1 // Copyright (c) 2012 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_FILES_FILE_UTIL_PROXY_H_ 6 #define BASE_FILES_FILE_UTIL_PROXY_H_ 7 8 #include "base/base_export.h" 9 #include "base/callback_forward.h" 10 #include "base/files/file_path.h" 11 #include "base/memory/ref_counted.h" 12 #include "base/platform_file.h" 13 14 namespace tracked_objects { 15 class Location; 16 }; 17 18 namespace base { 19 20 class TaskRunner; 21 class Time; 22 23 // This class provides asynchronous access to common file routines. 24 class BASE_EXPORT FileUtilProxy { 25 public: 26 // This callback is used by methods that report only an error code. It is 27 // valid to pass a null callback to any function that takes a StatusCallback, 28 // in which case the operation will complete silently. 29 typedef Callback<void(PlatformFileError)> StatusCallback; 30 31 typedef Callback<void(PlatformFileError, 32 PassPlatformFile, 33 bool /* created */)> CreateOrOpenCallback; 34 typedef Callback<void(PlatformFileError, 35 PassPlatformFile, 36 const FilePath&)> CreateTemporaryCallback; 37 typedef Callback<void(PlatformFileError, 38 const PlatformFileInfo&)> GetFileInfoCallback; 39 typedef Callback<void(PlatformFileError, 40 const char* /* data */, 41 int /* bytes read */)> ReadCallback; 42 typedef Callback<void(PlatformFileError, 43 int /* bytes written */)> WriteCallback; 44 45 typedef Callback<PlatformFileError(PlatformFile*, bool*)> CreateOrOpenTask; 46 typedef Callback<PlatformFileError(PlatformFile)> CloseTask; 47 typedef Callback<PlatformFileError(void)> FileTask; 48 49 // Creates or opens a file with the given flags. It is invalid to pass a null 50 // callback. If PLATFORM_FILE_CREATE is set in |file_flags| it always tries to 51 // create a new file at the given |file_path| and calls back with 52 // PLATFORM_FILE_ERROR_FILE_EXISTS if the |file_path| already exists. 53 // 54 // This returns false if task posting to |task_runner| has failed. 55 static bool CreateOrOpen(TaskRunner* task_runner, 56 const FilePath& file_path, 57 int file_flags, 58 const CreateOrOpenCallback& callback); 59 60 // Creates a temporary file for writing. The path and an open file handle are 61 // returned. It is invalid to pass a null callback. The additional file flags 62 // will be added on top of the default file flags which are: 63 // base::PLATFORM_FILE_CREATE_ALWAYS 64 // base::PLATFORM_FILE_WRITE 65 // base::PLATFORM_FILE_TEMPORARY. 66 // Set |additional_file_flags| to 0 for synchronous writes and set to 67 // base::PLATFORM_FILE_ASYNC to support asynchronous file operations. 68 // 69 // This returns false if task posting to |task_runner| has failed. 70 static bool CreateTemporary( 71 TaskRunner* task_runner, 72 int additional_file_flags, 73 const CreateTemporaryCallback& callback); 74 75 // Close the given file handle. 76 // This returns false if task posting to |task_runner| has failed. 77 static bool Close(TaskRunner* task_runner, 78 PlatformFile, 79 const StatusCallback& callback); 80 81 // Retrieves the information about a file. It is invalid to pass a null 82 // callback. 83 // This returns false if task posting to |task_runner| has failed. 84 static bool GetFileInfo( 85 TaskRunner* task_runner, 86 const FilePath& file_path, 87 const GetFileInfoCallback& callback); 88 89 // Does the same as GetFileInfo but takes PlatformFile instead of FilePath. 90 // This returns false if task posting to |task_runner| has failed. 91 static bool GetFileInfoFromPlatformFile( 92 TaskRunner* task_runner, 93 PlatformFile file, 94 const GetFileInfoCallback& callback); 95 96 // Deletes a file or a directory. 97 // It is an error to delete a non-empty directory with recursive=false. 98 // This returns false if task posting to |task_runner| has failed. 99 static bool DeleteFile(TaskRunner* task_runner, 100 const FilePath& file_path, 101 bool recursive, 102 const StatusCallback& callback); 103 104 // Reads from a file. On success, the file pointer is moved to position 105 // |offset + bytes_to_read| in the file. The callback can be null. 106 // 107 // This returns false if |bytes_to_read| is less than zero, or 108 // if task posting to |task_runner| has failed. 109 static bool Read( 110 TaskRunner* task_runner, 111 PlatformFile file, 112 int64 offset, 113 int bytes_to_read, 114 const ReadCallback& callback); 115 116 // Writes to a file. If |offset| is greater than the length of the file, 117 // |false| is returned. On success, the file pointer is moved to position 118 // |offset + bytes_to_write| in the file. The callback can be null. 119 // |bytes_to_write| must be greater than zero. 120 // 121 // This returns false if |bytes_to_write| is less than or equal to zero, 122 // if |buffer| is NULL, or if task posting to |task_runner| has failed. 123 static bool Write( 124 TaskRunner* task_runner, 125 PlatformFile file, 126 int64 offset, 127 const char* buffer, 128 int bytes_to_write, 129 const WriteCallback& callback); 130 131 // Touches a file. The callback can be null. 132 // This returns false if task posting to |task_runner| has failed. 133 static bool Touch( 134 TaskRunner* task_runner, 135 PlatformFile file, 136 const Time& last_access_time, 137 const Time& last_modified_time, 138 const StatusCallback& callback); 139 140 // Touches a file. The callback can be null. 141 // This returns false if task posting to |task_runner| has failed. 142 static bool Touch( 143 TaskRunner* task_runner, 144 const FilePath& file_path, 145 const Time& last_access_time, 146 const Time& last_modified_time, 147 const StatusCallback& callback); 148 149 // Truncates a file to the given length. If |length| is greater than the 150 // current length of the file, the file will be extended with zeroes. 151 // The callback can be null. 152 // This returns false if task posting to |task_runner| has failed. 153 static bool Truncate( 154 TaskRunner* task_runner, 155 PlatformFile file, 156 int64 length, 157 const StatusCallback& callback); 158 159 // Truncates a file to the given length. If |length| is greater than the 160 // current length of the file, the file will be extended with zeroes. 161 // The callback can be null. 162 // This returns false if task posting to |task_runner| has failed. 163 static bool Truncate( 164 TaskRunner* task_runner, 165 const FilePath& path, 166 int64 length, 167 const StatusCallback& callback); 168 169 // Flushes a file. The callback can be null. 170 // This returns false if task posting to |task_runner| has failed. 171 static bool Flush( 172 TaskRunner* task_runner, 173 PlatformFile file, 174 const StatusCallback& callback); 175 176 // Relay helpers. 177 // They return false if posting a given task to |task_runner| has failed. 178 static bool RelayCreateOrOpen( 179 TaskRunner* task_runner, 180 const CreateOrOpenTask& open_task, 181 const CloseTask& close_task, 182 const CreateOrOpenCallback& callback); 183 static bool RelayClose( 184 TaskRunner* task_runner, 185 const CloseTask& close_task, 186 PlatformFile, 187 const StatusCallback& callback); 188 189 private: 190 DISALLOW_IMPLICIT_CONSTRUCTORS(FileUtilProxy); 191 }; 192 193 } // namespace base 194 195 #endif // BASE_FILES_FILE_UTIL_PROXY_H_ 196
