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// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "mojo/public/cpp/base/big_buffer.h"
#include "base/logging.h"
namespace mojo_base {
namespace internal {
BigBufferSharedMemoryRegion::BigBufferSharedMemoryRegion() = default;
BigBufferSharedMemoryRegion::BigBufferSharedMemoryRegion(
mojo::ScopedSharedBufferHandle buffer_handle,
size_t size)
: size_(size),
buffer_handle_(std::move(buffer_handle)),
buffer_mapping_(buffer_handle_->Map(size)) {}
BigBufferSharedMemoryRegion::BigBufferSharedMemoryRegion(
BigBufferSharedMemoryRegion&& other) = default;
BigBufferSharedMemoryRegion::~BigBufferSharedMemoryRegion() = default;
BigBufferSharedMemoryRegion& BigBufferSharedMemoryRegion::operator=(
BigBufferSharedMemoryRegion&& other) = default;
mojo::ScopedSharedBufferHandle BigBufferSharedMemoryRegion::TakeBufferHandle() {
DCHECK(buffer_handle_.is_valid());
buffer_mapping_.reset();
return std::move(buffer_handle_);
}
} // namespace internal
// static
constexpr size_t BigBuffer::kMaxInlineBytes;
BigBuffer::BigBuffer() : storage_type_(StorageType::kBytes) {}
BigBuffer::BigBuffer(BigBuffer&& other) = default;
BigBuffer::BigBuffer(base::span<const uint8_t> data) {
*this = BigBufferView::ToBigBuffer(BigBufferView(data));
}
BigBuffer::BigBuffer(const std::vector<uint8_t>& data)
: BigBuffer(base::make_span(data)) {}
BigBuffer::BigBuffer(internal::BigBufferSharedMemoryRegion shared_memory)
: storage_type_(StorageType::kSharedMemory),
shared_memory_(std::move(shared_memory)) {}
BigBuffer::~BigBuffer() = default;
BigBuffer& BigBuffer::operator=(BigBuffer&& other) = default;
uint8_t* BigBuffer::data() {
return const_cast<uint8_t*>(const_cast<const BigBuffer*>(this)->data());
}
const uint8_t* BigBuffer::data() const {
switch (storage_type_) {
case StorageType::kBytes:
return bytes_.data();
case StorageType::kSharedMemory:
DCHECK(shared_memory_->buffer_mapping_);
return static_cast<const uint8_t*>(
const_cast<const void*>(shared_memory_->buffer_mapping_.get()));
default:
NOTREACHED();
return nullptr;
}
}
size_t BigBuffer::size() const {
switch (storage_type_) {
case StorageType::kBytes:
return bytes_.size();
case StorageType::kSharedMemory:
return shared_memory_->size();
default:
NOTREACHED();
return 0;
}
}
BigBufferView::BigBufferView() = default;
BigBufferView::BigBufferView(BigBufferView&& other) = default;
BigBufferView::BigBufferView(base::span<const uint8_t> bytes) {
if (bytes.size() > BigBuffer::kMaxInlineBytes) {
auto buffer = mojo::SharedBufferHandle::Create(bytes.size());
if (buffer.is_valid()) {
storage_type_ = BigBuffer::StorageType::kSharedMemory;
shared_memory_.emplace(std::move(buffer), bytes.size());
std::copy(bytes.begin(), bytes.end(),
static_cast<uint8_t*>(shared_memory_->buffer_mapping_.get()));
return;
}
}
// Either the data is small enough or shared memory allocation failed. Either
// way we fall back to directly referencing the input bytes.
storage_type_ = BigBuffer::StorageType::kBytes;
bytes_ = bytes;
}
BigBufferView::~BigBufferView() = default;
BigBufferView& BigBufferView::operator=(BigBufferView&& other) = default;
void BigBufferView::SetBytes(base::span<const uint8_t> bytes) {
DCHECK(bytes_.empty());
DCHECK(!shared_memory_);
storage_type_ = BigBuffer::StorageType::kBytes;
bytes_ = bytes;
}
void BigBufferView::SetSharedMemory(
internal::BigBufferSharedMemoryRegion shared_memory) {
DCHECK(bytes_.empty());
DCHECK(!shared_memory_);
storage_type_ = BigBuffer::StorageType::kSharedMemory;
shared_memory_ = std::move(shared_memory);
}
base::span<const uint8_t> BigBufferView::data() const {
if (storage_type_ == BigBuffer::StorageType::kBytes) {
return bytes_;
} else {
DCHECK(shared_memory_.has_value());
return base::make_span(static_cast<const uint8_t*>(const_cast<const void*>(
shared_memory_->memory())),
shared_memory_->size());
}
}
// static
BigBuffer BigBufferView::ToBigBuffer(BigBufferView view) {
BigBuffer buffer;
buffer.storage_type_ = view.storage_type_;
if (view.storage_type_ == BigBuffer::StorageType::kBytes) {
std::copy(view.bytes_.begin(), view.bytes_.end(),
std::back_inserter(buffer.bytes_));
} else {
buffer.shared_memory_ = std::move(*view.shared_memory_);
}
return buffer;
}
} // namespace mojo_base