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dd29ad4223
Summary: Replace `BlockIter::comparator_` and `IndexBlockIter::user_comparator_wrapper_` with a concrete `UserComparatorWrapper` and `InternalKeyComparator`. The motivation for this change was the inconvenience of not knowing the concrete type of `BlockIter::comparator_`, which prevented calling specialized internal key comparison functions to optimize comparison of keys with global seqno applied. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6944 Test Plan: benchmark setup -- single file DBs, in-memory, no compression. "normal_db" created by regular flush; "ingestion_db" created by ingesting a file. Both DBs have same contents. ``` $ TEST_TMPDIR=/dev/shm/normal_db/ ./db_bench -benchmarks=fillrandom,compact -write_buffer_size=10485760000 -disable_auto_compactions=true -compression_type=none -num=1000000 $ ./ldb write_extern_sst ./tmp.sst --db=/dev/shm/ingestion_db/dbbench/ --compression_type=no --hex --create_if_missing < <(./sst_dump --command=scan --output_hex --file=/dev/shm/normal_db/dbbench/000007.sst | awk 'began {print "0x" substr($1, 2, length($1) - 2), "==>", "0x" $5} ; /^Sst file format: block-based/ {began=1}') $ ./ldb ingest_extern_sst ./tmp.sst --db=/dev/shm/ingestion_db/dbbench/ ``` benchmark run command: ``` $ TEST_TMPDIR=/dev/shm/$DB/ ./db_bench -benchmarks=seekrandom -seek_nexts=$SEEK_NEXT -use_existing_db=true -cache_index_and_filter_blocks=false -num=1000000 -cache_size=0 -threads=1 -reads=200000000 -mmap_read=1 -verify_checksum=false ``` results: perf improved marginally for ingestion_db and did not change significantly for normal_db: SEEK_NEXT | DB | code | ops/sec | % change -- | -- | -- | -- | -- 0 | normal_db | master | 350880 | 0 | normal_db | PR6944 | 351040 | 0.0 0 | ingestion_db | master | 343255 | 0 | ingestion_db | PR6944 | 349424 | 1.8 10 | normal_db | master | 218711 | 10 | normal_db | PR6944 | 217892 | -0.4 10 | ingestion_db | master | 220334 | 10 | ingestion_db | PR6944 | 226437 | 2.8 Reviewed By: pdillinger Differential Revision: D21924676 Pulled By: ajkr fbshipit-source-id: ea4288a2eefa8112eb6c651a671c1de18c12e538
81 lines
2.9 KiB
C++
81 lines
2.9 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root 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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#pragma once
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#include "monitoring/perf_context_imp.h"
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#include "rocksdb/comparator.h"
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namespace ROCKSDB_NAMESPACE {
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// Wrapper of user comparator, with auto increment to
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// perf_context.user_key_comparison_count.
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class UserComparatorWrapper final : public Comparator {
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public:
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// `UserComparatorWrapper`s constructed with the default constructor are not
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// usable and will segfault on any attempt to use them for comparisons.
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UserComparatorWrapper() : user_comparator_(nullptr) {}
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explicit UserComparatorWrapper(const Comparator* const user_cmp)
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: Comparator(user_cmp->timestamp_size()), user_comparator_(user_cmp) {}
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~UserComparatorWrapper() = default;
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const Comparator* user_comparator() const { return user_comparator_; }
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int Compare(const Slice& a, const Slice& b) const override {
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PERF_COUNTER_ADD(user_key_comparison_count, 1);
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return user_comparator_->Compare(a, b);
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}
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bool Equal(const Slice& a, const Slice& b) const override {
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PERF_COUNTER_ADD(user_key_comparison_count, 1);
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return user_comparator_->Equal(a, b);
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}
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const char* Name() const override { return user_comparator_->Name(); }
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void FindShortestSeparator(std::string* start,
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const Slice& limit) const override {
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return user_comparator_->FindShortestSeparator(start, limit);
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}
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void FindShortSuccessor(std::string* key) const override {
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return user_comparator_->FindShortSuccessor(key);
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}
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const Comparator* GetRootComparator() const override {
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return user_comparator_->GetRootComparator();
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}
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bool IsSameLengthImmediateSuccessor(const Slice& s,
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const Slice& t) const override {
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return user_comparator_->IsSameLengthImmediateSuccessor(s, t);
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}
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bool CanKeysWithDifferentByteContentsBeEqual() const override {
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return user_comparator_->CanKeysWithDifferentByteContentsBeEqual();
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}
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int CompareTimestamp(const Slice& ts1, const Slice& ts2) const override {
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return user_comparator_->CompareTimestamp(ts1, ts2);
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}
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using Comparator::CompareWithoutTimestamp;
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int CompareWithoutTimestamp(const Slice& a, bool a_has_ts, const Slice& b,
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bool b_has_ts) const override {
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PERF_COUNTER_ADD(user_key_comparison_count, 1);
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return user_comparator_->CompareWithoutTimestamp(a, a_has_ts, b, b_has_ts);
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}
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private:
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const Comparator* user_comparator_;
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};
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} // namespace ROCKSDB_NAMESPACE
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