gecko-dev/dom/ipc/StructuredCloneData.h

163 строки
3.9 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_ipc_StructuredCloneData_h
#define mozilla_dom_ipc_StructuredCloneData_h
#include <algorithm>
#include "mozilla/RefPtr.h"
#include "mozilla/dom/StructuredCloneHolder.h"
#include "nsISupportsImpl.h"
namespace IPC {
class Message;
}
class PickleIterator;
namespace mozilla {
namespace dom {
namespace ipc {
class SharedJSAllocatedData final
{
public:
SharedJSAllocatedData(uint64_t* aData, size_t aDataLength)
: mData(aData), mDataLength(aDataLength)
{
MOZ_ASSERT(mData);
}
static already_AddRefed<SharedJSAllocatedData>
AllocateForExternalData(size_t aDataLength)
{
uint64_t* data = Allocate64bitSafely(aDataLength);
if (!data) {
return nullptr;
}
RefPtr<SharedJSAllocatedData> sharedData =
new SharedJSAllocatedData(data, aDataLength);
return sharedData.forget();
}
static already_AddRefed<SharedJSAllocatedData>
CreateFromExternalData(const void* aData, size_t aDataLength)
{
RefPtr<SharedJSAllocatedData> sharedData =
AllocateForExternalData(aDataLength);
memcpy(sharedData->Data(), aData, aDataLength);
return sharedData.forget();
}
NS_INLINE_DECL_REFCOUNTING(SharedJSAllocatedData)
uint64_t* Data() const { return mData; }
size_t DataLength() const { return mDataLength; }
private:
~SharedJSAllocatedData()
{
js_free(mData);
}
static uint64_t*
Allocate64bitSafely(size_t aSize)
{
// Structured cloning requires 64-bit aligment.
return static_cast<uint64_t*>(js_malloc(std::max(sizeof(uint64_t), aSize)));
}
uint64_t* mData;
size_t mDataLength;
};
class StructuredCloneData : public StructuredCloneHolder
{
public:
StructuredCloneData()
: StructuredCloneHolder(StructuredCloneHolder::CloningSupported,
StructuredCloneHolder::TransferringSupported,
StructuredCloneHolder::DifferentProcess)
, mExternalData(nullptr)
, mExternalDataLength(0)
{}
StructuredCloneData(const StructuredCloneData&) = delete;
~StructuredCloneData()
{
MOZ_ASSERT(!(mExternalData && mSharedData));
}
StructuredCloneData&
operator=(const StructuredCloneData& aOther) = delete;
const nsTArray<RefPtr<BlobImpl>>& BlobImpls() const
{
return mBlobImplArray;
}
nsTArray<RefPtr<BlobImpl>>& BlobImpls()
{
return mBlobImplArray;
}
bool Copy(const StructuredCloneData& aData);
void Read(JSContext* aCx,
JS::MutableHandle<JS::Value> aValue,
ErrorResult &aRv);
void Write(JSContext* aCx,
JS::Handle<JS::Value> aValue,
ErrorResult &aRv);
void Write(JSContext* aCx,
JS::Handle<JS::Value> aValue,
JS::Handle<JS::Value> aTransfers,
ErrorResult &aRv);
void UseExternalData(uint64_t* aData, size_t aDataLength)
{
MOZ_ASSERT(!Data());
mExternalData = aData;
mExternalDataLength = aDataLength;
}
bool CopyExternalData(const void* aData, size_t aDataLength);
uint64_t* Data() const
{
return mSharedData ? mSharedData->Data() : mExternalData;
}
size_t DataLength() const
{
return mSharedData ? mSharedData->DataLength() : mExternalDataLength;
}
SharedJSAllocatedData* SharedData() const
{
return mSharedData;
}
// For IPC serialization
void WriteIPCParams(IPC::Message* aMessage) const;
bool ReadIPCParams(const IPC::Message* aMessage, PickleIterator* aIter);
private:
uint64_t* MOZ_NON_OWNING_REF mExternalData;
size_t mExternalDataLength;
RefPtr<SharedJSAllocatedData> mSharedData;
};
} // namespace ipc
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_ipc_StructuredCloneData_h