Implement sourceAddId() & sourceRemoveId()

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 <list>
+#include <string>
 
 #include "base/synchronization/lock.h"
 #include "media/base/byte_queue.h"
 #include "media/base/demuxer.h"
 #include "media/base/stream_parser.h"
 
 namespace media {
 
 class ChunkDemuxerClient;
 class ChunkDemuxerStream;
 class FFmpegURLProtocol;
 
 // Demuxer implementation that allows chunks of media data to be passed
 // from JavaScript to the media stack.
 class MEDIA_EXPORT ChunkDemuxer : public Demuxer, public StreamParserHost {
  public:
+  enum Status {
+    kOk,              // ID added w/o error.
+    kNotSupported,    // Type specified is not supported.
+    kReachedIdLimit,  // Reached ID limit. We can't handle any more IDs.
+  };
+
   explicit ChunkDemuxer(ChunkDemuxerClient* client);
   virtual ~ChunkDemuxer();
 
   // Demuxer implementation.
   virtual void Initialize(DemuxerHost* host,
                           const PipelineStatusCB& 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 scoped_refptr<DemuxerStream> GetStream(
       DemuxerStream::Type type) OVERRIDE;
   virtual base::TimeDelta GetStartTime() const OVERRIDE;
   virtual int GetBitrate() OVERRIDE;
   virtual bool IsLocalSource() OVERRIDE;
   virtual bool IsSeekable() OVERRIDE;
 
   // Methods used by an external object to control this demuxer.
   void FlushData();
 
-  // Appends media data to the stream. Returns false if this method
-  // is called in an invalid state.
-  bool AppendData(const uint8* data, size_t length);
+  // Registers a new |id| to use for AppendData() calls. |type| indicates
+  // the MIME type for the data that we intend to append for this ID.
+  // kOk is returned if the demuxer has enough resources to support another ID
+  //    and supports the format indicated by |type|.
+  // kNotSupported is returned if |type| is not a supported format.
+  // kReachedIdLimit is returned if the demuxer cannot handle another ID right
+  //    now.
+  Status AddId(const std::string& id, const std::string& type);
+
+  // Removed an ID & associated resources that were previously added with
+  // AddId().
+  bool RemoveId(const std::string& id);

[scherkus (not reviewing), 2012/04/23 19:24:17]

what does true/false mean? could we have void?

is it CHECK-failable if you remove an ID that doesn't exist?

[acolwell GONE FROM CHROMIUM, 2012/04/23 22:15:23]

Yes we could have void. Eric wanted a bool returned in the WebKit code, "just in
case" we needed to signal an error. Since the WebKit call had a bool I figured
it made sense to pipe it all the way to here. I'll remove it and put the return
true in WebMediaPlayerImpl until we actually have a reason to plumb it all the
way to ChunkDemuxer.
Yes. Done

+
+  // Appends media data to the source buffer associated with |id|. Returns
+  // false if this method is called in an invalid state.
+  bool AppendData(const std::string& id, const uint8* data, size_t length);

[scherkus (not reviewing), 2012/04/23 19:24:17]

CHECK-fail instead?

[acolwell GONE FROM CHROMIUM, 2012/04/23 22:15:23]

No. It is possible for appends to happen when the ChunkDemuxer is in an error
state. We need to be able to return an error here. An error could have occurred,
but WebKit doesn't know about it yet.

   void EndOfStream(PipelineStatus status);
   bool HasEnded();
   void Shutdown();
 
  private:
   enum State {
     WAITING_FOR_INIT,
     INITIALIZING,
     INITIALIZED,
     ENDED,
@@ skipping 31 matching lines @@
   base::TimeDelta duration_;
 
   scoped_ptr<StreamParser> stream_parser_;
 
   // Should a Seek() call wait for more data before calling the
   // callback.
   bool seek_waits_for_data_;
 
   ByteQueue byte_queue_;
 
+  // TODO(acolwell): Remove this when fixing http://crbug.com/122909 .

[scherkus (not reviewing), 2012/04/23 19:24:17]

nit: I'd just leave off that trailing period in this case :)

[acolwell GONE FROM CHROMIUM, 2012/04/23 22:15:23]

Done.

+  std::string source_id_;
+
   DISALLOW_COPY_AND_ASSIGN(ChunkDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_CHUNK_DEMUXER_H_