media/audio/audio_output_dispatcher_impl.h

   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 <map>
  17 #include <vector>
  18
  19 #include "base/basictypes.h"
  20 #include "base/memory/ref_counted.h"
  21 #include "base/timer/timer.h"
  22 #include "media/audio/audio_io.h"
  23 #include "media/audio/audio_logging.h"
  24 #include "media/audio/audio_manager.h"
  25 #include "media/audio/audio_output_dispatcher.h"
  26 #include "media/audio/audio_parameters.h"
  27
  28 namespace media {
  29
  30 class AudioOutputProxy;
  31
  32 class MEDIA_EXPORT AudioOutputDispatcherImpl : public AudioOutputDispatcher {
  33  public:
  34   // |close_delay| specifies delay after the stream is idle until the audio
  35   // 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   // Stops the stream assigned to the specified proxy and moves it into
  52   // |idle_streams_| for reuse by other proxies.
  53   virtual void StopStream(AudioOutputProxy* stream_proxy) OVERRIDE;
  54
  55   virtual void StreamVolumeSet(AudioOutputProxy* stream_proxy,
  56                                double volume) OVERRIDE;
  57
  58   // Closes |idle_streams_| until the number of |idle_streams_| is equal to the
  59   // |idle_proxies_| count.  If there are no |idle_proxies_| a single stream is
  60   // kept alive until |close_timer_| fires.
  61   virtual void CloseStream(AudioOutputProxy* stream_proxy) OVERRIDE;
  62
  63   virtual void Shutdown() OVERRIDE;
  64
  65   virtual void CloseStreamsForWedgeFix() OVERRIDE;
  66   virtual void RestartStreamsForWedgeFix() OVERRIDE;
  67
  68  private:
  69   friend class base::RefCountedThreadSafe<AudioOutputDispatcherImpl>;
  70   virtual ~AudioOutputDispatcherImpl();
  71
  72   // Creates a new physical output stream, opens it and pushes to
  73   // |idle_streams_|.  Returns false if the stream couldn't be created or
  74   // opened.
  75   bool CreateAndOpenStream();
  76
  77   // Closes all |idle_streams_|.
  78   void CloseAllIdleStreams();
  79   // Similar to CloseAllIdleStreams(), but keeps |keep_alive| streams alive.
  80   void CloseIdleStreams(size_t keep_alive);
  81
  82   size_t idle_proxies_;
  83   std::vector<AudioOutputStream*> idle_streams_;
  84
  85   // When streams are stopped they're added to |idle_streams_|, if no stream is
  86   // reused before |close_delay_| elapses |close_timer_| will run
  87   // CloseIdleStreams().
  88   base::DelayTimer<AudioOutputDispatcherImpl> close_timer_;
  89
  90   typedef std::map<AudioOutputProxy*, AudioOutputStream*> AudioStreamMap;
  91   AudioStreamMap proxy_to_physical_map_;
  92
  93   scoped_ptr<AudioLog> audio_log_;
  94   typedef std::map<AudioOutputStream*, int> AudioStreamIDMap;
  95   AudioStreamIDMap audio_stream_ids_;
  96   int audio_stream_id_;
  97
  98   DISALLOW_COPY_AND_ASSIGN(AudioOutputDispatcherImpl);
  99 };
 100
 101 }  // namespace media
 102
 103 #endif  // MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_IMPL_H_