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 "core/dom/ExceptionCode.h"
+#include "core/events/EventQueue.h"
+#include "core/events/MessageEvent.h"
+
+namespace blink {
+
+// static
+BroadcastChannel* BroadcastChannel::create(ExecutionContext* executionContext, const String& name, ExceptionState& exceptionState)
+{
+    if (executionContext->getSecurityOrigin()->isUnique()) {
+        // TODO(mek): Decide what to do here depending on https://github.com/whatwg/html/issues/1319
+        exceptionState.throwDOMException(NotSupportedError, "Can't create BroadcastChannel in an opaque origin");
+        return nullptr;
+    }
+    BroadcastChannel* channel = new BroadcastChannel(executionContext, name);
+    channel->suspendIfNeeded();

[haraken, 2016/06/02 04:23:41]

If you make BroadcastChannel a ContextLifecycleObserver, you don't need to call
channel->suspendIfNeeded().

[Marijn Kruisselbrink, 2016/06/02 18:33:29]

Done

+    return channel;
+}
+
+BroadcastChannel::~BroadcastChannel()
+{
+    close();
+}
+
+void BroadcastChannel::postMessage(const ScriptValue& message, ExceptionState& exceptionState)
+{
+    if (!m_connection) {
+        exceptionState.throwDOMException(InvalidStateError, "Channel is closed");
+        return;
+    }
+    RefPtr<SerializedScriptValue> value = SerializedScriptValue::serialize(message.isolate(), message.v8Value(), nullptr, nullptr, exceptionState);
+    if (exceptionState.hadException())
+        return;
+
+    String data = value->toWireString();
+    m_connection->broadcast(this, data);
+}
+
+void BroadcastChannel::close()
+{
+    if (m_connection)
+        m_connection->unregisterClient(this);
+    m_connection = nullptr;
+}
+
+void BroadcastChannel::onMessage(const String& message)
+{
+    // Queue a task to dispatch the event.
+    RefPtr<SerializedScriptValue> value = SerializedScriptValue::create(message);
+    MessageEvent* event = MessageEvent::create(nullptr, value.release(), getExecutionContext()->getSecurityOrigin()->toString());
+    event->setTarget(this);
+    bool success = getExecutionContext()->getEventQueue()->enqueueEvent(event);
+    DCHECK(success);
+    ALLOW_UNUSED_LOCAL(success);
+}
+
+void BroadcastChannel::onError()
+{
+    m_connection = nullptr;
+    close();
+}
+
+const AtomicString& BroadcastChannel::interfaceName() const
+{
+    return EventTargetNames::BroadcastChannel;
+}
+
+bool BroadcastChannel::hasPendingActivity() const
+{
+    return m_connection && hasEventListeners(EventTypeNames::message);
+}
+
+DEFINE_TRACE(BroadcastChannel)
+{
+    ActiveDOMObject::trace(visitor);
+    EventTargetWithInlineData::trace(visitor);
+}
+
+BroadcastChannel::BroadcastChannel(ExecutionContext* executionContext, const String& name)
+    : ActiveScriptWrappable(this)
+    , ActiveDOMObject(executionContext)
+    , m_origin(executionContext->getSecurityOrigin())
+    , m_name(name)
+    , m_connection(BroadcastChannelConnection::getForChannel(m_origin, m_name))
+{
+    m_connection->registerClient(this);
+}
+
+} // namespace blink