| // 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/files/file.h" |
| #include "base/files/file_path.h" |
| #include "base/files/file_path_watcher.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" |
| #include "remoting/proto/audio.pb.h" |
| |
| 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: |
| // PulseAudio's module-pipe-sink must be configured to use the following |
| // parameters for the sink we read from. |
| static const AudioPacket_SamplingRate kSamplingRate = |
| AudioPacket::SAMPLING_RATE_48000; |
| static const AudioPacket_BytesPerSample kBytesPerSample = |
| AudioPacket::BYTES_PER_SAMPLE_2; |
| static const AudioPacket_Channels kChannels = AudioPacket::CHANNELS_STEREO; |
| |
| 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_path); |
| |
| // 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, |
| const base::FilePath& pipe_path); |
| virtual ~AudioPipeReader(); |
| |
| void StartOnAudioThread(); |
| void OnDirectoryChanged(const base::FilePath& path, bool error); |
| void TryOpenPipe(); |
| void StartTimer(); |
| void DoCapture(); |
| void WaitForPipeReadable(); |
| |
| scoped_refptr<base::SingleThreadTaskRunner> task_runner_; |
| base::FilePath pipe_path_; |
| |
| // Watcher for the directory that contains audio pipe we are reading from, to |
| // monitor when pulseaudio creates or deletes it. |
| base::FilePathWatcher file_watcher_; |
| |
| base::File pipe_; |
| 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_ |