AudioContext.decodeAudioData returns a Promise

Source/modules/webaudio/AudioContext.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 219 matching lines @@
     size_t currentSampleFrame() const;
     double currentTime() const;
 
     float sampleRate() const { return m_destinationNode ? m_destinationNode->handler().sampleRate() : 0; }
 
     String state() const;
 
     AudioBuffer* createBuffer(unsigned numberOfChannels, size_t numberOfFrames, float sampleRate, ExceptionState&);
 
     // Asynchronous audio file data decoding.
-    void decodeAudioData(DOMArrayBuffer*, AudioBufferCallback*, AudioBufferCallback*, ExceptionState&);
+    ScriptPromise decodeAudioData(ScriptState*, DOMArrayBuffer*, AudioBufferCallback*, AudioBufferCallback*, ExceptionState&);
 
     AudioListener* listener() { return m_listener.get(); }
 
     // The AudioNode create methods are called on the main thread (from JavaScript).
     AudioBufferSourceNode* createBufferSource(ExceptionState&);
     MediaElementAudioSourceNode* createMediaElementSource(HTMLMediaElement*, ExceptionState&);
     MediaStreamAudioSourceNode* createMediaStreamSource(MediaStream*, ExceptionState&);
     MediaStreamAudioDestinationNode* createMediaStreamDestination(ExceptionState&);
     GainNode* createGain(ExceptionState&);
     BiquadFilterNode* createBiquadFilter(ExceptionState&);
@@ skipping 90 matching lines @@
     // A context is considered closed if closeContext() has been called, even if the audio HW has
     // not yet been stopped.  It will be stopped eventually.
     bool isContextClosed() const { return m_closeResolver; }
 
     static unsigned s_hardwareContextCount;
     static unsigned s_contextId;
 
     // Get the security origin for this audio context.
     SecurityOrigin* securityOrigin() const;
 
+    void removeAudioDecoderResolver(ScriptPromiseResolver*);
 protected:
     explicit AudioContext(Document*);
     AudioContext(Document*, unsigned numberOfChannels, size_t numberOfFrames, float sampleRate);
 
     RefPtrWillBeMember<ScriptPromiseResolver> m_offlineResolver;
 private:
     void initialize();
     void uninitialize();
 
     // ExecutionContext calls stop twice.
@@ skipping 66 matching lines @@
 
     Member<AudioBuffer> m_renderTarget;
 
     bool m_isOfflineContext;
 
     // The state of the AudioContext.
     AudioContextState m_contextState;
     void setContextState(AudioContextState);
 
     AsyncAudioDecoder m_audioDecoder;
+    // A vector of the ScriptPromiseResolvers the decodeAudioData method uses.
+    WillBeHeapVector<RefPtrWillBeMember<ScriptPromiseResolver>> m_audioDecoderResolvers;

[yhirano, 2015/04/10 04:55:23]

Is using WillBeHeapHashSet better?

[Raymond Toy, 2015/04/10 20:54:57]

I was just following what was done for the suspend and resume resolvers.  If you
think WillBeHeapHashSet is better, I will change it for the suspend and resume
resolvers too.  (In a separate CL.)

 
     // The Promise that is returned by close();
     RefPtrWillBeMember<ScriptPromiseResolver> m_closeResolver;
 
     // Follows the destination's currentSampleFrame, but might be slightly behind due to locking.
     size_t m_cachedSampleFrame;
 
+    // When a context is closed, the sample rate is cleared.  But decodeAudioData can be called
+    // after the context has been closed and it needs the sample rate.  When the context is closed,
+    // the sample rate is saved here.
+    float m_closedContextSampleRate;
+
     // Tries to handle AudioBufferSourceNodes that were started but became disconnected or was never
     // connected. Because these never get pulled anymore, they will stay around forever. So if we
     // can, try to stop them so they can be collected.
     void handleStoppableSourceNodes();
 
     // This is considering 32 is large enough for multiple channels audio.
     // It is somewhat arbitrary and could be increased if necessary.
     enum { MaxNumberOfChannels = 32 };
 
     unsigned m_contextId;
 };
 
 } // namespace blink
 
 #endif // AudioContext_h