14b3f683a1
Summary: WriteUnPrepared adds a virtual function, MaxUnpreparedSequenceNumber, to ReadCallback, which returns 0 unless WriteUnPrepared is enabled and the transaction has uncommitted data written to the DB. Together with snapshot sequence number, this determines the last sequence that is visible to reads. The patch clarifies the guarantees of the GetIterator API in WriteUnPrepared transactions and make use of that to statically initialize the read callback and thus avoid the virtual call. Furthermore it increases the minimum value for min_uncommitted from 0 to 1 as seq 0 is used only for last level keys that are committed in all snapshots. The following benchmark shows +0.26% higher throughput in seekrandom benchmark. Benchmark: ./db_bench --benchmarks=fillrandom --use_existing_db=0 --num=1000000 --db=/dev/shm/dbbench ./db_bench --benchmarks=seekrandom[X10] --use_existing_db=1 --db=/dev/shm/dbbench --num=1000000 --duration=60 --seek_nexts=100 seekrandom [AVG 10 runs] : 20355 ops/sec; 225.2 MB/sec seekrandom [MEDIAN 10 runs] : 20425 ops/sec; 225.9 MB/sec ./db_bench_lessvirtual3 --benchmarks=seekrandom[X10] --use_existing_db=1 --db=/dev/shm/dbbench --num=1000000 --duration=60 --seek_nexts=100 seekrandom [AVG 10 runs] : 20409 ops/sec; 225.8 MB/sec seekrandom [MEDIAN 10 runs] : 20487 ops/sec; 226.6 MB/sec Pull Request resolved: https://github.com/facebook/rocksdb/pull/5049 Differential Revision: D14366459 Pulled By: maysamyabandeh fbshipit-source-id: ebaff8908332a5ae9af7defeadabcb624be660ef
55 lines
1.4 KiB
C++
55 lines
1.4 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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#pragma once
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#include <stdint.h>
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#include "rocksdb/slice.h"
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namespace rocksdb {
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// Define all public custom types here.
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// Represents a sequence number in a WAL file.
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typedef uint64_t SequenceNumber;
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const SequenceNumber kMinUnCommittedSeq = 1; // 0 is always committed
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// User-oriented representation of internal key types.
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enum EntryType {
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kEntryPut,
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kEntryDelete,
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kEntrySingleDelete,
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kEntryMerge,
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kEntryRangeDeletion,
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kEntryBlobIndex,
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kEntryOther,
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};
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// <user key, sequence number, and entry type> tuple.
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struct FullKey {
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Slice user_key;
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SequenceNumber sequence;
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EntryType type;
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FullKey() : sequence(0) {} // Intentionally left uninitialized (for speed)
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FullKey(const Slice& u, const SequenceNumber& seq, EntryType t)
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: user_key(u), sequence(seq), type(t) {}
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std::string DebugString(bool hex = false) const;
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void clear() {
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user_key.clear();
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sequence = 0;
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type = EntryType::kEntryPut;
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}
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};
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// Parse slice representing internal key to FullKey
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// Parsed FullKey is valid for as long as the memory pointed to by
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// internal_key is alive.
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bool ParseFullKey(const Slice& internal_key, FullKey* result);
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} // namespace rocksdb
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