audio_output_dispatcher_impl.h revision 0f1bc08d4cfcc34181b0b5cbf065c40f687bf740
1// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5// AudioOutputDispatcherImpl is an implementation of AudioOutputDispatcher. 6// 7// To avoid opening and closing audio devices more frequently than necessary, 8// each dispatcher has a pool of inactive physical streams. A stream is closed 9// only if it hasn't been used for a certain period of time (specified via the 10// constructor). 11// 12 13#ifndef MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_IMPL_H_ 14#define MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_IMPL_H_ 15 16#include <list> 17#include <map> 18 19#include "base/basictypes.h" 20#include "base/memory/ref_counted.h" 21#include "base/memory/weak_ptr.h" 22#include "base/timer/timer.h" 23#include "media/audio/audio_io.h" 24#include "media/audio/audio_manager.h" 25#include "media/audio/audio_output_dispatcher.h" 26#include "media/audio/audio_parameters.h" 27 28namespace media { 29 30class AudioOutputProxy; 31 32class MEDIA_EXPORT AudioOutputDispatcherImpl : public AudioOutputDispatcher { 33 public: 34 // |close_delay_ms| specifies delay after the stream is paused until 35 // the audio device is closed. 36 AudioOutputDispatcherImpl(AudioManager* audio_manager, 37 const AudioParameters& params, 38 const std::string& output_device_id, 39 const std::string& input_device_id, 40 const base::TimeDelta& close_delay); 41 42 // Opens a new physical stream if there are no pending streams in 43 // |idle_streams_|. Do not call Close() or Stop() if this method fails. 44 virtual bool OpenStream() OVERRIDE; 45 46 // If there are pending streams in |idle_streams_| then it reuses one of 47 // them, otherwise creates a new one. 48 virtual bool StartStream(AudioOutputStream::AudioSourceCallback* callback, 49 AudioOutputProxy* stream_proxy) OVERRIDE; 50 51 // Holds the physical stream temporarily in |pausing_streams_| and then 52 // |stream| is added to the pool of pending streams (i.e. |idle_streams_|). 53 virtual void StopStream(AudioOutputProxy* stream_proxy) OVERRIDE; 54 55 virtual void StreamVolumeSet(AudioOutputProxy* stream_proxy, 56 double volume) OVERRIDE; 57 58 virtual void CloseStream(AudioOutputProxy* stream_proxy) OVERRIDE; 59 60 virtual void Shutdown() OVERRIDE; 61 62 private: 63 typedef std::map<AudioOutputProxy*, AudioOutputStream*> AudioStreamMap; 64 friend class base::RefCountedThreadSafe<AudioOutputDispatcherImpl>; 65 virtual ~AudioOutputDispatcherImpl(); 66 67 friend class AudioOutputProxyTest; 68 69 // Creates a new physical output stream, opens it and pushes to 70 // |idle_streams_|. Returns false if the stream couldn't be created or 71 // opened. 72 bool CreateAndOpenStream(); 73 74 // Before a stream is reused, it should sit idle for a bit. This task is 75 // called once that time has elapsed. 76 void StopStreamTask(); 77 78 // Called by |close_timer_|. Closes all pending streams. 79 void ClosePendingStreams(); 80 81 base::TimeDelta pause_delay_; 82 size_t paused_proxies_; 83 typedef std::list<AudioOutputStream*> AudioOutputStreamList; 84 AudioOutputStreamList idle_streams_; 85 AudioOutputStreamList pausing_streams_; 86 87 // Used to post delayed tasks to ourselves that we cancel inside Shutdown(). 88 base::WeakPtrFactory<AudioOutputDispatcherImpl> weak_this_; 89 base::DelayTimer<AudioOutputDispatcherImpl> close_timer_; 90 91 AudioStreamMap proxy_to_physical_map_; 92 93 DISALLOW_COPY_AND_ASSIGN(AudioOutputDispatcherImpl); 94}; 95 96} // namespace media 97 98#endif // MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_IMPL_H_ 99