file_util_proxy.h revision 513209b27ff55e2841eac0e4120199c23acce758 
1// Copyright (c) 2010 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef BASE_FILE_UTIL_PROXY_H_
6#define BASE_FILE_UTIL_PROXY_H_
7
8#include <vector>
9
10#include "base/callback.h"
11#include "base/file_path.h"
12#include "base/file_util.h"
13#include "base/platform_file.h"
14#include "base/ref_counted.h"
15#include "base/tracked_objects.h"
16
17namespace base {
18
19class MessageLoopProxy;
20class Time;
21
22// This class provides asynchronous access to common file routines.
23class FileUtilProxy {
24 public:
25  // Holds metadata for file or directory entry. Used by ReadDirectoryCallback.
26  struct Entry {
27    FilePath::StringType name;
28    bool is_directory;
29  };
30
31  // This callback is used by methods that report only an error code.  It is
32  // valid to pass NULL as the callback parameter to any function that takes a
33  // StatusCallback, in which case the operation will complete silently.
34  typedef Callback1<PlatformFileError /* error code */>::Type StatusCallback;
35
36  // Creates or opens a file with the given flags.  It is invalid to pass NULL
37  // for the callback.
38  // If PLATFORM_FILE_CREATE is set in |file_flags| it always tries to create
39  // a new file at the given |file_path| and calls back with
40  // PLATFORM_FILE_ERROR_FILE_EXISTS if the |file_path| already exists.
41  typedef Callback3<PlatformFileError /* error code */,
42                    PassPlatformFile,
43                    bool /* created */>::Type CreateOrOpenCallback;
44  static bool CreateOrOpen(scoped_refptr<MessageLoopProxy> message_loop_proxy,
45                           const FilePath& file_path,
46                           int file_flags,
47                           CreateOrOpenCallback* callback);
48
49  // Creates a temporary file for writing.  The path and an open file handle
50  // are returned.  It is invalid to pass NULL for the callback.
51  typedef Callback3<PlatformFileError /* error code */,
52                    PassPlatformFile,
53                    FilePath>::Type CreateTemporaryCallback;
54  static bool CreateTemporary(
55      scoped_refptr<MessageLoopProxy> message_loop_proxy,
56      CreateTemporaryCallback* callback);
57
58  // Close the given file handle.
59  static bool Close(scoped_refptr<MessageLoopProxy> message_loop_proxy,
60                    PlatformFile,
61                    StatusCallback* callback);
62
63  // Ensures that the given |file_path| exist.  This creates a empty new file
64  // at |file_path| if the |file_path| does not exist.
65  // If a new file han not existed and is created at the |file_path|,
66  // |created| of the callback argument is set true and |error code|
67  // is set PLATFORM_FILE_OK.
68  // If the file already exists, |created| is set false and |error code|
69  // is set PLATFORM_FILE_OK.
70  // If the file hasn't existed but it couldn't be created for some other
71  // reasons, |created| is set false and |error code| indicates the error.
72  typedef Callback2<PlatformFileError /* error code */,
73                    bool /* created */>::Type EnsureFileExistsCallback;
74  static bool EnsureFileExists(
75      scoped_refptr<MessageLoopProxy> message_loop_proxy,
76      const FilePath& file_path,
77      EnsureFileExistsCallback* callback);
78
79  // Retrieves the information about a file. It is invalid to pass NULL for the
80  // callback.
81  typedef Callback2<PlatformFileError /* error code */,
82                    const PlatformFileInfo& /* file_info */
83                    >::Type GetFileInfoCallback;
84  static bool GetFileInfo(
85      scoped_refptr<MessageLoopProxy> message_loop_proxy,
86      const FilePath& file_path,
87      GetFileInfoCallback* callback);
88
89  static bool GetFileInfoFromPlatformFile(
90      scoped_refptr<MessageLoopProxy> message_loop_proxy,
91      PlatformFile file,
92      GetFileInfoCallback* callback);
93
94  typedef Callback2<PlatformFileError /* error code */,
95      const std::vector<Entry>&>::Type ReadDirectoryCallback;
96  static bool ReadDirectory(scoped_refptr<MessageLoopProxy> message_loop_proxy,
97                            const FilePath& file_path,
98                            ReadDirectoryCallback* callback);
99
100  // Copies a file or a directory from |src_file_path| to |dest_file_path|
101  // Error cases:
102  // If destination file doesn't exist or destination's parent
103  // doesn't exists.
104  // If source dir exists but destination path is an existing file.
105  // If source file exists but destination path is an existing directory.
106  // If source is a parent of destination.
107  // If source doesn't exists.
108  static bool Copy(scoped_refptr<MessageLoopProxy> message_loop_proxy,
109                   const FilePath& src_file_path,
110                   const FilePath& dest_file_path,
111                   StatusCallback* callback);
112
113  // Creates directory at given path. It's an error to create
114  // if |exclusive| is true and dir already exists.
115  static bool CreateDirectory(
116      scoped_refptr<MessageLoopProxy> message_loop_proxy,
117      const FilePath& file_path,
118      bool exclusive,
119      bool recursive,
120      StatusCallback* callback);
121
122  // Deletes a file or a directory.
123  // It is an error to delete a non-empty directory with recursive=false.
124  static bool Delete(scoped_refptr<MessageLoopProxy> message_loop_proxy,
125                     const FilePath& file_path,
126                     bool recursive,
127                     StatusCallback* callback);
128
129  // Moves a file or a directory from src_file_path to dest_file_path.
130  // Error cases are similar to Copy method's error cases.
131  static bool Move(
132      scoped_refptr<MessageLoopProxy> message_loop_proxy,
133      const FilePath& src_file_path,
134      const FilePath& dest_file_path,
135      StatusCallback* callback);
136
137  // Deletes a directory and all of its contents.
138  static bool RecursiveDelete(
139      scoped_refptr<MessageLoopProxy> message_loop_proxy,
140      const FilePath& file_path,
141      StatusCallback* callback);
142
143  // Reads from a file. On success, the file pointer is moved to position
144  // |offset + bytes_to_read| in the file. The callback can be NULL.
145  typedef Callback2<PlatformFileError /* error code */,
146                    int /* bytes read/written */>::Type ReadWriteCallback;
147  static bool Read(
148      scoped_refptr<MessageLoopProxy> message_loop_proxy,
149      PlatformFile file,
150      int64 offset,
151      char* buffer,
152      int bytes_to_read,
153      ReadWriteCallback* callback);
154
155  // Writes to a file. If |offset| is greater than the length of the file,
156  // |false| is returned. On success, the file pointer is moved to position
157  // |offset + bytes_to_write| in the file. The callback can be NULL.
158  static bool Write(
159      scoped_refptr<MessageLoopProxy> message_loop_proxy,
160      PlatformFile file,
161      int64 offset,
162      const char* buffer,
163      int bytes_to_write,
164      ReadWriteCallback* callback);
165
166  // Touches a file. The callback can be NULL.
167  static bool Touch(
168      scoped_refptr<MessageLoopProxy> message_loop_proxy,
169      PlatformFile file,
170      const Time& last_access_time,
171      const Time& last_modified_time,
172      StatusCallback* callback);
173
174  // Touches a file. The callback can be NULL.
175  static bool Touch(
176      scoped_refptr<MessageLoopProxy> message_loop_proxy,
177      const FilePath& file_path,
178      const Time& last_access_time,
179      const Time& last_modified_time,
180      StatusCallback* callback);
181
182  // Truncates a file to the given length. If |length| is greater than the
183  // current length of the file, the file will be extended with zeroes.
184  // The callback can be NULL.
185  static bool Truncate(
186      scoped_refptr<MessageLoopProxy> message_loop_proxy,
187      PlatformFile file,
188      int64 length,
189      StatusCallback* callback);
190
191  // Truncates a file to the given length. If |length| is greater than the
192  // current length of the file, the file will be extended with zeroes.
193  // The callback can be NULL.
194  static bool Truncate(
195      scoped_refptr<MessageLoopProxy> message_loop_proxy,
196      const FilePath& path,
197      int64 length,
198      StatusCallback* callback);
199
200  // Flushes a file. The callback can be NULL.
201  static bool Flush(
202      scoped_refptr<MessageLoopProxy> message_loop_proxy,
203      PlatformFile file,
204      StatusCallback* callback);
205
206 private:
207  DISALLOW_IMPLICIT_CONSTRUCTORS(FileUtilProxy);
208};
209
210}  // namespace base
211
212#endif  // BASE_FILE_UTIL_PROXY_H_
213