95b0e89b5d
Summary: Improve write buffer manager in several ways: 1. Size is tracked when arena block is allocated, rather than every allocation, so that it can better track actual memory usage and the tracking overhead is slightly lower. 2. We start to trigger memtable flush when 7/8 of the memory cap hits, instead of 100%, and make 100% much harder to hit. 3. Allow a cache object to be passed into buffer manager and the size allocated by memtable can be costed there. This can help users have one single memory cap across block cache and memtable. Closes https://github.com/facebook/rocksdb/pull/2350 Differential Revision: D5110648 Pulled By: siying fbshipit-source-id: b4238113094bf22574001e446b5d88523ba00017
60 lines
1.8 KiB
C++
60 lines
1.8 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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// This source code is also licensed under the GPLv2 license found in the
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// COPYING file in the root directory of this source tree.
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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//
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// Abstract interface for allocating memory in blocks. This memory is freed
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// when the allocator object is destroyed. See the Arena class for more info.
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#pragma once
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#include <cerrno>
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#include <cstddef>
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#include "rocksdb/write_buffer_manager.h"
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namespace rocksdb {
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class Logger;
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class Allocator {
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public:
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virtual ~Allocator() {}
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virtual char* Allocate(size_t bytes) = 0;
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virtual char* AllocateAligned(size_t bytes, size_t huge_page_size = 0,
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Logger* logger = nullptr) = 0;
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virtual size_t BlockSize() const = 0;
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};
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class AllocTracker {
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public:
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explicit AllocTracker(WriteBufferManager* write_buffer_manager);
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~AllocTracker();
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void Allocate(size_t bytes);
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// Call when we're finished allocating memory so we can free it from
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// the write buffer's limit.
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void DoneAllocating();
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void FreeMem();
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bool is_freed() const { return write_buffer_manager_ == nullptr || freed_; }
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private:
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WriteBufferManager* write_buffer_manager_;
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std::atomic<size_t> bytes_allocated_;
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bool done_allocating_;
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bool freed_;
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// No copying allowed
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AllocTracker(const AllocTracker&);
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void operator=(const AllocTracker&);
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};
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} // namespace rocksdb
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