ceph/src/rocksdb/memtable/memtable_allocator.h

   1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under the BSD-style license found in the
   3 //  LICENSE file in the root directory of this source tree. An additional grant
   4 //  of patent rights can be found in the PATENTS file in the same directory.
   5 //
   6 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
   7 // Use of this source code is governed by a BSD-style license that can be
   8 // found in the LICENSE file. See the AUTHORS file for names of contributors.
   9 //
  10 // This is used by the MemTable to allocate write buffer memory. It connects
  11 // to WriteBufferManager so we can track and enforce overall write buffer
  12 // limits.
  13
  14 #pragma once
  15
  16 #include <atomic>
  17 #include "rocksdb/write_buffer_manager.h"
  18 #include "util/allocator.h"
  19
  20 namespace rocksdb {
  21
  22 class Logger;
  23
  24 class MemTableAllocator : public Allocator {
  25  public:
  26   explicit MemTableAllocator(Allocator* allocator,
  27                              WriteBufferManager* write_buffer_manager);
  28   ~MemTableAllocator();
  29
  30   // Allocator interface
  31   char* Allocate(size_t bytes) override;
  32   char* AllocateAligned(size_t bytes, size_t huge_page_size = 0,
  33                         Logger* logger = nullptr) override;
  34   size_t BlockSize() const override;
  35
  36   // Call when we're finished allocating memory so we can free it from
  37   // the write buffer's limit.
  38   void DoneAllocating();
  39
  40  private:
  41   Allocator* allocator_;
  42   WriteBufferManager* write_buffer_manager_;
  43   std::atomic<size_t> bytes_allocated_;
  44
  45   // No copying allowed
  46   MemTableAllocator(const MemTableAllocator&);
  47   void operator=(const MemTableAllocator&);
  48 };
  49
  50 }  // namespace rocksdb