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      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.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.
     68   static bool CreateTemporary(
     69       scoped_refptr<MessageLoopProxy> message_loop_proxy,
     70       CreateTemporaryCallback* callback);
     71 
     72   // Close the given file handle.
     73   static bool Close(scoped_refptr<MessageLoopProxy> message_loop_proxy,
     74                     PlatformFile,
     75                     StatusCallback* callback);
     76 
     77   // Ensures that the given |file_path| exist.  This creates a empty new file
     78   // at |file_path| if the |file_path| does not exist.
     79   // If a new file han not existed and is created at the |file_path|,
     80   // |created| of the callback argument is set true and |error code|
     81   // is set PLATFORM_FILE_OK.
     82   // If the file already exists, |created| is set false and |error code|
     83   // is set PLATFORM_FILE_OK.
     84   // If the file hasn't existed but it couldn't be created for some other
     85   // reasons, |created| is set false and |error code| indicates the error.
     86   static bool EnsureFileExists(
     87       scoped_refptr<MessageLoopProxy> message_loop_proxy,
     88       const FilePath& file_path,
     89       EnsureFileExistsCallback* callback);
     90 
     91   // Retrieves the information about a file. It is invalid to pass NULL for the
     92   // callback.
     93   static bool GetFileInfo(
     94       scoped_refptr<MessageLoopProxy> message_loop_proxy,
     95       const FilePath& file_path,
     96       GetFileInfoCallback* callback);
     97 
     98   static bool GetFileInfoFromPlatformFile(
     99       scoped_refptr<MessageLoopProxy> message_loop_proxy,
    100       PlatformFile file,
    101       GetFileInfoCallback* callback);
    102 
    103   static bool ReadDirectory(scoped_refptr<MessageLoopProxy> message_loop_proxy,
    104                             const FilePath& file_path,
    105                             ReadDirectoryCallback* callback);
    106 
    107   // Creates directory at given path. It's an error to create
    108   // if |exclusive| is true and dir already exists.
    109   static bool CreateDirectory(
    110       scoped_refptr<MessageLoopProxy> message_loop_proxy,
    111       const FilePath& file_path,
    112       bool exclusive,
    113       bool recursive,
    114       StatusCallback* callback);
    115 
    116   // Copies a file or a directory from |src_file_path| to |dest_file_path|
    117   // Error cases:
    118   // If destination file doesn't exist or destination's parent
    119   // doesn't exists.
    120   // If source dir exists but destination path is an existing file.
    121   // If source file exists but destination path is an existing directory.
    122   // If source is a parent of destination.
    123   // If source doesn't exists.
    124   static bool Copy(scoped_refptr<MessageLoopProxy> message_loop_proxy,
    125                    const FilePath& src_file_path,
    126                    const FilePath& dest_file_path,
    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 file or a directory.
    138   // It is an error to delete a non-empty directory with recursive=false.
    139   static bool Delete(scoped_refptr<MessageLoopProxy> message_loop_proxy,
    140                      const FilePath& file_path,
    141                      bool recursive,
    142                      StatusCallback* callback);
    143 
    144   // Deletes a directory and all of its contents.
    145   static bool RecursiveDelete(
    146       scoped_refptr<MessageLoopProxy> message_loop_proxy,
    147       const FilePath& file_path,
    148       StatusCallback* callback);
    149 
    150   // Reads from a file. On success, the file pointer is moved to position
    151   // |offset + bytes_to_read| in the file. The callback can be NULL.
    152   static bool Read(
    153       scoped_refptr<MessageLoopProxy> message_loop_proxy,
    154       PlatformFile file,
    155       int64 offset,
    156       int bytes_to_read,
    157       ReadCallback* callback);
    158 
    159   // Writes to a file. If |offset| is greater than the length of the file,
    160   // |false| is returned. On success, the file pointer is moved to position
    161   // |offset + bytes_to_write| in the file. The callback can be NULL.
    162   static bool Write(
    163       scoped_refptr<MessageLoopProxy> message_loop_proxy,
    164       PlatformFile file,
    165       int64 offset,
    166       const char* buffer,
    167       int bytes_to_write,
    168       WriteCallback* callback);
    169 
    170   // Touches a file. The callback can be NULL.
    171   static bool Touch(
    172       scoped_refptr<MessageLoopProxy> message_loop_proxy,
    173       PlatformFile file,
    174       const Time& last_access_time,
    175       const Time& last_modified_time,
    176       StatusCallback* callback);
    177 
    178   // Touches a file. The callback can be NULL.
    179   static bool Touch(
    180       scoped_refptr<MessageLoopProxy> message_loop_proxy,
    181       const FilePath& file_path,
    182       const Time& last_access_time,
    183       const Time& last_modified_time,
    184       StatusCallback* callback);
    185 
    186   // Truncates a file to the given length. If |length| is greater than the
    187   // current length of the file, the file will be extended with zeroes.
    188   // The callback can be NULL.
    189   static bool Truncate(
    190       scoped_refptr<MessageLoopProxy> message_loop_proxy,
    191       PlatformFile file,
    192       int64 length,
    193       StatusCallback* callback);
    194 
    195   // Truncates a file to the given length. If |length| is greater than the
    196   // current length of the file, the file will be extended with zeroes.
    197   // The callback can be NULL.
    198   static bool Truncate(
    199       scoped_refptr<MessageLoopProxy> message_loop_proxy,
    200       const FilePath& path,
    201       int64 length,
    202       StatusCallback* callback);
    203 
    204   // Flushes a file. The callback can be NULL.
    205   static bool Flush(
    206       scoped_refptr<MessageLoopProxy> message_loop_proxy,
    207       PlatformFile file,
    208       StatusCallback* callback);
    209 
    210  private:
    211   DISALLOW_IMPLICIT_CONSTRUCTORS(FileUtilProxy);
    212 };
    213 
    214 }  // namespace base
    215 
    216 #endif  // BASE_FILE_UTIL_PROXY_H_
    217