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https://github.com/facebook/rocksdb.git
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b45b1cde3e
Summary: This is a feature to sample data-block compressibility and and report them as stats. 1 in N (tunable) blocks is sampled for compressibility using two algorithms: 1. lz4 or snappy for fast compression 2. zstd or zlib for slow but higher compression. The stats are reported to the caller as raw-bytes and compressed-bytes. The block continues to be compressed for storage using the specified CompressionType. The db_bench_tool how has a command line option for specifying the sampling rate. It's default value is 0 (no sampling). To test the overhead for a certain value, users can compare the performance of db_bench_tool, varying the sampling rate. It is unlikely to have a noticeable impact for high values like 20. Pull Request resolved: https://github.com/facebook/rocksdb/pull/4842 Differential Revision: D13629011 Pulled By: shobhitdayal fbshipit-source-id: 14ca668bcab6499b2a1734edf848eb62a4f4fafa
108 lines
3.5 KiB
C++
108 lines
3.5 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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//
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// This file defines a collection of statistics collectors.
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#pragma once
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#include "rocksdb/table_properties.h"
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#include <memory>
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#include <string>
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#include <vector>
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namespace rocksdb {
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// Base class for internal table properties collector.
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class IntTblPropCollector {
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public:
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virtual ~IntTblPropCollector() {}
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virtual Status Finish(UserCollectedProperties* properties) = 0;
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virtual const char* Name() const = 0;
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// @params key the user key that is inserted into the table.
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// @params value the value that is inserted into the table.
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virtual Status InternalAdd(const Slice& key, const Slice& value,
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uint64_t file_size) = 0;
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virtual void BlockAdd(uint64_t blockRawBytes,
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uint64_t blockCompressedBytesFast,
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uint64_t blockCompressedBytesSlow) = 0;
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virtual UserCollectedProperties GetReadableProperties() const = 0;
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virtual bool NeedCompact() const { return false; }
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};
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// Factory for internal table properties collector.
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class IntTblPropCollectorFactory {
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public:
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virtual ~IntTblPropCollectorFactory() {}
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// has to be thread-safe
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virtual IntTblPropCollector* CreateIntTblPropCollector(
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uint32_t column_family_id) = 0;
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// The name of the properties collector can be used for debugging purpose.
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virtual const char* Name() const = 0;
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};
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// When rocksdb creates a new table, it will encode all "user keys" into
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// "internal keys", which contains meta information of a given entry.
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//
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// This class extracts user key from the encoded internal key when Add() is
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// invoked.
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class UserKeyTablePropertiesCollector : public IntTblPropCollector {
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public:
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// transfer of ownership
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explicit UserKeyTablePropertiesCollector(TablePropertiesCollector* collector)
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: collector_(collector) {}
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virtual ~UserKeyTablePropertiesCollector() {}
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virtual Status InternalAdd(const Slice& key, const Slice& value,
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uint64_t file_size) override;
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virtual void BlockAdd(uint64_t blockRawBytes,
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uint64_t blockCompressedBytesFast,
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uint64_t blockCompressedBytesSlow) override;
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virtual Status Finish(UserCollectedProperties* properties) override;
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virtual const char* Name() const override { return collector_->Name(); }
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UserCollectedProperties GetReadableProperties() const override;
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virtual bool NeedCompact() const override {
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return collector_->NeedCompact();
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}
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protected:
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std::unique_ptr<TablePropertiesCollector> collector_;
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};
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class UserKeyTablePropertiesCollectorFactory
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: public IntTblPropCollectorFactory {
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public:
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explicit UserKeyTablePropertiesCollectorFactory(
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std::shared_ptr<TablePropertiesCollectorFactory> user_collector_factory)
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: user_collector_factory_(user_collector_factory) {}
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virtual IntTblPropCollector* CreateIntTblPropCollector(
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uint32_t column_family_id) override {
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TablePropertiesCollectorFactory::Context context;
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context.column_family_id = column_family_id;
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return new UserKeyTablePropertiesCollector(
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user_collector_factory_->CreateTablePropertiesCollector(context));
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}
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virtual const char* Name() const override {
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return user_collector_factory_->Name();
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}
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private:
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std::shared_ptr<TablePropertiesCollectorFactory> user_collector_factory_;
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};
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} // namespace rocksdb
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