chrome/browser/media_galleries/win/mtp_device_operations_util.h

   1 // Copyright (c) 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 // This file has several utility functions to open a media transfer protocol
   6 // (MTP) device for communication, to enumerate the device contents, to read the
   7 // device file object, etc. All these tasks may take an arbitary long time
   8 // to complete. This file segregates those functionalities and runs them
   9 // in the blocking pool thread rather than in the UI thread.
  10
  11 #ifndef CHROME_BROWSER_MEDIA_GALLERIES_WIN_MTP_DEVICE_OPERATIONS_UTIL_H_
  12 #define CHROME_BROWSER_MEDIA_GALLERIES_WIN_MTP_DEVICE_OPERATIONS_UTIL_H_
  13
  14 #include <portabledeviceapi.h>
  15
  16 #include <string>
  17
  18 #include "base/files/file.h"
  19 #include "base/strings/string16.h"
  20 #include "base/win/scoped_comptr.h"
  21 #include "chrome/browser/media_galleries/win/mtp_device_object_entry.h"
  22
  23 namespace media_transfer_protocol {
  24
  25 // Opens the device for communication. |pnp_device_id| specifies the plug and
  26 // play device ID string. On success, returns the IPortableDevice interface.
  27 // On failure, returns NULL.
  28 base::win::ScopedComPtr<IPortableDevice> OpenDevice(
  29     const base::string16& pnp_device_id);
  30
  31 // Gets the details of the object specified by |object_id| from the given MTP
  32 // |device|. On success, returns no error (base::File::FILE_OK) and fills in
  33 // |file_entry_info|. On failure, returns the corresponding platform file error
  34 // and |file_entry_info| is not set.
  35 base::File::Error GetFileEntryInfo(
  36     IPortableDevice* device,
  37     const base::string16& object_id,
  38     base::File::Info* file_entry_info);
  39
  40 // Gets the entries of the directory specified by |directory_object_id| from
  41 // the given MTP |device|. On success, returns true and fills in
  42 // |object_entries|. On failure, returns false and |object_entries| is not
  43 // set.
  44 bool GetDirectoryEntries(IPortableDevice* device,
  45                          const base::string16& directory_object_id,
  46                          MTPDeviceObjectEntries* object_entries);
  47
  48 // Gets an IStream interface to read the object content data from the |device|.
  49 // |file_object_id| specifies the device file object identifier.
  50 // On success, returns S_OK and sets |file_stream| and |optimal_transfer_size|.
  51 // On failure, returns an error code and |file_stream| and
  52 // |optimal_transfer_size| are not set.
  53 HRESULT GetFileStreamForObject(IPortableDevice* device,
  54                                const base::string16& file_object_id,
  55                                IStream** file_stream,
  56                                DWORD* optimal_transfer_size);
  57
  58 // Copies a data chunk from |stream| to the file specified by the |local_path|.
  59 // |optimal_transfer_size| specifies the optimal data transfer size.
  60 //
  61 // On success, appends the data chunk in |local_path| and returns a non-zero
  62 // value indicating the total number of bytes written to the file specified
  63 // by the |local_path|. If the end of the |stream| is not reached,
  64 // the return value will be equal to |optimal_transfer_size|. If the end of the
  65 // |stream| is reached, the return value will be less than or equal to
  66 // |optimal_transfer_size|.
  67 //
  68 // On failure, returns 0.
  69 DWORD CopyDataChunkToLocalFile(IStream* stream,
  70                                const base::FilePath& local_path,
  71                                size_t optimal_transfer_size);
  72
  73 // Returns the identifier of the object specified by the |object_name|.
  74 // |parent_id| specifies the object's parent identifier.
  75 // |object_name| specifies the friendly name of the object.
  76 base::string16 GetObjectIdFromName(IPortableDevice* device,
  77                                    const base::string16& parent_id,
  78                                    const base::string16& object_name);
  79
  80 }  // namespace media_transfer_protocol
  81
  82 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_WIN_MTP_DEVICE_OPERATIONS_UTIL_H_