9c332aa11a
Summary: In this patch, we enhance HashLinkList memtable to reduce performance outliers when a bucket contains too many entries. We switch to skip list for this case to enable binary search. Add threshold_use_skiplist parameter to determine when a bucket needs to switch to skip list. The new data structure is documented in comments in the codes. Test Plan: make all check set threshold_use_skiplist in several tests Reviewers: yhchiang, haobo, ljin Reviewed By: yhchiang, ljin Subscribers: nkg-, xjin, dhruba, yhchiang, leveldb Differential Revision: https://reviews.facebook.net/D19299
49 lines
1.8 KiB
C++
49 lines
1.8 KiB
C++
// Copyright (c) 2013, 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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// 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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#ifndef ROCKSDB_LITE
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#pragma once
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#include "rocksdb/slice_transform.h"
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#include "rocksdb/memtablerep.h"
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namespace rocksdb {
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class HashLinkListRepFactory : public MemTableRepFactory {
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public:
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explicit HashLinkListRepFactory(size_t bucket_count,
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uint32_t threshold_use_skiplist,
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size_t huge_page_tlb_size,
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int bucket_entries_logging_threshold,
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bool if_log_bucket_dist_when_flash)
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: bucket_count_(bucket_count),
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threshold_use_skiplist_(threshold_use_skiplist),
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huge_page_tlb_size_(huge_page_tlb_size),
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bucket_entries_logging_threshold_(bucket_entries_logging_threshold),
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if_log_bucket_dist_when_flash_(if_log_bucket_dist_when_flash) {}
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virtual ~HashLinkListRepFactory() {}
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virtual MemTableRep* CreateMemTableRep(
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const MemTableRep::KeyComparator& compare, Arena* arena,
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const SliceTransform* transform, Logger* logger) override;
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virtual const char* Name() const override {
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return "HashLinkListRepFactory";
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}
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private:
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const size_t bucket_count_;
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const uint32_t threshold_use_skiplist_;
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const size_t huge_page_tlb_size_;
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int bucket_entries_logging_threshold_;
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bool if_log_bucket_dist_when_flash_;
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};
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}
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#endif // ROCKSDB_LITE
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