Implement BroadcastChannel

third_party/WebKit/Source/modules/broadcastchannel/BroadcastChannel.cpp

+// 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 "modules/broadcastchannel/BroadcastChannel.h"
+
+#include "bindings/core/v8/SerializedScriptValue.h"
+#include "bindings/core/v8/SerializedScriptValueFactory.h"
+#include "core/dom/ExceptionCode.h"
+#include "core/events/MessageEvent.h"
+#include "platform/ThreadSafeFunctional.h"
+#include "platform/mojo/MojoHelper.h"
+#include "public/platform/Platform.h"
+#include "public/platform/ServiceRegistry.h"
+#include "public/platform/WebBlobInfo.h"
+
+namespace blink {
+
+namespace {
+
+    void connectToService(mojo::InterfaceRequest<webmessaging::mojom::blink::BroadcastChannelService> request)
+    {
+        DCHECK(Platform::current()->mainThread()->isCurrentThread());
+        Platform::current()->serviceRegistry()->connectToRemoteService(std::move(request));
+    }
+
+    webmessaging::mojom::blink::BroadcastChannelServicePtr& getThreadSpecificService()
+    {
+        DEFINE_THREAD_SAFE_STATIC_LOCAL(ThreadSpecific<webmessaging::mojom::blink::BroadcastChannelServicePtr>, service, new ThreadSpecific<webmessaging::mojom::blink::BroadcastChannelServicePtr>);
+        if (!service.isSet()) {
+            Platform::current()->mainThread()->getWebTaskRunner()->postTask(BLINK_FROM_HERE,
+                threadSafeBind(&connectToService, passed(mojo::GetProxy(&*service))));
+        }
+        return *service;
+    }
+
+} // namespace
+
+// static
+BroadcastChannel* BroadcastChannel::create(ExecutionContext* executionContext, const String& name)
+{
+    BroadcastChannel* channel = new BroadcastChannel(executionContext, name);
+    channel->suspendIfNeeded();
+    return channel;
+}
+
+BroadcastChannel::~BroadcastChannel()
+{
+}
+
+void BroadcastChannel::postMessage(const ScriptValue& message, ExceptionState& exceptionState)
+{
+    if (!m_binding.is_bound()) {
+        exceptionState.throwDOMException(InvalidStateError, "Channel is closed");
+        return;
+    }
+    WebBlobInfoArray blobInfo;
+    RefPtr<SerializedScriptValue> value = SerializedScriptValueFactory::instance().create(message.isolate(), message, &blobInfo, exceptionState);
+    if (exceptionState.hadException())
+        return;
+
+    String data = value->toWireString();
+    m_remoteClient->OnMessage(data);
+}
+
+void BroadcastChannel::close()
+{
+    m_remoteClient.reset();
+    m_binding.Close();
+}
+
+const AtomicString& BroadcastChannel::interfaceName() const
+{
+    return EventTargetNames::BroadcastChannel;
+}
+
+bool BroadcastChannel::hasPendingActivity() const
+{
+    return m_binding.is_bound() && hasEventListeners(EventTypeNames::message);
+}
+
+DEFINE_TRACE(BroadcastChannel)
+{
+    ActiveDOMObject::trace(visitor);
+    EventTargetWithInlineData::trace(visitor);
+}
+
+BroadcastChannel::BroadcastChannel(ExecutionContext* executionContext, const String& name)
+    : ActiveScriptWrappable(this)
+    , ActiveDOMObject(executionContext)
+    , m_name(name)
+    , m_binding(this)
+{
+    webmessaging::mojom::blink::BroadcastChannelServicePtr& service = getThreadSpecificService();
+
+    // m_binding is for messages sent to this instance of the channel.
+    webmessaging::mojom::blink::BroadcastChannelClientAssociatedPtrInfo localClientInfo;
+    m_binding.Bind(&localClientInfo, service.associated_group());
+    m_binding.set_connection_error_handler(createBaseCallback(bind(&BroadcastChannel::OnError, this)));
+
+    // m_connection is for messages sent from this instance of the channel.
+    webmessaging::mojom::blink::BroadcastChannelClientAssociatedPtrInfo remoteClientInfo;
+    mojo::AssociatedInterfaceRequest<webmessaging::mojom::blink::BroadcastChannelClient> remoteCientRequest;
+    service.associated_group()->CreateAssociatedInterface(mojo::AssociatedGroup::WILL_PASS_REQUEST, &remoteClientInfo, &remoteCientRequest);
+    m_remoteClient.Bind(std::move(remoteClientInfo));
+    m_remoteClient.set_connection_error_handler(createBaseCallback(bind(&BroadcastChannel::OnError, this)));
+
+    service->ConnectToChannel(executionContext->getSecurityOrigin()->toString(), name, std::move(localClientInfo), std::move(remoteCientRequest));
+}
+
+void BroadcastChannel::OnMessage(const String& message)
+{
+    RefPtr<SerializedScriptValue> value = SerializedScriptValueFactory::instance().createFromWire(message);
+    dispatchEvent(MessageEvent::create(nullptr, value.release(), getExecutionContext()->getSecurityOrigin()->toString()));
+}
+
+void BroadcastChannel::OnError()
+{
+    close();
+}
+
+} // namespace blink