chrome/browser/media_galleries/linux/mtp_device_task_helper.h

   1 // Copyright 2013 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_DEVICE_TASK_HELPER_H_
   6 #define CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_DEVICE_TASK_HELPER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/callback.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/memory/weak_ptr.h"
  14 #include "chrome/browser/media_galleries/fileapi/mtp_device_async_delegate.h"
  15 #include "device/media_transfer_protocol/mtp_file_entry.pb.h"
  16 #include "storage/browser/fileapi/async_file_util.h"
  17
  18 class MTPReadFileWorker;
  19 struct SnapshotRequestInfo;
  20
  21 // MTPDeviceTaskHelper dispatches the media transfer protocol (MTP) device
  22 // operation requests (such as GetFileInfo, ReadDirectory, CreateSnapshotFile,
  23 // OpenStorage and CloseStorage) to the MediaTransferProtocolManager.
  24 // MTPDeviceTaskHelper lives on the UI thread. MTPDeviceTaskHelperMapService
  25 // owns the MTPDeviceTaskHelper objects. MTPDeviceTaskHelper is instantiated per
  26 // MTP device storage.
  27 class MTPDeviceTaskHelper {
  28  public:
  29   typedef base::Callback<void(bool succeeded)> OpenStorageCallback;
  30
  31   typedef MTPDeviceAsyncDelegate::GetFileInfoSuccessCallback
  32       GetFileInfoSuccessCallback;
  33
  34   // NOTE: The file names in the entry list have their file id appended at the
  35   // end. e.g. foo.jpg with file id 45 becomes foo.jpg,45.
  36   typedef base::Callback<void(const storage::AsyncFileUtil::EntryList& entries,
  37                               bool has_more)> ReadDirectorySuccessCallback;
  38
  39   typedef MTPDeviceAsyncDelegate::ErrorCallback ErrorCallback;
  40
  41   MTPDeviceTaskHelper();
  42   ~MTPDeviceTaskHelper();
  43
  44   // Dispatches the request to the MediaTransferProtocolManager to open the MTP
  45   // storage for communication.
  46   //
  47   // |storage_name| specifies the name of the storage device.
  48   // |callback| is called when the OpenStorage request completes. |callback|
  49   // runs on the IO thread.
  50   void OpenStorage(const std::string& storage_name,
  51                    const OpenStorageCallback& callback);
  52
  53   // Dispatches the GetFileInfo request to the MediaTransferProtocolManager.
  54   //
  55   // |file_id| specifies the id of the file whose details are requested.
  56   //
  57   // If the file details are fetched successfully, |success_callback| is invoked
  58   // on the IO thread to notify the caller about the file details.
  59   //
  60   // If there is an error, |error_callback| is invoked on the IO thread to
  61   // notify the caller about the file error.
  62   void GetFileInfo(uint32 file_id,
  63                    const GetFileInfoSuccessCallback& success_callback,
  64                    const ErrorCallback& error_callback);
  65
  66   // Dispatches the read directory request to the MediaTransferProtocolManager.
  67   //
  68   // |dir_id| specifies the directory id.
  69   //
  70   // If the directory file entries are enumerated successfully,
  71   // |success_callback| is invoked on the IO thread to notify the caller about
  72   // the directory file entries. Please see the note in the
  73   // ReadDirectorySuccessCallback typedef regarding the special treatment of
  74   // file names.
  75   //
  76   // If there is an error, |error_callback| is invoked on the IO thread to
  77   // notify the caller about the file error.
  78   void ReadDirectory(uint32 dir_id,
  79                      const ReadDirectorySuccessCallback& success_callback,
  80                      const ErrorCallback& error_callback);
  81
  82   // Forwards the WriteDataIntoSnapshotFile request to the MTPReadFileWorker
  83   // object.
  84   //
  85   // |request_info| specifies the snapshot file request params.
  86   // |snapshot_file_info| specifies the metadata of the snapshot file.
  87   void WriteDataIntoSnapshotFile(
  88       const SnapshotRequestInfo& request_info,
  89       const base::File::Info& snapshot_file_info);
  90
  91   // Dispatches the read bytes request to the MediaTransferProtocolManager.
  92   //
  93   // |request| contains details about the byte request including the file path,
  94   // byte range, and the callbacks. The callbacks specified within |request| are
  95   // called on the IO thread to notify the caller about success or failure.
  96   void ReadBytes(const MTPDeviceAsyncDelegate::ReadBytesRequest& request);
  97
  98   // Dispatches the CloseStorage request to the MediaTransferProtocolManager.
  99   void CloseStorage() const;
 100
 101  private:
 102   // Query callback for OpenStorage() to run |callback| on the IO thread.
 103   //
 104   // If OpenStorage request succeeds, |error| is set to false and
 105   // |device_handle| contains the handle to communicate with the MTP device.
 106   //
 107   // If OpenStorage request fails, |error| is set to true and |device_handle| is
 108   // set to an empty string.
 109   void OnDidOpenStorage(const OpenStorageCallback& callback,
 110                         const std::string& device_handle,
 111                         bool error);
 112
 113   // Query callback for GetFileInfo().
 114   //
 115   // If there is no error, |file_entry| will contain the
 116   // requested media device file details and |error| is set to false.
 117   // |success_callback| is invoked on the IO thread to notify the caller.
 118   //
 119   // If there is an error, |file_entry| is invalid and |error| is
 120   // set to true. |error_callback| is invoked on the IO thread to notify the
 121   // caller.
 122   void OnGetFileInfo(const GetFileInfoSuccessCallback& success_callback,
 123                      const ErrorCallback& error_callback,
 124                      const MtpFileEntry& file_entry,
 125                      bool error) const;
 126
 127   // Query callback for ReadDirectory().
 128   //
 129   // If there is no error, |error| is set to false, |file_entries| has the
 130   // directory file entries and |success_callback| is invoked on the IO thread
 131   // to notify the caller.
 132   //
 133   // If there is an error, |error| is set to true, |file_entries| is empty
 134   // and |error_callback| is invoked on the IO thread to notify the caller.
 135   void OnDidReadDirectory(const ReadDirectorySuccessCallback& success_callback,
 136                           const ErrorCallback& error_callback,
 137                           const std::vector<MtpFileEntry>& file_entries,
 138                           bool has_more,
 139                           bool error) const;
 140
 141   // Intermediate step to finish a ReadBytes request.
 142   void OnGetFileInfoToReadBytes(
 143       const MTPDeviceAsyncDelegate::ReadBytesRequest& request,
 144       const MtpFileEntry& file_entry,
 145       bool error);
 146
 147   // Query callback for ReadBytes();
 148   //
 149   // If there is no error, |error| is set to false, the buffer within |request|
 150   // is written to, and the success callback within |request| is invoked on the
 151   // IO thread to notify the caller.
 152   //
 153   // If there is an error, |error| is set to true, the buffer within |request|
 154   // is untouched, and the error callback within |request| is invoked on the
 155   // IO thread to notify the caller.
 156   void OnDidReadBytes(
 157       const MTPDeviceAsyncDelegate::ReadBytesRequest& request,
 158       const base::File::Info& file_info,
 159       const std::string& data,
 160       bool error) const;
 161
 162   // Called when the device is uninitialized.
 163   //
 164   // Runs |error_callback| on the IO thread to notify the caller about the
 165   // device |error|.
 166   void HandleDeviceError(const ErrorCallback& error_callback,
 167                          base::File::Error error) const;
 168
 169   // Handle to communicate with the MTP device.
 170   std::string device_handle_;
 171
 172   // Used to handle WriteDataInfoSnapshotFile request.
 173   scoped_ptr<MTPReadFileWorker> read_file_worker_;
 174
 175   // For callbacks that may run after destruction.
 176   base::WeakPtrFactory<MTPDeviceTaskHelper> weak_ptr_factory_;
 177
 178   DISALLOW_COPY_AND_ASSIGN(MTPDeviceTaskHelper);
 179 };
 180
 181 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_DEVICE_TASK_HELPER_H_