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/* -*- 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/. */
/* A type that can be sent without needing to make a copy during
* serialization. In addition the receiver can take ownership of the
* data to avoid having to make an additional copy. */
#ifndef mozilla_ipc_ByteBufUtils_h
#define mozilla_ipc_ByteBufUtils_h
#include "mozilla/ipc/ByteBuf.h"
#include "ipc/IPCMessageUtils.h"
namespace IPC {
template <>
struct ParamTraits<mozilla::ipc::ByteBuf> {
typedef mozilla::ipc::ByteBuf paramType;
// this is where we transfer the memory from the ByteBuf to IPDL, avoiding a
// copy
static void Write(Message* aMsg, paramType&& aParam) {
WriteParam(aMsg, aParam.mLen);
// hand over ownership of the buffer to the Message
aMsg->WriteBytesZeroCopy(aParam.mData, aParam.mLen, aParam.mCapacity);
aParam.mData = nullptr;
aParam.mCapacity = 0;
aParam.mLen = 0;
}
static bool Read(const Message* aMsg, PickleIterator* aIter,
paramType* aResult) {
// We make a copy from the BufferList so that we get a contigous result.
// For users the can handle a non-contiguous result using ExtractBuffers
// is an option, alternatively if the users don't need to take ownership of
// the data they can use the removed FlattenBytes (bug 1297981)
size_t length;
return ReadParam(aMsg, aIter, &length) && aResult->Allocate(length) &&
aMsg->ReadBytesInto(aIter, aResult->mData, length);
}
static void Log(const paramType& aParam, std::wstring* aLog) {
aLog->append(L"(byte buf)");
}
};
} // namespace IPC
#endif // ifndef mozilla_ipc_ByteBufUtils_h
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