Experiment with more aggressive MSE GC on memory pressure

media/filters/chunk_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.
 
 #ifndef MEDIA_FILTERS_CHUNK_DEMUXER_H_
 #define MEDIA_FILTERS_CHUNK_DEMUXER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <deque>
 #include <map>
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/macros.h"
+#include "base/memory/memory_pressure_listener.h"
 #include "base/synchronization/lock.h"
 #include "media/base/byte_queue.h"
 #include "media/base/demuxer.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/media_tracks.h"
 #include "media/base/ranges.h"
 #include "media/base/stream_parser.h"
 #include "media/filters/source_buffer_state.h"
 #include "media/filters/source_buffer_stream.h"
 
@@ skipping 24 matching lines @@
   // Removes buffers between |start| and |end| according to the steps
   // in the "Coded Frame Removal Algorithm" in the Media Source
   // Extensions Spec.
   // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#sourcebuffer-coded-frame-removal
   //
   // |duration| is the current duration of the presentation. It is
   // required by the computation outlined in the spec.
   void Remove(base::TimeDelta start, base::TimeDelta end,
               base::TimeDelta duration);
 
-  // If the buffer is full, attempts to try to free up space, as specified in
-  // the "Coded Frame Eviction Algorithm" in the Media Source Extensions Spec.
+  // Runs the "Coded Frame Eviction Algorithm" from the Media Source Extensions
+  // spec: https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
+  // |eviction_size| is an input parameter specifying how much space we want to
+  // be available in the buffer after eviction.
+  // |bytes_released| is an optional output parameter, if non-null it will
+  // indicate how much buffer space was actually released.
   // Returns false iff buffer is still full after running eviction.
-  // https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
-  bool EvictCodedFrames(DecodeTimestamp media_time, size_t newDataSize);
+  bool EvictCodedFrames(DecodeTimestamp media_time,
+                        size_t eviction_size,
+                        size_t* bytes_released = nullptr);
 
   // Signal to the stream that duration has changed to |duration|.
   void OnSetDuration(base::TimeDelta duration);
 
   // Returns the range of buffered data in this stream, capped at |duration|.
   Ranges<base::TimeDelta> GetBufferedRanges(base::TimeDelta duration) const;
 
   // Returns the highest PTS of the buffered data.
   // Returns base::TimeDelta() if the stream has no buffered data.
   base::TimeDelta GetHighestPresentationTimestamp() const;
@@ skipping 33 matching lines @@
   bool enabled() const override;
   void set_enabled(bool enabled, base::TimeDelta timestamp) override;
   void SetStreamStatusChangeCB(const StreamStatusChangeCB& cb) override;
 
   // Returns the text track configuration.  It is an error to call this method
   // if type() != TEXT.
   TextTrackConfig text_track_config();
 
   // Sets the memory limit, in bytes, on the SourceBufferStream.
   void SetStreamMemoryLimit(size_t memory_limit);
+  size_t stream_memory_limit() const;
 
   bool supports_partial_append_window_trimming() const {
     return partial_append_window_trimming_enabled_;
   }
 
   void SetLiveness(Liveness liveness);
 
   MediaTrack::Id media_track_id() const { return media_track_id_; }
 
  private:
@@ skipping 124 matching lines @@
   void ResetParserState(const std::string& id,
                         base::TimeDelta append_window_start,
                         base::TimeDelta append_window_end,
                         base::TimeDelta* timestamp_offset);
 
   // Remove buffers between |start| and |end| for the source buffer
   // associated with |id|.
   void Remove(const std::string& id, base::TimeDelta start,
               base::TimeDelta end);
 
-  // If the buffer is full, attempts to try to free up space, as specified in
-  // the "Coded Frame Eviction Algorithm" in the Media Source Extensions Spec.
+  // Runs the "Coded Frame Eviction Algorithm" from the Media Source Extensions
+  // spec: https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
+  // |eviction_size| is an input parameter specifying how much space we want to
+  // be available in the buffer after eviction.
+  // |bytes_released| is an optional output parameter, if non-null it will

[wolenetz, 2017/01/12 22:21:49]

Where is this param decl'ed?

[servolk, 2017/01/12 22:58:41]

Oops, I've copy/pasted this comment from ChunkDemuxerStream::EvictCodedFrames,
where I've added the optional bytes_released parameter. I'll remove it here.

+  // indicate how much buffer space was actually released.
   // Returns false iff buffer is still full after running eviction.
-  // https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
   bool EvictCodedFrames(const std::string& id,
                         base::TimeDelta currentMediaTime,
-                        size_t newDataSize);
+                        size_t eviction_size);
+
+  void OnMemoryPressure(
+      base::TimeDelta currentMediaTime,
+      base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
 
   // Returns the current presentation duration.
   double GetDuration();
   double GetDuration_Locked();
 
   // Notifies the demuxer that the duration of the media has changed to
   // |duration|.
   void SetDuration(double duration);
 
   // Returns true if the source buffer associated with |id| is currently parsing
@@ skipping 159 matching lines @@
   int detected_text_track_count_;
 
   std::map<MediaTrack::Id, DemuxerStream*> track_id_to_demux_stream_map_;
 
   DISALLOW_COPY_AND_ASSIGN(ChunkDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_CHUNK_DEMUXER_H_