| // Copyright 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 "quiche/common/quiche_simple_arena.h" |
| |
| #include <algorithm> |
| #include <cstring> |
| |
| #include "quiche/common/platform/api/quiche_logging.h" |
| |
| namespace quiche { |
| |
| QuicheSimpleArena::QuicheSimpleArena(size_t block_size) |
| : block_size_(block_size) {} |
| |
| QuicheSimpleArena::~QuicheSimpleArena() = default; |
| |
| QuicheSimpleArena::QuicheSimpleArena(QuicheSimpleArena&& other) = default; |
| QuicheSimpleArena& QuicheSimpleArena::operator=(QuicheSimpleArena&& other) = |
| default; |
| |
| char* QuicheSimpleArena::Alloc(size_t size) { |
| Reserve(size); |
| Block& b = blocks_.back(); |
| QUICHE_DCHECK_GE(b.size, b.used + size); |
| char* out = b.data.get() + b.used; |
| b.used += size; |
| return out; |
| } |
| |
| char* QuicheSimpleArena::Realloc(char* original, size_t oldsize, |
| size_t newsize) { |
| QUICHE_DCHECK(!blocks_.empty()); |
| Block& last = blocks_.back(); |
| if (last.data.get() <= original && original < last.data.get() + last.size) { |
| // (original, oldsize) is in the last Block. |
| QUICHE_DCHECK_GE(last.data.get() + last.used, original + oldsize); |
| if (original + oldsize == last.data.get() + last.used) { |
| // (original, oldsize) was the most recent allocation, |
| if (original + newsize < last.data.get() + last.size) { |
| // (original, newsize) fits in the same Block. |
| last.used += newsize - oldsize; |
| return original; |
| } |
| } |
| } |
| char* out = Alloc(newsize); |
| memcpy(out, original, oldsize); |
| return out; |
| } |
| |
| char* QuicheSimpleArena::Memdup(const char* data, size_t size) { |
| char* out = Alloc(size); |
| memcpy(out, data, size); |
| return out; |
| } |
| |
| void QuicheSimpleArena::Free(char* data, size_t size) { |
| if (blocks_.empty()) { |
| return; |
| } |
| Block& b = blocks_.back(); |
| if (size <= b.used && 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 QuicheSimpleArena::Reset() { |
| blocks_.clear(); |
| status_.bytes_allocated_ = 0; |
| } |
| |
| void QuicheSimpleArena::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 QuicheSimpleArena::AllocBlock(size_t size) { |
| blocks_.push_back(Block(size)); |
| status_.bytes_allocated_ += size; |
| } |
| |
| QuicheSimpleArena::Block::Block(size_t s) |
| : data(new char[s]), size(s), used(0) {} |
| |
| QuicheSimpleArena::Block::~Block() = default; |
| |
| QuicheSimpleArena::Block::Block(QuicheSimpleArena::Block&& other) |
| : size(other.size), used(other.used) { |
| data = std::move(other.data); |
| } |
| |
| QuicheSimpleArena::Block& QuicheSimpleArena::Block::operator=( |
| QuicheSimpleArena::Block&& other) { |
| size = other.size; |
| used = other.used; |
| data = std::move(other.data); |
| return *this; |
| } |
| |
| } // namespace quiche |