Removing DataSource from Filter hierarchy

media/base/filters.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.
 
 // Filters are connected in a strongly typed manner, with downstream filters
 // always reading data from upstream filters.  Upstream filters have no clue
 // who is actually reading from them, and return the results via callbacks.
 //
 //                         DemuxerStream(Video) <- VideoDecoder <- VideoRenderer
 // DataSource <- Demuxer <
@@ skipping 28 matching lines @@
 namespace media {
 
 class Buffer;
 class Decoder;
 class DemuxerStream;
 class Filter;
 class FilterHost;
 
 struct PipelineStatistics;
 
-// Used to specify video preload states. They are "hints" to the browser about
-// how aggressively the browser should load and buffer data.
-// Please see the HTML5 spec for the descriptions of these values:
-// http://www.w3.org/TR/html5/video.html#attr-media-preload
-//
-// Enum values must match the values in WebCore::MediaPlayer::Preload and
-// there will be assertions at compile time if they do not match.
-enum Preload {
-  NONE,
-  METADATA,
-  AUTO,
-};
-
 // Used for completing asynchronous methods.
 typedef base::Callback<void(PipelineStatus)> FilterStatusCB;
 
 // These functions copy |*cb|, call Reset() on |*cb|, and then call Run()
 // on the copy.  This is used in the common case where you need to clear
 // a callback member variable before running the callback.
 MEDIA_EXPORT void ResetAndRunCB(FilterStatusCB* cb, PipelineStatus status);
 MEDIA_EXPORT void ResetAndRunCB(base::Closure* cb);
 
 // Used for updating pipeline statistics.
@@ skipping 54 matching lines @@
   virtual ~Filter();
 
   FilterHost* host() const { return host_; }
 
  private:
   FilterHost* host_;
 
   DISALLOW_COPY_AND_ASSIGN(Filter);
 };
 
-class MEDIA_EXPORT DataSource : public Filter {

[Ami GONE FROM CHROMIUM, 2011/12/15 18:39:08]

This is actually the more notable part of this CL to me (DS is no longer a
Filter).  I'd call that out in the CL description (as well as a general
explanation for why this is a good idea)

[acolwell GONE FROM CHROMIUM, 2011/12/15 20:57:59]

Done.

- public:
-  typedef base::Callback<void(size_t)> ReadCallback;
-  static const size_t kReadError;
-
-  // Reads |size| bytes from |position| into |data|. And when the read is done
-  // or failed, |read_callback| is called with the number of bytes read or
-  // kReadError in case of error.
-  // TODO(hclam): should change |size| to int! It makes the code so messy
-  // with size_t and int all over the place..
-  virtual void Read(int64 position, size_t size,
-                    uint8* data,
-                    const DataSource::ReadCallback& read_callback) = 0;
-
-  // Returns true and the file size, false if the file size could not be
-  // retrieved.
-  virtual bool GetSize(int64* size_out) = 0;
-
-  // Returns true if we are performing streaming. In this case seeking is
-  // not possible.
-  virtual bool IsStreaming() = 0;
-
-  // Alert the DataSource that the video preload value has been changed.
-  virtual void SetPreload(Preload preload) = 0;
-
-  // Notify the DataSource of the bitrate of the media.
-  // Values of |bitrate| <= 0 are invalid and should be ignored.
-  virtual void SetBitrate(int bitrate) = 0;
-};
-
 class MEDIA_EXPORT VideoDecoder : public Filter {
  public:
   // Initialize a VideoDecoder with the given DemuxerStream, executing the
   // callback upon completion.
   // stats_callback is used to update global pipeline statistics.
   virtual void Initialize(DemuxerStream* stream,
                           const PipelineStatusCB& callback,
                           const StatisticsCallback& stats_callback) = 0;
 
   // Request a frame to be decoded and returned via the provided callback.
@@ skipping 95 matching lines @@
 
   // Resumes playback after underflow occurs.
   // |buffer_more_audio| is set to true if you want to increase the size of the
   // decoded audio buffer.
   virtual void ResumeAfterUnderflow(bool buffer_more_audio) = 0;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_FILTERS_H_