is always "i-default" the language you get without
170 *    explicit negotiation.  Language 1 is always "en", English
171 *    which has been explicitly negotiated.  Additional language
172 *    codes are defined by an application-provided localization plugin.
173 */
174typedef PRUint32 PRLanguageCode;
175#define PR_LANGUAGE_I_DEFAULT 0 /* i-default, the default language */
176#define PR_LANGUAGE_EN 1 /* English, explicitly negotiated */
177
178/*
179 * struct PRErrorMessage --
180 *
181 *    An error message in an error table.
182 */
183struct PRErrorMessage {
184    const char * name;    /* Macro name for error */
185    const char * en_text; /* Default English text */
186};
187
188/*
189 * struct PRErrorTable --
190 *
191 *    An error table, provided by a library.
192 */
193struct PRErrorTable {
194    const struct PRErrorMessage * msgs; /* Array of error information */
195    const char *name; /* Name of error table source */
196    PRErrorCode base; /* Error code for first error in table */
197    int n_msgs; /* Number of codes in table */
198};
199
200/*
201 * struct PRErrorCallbackPrivate --
202 *
203 *    A private structure for the localization plugin
204 */
205struct PRErrorCallbackPrivate;
206
207/*
208 * struct PRErrorCallbackTablePrivate --
209 *
210 *    A data structure under which the localization plugin may store information,
211 *    associated with an error table, that is private to itself.
212 */
213struct PRErrorCallbackTablePrivate;
214
215/*
216 * PRErrorCallbackLookupFn --
217 *
218 *    A function of PRErrorCallbackLookupFn type is a localization
219 *    plugin callback which converts an error code into a description
220 *    in the requested language.  The callback is provided the
221 *    appropriate error table, private data for the plugin and the table.
222 *    The callback returns the appropriate UTF-8 encoded description, or NULL
223 *    if no description can be found.
224 */
225typedef const char *
226PRErrorCallbackLookupFn(PRErrorCode code, PRLanguageCode language,
227		   const struct PRErrorTable *table,
228		   struct PRErrorCallbackPrivate *cb_private,
229		   struct PRErrorCallbackTablePrivate *table_private);
230
231/*
232 * PRErrorCallbackNewTableFn --
233 *
234 *    A function PRErrorCallbackNewTableFn type is a localization plugin
235 *    callback which is called once with each error table registered
236 *    with NSPR.  The callback is provided with the error table and
237 *    the plugin's private structure.  The callback returns any table private
238 *    data it wishes to associate with the error table.  Does not need to be thread
239 *    safe.
240 */
241typedef struct PRErrorCallbackTablePrivate *
242PRErrorCallbackNewTableFn(const struct PRErrorTable *table,
243			struct PRErrorCallbackPrivate *cb_private);
244
245/**********************************************************************/
246/****************************** FUNCTIONS *****************************/
247/**********************************************************************/
248
249/***********************************************************************
250** FUNCTION:    PR_ErrorToString
251** DESCRIPTION:
252**  Returns the UTF-8 message for an error code in
253**  the requested language.  May return the message
254**  in the default language if a translation in the requested
255**  language is not available.  The returned string is
256**  valid for the duration of the process.  Never returns NULL.
257**
258***********************************************************************/
259NSPR_API(const char *) PR_ErrorToString(PRErrorCode code,
260    PRLanguageCode language);
261
262
263/***********************************************************************
264** FUNCTION:    PR_ErrorToName
265** DESCRIPTION:
266**  Returns the macro name for an error code, or NULL
267**  if the error code is not known.  The returned string is
268**  valid for the duration of the process.
269**
270**  Does not work for error table 0, the system error codes.
271**
272***********************************************************************/
273NSPR_API(const char *) PR_ErrorToName(PRErrorCode code);
274
275
276/***********************************************************************
277** FUNCTION:    PR_ErrorLanguages
278** DESCRIPTION:
279**  Returns the RFC 1766 language tags for the language
280**  codes PR_ErrorToString() supports.  The returned array is valid
281**  for the duration of the process.  Never returns NULL.  The first
282**  item in the returned array is the language tag for PRLanguageCode 0,
283**  the second is for PRLanguageCode 1, and so on.  The array is terminated
284**  with a null pointer.
285**
286***********************************************************************/
287NSPR_API(const char * const *) PR_ErrorLanguages(void);
288
289
290/***********************************************************************
291** FUNCTION:    PR_ErrorInstallTable
292** DESCRIPTION:
293**  Registers an error table with NSPR.  Must be done exactly once per
294**  table.  Memory pointed to by `table' must remain valid for the life
295**  of the process.
296**
297**  NOT THREAD SAFE!
298**
299***********************************************************************/
300NSPR_API(PRErrorCode) PR_ErrorInstallTable(const struct PRErrorTable *table);
301
302
303/***********************************************************************
304** FUNCTION:    PR_ErrorInstallCallback
305** DESCRIPTION:
306**  Registers an error localization plugin with NSPR.  May be called
307**  at most one time.  `languages' contains the language codes supported
308**  by this plugin.  Languages 0 and 1 must be "i-default" and "en"
309**  respectively.  `lookup' and `newtable' contain pointers to
310**  the plugin callback functions.  `cb_private' contains any information
311**  private to the plugin functions.
312**
313**  NOT THREAD SAFE!
314**
315***********************************************************************/
316NSPR_API(void) PR_ErrorInstallCallback(const char * const * languages,
317			      PRErrorCallbackLookupFn *lookup,
318			      PRErrorCallbackNewTableFn *newtable,
319			      struct PRErrorCallbackPrivate *cb_private);
320
321PR_END_EXTERN_C
322
323#endif /* prerror_h___ */
324