| // Copyright (c) 2016 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 "net/base/arena.h" |
| |
| #include <string.h> |
| |
| #include <algorithm> |
| |
| #include "base/logging.h" |
| |
| namespace net { |
| |
| UnsafeArena::UnsafeArena(size_t block_size) : block_size_(block_size) {} |
| |
| UnsafeArena::~UnsafeArena() {} |
| |
| UnsafeArena::UnsafeArena(UnsafeArena&& other) = default; |
| UnsafeArena& UnsafeArena::operator=(UnsafeArena&& other) = default; |
| |
| char* UnsafeArena::Memdup(const char* data, size_t size) { |
| Reserve(size); |
| Block& b = blocks_.back(); |
| DCHECK_GE(b.size, b.used + size); |
| char* out = b.data.get() + b.used; |
| b.used += size; |
| memcpy(out, data, size); |
| return out; |
| } |
| |
| void UnsafeArena::Free(void* data, size_t size) { |
| if (blocks_.empty()) { |
| return; |
| } |
| Block& b = blocks_.back(); |
| if (size <= b.used && |
| reinterpret_cast<char*>(data) + size == b.data.get() + b.used) { |
| // The memory region passed by the caller was the most recent allocation |
| // from the final block in this arena. |
| b.used -= size; |
| } |
| } |
| |
| void UnsafeArena::Reset() { |
| blocks_.clear(); |
| } |
| |
| void UnsafeArena::Reserve(size_t additional_space) { |
| if (blocks_.empty()) { |
| AllocBlock(std::max(additional_space, block_size_)); |
| } else { |
| const Block& last = blocks_.back(); |
| if (last.size < last.used + additional_space) { |
| AllocBlock(std::max(additional_space, block_size_)); |
| } |
| } |
| } |
| |
| void UnsafeArena::AllocBlock(size_t size) { |
| blocks_.push_back(Block(size)); |
| } |
| |
| UnsafeArena::Block::Block(size_t s) : data(new char[s]), size(s), used(0) {} |
| |
| UnsafeArena::Block::~Block() {} |
| |
| UnsafeArena::Block::Block(UnsafeArena::Block&& other) |
| : size(other.size), used(other.used) { |
| data = std::move(other.data); |
| } |
| |
| UnsafeArena::Block& UnsafeArena::Block::operator=(UnsafeArena::Block&& other) { |
| size = other.size; |
| used = other.used; |
| data = std::move(other.data); |
| return *this; |
| } |
| |
| } // namespace net |