Implementing preload=metadata for video

webkit/glue/media/buffered_data_source.h

 // Copyright (c) 2011 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 WEBKIT_GLUE_MEDIA_BUFFERED_DATA_SOURCE_H_
 #define WEBKIT_GLUE_MEDIA_BUFFERED_DATA_SOURCE_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "media/base/filter_factories.h"
+#include "media/base/filters.h"
 #include "webkit/glue/media/buffered_resource_loader.h"
 
 namespace webkit_glue {
 
 class BufferedDataSource : public WebDataSource {
  public:
   // Creates a DataSourceFactory for building BufferedDataSource objects.
   static media::DataSourceFactory* CreateFactory(
       MessageLoop* render_loop,
       WebKit::WebFrame* frame,
       WebDataSourceBuildObserverHack* build_observer);
 
   BufferedDataSource(MessageLoop* render_loop,
                      WebKit::WebFrame* frame);
 
   virtual ~BufferedDataSource();
 
   // media::Filter implementation.
   virtual void set_host(media::FilterHost* host);
   virtual void Stop(media::FilterCallback* callback);
   virtual void SetPlaybackRate(float playback_rate);
+  virtual void SetPreload(media::Preload preload);
+
+  // Decides which DeferStrategy to used based on the current state of the
+  // BufferedDataSource.
+  DeferStrategy* ChooseDeferStrategy();
 
   // media::DataSource implementation.
   // Called from demuxer thread.
   virtual void Read(int64 position, size_t size,
                     uint8* data,
                     media::DataSource::ReadCallback* read_callback);
   virtual bool GetSize(int64* size_out);
   virtual bool IsStreaming();
 
   const media::MediaFormat& media_format() {
@@ skipping 37 matching lines @@
 
   // This task monitors the current active read request. If the current read
   // request has timed out, this task will destroy the current loader and
   // creates a new one to accommodate the read request.
   void WatchDogTask();
 
   // This task uses the current playback rate with the previous playback rate
   // to determine whether we are going from pause to play and play to pause,
   // and signals the buffered resource loader accordingly.
   void SetPlaybackRateTask(float playback_rate);
+  void SetPreloadTask(media::Preload preload);
 
   // The method that performs actual read. This method can only be executed on
   // the render thread.
   void ReadInternal();
 
   // Calls |read_callback_| and reset all read parameters.
   void DoneRead_Locked(int error);
 
   // Calls |initialize_callback_| and reset it.
   void DoneInitialization_Locked(media::PipelineStatus status);
@@ skipping 87 matching lines @@
   bool stop_signal_received_;
 
   // This variable is set by CleanupTask() that indicates this object is stopped
   // on the render thread and work should no longer progress.
   bool stopped_on_render_loop_;
 
   // This variable is true when we are in a paused state and false when we
   // are in a playing state.
   bool media_is_paused_;
 
+  // This variable is true when the user has requested the video to play at
+  // least once.
+  bool media_has_played_;
+
+  // This variable holds the value of the preload attribute for the video
+  // element.
+  media::Preload preload_;
+
   // This timer is to run the WatchDogTask repeatedly. We use a timer instead
   // of doing PostDelayedTask() reduce the extra reference held by the message
   // loop. The RepeatingTimer does PostDelayedTask() internally, by using it
   // the message loop doesn't hold a reference for the watch dog task.
   base::RepeatingTimer<BufferedDataSource> watch_dog_timer_;
 
   // Keeps track of whether we used a Range header in the initialization
   // request.
   bool using_range_request_;
 
   DISALLOW_COPY_AND_ASSIGN(BufferedDataSource);
 };
 
 }  // namespace webkit_glue
 
 #endif  // WEBKIT_GLUE_MEDIA_BUFFERED_DATA_SOURCE_H_