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// 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 <map>
#include <vector>
#include "base/basictypes.h"
#include "base/memory/ref_counted.h"
#include "base/timer/timer.h"
#include "media/audio/audio_io.h"
#include "media/audio/audio_logging.h"
#include "media/audio/audio_manager.h"
#include "media/audio/audio_output_dispatcher.h"
#include "media/audio/audio_parameters.h"
namespace media {
class AudioOutputProxy;
class MEDIA_EXPORT AudioOutputDispatcherImpl : public AudioOutputDispatcher {
public:
// |close_delay| specifies delay after the stream is idle until the audio
// device is closed.
AudioOutputDispatcherImpl(AudioManager* audio_manager,
const AudioParameters& params,
const std::string& output_device_id,
const base::TimeDelta& close_delay);
// Opens a new physical stream if there are no pending streams in
// |idle_streams_|. Do not call Close() or Stop() if this method fails.
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;
// Stops the stream assigned to the specified proxy and moves it into
// |idle_streams_| for reuse by other proxies.
virtual void StopStream(AudioOutputProxy* stream_proxy) OVERRIDE;
virtual void StreamVolumeSet(AudioOutputProxy* stream_proxy,
double volume) OVERRIDE;
// Closes |idle_streams_| until the number of |idle_streams_| is equal to the
// |idle_proxies_| count. If there are no |idle_proxies_| a single stream is
// kept alive until |close_timer_| fires.
virtual void CloseStream(AudioOutputProxy* stream_proxy) OVERRIDE;
virtual void Shutdown() OVERRIDE;
private:
friend class base::RefCountedThreadSafe<AudioOutputDispatcherImpl>;
virtual ~AudioOutputDispatcherImpl();
// 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();
// Closes all |idle_streams_|.
void CloseAllIdleStreams();
// Similar to CloseAllIdleStreams(), but keeps |keep_alive| streams alive.
void CloseIdleStreams(size_t keep_alive);
size_t idle_proxies_;
std::vector<AudioOutputStream*> idle_streams_;
// When streams are stopped they're added to |idle_streams_|, if no stream is
// reused before |close_delay_| elapses |close_timer_| will run
// CloseIdleStreams().
base::DelayTimer<AudioOutputDispatcherImpl> close_timer_;
typedef std::map<AudioOutputProxy*, AudioOutputStream*> AudioStreamMap;
AudioStreamMap proxy_to_physical_map_;
scoped_ptr<AudioLog> audio_log_;
typedef std::map<AudioOutputStream*, int> AudioStreamIDMap;
AudioStreamIDMap audio_stream_ids_;
int audio_stream_id_;
DISALLOW_COPY_AND_ASSIGN(AudioOutputDispatcherImpl);
};
} // namespace media
#endif // MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_IMPL_H_