gecko-dev/dom/serviceworkers/ServiceWorkerCloneData.h

72 строки
2.5 KiB
C++

/* -*- 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/. */
#ifndef mozilla_dom_ServiceWorkerCloneData_h__
#define mozilla_dom_ServiceWorkerCloneData_h__
#include "mozilla/Assertions.h"
#include "mozilla/dom/DOMTypes.h"
#include "mozilla/dom/ipc/StructuredCloneData.h"
#include "nsCOMPtr.h"
#include "nsISupports.h"
class nsISerialEventTarget;
namespace mozilla {
namespace ipc {
class PBackgroundChild;
class PBackgroundParent;
} // namespace ipc
namespace dom {
class ClonedOrErrorMessageData;
// Helper class used to pack structured clone data so that it can be
// passed across thread and process boundaries. Currently the raw
// StructuredCloneData and StructureCloneHolder APIs both make it
// difficult to meet this needs directly. This helper class improves
// the situation by:
//
// 1. Provides a ref-counted version of StructuredCloneData. We need
// StructuredCloneData so we can serialize/deserialize across IPC.
// The move constructor problems in StructuredCloneData (bug 1462676),
// though, makes it hard to pass it around. Passing a ref-counted
// pointer addresses this problem.
// 2. Normally StructuredCloneData runs into problems if you try to move
// it across thread boundaries because it releases its SharedJSAllocatedData
// on the wrong thread. This helper will correctly proxy release the
// shared data on the correct thread.
//
// This helper class should really just be used to serialize on one thread
// and then move the reference across thread/process boundries to the
// target worker thread. This class is not intended to support simultaneous
// read/write operations from different threads at the same time.
class ServiceWorkerCloneData final : public ipc::StructuredCloneData {
nsCOMPtr<nsISerialEventTarget> mEventTarget;
bool mIsErrorMessageData;
~ServiceWorkerCloneData();
public:
ServiceWorkerCloneData();
bool BuildClonedMessageData(ClonedOrErrorMessageData& aClonedData);
void CopyFromClonedMessageData(const ClonedOrErrorMessageData& aClonedData);
void SetAsErrorMessageData();
bool IsErrorMessageData() const;
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ServiceWorkerCloneData)
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_ServiceWorkerCloneData_h__