5582123dee
Summary: We estimate number of reads per SST files, by updating the counter per file in sampled read requests. This information can later be used to trigger compactions to improve read performacne. Closes https://github.com/facebook/rocksdb/pull/2417 Differential Revision: D5193528 Pulled By: siying fbshipit-source-id: b4241c5ad0eaf444b61afb53f8e6290d9f5da2df
26 lines
974 B
C++
26 lines
974 B
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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#pragma once
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#include "db/version_edit.h"
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#include "util/random.h"
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namespace rocksdb {
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static const uint32_t kFileReadSampleRate = 1024;
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extern bool should_sample_file_read();
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extern void sample_file_read_inc(FileMetaData*);
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inline bool should_sample_file_read() {
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return (Random::GetTLSInstance()->Next() % kFileReadSampleRate == 307);
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}
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inline void sample_file_read_inc(FileMetaData* meta) {
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meta->stats.num_reads_sampled.fetch_add(kFileReadSampleRate,
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std::memory_order_relaxed);
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}
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}
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