Refactor FFmpegURLProtocol code from FFmpegDemuxer into BlockingUrlProtocol.

media/filters/ffmpeg_demuxer.h

 // Copyright (c) 2012 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.
 
 // Implements the Demuxer interface using FFmpeg's libavformat.  At this time
 // will support demuxing any audio/video format thrown at it.  The streams
 // output mime types audio/x-ffmpeg and video/x-ffmpeg and include an integer
 // key FFmpegCodecID which contains the CodecID enumeration value.  The CodecIDs
 // can be used to create and initialize the corresponding FFmpeg decoder.
 //
 // FFmpegDemuxer sets the duration of pipeline during initialization by using
 // the duration of the longest audio/video stream.
 //
 // NOTE: since FFmpegDemuxer reads packets sequentially without seeking, media
 // files with very large drift between audio/video streams may result in
 // excessive memory consumption.
 //
 // When stopped, FFmpegDemuxer and FFmpegDemuxerStream release all callbacks
 // and buffered packets.  Reads from a stopped FFmpegDemuxerStream will not be
 // replied to.
 
 #ifndef MEDIA_FILTERS_FFMPEG_DEMUXER_H_
 #define MEDIA_FILTERS_FFMPEG_DEMUXER_H_
 
 #include <deque>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
-#include "base/synchronization/waitable_event.h"
 #include "media/base/audio_decoder_config.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/demuxer.h"
 #include "media/base/pipeline.h"
 #include "media/base/video_decoder_config.h"
-#include "media/filters/ffmpeg_glue.h"
+#include "media/filters/blocking_url_protocol.h"
 
 // FFmpeg forward declarations.
 struct AVPacket;
 struct AVRational;
 struct AVStream;
 
 namespace media {
 
 class FFmpegDemuxer;
+class FFmpegGlue;
 class FFmpegH264ToAnnexBBitstreamConverter;
 class ScopedPtrAVFreePacket;
 
 class FFmpegDemuxerStream : public DemuxerStream {
  public:
   // Keeps a copy of |demuxer| and initializes itself using information
   // inside |stream|.  Both parameters must outlive |this|.
   FFmpegDemuxerStream(FFmpegDemuxer* demuxer, AVStream* stream);
 
   // Returns true is this stream has pending reads, false otherwise.
@@ skipping 75 matching lines @@
   // Used to synchronize access to |buffer_queue_|, |read_queue_|, and
   // |stopped_|. This is so other threads can get access to buffers that have
   // already been demuxed without having the demuxer thread sending the
   // buffers. |lock_| must be acquired before any access to |buffer_queue_|,
   // |read_queue_|, or |stopped_|.
   mutable base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(FFmpegDemuxerStream);
 };
 
-class MEDIA_EXPORT FFmpegDemuxer : public Demuxer, public FFmpegURLProtocol {
+class MEDIA_EXPORT FFmpegDemuxer : public Demuxer {
  public:
   FFmpegDemuxer(const scoped_refptr<base::MessageLoopProxy>& message_loop,
                 const scoped_refptr<DataSource>& data_source);
 
   // Posts a task to perform additional demuxing.
   virtual void PostDemuxTask();
 
   // Demuxer implementation.
   virtual void Initialize(DemuxerHost* host,
                           const PipelineStatusCB& status_cb) OVERRIDE;
   virtual void Stop(const base::Closure& callback) OVERRIDE;
   virtual void Seek(base::TimeDelta time, const PipelineStatusCB& cb) OVERRIDE;
   virtual void OnAudioRendererDisabled() OVERRIDE;
   virtual void SetPlaybackRate(float playback_rate) OVERRIDE;
   virtual scoped_refptr<DemuxerStream> GetStream(
       DemuxerStream::Type type) OVERRIDE;
   virtual base::TimeDelta GetStartTime() const OVERRIDE;
 
-  // FFmpegURLProtocol implementation.
-  virtual int Read(int size, uint8* data) OVERRIDE;
-  virtual bool GetPosition(int64* position_out) OVERRIDE;
-  virtual bool SetPosition(int64 position) OVERRIDE;
-  virtual bool GetSize(int64* size_out) OVERRIDE;
-  virtual bool IsStreaming() OVERRIDE;
-
   // Provide access to FFmpegDemuxerStream.
   scoped_refptr<base::MessageLoopProxy> message_loop();
 
   // Allow FFmpegDemuxerStream to notify us when there is updated information
   // about what buffered data is available.
   void NotifyBufferingChanged();
 
  private:
   // To allow tests access to privates.
   friend class FFmpegDemuxerTest;
@@ skipping 20 matching lines @@
   // the tasks if there is no work to do.
   //
   // Must be called on the demuxer thread.
   bool StreamsHavePendingReads();
 
   // Signal all FFmpegDemuxerStream that the stream has ended.
   //
   // Must be called on the demuxer thread.
   void StreamHasEnded();
 
-  // Wait for asynchronous read to complete and return number of bytes read.
-  virtual int WaitForRead();
-
-  // Signal the blocked thread that the read has completed, with |size| bytes
-  // read or kReadError in case of error.
-  virtual void SignalReadCompleted(int size);
+  // Called by |url_protocol_| whenever |data_source_| returns a read error.
+  void OnDataSourceError();
 
   // Returns the stream from |streams_| that matches |type| as an
   // FFmpegDemuxerStream.
   scoped_refptr<FFmpegDemuxerStream> GetFFmpegStream(
       DemuxerStream::Type type) const;
 
   DemuxerHost* host_;
 
   scoped_refptr<base::MessageLoopProxy> message_loop_;
 
   // |streams_| mirrors the AVStream array in |format_context_|. It contains
   // FFmpegDemuxerStreams encapsluating AVStream objects at the same index.
   //
   // Since we only support a single audio and video stream, |streams_| will
   // contain NULL entries for additional audio/video streams as well as for
   // stream types that we do not currently support.
   //
   // Once initialized, operations on FFmpegDemuxerStreams should be carried out
   // on the demuxer thread.
   typedef std::vector<scoped_refptr<FFmpegDemuxerStream> > StreamVector;
   StreamVector streams_;
 
   // Reference to the data source. Asynchronous read requests are submitted to
   // this object.
   scoped_refptr<DataSource> data_source_;
 
-  // This member is used to block on read method calls from FFmpeg and wait
-  // until the asynchronous reads in the data source to complete. It is also
-  // signaled when the demuxer is being stopped.
-  base::WaitableEvent read_event_;
-
-  // Flag to indicate if read has ever failed. Once set to true, it will
-  // never be reset. This flag is set true and accessed in Read().
-  bool read_has_failed_;
-
-  int last_read_bytes_;
-  int64 read_position_;
-
   // Derived bitrate after initialization has completed.
   int bitrate_;
 
   // The first timestamp of the opened media file. This is used to set the
   // starting clock value to match the timestamps in the media file. Default
   // is 0.
   base::TimeDelta start_time_;
 
   // Whether audio has been disabled for this demuxer (in which case this class
   // drops packets destined for AUDIO demuxer streams on the floor).
   bool audio_disabled_;
 
   // Set if we know duration of the audio stream. Used when processing end of
   // stream -- at this moment we definitely know duration.
   bool duration_known_;
 
+  // FFmpegURLProtocol implementation and corresponding glue bits.
+  BlockingUrlProtocol url_protocol_;
   scoped_ptr<FFmpegGlue> glue_;
 
   DISALLOW_COPY_AND_ASSIGN(FFmpegDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_FFMPEG_DEMUXER_H_