AudioWorklet prototype

third_party/WebKit/Source/modules/webaudio/AudioWorkletNode.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 AudioWorkletNode_h
+#define AudioWorkletNode_h
+
+
+#include "modules/webaudio/AudioNode.h"
+#include "modules/webaudio/AudioParamMap.h"
+#include "modules/webaudio/AudioWorkletProcessor.h"
+#include "platform/wtf/PassRefPtr.h"
+#include "platform/wtf/Threading.h"
+
+namespace blink {
+
+class BaseAudioContext;
+class ExceptionState;
+
+class AudioWorkletHandler final : public AudioHandler {
+ public:
+  static PassRefPtr<AudioWorkletHandler> Create(AudioNode&,
+                                                float sample_rate,
+                                                String name);
+
+  ~AudioWorkletHandler() override;
+
+  // AudioHandler
+  void Process(size_t frames_to_process) override;
+
+  // To make it work, as a source node.
+  double TailTime() const override;
+  double LatencyTime() const override;
+
+  // This is used by AudioWorkletMessagingProxy to attach
+  // |AudioWorkletProcessor| instance to this handler.
+  void SetProcessorOnRenderingThread(AudioWorkletProcessor*);
+
+ private:
+  AudioWorkletHandler(AudioNode&, float sample_rate, String name);
+
+  UntracedMember<AudioWorkletProcessor> processor_;
+  HashMap<String, RefPtr<AudioParamHandler>> param_handler_map_;
+};
+
+class AudioWorkletNode final : public AudioNode,
+                               public ActiveScriptWrappable<AudioWorkletNode> {
+  DEFINE_WRAPPERTYPEINFO();
+  USING_GARBAGE_COLLECTED_MIXIN(AudioWorkletNode);
+
+ public:
+  static AudioWorkletNode* Create(BaseAudioContext*,
+                                  const String& name,
+                                  ExceptionState&);
+
+  AudioParamMap* parameters() const;
+
+  // Called by handler to initialize AudioParamMap. This is only invoked when
+  // the node instantiation phase, and should never be used afterward.
+  void SetParameterMap(AudioParamMap*);
+
+  AudioWorkletHandler& GetWorkletHandler() const;
+
+  // ScriptWrappable
+  bool HasPendingActivity() const final;
+
+  DECLARE_VIRTUAL_TRACE();
+
+ private:
+  AudioWorkletNode(BaseAudioContext&, const String& name);
+
+  String name_;
+
+  Member<AudioParamMap> parameter_map_;
+};
+
+}  // namespace blink
+
+#endif  // AudioWorkletNode_h