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_ 83
