gecko-dev/dom/messagechannel/MessageChannel.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "MessageChannel.h"

#include "mozilla/dom/MessageChannelBinding.h"
#include "mozilla/dom/MessagePort.h"
#include "mozilla/dom/Navigator.h"
#include "mozilla/dom/WorkerRunnable.h"
#include "nsContentUtils.h"
#include "mozilla/dom/Document.h"
#include "nsIGlobalObject.h"
#include "nsIPrincipal.h"
#include "nsServiceManagerUtils.h"

namespace mozilla {
namespace dom {

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(MessageChannel, mGlobal, mPort1, mPort2)
NS_IMPL_CYCLE_COLLECTING_ADDREF(MessageChannel)
NS_IMPL_CYCLE_COLLECTING_RELEASE(MessageChannel)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MessageChannel)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

MessageChannel::MessageChannel(nsIGlobalObject* aGlobal) : mGlobal(aGlobal) {
  MOZ_ASSERT(aGlobal);
}

MessageChannel::~MessageChannel() {}

JSObject* MessageChannel::WrapObject(JSContext* aCx,
                                     JS::Handle<JSObject*> aGivenProto) {
  return MessageChannel_Binding::Wrap(aCx, this, aGivenProto);
}

/* static */
already_AddRefed<MessageChannel> MessageChannel::Constructor(
    const GlobalObject& aGlobal, ErrorResult& aRv) {
  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
  return Constructor(global, aRv);
}

/* static */
already_AddRefed<MessageChannel> MessageChannel::Constructor(
    nsIGlobalObject* aGlobal, ErrorResult& aRv) {
  MOZ_ASSERT(aGlobal);

  nsID portUUID1;
  aRv = nsContentUtils::GenerateUUIDInPlace(portUUID1);
  if (aRv.Failed()) {
    return nullptr;
  }

  nsID portUUID2;
  aRv = nsContentUtils::GenerateUUIDInPlace(portUUID2);
  if (aRv.Failed()) {
    return nullptr;
  }

  RefPtr<MessageChannel> channel = new MessageChannel(aGlobal);

  channel->mPort1 = MessagePort::Create(aGlobal, portUUID1, portUUID2, aRv);
  if (NS_WARN_IF(aRv.Failed())) {
    return nullptr;
  }

  channel->mPort2 = MessagePort::Create(aGlobal, portUUID2, portUUID1, aRv);
  if (NS_WARN_IF(aRv.Failed())) {
    return nullptr;
  }

  channel->mPort1->UnshippedEntangle(channel->mPort2);
  channel->mPort2->UnshippedEntangle(channel->mPort1);

  // MessagePorts should not work if created from a disconnected window.
  nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(aGlobal);
  if (window && !window->GetDocShell()) {
    // The 2 ports are entangled. We can close one of them to close the other
    // too.
    channel->mPort1->CloseForced();
  }

  return channel.forget();
}

}  // namespace dom
}  // namespace mozilla