// 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 REMOTING_HOST_LINUX_AUDIO_PIPE_READER_H_
#define REMOTING_HOST_LINUX_AUDIO_PIPE_READER_H_
#include "base/memory/ref_counted.h"
#include "base/memory/ref_counted_memory.h"
#include "base/message_loop/message_loop.h"
#include "base/observer_list_threadsafe.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
namespace base {
class FilePath;
}
namespace remoting {
struct AudioPipeReaderTraits;
// AudioPipeReader class reads from a named pipe to which an audio server (e.g.
// pulseaudio) writes the sound that's being played back and then sends data to
// all registered observers.
class AudioPipeReader
: public base::RefCountedThreadSafe<AudioPipeReader, AudioPipeReaderTraits>,
public base::MessageLoopForIO::Watcher {
public:
class StreamObserver {
public:
virtual void OnDataRead(scoped_refptr<base::RefCountedString> data) = 0;
};
// |task_runner| specifies the IO thread to use to read data from the pipe.
static scoped_refptr<AudioPipeReader> Create(
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
const base::FilePath& pipe_name);
// Register or unregister an observer. Each observer receives data on the
// thread on which it was registered and guaranteed not to be called after
// RemoveObserver().
void AddObserver(StreamObserver* observer);
void RemoveObserver(StreamObserver* observer);
// MessageLoopForIO::Watcher interface.
virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE;
private:
friend class base::DeleteHelper<AudioPipeReader>;
friend class base::RefCountedThreadSafe<AudioPipeReader>;
friend struct AudioPipeReaderTraits;
AudioPipeReader(scoped_refptr<base::SingleThreadTaskRunner> task_runner);
virtual ~AudioPipeReader();
void StartOnAudioThread(const base::FilePath& pipe_name);
void StartTimer();
void DoCapture();
void WaitForPipeReadable();
scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
int pipe_fd_;
base::RepeatingTimer<AudioPipeReader> timer_;
scoped_refptr<ObserverListThreadSafe<StreamObserver> > observers_;
// Time when capturing was started.
base::TimeTicks started_time_;
// Stream position of the last capture in bytes with zero position
// corresponding to |started_time_|. Must always be a multiple of the sample
// size.
int64 last_capture_position_;
// Bytes left from the previous read.
std::string left_over_bytes_;
base::MessageLoopForIO::FileDescriptorWatcher file_descriptor_watcher_;
DISALLOW_COPY_AND_ASSIGN(AudioPipeReader);
};
// Destroys |audio_pipe_reader| on the audio thread.
struct AudioPipeReaderTraits {
static void Destruct(const AudioPipeReader* audio_pipe_reader);
};
} // namespace remoting
#endif // REMOTING_HOST_LINUX_AUDIO_PIPE_READER_H_