content/browser/renderer_host/media/audio_input_sync_writer.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 CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_INPUT_SYNC_WRITER_H_
#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_INPUT_SYNC_WRITER_H_

#include "base/memory/scoped_vector.h"
#include "base/process/process.h"
#include "base/sync_socket.h"
#include "base/time/time.h"
#include "media/audio/audio_input_controller.h"
#include "media/audio/audio_parameters.h"
#include "media/base/audio_bus.h"

#if defined(OS_POSIX)
#include "base/file_descriptor_posix.h"
#endif

namespace base {
class SharedMemory;
}

namespace content {
// A AudioInputController::SyncWriter implementation using SyncSocket. This
// is used by AudioInputController to provide a low latency data source for
// transmitting audio packets between the browser process and the renderer
// process.
class AudioInputSyncWriter : public media::AudioInputController::SyncWriter {
 public:
  explicit AudioInputSyncWriter(base::SharedMemory* shared_memory,
                                int shared_memory_segment_count,
                                const media::AudioParameters& params);

  virtual ~AudioInputSyncWriter();

  // media::AudioInputController::SyncWriter implementation.
  virtual void UpdateRecordedBytes(uint32 bytes) OVERRIDE;
  virtual void Write(const media::AudioBus* data,
                     double volume,
                     bool key_pressed) OVERRIDE;
  virtual void Close() OVERRIDE;

  bool Init();
  bool PrepareForeignSocketHandle(base::ProcessHandle process_handle,
#if defined(OS_WIN)
                                  base::SyncSocket::Handle* foreign_handle);
#else
                                  base::FileDescriptor* foreign_handle);
#endif

 private:
  base::SharedMemory* shared_memory_;
  uint32 shared_memory_segment_size_;
  uint32 shared_memory_segment_count_;
  uint32 current_segment_id_;

  // Socket for transmitting audio data.
  scoped_ptr<base::CancelableSyncSocket> socket_;

  // Socket to be used by the renderer. The reference is released after
  // PrepareForeignSocketHandle() is called and ran successfully.
  scoped_ptr<base::CancelableSyncSocket> foreign_socket_;

  // The time of the creation of this object.
  base::Time creation_time_;

  // The time of the last Write call.
  base::Time last_write_time_;

  // Size in bytes of each audio bus.
  const int audio_bus_memory_size_;

  // Vector of audio buses allocated during construction and deleted in the
  // destructor.
  ScopedVector<media::AudioBus> audio_buses_;

  DISALLOW_IMPLICIT_CONSTRUCTORS(AudioInputSyncWriter);
};

}  // namespace content

#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_INPUT_SYNC_WRITER_H_