MTP Streaming: Readahead Buffer

chrome/browser/media_galleries/fileapi/device_media_async_file_util.cc

 // Copyright (c) 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.
 
 #include "chrome/browser/media_galleries/fileapi/device_media_async_file_util.h"
 
 #include "base/callback.h"
 #include "base/file_util.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner_util.h"
 #include "chrome/browser/media_galleries/fileapi/media_path_filter.h"
 #include "chrome/browser/media_galleries/fileapi/mtp_device_async_delegate.h"
 #include "chrome/browser/media_galleries/fileapi/mtp_device_map_service.h"
 #include "chrome/browser/media_galleries/fileapi/mtp_file_stream_reader.h"
 #include "chrome/browser/media_galleries/fileapi/native_media_file_util.h"
+#include "chrome/browser/media_galleries/fileapi/readahead_file_stream_reader.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/io_buffer.h"
 #include "net/base/mime_sniffer.h"
 #include "webkit/browser/blob/file_stream_reader.h"
 #include "webkit/browser/fileapi/file_system_context.h"
 #include "webkit/browser/fileapi/file_system_operation_context.h"
 #include "webkit/browser/fileapi/file_system_url.h"
 #include "webkit/common/blob/shareable_file_reference.h"
 
 using fileapi::FileSystemOperationContext;
@@ skipping 239 matching lines @@
 DeviceMediaAsyncFileUtil::GetFileStreamReader(
     const FileSystemURL& url,
     int64 offset,
     const base::Time& expected_modification_time,
     fileapi::FileSystemContext* context) {
   MTPDeviceAsyncDelegate* delegate = GetMTPDeviceDelegate(url);
   if (!delegate)
     return scoped_ptr<webkit_blob::FileStreamReader>();
 
   DCHECK(delegate->IsStreaming());
-  return scoped_ptr<webkit_blob::FileStreamReader>(new MTPFileStreamReader(
-      context, url, offset, expected_modification_time));
+  return scoped_ptr<webkit_blob::FileStreamReader>(
+      new ReadaheadFileStreamReader(new MTPFileStreamReader(
+          context, url, offset, expected_modification_time)));
 }
 
 DeviceMediaAsyncFileUtil::DeviceMediaAsyncFileUtil(
     const base::FilePath& profile_path)
     : profile_path_(profile_path),
       weak_ptr_factory_(this) {
 }
 
 void DeviceMediaAsyncFileUtil::OnDidGetFileInfo(
     const AsyncFileUtil::GetFileInfoCallback& callback,
@@ skipping 76 matching lines @@
       url.path(),  // device file path
       *snapshot_file_path,
       base::Bind(&DeviceMediaAsyncFileUtil::OnDidCreateSnapshotFile,
                  weak_ptr_factory_.GetWeakPtr(),
                  callback,
                  make_scoped_refptr(context->task_runner())),
       base::Bind(&DeviceMediaAsyncFileUtil::OnCreateSnapshotFileError,
                  weak_ptr_factory_.GetWeakPtr(),
                  callback));
 }