Media Galleries: Access MTP devices by file ids rather than file paths.

chrome/browser/media_galleries/linux/mtp_device_task_helper.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_DEVICE_TASK_HELPER_H_
 #define CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_DEVICE_TASK_HELPER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 13 matching lines @@
 // MTPDeviceTaskHelper lives on the UI thread. MTPDeviceTaskHelperMapService
 // owns the MTPDeviceTaskHelper objects. MTPDeviceTaskHelper is instantiated per
 // MTP device storage.
 class MTPDeviceTaskHelper {
  public:
   typedef base::Callback<void(bool succeeded)> OpenStorageCallback;
 
   typedef MTPDeviceAsyncDelegate::GetFileInfoSuccessCallback
       GetFileInfoSuccessCallback;
 
+  // NOTE: The file names in the entry list have their file id appended at the
+  // end. e.g. foo.jpg with file id 45 becomes foo.jpg,45.
   typedef base::Callback<void(const fileapi::AsyncFileUtil::EntryList&)>
       ReadDirectorySuccessCallback;
 
   typedef MTPDeviceAsyncDelegate::ErrorCallback ErrorCallback;
 
   MTPDeviceTaskHelper();
   ~MTPDeviceTaskHelper();
 
   // Dispatches the request to the MediaTransferProtocolManager to open the MTP
   // storage for communication.
   //
   // |storage_name| specifies the name of the storage device.
   // |callback| is called when the OpenStorage request completes. |callback|
   // runs on the IO thread.
   void OpenStorage(const std::string& storage_name,
                    const OpenStorageCallback& callback);
 
-  // Dispatches the GetFileInfoByPath request to the
+  // Dispatches the GetFileInfoById request to the
   // MediaTransferProtocolManager.
   //
-  // |file_path| specifies the relative of the file whose details are requested.
+  // |file_id| specifies the id of the file whose details are requested.
   //
   // If the file details are fetched successfully, |success_callback| is invoked
   // on the IO thread to notify the caller about the file details.
   //
   // If there is an error, |error_callback| is invoked on the IO thread to
   // notify the caller about the file error.
-  void GetFileInfoByPath(
-      const std::string& file_path,
+  void GetFileInfoById(
+      uint32 file_id,
       const GetFileInfoSuccessCallback& success_callback,
       const ErrorCallback& error_callback);
 
   // Dispatches the read directory request to the MediaTransferProtocolManager.
   //
-  // |dir_path| specifies the directory file path.
+  // |dir_id| specifies the directory id.
   //
   // If the directory file entries are enumerated successfully,
   // |success_callback| is invoked on the IO thread to notify the caller about
-  // the directory file entries.
+  // the directory file entries. Please see the note in the
+  // ReadDirectorySuccessCallback typedef regarding the special treatment of
+  // file names.
   //
   // If there is an error, |error_callback| is invoked on the IO thread to
   // notify the caller about the file error.
-  void ReadDirectoryByPath(const std::string& dir_path,
-                           const ReadDirectorySuccessCallback& success_callback,
-                           const ErrorCallback& error_callback);
+  void ReadDirectoryById(uint32 dir_id,
+                         const ReadDirectorySuccessCallback& success_callback,
+                         const ErrorCallback& error_callback);
 
   // Forwards the WriteDataIntoSnapshotFile request to the MTPReadFileWorker
   // object.
   //
   // |request_info| specifies the snapshot file request params.
   // |snapshot_file_info| specifies the metadata of the snapshot file.
   void WriteDataIntoSnapshotFile(
       const SnapshotRequestInfo& request_info,
       const base::File::Info& snapshot_file_info);
 
@@ skipping 26 matching lines @@
   // |success_callback| is invoked on the IO thread to notify the caller.
   //
   // If there is an error, |file_entry| is invalid and |error| is
   // set to true. |error_callback| is invoked on the IO thread to notify the
   // caller.
   void OnGetFileInfo(const GetFileInfoSuccessCallback& success_callback,
                      const ErrorCallback& error_callback,
                      const MtpFileEntry& file_entry,
                      bool error) const;
 
-  // Query callback for ReadDirectoryByPath().
+  // Query callback for ReadDirectoryById().
   //
   // If there is no error, |error| is set to false, |file_entries| has the
   // directory file entries and |success_callback| is invoked on the IO thread
   // to notify the caller.
   //
   // If there is an error, |error| is set to true, |file_entries| is empty
   // and |error_callback| is invoked on the IO thread to notify the caller.
-  void OnDidReadDirectoryByPath(
+  void OnDidReadDirectoryById(
       const ReadDirectorySuccessCallback& success_callback,
       const ErrorCallback& error_callback,
       const std::vector<MtpFileEntry>& file_entries,
       bool error) const;
 
   // Intermediate step to finish a ReadBytes request.
   void OnGetFileInfoToReadBytes(
       const MTPDeviceAsyncDelegate::ReadBytesRequest& request,
       const MtpFileEntry& file_entry,
       bool error);
@@ skipping 26 matching lines @@
   // Used to handle WriteDataInfoSnapshotFile request.
   scoped_ptr<MTPReadFileWorker> read_file_worker_;
 
   // For callbacks that may run after destruction.
   base::WeakPtrFactory<MTPDeviceTaskHelper> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MTPDeviceTaskHelper);
 };
 
 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_DEVICE_TASK_HELPER_H_