Merge WebKit at r75315: Initial merge by git.

Change-Id: I570314b346ce101c935ed22a626b48c2af266b84

1 files changed, 104 insertions, 0 deletions

diff --git a/Source/WebCore/webaudio/JavaScriptAudioNode.h b/Source/WebCore/webaudio/JavaScriptAudioNode.h
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+++ b/Source/WebCore/webaudio/JavaScriptAudioNode.h
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+/*
+ * 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
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef JavaScriptAudioNode_h
+#define JavaScriptAudioNode_h
+
+#include "ActiveDOMObject.h"
+#include "AudioNode.h"
+#include "EventListener.h"
+#include "EventTarget.h"
+#include <wtf/PassRefPtr.h>
+#include <wtf/RefPtr.h>
+#include <wtf/Vector.h>
+
+namespace WebCore {
+
+class AudioBuffer;
+class AudioContext;
+class AudioProcessingEvent;
+class Float32Array;
+
+// JavaScriptAudioNode is an AudioNode which allows for arbitrary synthesis or processing directly using JavaScript.
+// The API allows for a variable number of inputs and outputs, although it must have at least one input or output.
+// This basic implementation supports no more than one input and output.
+// The "onaudioprocess" attribute is an event listener which will get called periodically with an AudioProcessingEvent which has
+// AudioBuffers for each input and output.
+
+class JavaScriptAudioNode : public AudioNode, public EventTarget {
+public:
+    // bufferSize must be one of the following values: 256, 512, 1024, 2048, 4096, 8192, 16384.
+    // This value controls how frequently the onaudioprocess event handler is called and how many sample-frames need to be processed each call.
+    // Lower numbers for bufferSize will result in a lower (better) latency. Higher numbers will be necessary to avoid audio breakup and glitches.
+    // The value chosen must carefully balance between latency and audio quality.
+    static PassRefPtr<JavaScriptAudioNode> create(AudioContext*, double sampleRate, size_t bufferSize, unsigned numberOfInputs = 1, unsigned numberOfOutputs = 1);
+
+    virtual ~JavaScriptAudioNode();
+
+    // AudioNode
+    virtual void process(size_t framesToProcess);
+    virtual void reset();
+    virtual void initialize();
+    virtual void uninitialize();
+
+    // EventTarget
+    virtual ScriptExecutionContext* scriptExecutionContext() const;
+    virtual JavaScriptAudioNode* toJavaScriptAudioNode();
+    virtual EventTargetData* eventTargetData() { return &m_eventTargetData; }
+    virtual EventTargetData* ensureEventTargetData()  { return &m_eventTargetData; }
+
+    size_t bufferSize() const { return m_bufferSize; }
+
+    DEFINE_ATTRIBUTE_EVENT_LISTENER(audioprocess);
+
+    // Reconcile ref/deref which are defined both in AudioNode and EventTarget.
+    using AudioNode::ref;
+    using AudioNode::deref;
+    
+private:
+    JavaScriptAudioNode(AudioContext*, double sampleRate, size_t bufferSize, unsigned numberOfInputs, unsigned numberOfOutputs);
+
+    static void fireProcessEventDispatch(void* userData);
+    void fireProcessEvent();
+
+    // Double buffering
+    unsigned doubleBufferIndex() const { return m_doubleBufferIndex; }
+    void swapBuffers() { m_doubleBufferIndex = 1 - m_doubleBufferIndex; }
+    unsigned m_doubleBufferIndex;
+    unsigned m_doubleBufferIndexForEvent;
+    Vector<RefPtr<AudioBuffer> > m_inputBuffers;
+    Vector<RefPtr<AudioBuffer> > m_outputBuffers;
+
+    virtual void refEventTarget() { ref(); }
+    virtual void derefEventTarget() { deref(); }
+    EventTargetData m_eventTargetData;
+
+    size_t m_bufferSize;
+    unsigned m_bufferReadWriteIndex;
+    volatile bool m_isRequestOutstanding;
+};
+
+} // namespace WebCore
+
+#endif // JavaScriptAudioNode_h