Index: media/audio/audio_output_dispatcher_impl.h |
=================================================================== |
--- media/audio/audio_output_dispatcher_impl.h (revision 0) |
+++ media/audio/audio_output_dispatcher_impl.h (revision 0) |
@@ -0,0 +1,102 @@ |
+// 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. |
+ |
+// AudioOutputDispatcherImpl is an implementation of AudioOutputDispatcher. |
+// |
+// To avoid opening and closing audio devices more frequently than necessary, |
+// each dispatcher has a pool of inactive physical streams. A stream is closed |
+// only if it hasn't been used for a certain period of time (specified via the |
+// constructor). |
+// |
+ |
+#ifndef MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_IMPL_H_ |
+#define MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_IMPL_H_ |
+ |
+#include <list> |
+#include <map> |
+ |
+#include "base/basictypes.h" |
+#include "base/memory/ref_counted.h" |
+#include "base/memory/weak_ptr.h" |
+#include "base/timer.h" |
+#include "media/audio/audio_io.h" |
+#include "media/audio/audio_manager.h" |
+#include "media/audio/audio_output_dispatcher.h" |
+#include "media/audio/audio_parameters.h" |
+ |
+class MessageLoop; |
+ |
+namespace media { |
+ |
+class AudioOutputProxy; |
+ |
+class MEDIA_EXPORT AudioOutputDispatcherImpl : public AudioOutputDispatcher { |
+ public: |
+ // |close_delay_ms| specifies delay after the stream is paused until |
+ // the audio device is closed. |
+ AudioOutputDispatcherImpl(AudioManager* audio_manager, |
+ const AudioParameters& params, |
+ const base::TimeDelta& close_delay); |
+ |
+ // Opens a new physical stream if there are no pending streams in |
+ // |idle_streams_|. |
+ virtual bool OpenStream() OVERRIDE; |
+ |
+ // If there are pending streams in |idle_streams_| then it reuses one of |
+ // them, otherwise creates a new one. |
+ virtual bool StartStream(AudioOutputStream::AudioSourceCallback* callback, |
+ AudioOutputProxy* stream_proxy) OVERRIDE; |
+ |
+ // Holds the physical stream temporarily in |pausing_streams_| and then |
+ // |stream| is added to the pool of pending streams (i.e. |idle_streams_|). |
+ virtual void StopStream(AudioOutputProxy* stream_proxy) OVERRIDE; |
+ |
+ virtual void StreamVolumeSet(AudioOutputProxy* stream_proxy, |
+ double volume) OVERRIDE; |
+ |
+ virtual void CloseStream(AudioOutputProxy* stream_proxy) OVERRIDE; |
+ |
+ virtual void Shutdown() OVERRIDE; |
+ |
+ private: |
+ typedef std::map<AudioOutputProxy*, AudioOutputStream*> AudioStreamMap; |
+ friend class base::RefCountedThreadSafe<AudioOutputDispatcherImpl>; |
+ virtual ~AudioOutputDispatcherImpl(); |
+ |
+ friend class AudioOutputProxyTest; |
+ |
+ // Creates a new physical output stream, opens it and pushes to |
+ // |idle_streams_|. Returns false if the stream couldn't be created or |
+ // opened. |
+ bool CreateAndOpenStream(); |
+ |
+ // A task scheduled by StartStream(). Opens a new stream and puts |
+ // it in |idle_streams_|. |
+ void OpenTask(); |
+ |
+ // Before a stream is reused, it should sit idle for a bit. This task is |
+ // called once that time has elapsed. |
+ void StopStreamTask(); |
+ |
+ // Called by |close_timer_|. Closes all pending streams. |
+ void ClosePendingStreams(); |
+ |
+ base::TimeDelta pause_delay_; |
+ size_t paused_proxies_; |
+ typedef std::list<AudioOutputStream*> AudioOutputStreamList; |
+ AudioOutputStreamList idle_streams_; |
+ AudioOutputStreamList pausing_streams_; |
+ |
+ // Used to post delayed tasks to ourselves that we cancel inside Shutdown(). |
+ base::WeakPtrFactory<AudioOutputDispatcherImpl> weak_this_; |
+ base::DelayTimer<AudioOutputDispatcherImpl> close_timer_; |
+ |
+ AudioStreamMap proxy_to_physical_map_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(AudioOutputDispatcherImpl); |
+}; |
+ |
+} // namespace media |
+ |
+#endif // MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_IMPL_H_ |