text: // Copyright 2016 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.
  
  #include "third_party/blink/renderer/modules/webaudio/audio_worklet.h"
  
  #include "third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.h"
  #include "third_party/blink/renderer/bindings/core/v8/v8_binding_for_core.h"
  #include "third_party/blink/renderer/core/frame/local_dom_window.h"
  #include "third_party/blink/renderer/core/workers/worker_clients.h"
  #include "third_party/blink/renderer/modules/webaudio/audio_worklet_messaging_proxy.h"
  #include "third_party/blink/renderer/modules/webaudio/audio_worklet_node.h"
  #include "third_party/blink/renderer/modules/webaudio/base_audio_context.h"
  #include "third_party/blink/renderer/modules/webaudio/cross_thread_audio_worklet_processor_info.h"
  #include "third_party/blink/renderer/platform/instrumentation/use_counter.h"
  
  namespace blink {
  
  AudioWorklet::AudioWorklet(BaseAudioContext* context)
      : Worklet(*To<LocalDOMWindow>(context->GetExecutionContext())),
        context_(context) {}
  
  void AudioWorklet::CreateProcessor(
      scoped_refptr<AudioWorkletHandler> handler,
      MessagePortChannel message_port_channel,
      scoped_refptr<SerializedScriptValue> node_options) {
    DCHECK(IsMainThread());
    DCHECK(GetMessagingProxy());
    GetMessagingProxy()->CreateProcessor(std::move(handler),
                                         std::move(message_port_channel),
                                         std::move(node_options));
  }
  
  void AudioWorklet::NotifyGlobalScopeIsUpdated() {
    DCHECK(IsMainThread());
  
    if (!worklet_started_) {
      context_->NotifyWorkletIsReady();
      worklet_started_ = true;
    }
  }
  
  BaseAudioContext* AudioWorklet::GetBaseAudioContext() const {
    DCHECK(IsMainThread());
    return context_.Get();
  }
  
  const Vector<CrossThreadAudioParamInfo>
      AudioWorklet::GetParamInfoListForProcessor(
      const String& name) {
    DCHECK(IsMainThread());
    DCHECK(GetMessagingProxy());
    return GetMessagingProxy()->GetParamInfoListForProcessor(name);
  }
  
  bool AudioWorklet::IsProcessorRegistered(const String& name) {
    DCHECK(IsMainThread());
    DCHECK(GetMessagingProxy());
    return GetMessagingProxy()->IsProcessorRegistered(name);
  }
  
  bool AudioWorklet::IsReady() {
    DCHECK(IsMainThread());
    return GetMessagingProxy() && GetMessagingProxy()->GetBackingWorkerThread();
  }
  
  bool AudioWorklet::NeedsToCreateGlobalScope() {
    // This is a callback from |Worklet::FetchAndInvokeScript| call, which only
    // can be triggered by Worklet.addModule() call.
    UseCounter::Count(GetExecutionContext(), WebFeature::kAudioWorkletAddModule);
  
    return GetNumberOfGlobalScopes() == 0;
  }
  
  WorkletGlobalScopeProxy* AudioWorklet::CreateGlobalScope() {
    DCHECK_EQ(GetNumberOfGlobalScopes(), 0u);
  
    AudioWorkletMessagingProxy* proxy =
        MakeGarbageCollected<AudioWorkletMessagingProxy>(GetExecutionContext(),
                                                         this);
    proxy->Initialize(MakeGarbageCollected<WorkerClients>(),
                      ModuleResponsesMap());
    return proxy;
  }
  
  AudioWorkletMessagingProxy* AudioWorklet::GetMessagingProxy() {
    return GetNumberOfGlobalScopes() == 0
               ? nullptr
               : static_cast<AudioWorkletMessagingProxy*>(
                     FindAvailableGlobalScope());
  }
  
  void AudioWorklet::Trace(Visitor* visitor) {
    visitor->Trace(context_);
    Worklet::Trace(visitor);
  }
  
  }  // namespace blink
  