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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,
#include "mozilla/ipc/BigBuffer.h"
#include "mozilla/ipc/SharedMemoryBasic.h"
#include "nsDebug.h"
namespace mozilla::ipc {
BigBuffer::BigBuffer(Adopt, SharedMemory* aSharedMemory, size_t aSize)
: mSize(aSize), mData(AsVariant(RefPtr{aSharedMemory})) {
MOZ_RELEASE_ASSERT(aSharedMemory && aSharedMemory->memory(),
"shared memory must be non-null and mapped");
MOZ_RELEASE_ASSERT(mSize <= aSharedMemory->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()
: reinterpret_cast<uint8_t*>(mData.as<1>()->memory());
}
const uint8_t* BigBuffer::Data() const {
return mData.is<0>()
? mData.as<0>().get()
: reinterpret_cast<const uint8_t*>(mData.as<1>()->memory());
}
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)));
}
RefPtr<SharedMemory> shmem = new SharedMemoryBasic();
size_t capacity = SharedMemory::PageAlignedSize(aSize);
if (!shmem->Create(capacity) || !shmem->Map(capacity)) {
return {};
}
return Some(AsVariant(shmem));
}
} // 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) {
if (!data.as<1>()->WriteHandle(aWriter)) {
aWriter->FatalError("Failed to write data shmem");
}
} 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) {
RefPtr<SharedMemory> shmem = new SharedMemoryBasic();
size_t capacity = SharedMemory::PageAlignedSize(size);
if (!shmem->ReadHandle(aReader) || !shmem->Map(capacity)) {
aReader->FatalError("Failed to read data shmem");
return false;
}
*aResult = BigBuffer(BigBuffer::Adopt{}, shmem, 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;
}