allocator.h
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
//
// Abstract interface for allocating memory in blocks. This memory is freed
// when the allocator object is destroyed. See the Arena class for more info.
#pragma once
#include <cerrno>
#include <cstddef>
#include "rocksdb/write_buffer_manager.h"
namespace rocksdb {
class Logger;
class Allocator {
public:
virtual ~Allocator() {}
virtual char* Allocate(size_t bytes) = 0;
virtual char* AllocateAligned(size_t bytes, size_t huge_page_size = 0,
Logger* logger = nullptr) = 0;
virtual size_t BlockSize() const = 0;
};
class AllocTracker {
public:
explicit AllocTracker(WriteBufferManager* write_buffer_manager);
~AllocTracker();
void Allocate(size_t bytes);
// Call when we're finished allocating memory so we can free it from
// the write buffer's limit.
void DoneAllocating();
void FreeMem();
bool is_freed() const { return write_buffer_manager_ == nullptr || freed_; }
private:
WriteBufferManager* write_buffer_manager_;
std::atomic<size_t> bytes_allocated_;
bool done_allocating_;
bool freed_;
// No copying allowed
AllocTracker(const AllocTracker&);
void operator=(const AllocTracker&);
};
} // namespace rocksdb