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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/. */
#include "mozilla/ipc/BigBuffer.h"
#include "chrome/common/ipc_message_utils.h"
#include "nsDebug.h"
namespace mozilla::ipc {
BigBuffer::BigBuffer(Adopt, SharedMemoryMappingWithHandle&& aSharedMemory,
size_t aSize)
: mSize(aSize), mData(AsVariant(std::move(aSharedMemory))) {
MOZ_RELEASE_ASSERT(mData.as<1>(), "shared memory must be valid");
MOZ_RELEASE_ASSERT(mSize <= mData.as<1>().Size(),
"shared memory region isn't large enough");
}
BigBuffer::BigBuffer(Adopt, uint8_t* aData, size_t aSize)
: mSize(aSize), mData(AsVariant(UniqueFreePtr<uint8_t[]>{aData})) {}
uint8_t* BigBuffer::Data() {
return mData.is<0>() ? mData.as<0>().get() : mData.as<1>().DataAs<uint8_t>();
}
const uint8_t* BigBuffer::Data() const {
return mData.is<0>() ? mData.as<0>().get()
: mData.as<1>().DataAs<const uint8_t>();
}
auto BigBuffer::TryAllocBuffer(size_t aSize) -> Maybe<Storage> {
if (aSize <= kShmemThreshold) {
auto mem = UniqueFreePtr<uint8_t[]>{
reinterpret_cast<uint8_t*>(malloc(aSize))}; // Fallible!
if (!mem) return {};
return Some(AsVariant(std::move(mem)));
}
size_t capacity = shared_memory::PageAlignedSize(aSize);
auto mapping = shared_memory::Create(capacity).MapWithHandle();
if (!mapping) {
return {};
}
return Some(AsVariant(std::move(mapping)));
}
} // namespace mozilla::ipc
void IPC::ParamTraits<mozilla::ipc::BigBuffer>::Write(MessageWriter* aWriter,
paramType&& aParam) {
using namespace mozilla::ipc;
size_t size = std::exchange(aParam.mSize, 0);
auto data = std::exchange(aParam.mData, BigBuffer::NoData());
WriteParam(aWriter, size);
bool isShmem = data.is<1>();
WriteParam(aWriter, isShmem);
if (isShmem) {
auto handle = data.as<1>().Handle().Clone();
if (!handle) {
aWriter->FatalError("Failed to write data shmem");
} else {
WriteParam(aWriter, std::move(handle));
}
} else {
aWriter->WriteBytes(data.as<0>().get(), size);
}
}
bool IPC::ParamTraits<mozilla::ipc::BigBuffer>::Read(MessageReader* aReader,
paramType* aResult) {
using namespace mozilla::ipc;
size_t size = 0;
bool isShmem = false;
if (!ReadParam(aReader, &size) || !ReadParam(aReader, &isShmem)) {
aReader->FatalError("Failed to read data size and format");
return false;
}
if (isShmem) {
MutableSharedMemoryHandle handle;
size_t expected_size = shared_memory::PageAlignedSize(size);
if (!ReadParam(aReader, &handle) || !handle) {
aReader->FatalError("Failed to read data shmem");
return false;
}
auto mapping = std::move(handle).MapWithHandle();
if (!mapping || mapping.Size() != expected_size) {
aReader->FatalError("Failed to map data shmem");
return false;
}
*aResult = BigBuffer(BigBuffer::Adopt{}, std::move(mapping), size);
return true;
}
mozilla::UniqueFreePtr<uint8_t[]> buf{
reinterpret_cast<uint8_t*>(malloc(size))};
if (!buf) {
aReader->FatalError("Failed to allocate data buffer");
return false;
}
if (!aReader->ReadBytesInto(buf.get(), size)) {
aReader->FatalError("Failed to read data");
return false;
}
*aResult = BigBuffer(BigBuffer::Adopt{}, buf.release(), size);
return true;
}
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