rocksdb/db/memtable_allocator.h
sdong 32df9733d1 Add options.write_buffer_manager: control total memtable size across DB instances
Summary: Add option write_buffer_manager to help users control total memory spent on memtables across multiple DB instances.

Test Plan: Add a new unit test.

Reviewers: yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: adela, benj, sumeet, muthu, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59925
2016-07-05 18:11:25 -07:00

51 lines
1.6 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same 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.
//
// This is used by the MemTable to allocate write buffer memory. It connects
// to WriteBufferManager so we can track and enforce overall write buffer
// limits.
#pragma once
#include <atomic>
#include "rocksdb/write_buffer_manager.h"
#include "util/allocator.h"
namespace rocksdb {
class Logger;
class MemTableAllocator : public Allocator {
public:
explicit MemTableAllocator(Allocator* allocator,
WriteBufferManager* write_buffer_manager);
~MemTableAllocator();
// Allocator interface
char* Allocate(size_t bytes) override;
char* AllocateAligned(size_t bytes, size_t huge_page_size = 0,
Logger* logger = nullptr) override;
size_t BlockSize() const override;
// Call when we're finished allocating memory so we can free it from
// the write buffer's limit.
void DoneAllocating();
private:
Allocator* allocator_;
WriteBufferManager* write_buffer_manager_;
std::atomic<size_t> bytes_allocated_;
// No copying allowed
MemTableAllocator(const MemTableAllocator&);
void operator=(const MemTableAllocator&);
};
} // namespace rocksdb