[DO NOT SUBMIT] AudioWorklet FS2: audio thread

third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 23 matching lines @@
 namespace blink {
 
 class AudioBus;
 class AbstractAudioContext;
 
 class AudioDestinationHandler : public AudioHandler, public AudioIOCallback {
 public:
     AudioDestinationHandler(AudioNode&, float sampleRate);
     ~AudioDestinationHandler() override;
 
-    // AudioHandler
-    void process(size_t) final { } // we're pulled by hardware so this is never called
+    // Implements AudioHandler::process. However, this node is pulled by
+    // hardware isochronously so this is never called.
+    void process(size_t) final { }
 
-    // The audio hardware calls render() to get the next render quantum of audio into destinationBus.
-    // It will optionally give us local/live audio input in sourceBus (if it's not 0).
-    void render(AudioBus* sourceBus, AudioBus* destinationBus, size_t numberOfFrames) final;
+    // Implements AudioIOCallback::render. The audio hardware periodically calls
+    // render() to get the next render quantum of audio into the destination
+    // bus.
+    void render(AudioBus* sourceBus, AudioBus* destinationBus, size_t framesToProcess) final;
 
     size_t currentSampleFrame() const { return acquireLoad(&m_currentSampleFrame); }
     double currentTime() const { return currentSampleFrame() / static_cast<double>(sampleRate()); }
 
     virtual unsigned long maxChannelCount() const { return 0; }
 
     virtual void startRendering() = 0;
     virtual void stopRendering() = 0;
 
 protected:
-    // LocalAudioInputProvider allows us to expose an AudioSourceProvider for local/live audio input.
-    // If there is local/live audio input, we call set() with the audio input data every render quantum.
+    // LocalAudioInputProvider allows us to expose an AudioSourceProvider for
+    // local/live audio input. If there is local/live audio input, we call set()
+    // with the audio input data every render quantum.
     class LocalAudioInputProvider final : public AudioSourceProvider {
     public:
+        // TODO(hongchan): handle non-stereo local input.
         LocalAudioInputProvider()
-            : m_sourceBus(AudioBus::create(2, ProcessingSizeInFrames)) // FIXME: handle non-stereo local input.
+            : m_sourceBus(AudioBus::create(2, ProcessingSizeInFrames))
         {
         }
 
-        void set(AudioBus* bus)
+        void setSourceBus(AudioBus* sourceBus)
         {
-            if (bus)
-                m_sourceBus->copyFrom(*bus);
+            if (sourceBus)
+                m_sourceBus->copyFrom(*sourceBus);
         }
 
-        // AudioSourceProvider.
+        // Implements AudioSourceProvider::provideInput.
         void provideInput(AudioBus* destinationBus, size_t numberOfFrames) override
         {
-            bool isGood = destinationBus && destinationBus->length() == numberOfFrames && m_sourceBus->length() == numberOfFrames;
+            bool isGood =
+                destinationBus && destinationBus->length() == numberOfFrames
+                && m_sourceBus->length() == numberOfFrames;
+
             ASSERT(isGood);
             if (isGood)
                 destinationBus->copyFrom(*m_sourceBus);
         }
 
     private:
         RefPtr<AudioBus> m_sourceBus;
     };
 
     // Counts the number of sample-frames processed by the destination.
     size_t m_currentSampleFrame;
 
     LocalAudioInputProvider m_localAudioInputProvider;
 };
 
 class AudioDestinationNode : public AudioNode {
     DEFINE_WRAPPERTYPEINFO();
 public:
     AudioDestinationHandler& audioDestinationHandler() const;
 
     unsigned long maxChannelCount() const;
 
 protected:
     AudioDestinationNode(AbstractAudioContext&);
 };
 
 } // namespace blink
 
 #endif // AudioDestinationNode_h