chrome/browser/media_galleries/linux/mtp_read_file_worker.h

   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 CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_READ_FILE_WORKER_H_
   6 #define CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_READ_FILE_WORKER_H_
   7
   8 #include <string>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "base/platform_file.h"
  14
  15 namespace base {
  16 class FilePath;
  17 }
  18
  19 class SnapshotFileDetails;
  20 struct SnapshotRequestInfo;
  21
  22 // Worker class to copy the contents of the media transfer protocol(MTP) device
  23 // file to the given snapshot file.
  24 class MTPReadFileWorker {
  25  public:
  26   explicit MTPReadFileWorker(const std::string& device_handle);
  27   ~MTPReadFileWorker();
  28
  29   // Dispatches the request to MediaTransferProtocolManager to get the media
  30   // file contents.
  31   //
  32   // |request_info| specifies the snapshot file request params.
  33   // |snapshot_file_info| specifies the metadata of the snapshot file.
  34   void WriteDataIntoSnapshotFile(
  35       const SnapshotRequestInfo& request_info,
  36       const base::PlatformFileInfo& snapshot_file_info);
  37
  38  private:
  39   // Called when WriteDataIntoSnapshotFile() completes.
  40   //
  41   // |snapshot_file_details| contains the current state of the snapshot file
  42   // (such as how many bytes written to the snapshot file, media device file
  43   // path, snapshot file path, bytes remaining, etc).
  44   //
  45   // If there is an error, |snapshot_file_details.error_callback| is invoked on
  46   // the IO thread to notify the caller about the failure.
  47   //
  48   // If there is no error, |snapshot_file_details.success_callback| is invoked
  49   // on the IO thread to notify the caller about the success.
  50   void OnDidWriteIntoSnapshotFile(
  51       scoped_ptr<SnapshotFileDetails> snapshot_file_details);
  52
  53   // Dispatches the request to MediaTransferProtocolManager to get the device
  54   // media file data chunk based on the parameters in |snapshot_file_details|.
  55   void ReadDataChunkFromDeviceFile(
  56       scoped_ptr<SnapshotFileDetails> snapshot_file_details);
  57
  58   // Called when ReadDataChunkFromDeviceFile() completes.
  59   //
  60   // If there is no error, |data| will contain the data chunk and |error| is
  61   // set to false.
  62   //
  63   // If there is an error, |data| is empty and |error| is set to true.
  64   void OnDidReadDataChunkFromDeviceFile(
  65       scoped_ptr<SnapshotFileDetails> snapshot_file_details,
  66       const std::string& data,
  67       bool error);
  68
  69   // Called when the data chunk is written to the
  70   // |snapshot_file_details_.snapshot_file_path|.
  71   //
  72   // If the write operation succeeds, |bytes_written| is set to a non-zero
  73   // value.
  74   //
  75   // If the write operation fails, |bytes_written| is set to zero.
  76   void OnDidWriteDataChunkIntoSnapshotFile(
  77       scoped_ptr<SnapshotFileDetails> snapshot_file_details,
  78       uint32 bytes_written);
  79
  80   // The device unique identifier to query the device.
  81   const std::string device_handle_;
  82
  83   // For callbacks that may run after destruction.
  84   base::WeakPtrFactory<MTPReadFileWorker> weak_ptr_factory_;
  85
  86   DISALLOW_COPY_AND_ASSIGN(MTPReadFileWorker);
  87 };
  88
  89 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_READ_FILE_WORKER_H_