Index: third_party/WebKit/Source/platform/audio/PushPullFIFO.h |
diff --git a/third_party/WebKit/Source/platform/audio/PushPullFIFO.h b/third_party/WebKit/Source/platform/audio/PushPullFIFO.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..2668fc50bda67f2affb275851287c0ce4f680b2b |
--- /dev/null |
+++ b/third_party/WebKit/Source/platform/audio/PushPullFIFO.h |
@@ -0,0 +1,52 @@ |
+// Copyright 2016 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 PushPullFIFO_h |
+#define PushPullFIFO_h |
+ |
+#include "platform/audio/AudioBus.h" |
+#include "public/platform/WebCommon.h" |
+#include "wtf/Allocator.h" |
+ |
+namespace blink { |
+ |
+class BLINK_PLATFORM_EXPORT PushPullFIFO { |
+ USING_FAST_MALLOC(PushPullFIFO); |
+ WTF_MAKE_NONCOPYABLE(PushPullFIFO); |
+ |
+ public: |
+ PushPullFIFO(unsigned numberOfChannels, size_t fifoLength); |
+ ~PushPullFIFO(); |
+ |
+ // Pushing audio data is done by the WebAudio render-backing thread. The |
+ // priority of this thread is lower than the actual audio device thread, |
+ // thus the thread can be blocked when the audio device thread is pulling |
+ // data from the FIFO. |
+ void push(const AudioBus* inputBus); |
+ |
+ // Pulling audio data is done by the audio device thread. This process must |
+ // be non-blocking to ensure the glitch-less audio playback. |
o1ka
2017/01/13 11:23:44
What are the plans regarding thread safety?
hongchan
2017/01/13 23:29:23
Giving a higher priority to pulling operation is o
|
+ void pull(AudioBus* outputBus, size_t framesToPull); |
+ |
+ int framesAvailable() const { return std::max(0, m_framesAvailable); } |
+ int length() const { return m_fifoLength; } |
+ unsigned numberOfChannels() const { return m_fifoBus->numberOfChannels(); } |
+ AudioBus* bus() { return m_fifoBus.get(); } |
+ |
+ private: |
+ RefPtr<AudioBus> m_fifoBus; |
+ |
+ // The size of the FIFO. |
+ const int m_fifoLength; |
+ |
+ // The number of frames in the FIFO actually available for pulling. |
+ int m_framesAvailable; |
+ |
+ int m_indexRead; |
+ int m_indexWrite; |
+}; |
+ |
+} // namespace blink |
+ |
+#endif // PushPullFIFO_h |