base/file_util_proxy.h

   1 // Copyright (c) 2011 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/base_api.h"
  11 #include "base/callback_old.h"
  12 #include "base/file_path.h"
  13 #include "base/file_util.h"
  14 #include "base/memory/ref_counted.h"
  15 #include "base/platform_file.h"
  16 #include "base/tracked_objects.h"
  17
  18 namespace base {
  19
  20 class MessageLoopProxy;
  21 class Time;
  22
  23 // This class provides asynchronous access to common file routines.
  24 class BASE_API FileUtilProxy {
  25  public:
  26   // Holds metadata for file or directory entry. Used by ReadDirectoryCallback.
  27   struct Entry {
  28     FilePath::StringType name;
  29     bool is_directory;
  30   };
  31
  32   // This callback is used by methods that report only an error code.  It is
  33   // valid to pass NULL as the callback parameter to any function that takes a
  34   // StatusCallback, in which case the operation will complete silently.
  35   typedef Callback1<PlatformFileError /* error code */>::Type StatusCallback;
  36
  37   typedef Callback3<PlatformFileError /* error code */,
  38                     PassPlatformFile,
  39                     bool /* created */>::Type CreateOrOpenCallback;
  40   typedef Callback3<PlatformFileError /* error code */,
  41                     PassPlatformFile,
  42                     FilePath>::Type CreateTemporaryCallback;
  43   typedef Callback2<PlatformFileError /* error code */,
  44                     bool /* created */>::Type EnsureFileExistsCallback;
  45   typedef Callback2<PlatformFileError /* error code */,
  46                     const PlatformFileInfo& /* file_info */
  47                     >::Type GetFileInfoCallback;
  48   typedef Callback2<PlatformFileError /* error code */,
  49                     const std::vector<Entry>&>::Type ReadDirectoryCallback;
  50   typedef Callback3<PlatformFileError /* error code */,
  51                     const char* /* data */,
  52                     int /* bytes read/written */>::Type ReadCallback;
  53   typedef Callback2<PlatformFileError /* error code */,
  54                     int /* bytes written */>::Type WriteCallback;
  55
  56   // Creates or opens a file with the given flags.  It is invalid to pass NULL
  57   // for the callback.
  58   // If PLATFORM_FILE_CREATE is set in |file_flags| it always tries to create
  59   // a new file at the given |file_path| and calls back with
  60   // PLATFORM_FILE_ERROR_FILE_EXISTS if the |file_path| already exists.
  61   static bool CreateOrOpen(scoped_refptr<MessageLoopProxy> message_loop_proxy,
  62                            const FilePath& file_path,
  63                            int file_flags,
  64                            CreateOrOpenCallback* callback);
  65
  66   // Creates a temporary file for writing.  The path and an open file handle
  67   // are returned.  It is invalid to pass NULL for the callback.  The additional
  68   // file flags will be added on top of the default file flags which are:
  69   //   base::PLATFORM_FILE_CREATE_ALWAYS
  70   //   base::PLATFORM_FILE_WRITE
  71   //   base::PLATFORM_FILE_TEMPORARY.
  72   // Set |additional_file_flags| to 0 for synchronous writes and set to
  73   // base::PLATFORM_FILE_ASYNC to support asynchronous file operations.
  74   static bool CreateTemporary(
  75       scoped_refptr<MessageLoopProxy> message_loop_proxy,
  76       int additional_file_flags,
  77       CreateTemporaryCallback* callback);
  78
  79   // Close the given file handle.
  80   static bool Close(scoped_refptr<MessageLoopProxy> message_loop_proxy,
  81                     PlatformFile,
  82                     StatusCallback* callback);
  83
  84   // Ensures that the given |file_path| exist.  This creates a empty new file
  85   // at |file_path| if the |file_path| does not exist.
  86   // If a new file han not existed and is created at the |file_path|,
  87   // |created| of the callback argument is set true and |error code|
  88   // is set PLATFORM_FILE_OK.
  89   // If the file already exists, |created| is set false and |error code|
  90   // is set PLATFORM_FILE_OK.
  91   // If the file hasn't existed but it couldn't be created for some other
  92   // reasons, |created| is set false and |error code| indicates the error.
  93   static bool EnsureFileExists(
  94       scoped_refptr<MessageLoopProxy> message_loop_proxy,
  95       const FilePath& file_path,
  96       EnsureFileExistsCallback* callback);
  97
  98   // Retrieves the information about a file. It is invalid to pass NULL for the
  99   // callback.
 100   static bool GetFileInfo(
 101       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 102       const FilePath& file_path,
 103       GetFileInfoCallback* callback);
 104
 105   static bool GetFileInfoFromPlatformFile(
 106       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 107       PlatformFile file,
 108       GetFileInfoCallback* callback);
 109
 110   static bool ReadDirectory(scoped_refptr<MessageLoopProxy> message_loop_proxy,
 111                             const FilePath& file_path,
 112                             ReadDirectoryCallback* callback);
 113
 114   // Creates directory at given path. It's an error to create
 115   // if |exclusive| is true and dir already exists.
 116   static bool CreateDirectory(
 117       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 118       const FilePath& file_path,
 119       bool exclusive,
 120       bool recursive,
 121       StatusCallback* callback);
 122
 123   // Copies a file or a directory from |src_file_path| to |dest_file_path|
 124   // Error cases:
 125   // If destination file doesn't exist or destination's parent
 126   // doesn't exists.
 127   // If source dir exists but destination path is an existing file.
 128   // If source file exists but destination path is an existing directory.
 129   // If source is a parent of destination.
 130   // If source doesn't exists.
 131   static bool Copy(scoped_refptr<MessageLoopProxy> message_loop_proxy,
 132                    const FilePath& src_file_path,
 133                    const FilePath& dest_file_path,
 134                    StatusCallback* callback);
 135
 136   // Moves a file or a directory from src_file_path to dest_file_path.
 137   // Error cases are similar to Copy method's error cases.
 138   static bool Move(
 139       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 140       const FilePath& src_file_path,
 141       const FilePath& dest_file_path,
 142       StatusCallback* callback);
 143
 144   // Deletes a file or a directory.
 145   // It is an error to delete a non-empty directory with recursive=false.
 146   static bool Delete(scoped_refptr<MessageLoopProxy> message_loop_proxy,
 147                      const FilePath& file_path,
 148                      bool recursive,
 149                      StatusCallback* callback);
 150
 151   // Deletes a directory and all of its contents.
 152   static bool RecursiveDelete(
 153       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 154       const FilePath& file_path,
 155       StatusCallback* callback);
 156
 157   // Reads from a file. On success, the file pointer is moved to position
 158   // |offset + bytes_to_read| in the file. The callback can be NULL.
 159   static bool Read(
 160       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 161       PlatformFile file,
 162       int64 offset,
 163       int bytes_to_read,
 164       ReadCallback* callback);
 165
 166   // Writes to a file. If |offset| is greater than the length of the file,
 167   // |false| is returned. On success, the file pointer is moved to position
 168   // |offset + bytes_to_write| in the file. The callback can be NULL.
 169   static bool Write(
 170       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 171       PlatformFile file,
 172       int64 offset,
 173       const char* buffer,
 174       int bytes_to_write,
 175       WriteCallback* callback);
 176
 177   // Touches a file. The callback can be NULL.
 178   static bool Touch(
 179       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 180       PlatformFile file,
 181       const Time& last_access_time,
 182       const Time& last_modified_time,
 183       StatusCallback* callback);
 184
 185   // Touches a file. The callback can be NULL.
 186   static bool Touch(
 187       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 188       const FilePath& file_path,
 189       const Time& last_access_time,
 190       const Time& last_modified_time,
 191       StatusCallback* callback);
 192
 193   // Truncates a file to the given length. If |length| is greater than the
 194   // current length of the file, the file will be extended with zeroes.
 195   // The callback can be NULL.
 196   static bool Truncate(
 197       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 198       PlatformFile file,
 199       int64 length,
 200       StatusCallback* callback);
 201
 202   // Truncates a file to the given length. If |length| is greater than the
 203   // current length of the file, the file will be extended with zeroes.
 204   // The callback can be NULL.
 205   static bool Truncate(
 206       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 207       const FilePath& path,
 208       int64 length,
 209       StatusCallback* callback);
 210
 211   // Flushes a file. The callback can be NULL.
 212   static bool Flush(
 213       scoped_refptr<MessageLoopProxy> message_loop_proxy,
 214       PlatformFile file,
 215       StatusCallback* callback);
 216
 217  private:
 218   DISALLOW_IMPLICIT_CONSTRUCTORS(FileUtilProxy);
 219 };
 220
 221 }  // namespace base
 222
 223 #endif  // BASE_FILE_UTIL_PROXY_H_