Implement AudioWorkletProcessor interface

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

+// Copyright 2017 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 AudioWorkletProcessorDefinition_h
+#define AudioWorkletProcessorDefinition_h
+
+#include "bindings/core/v8/ScopedPersistent.h"
+#include "platform/heap/Handle.h"
+#include "v8/include/v8.h"
+
+namespace blink {
+
+class AudioBuffer;
+class ScriptState;
+
+// Represents a JavaScript class definition registered in the
+// AudioWorkletGlobalScope. After the registration, a definition class contains

[nhiroki, 2017/03/06 10:08:44]

Can you explain the thread that this class lives on? For example, "This is
constructed and destroyed on a worker thread. All methods must be called on the
worker thread."

[hongchan, 2017/03/06 20:06:12]

Done.

+// the V8 representation of class components (constructor, process callback,
+// prototypes and parameter descriptors).
+class AudioWorkletProcessorDefinition final
+    : public GarbageCollectedFinalized<AudioWorkletProcessorDefinition> {
+ public:
+  static AudioWorkletProcessorDefinition* create(
+      ScriptState*,
+      v8::Local<v8::Function> constructor,
+      v8::Local<v8::Function> process);
+
+  virtual ~AudioWorkletProcessorDefinition();
+
+  // Create a V8 object instance of AudioWorkletProcessor from the definition.
+  v8::Local<v8::Object> createInstance();
+
+  // Perform process() call with a instance.

[haraken, 2017/03/06 11:51:12]

an instance

[hongchan, 2017/03/06 20:06:12]

Done.

+  bool process(v8::Local<v8::Object> instance,
+               AudioBuffer* inputBuffer,
+               AudioBuffer* outputBuffer);
+
+  ScriptState* getScriptState() const { return m_scriptState.get(); }
+
+  DEFINE_INLINE_TRACE(){};
+
+ private:
+  AudioWorkletProcessorDefinition(ScriptState*,
+                                  v8::Local<v8::Function> constructor,
+                                  v8::Local<v8::Function> process);
+
+  RefPtr<ScriptState> m_scriptState;

[haraken, 2017/03/06 11:51:12]

I'd like to remove this ScriptState since it should be equal to
AudioWorkletGlobalScope's ScriptState.

[hongchan, 2017/03/06 20:06:12]

ikilpatrick@ responded to this - I think the definition needs to keep the state
in order to invoke constructor and process method properly.

[haraken, 2017/03/06 20:49:44]

So my proposal is to move process() and createInstance() to
AudioWorkletGlobalScope. I'd prefer centralizing script controlling logics into
AudioWorkletGlobalScope.

+
+  // The definition is per global scope. The active instance of
+  // AudioProcessorWorklet should be passed into these to perform JS function.
+  ScopedPersistent<v8::Function> m_constructor;
+  ScopedPersistent<v8::Function> m_process;
+
+  // TODO:
+  // ScopedPersistent<v8::Array> m_parameterDescriptors;
+};
+
+}  // namespace blink
+
+#endif  // AudioWorkletProcessorDefinition_h