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 #ifndef REMOTING_HOST_LINUX_AUDIO_PIPE_READER_H_ 6 #define REMOTING_HOST_LINUX_AUDIO_PIPE_READER_H_ 7 8 #include "base/memory/ref_counted.h" 9 #include "base/memory/ref_counted_memory.h" 10 #include "base/message_loop/message_loop.h" 11 #include "base/observer_list_threadsafe.h" 12 #include "base/time/time.h" 13 #include "base/timer/timer.h" 14 15 namespace base { 16 class FilePath; 17 } 18 19 namespace remoting { 20 21 struct AudioPipeReaderTraits; 22 23 // AudioPipeReader class reads from a named pipe to which an audio server (e.g. 24 // pulseaudio) writes the sound that's being played back and then sends data to 25 // all registered observers. 26 class AudioPipeReader 27 : public base::RefCountedThreadSafe<AudioPipeReader, AudioPipeReaderTraits>, 28 public base::MessageLoopForIO::Watcher { 29 public: 30 class StreamObserver { 31 public: 32 virtual void OnDataRead(scoped_refptr<base::RefCountedString> data) = 0; 33 }; 34 35 // |task_runner| specifies the IO thread to use to read data from the pipe. 36 static scoped_refptr<AudioPipeReader> Create( 37 scoped_refptr<base::SingleThreadTaskRunner> task_runner, 38 const base::FilePath& pipe_name); 39 40 // Register or unregister an observer. Each observer receives data on the 41 // thread on which it was registered and guaranteed not to be called after 42 // RemoveObserver(). 43 void AddObserver(StreamObserver* observer); 44 void RemoveObserver(StreamObserver* observer); 45 46 // MessageLoopForIO::Watcher interface. 47 virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE; 48 virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE; 49 50 private: 51 friend class base::DeleteHelper<AudioPipeReader>; 52 friend class base::RefCountedThreadSafe<AudioPipeReader>; 53 friend struct AudioPipeReaderTraits; 54 55 AudioPipeReader(scoped_refptr<base::SingleThreadTaskRunner> task_runner); 56 virtual ~AudioPipeReader(); 57 58 void StartOnAudioThread(const base::FilePath& pipe_name); 59 void StartTimer(); 60 void DoCapture(); 61 void WaitForPipeReadable(); 62 63 scoped_refptr<base::SingleThreadTaskRunner> task_runner_; 64 65 int pipe_fd_; 66 base::RepeatingTimer<AudioPipeReader> timer_; 67 scoped_refptr<ObserverListThreadSafe<StreamObserver> > observers_; 68 69 // Time when capturing was started. 70 base::TimeTicks started_time_; 71 72 // Stream position of the last capture in bytes with zero position 73 // corresponding to |started_time_|. Must always be a multiple of the sample 74 // size. 75 int64 last_capture_position_; 76 77 // Bytes left from the previous read. 78 std::string left_over_bytes_; 79 80 base::MessageLoopForIO::FileDescriptorWatcher file_descriptor_watcher_; 81 82 DISALLOW_COPY_AND_ASSIGN(AudioPipeReader); 83 }; 84 85 // Destroys |audio_pipe_reader| on the audio thread. 86 struct AudioPipeReaderTraits { 87 static void Destruct(const AudioPipeReader* audio_pipe_reader); 88 }; 89 90 } // namespace remoting 91 92 #endif // REMOTING_HOST_LINUX_AUDIO_PIPE_READER_H_ 93