cda4006e87
Summary: * PartialMerge api now takes a list of operands instead of two operands. * Add min_pertial_merge_operands to Options, indicating the minimum number of operands to trigger partial merge. * This diff is based on Schalk's previous diff (D14601), but it also includes necessary changes such as updating the pure C api for partial merge. Test Plan: * make check all * develop tests for cases where partial merge takes more than two operands. TODOs (from Schalk): * Add test with min_partial_merge_operands > 2. * Perform benchmarks to measure the performance improvements (can probably use results of task #2837810.) * Add description of problem to doc/index.html. * Change wiki pages to reflect the interface changes. Reviewers: haobo, igor, vamsi Reviewed By: haobo CC: leveldb, dhruba Differential Revision: https://reviews.facebook.net/D16815
52 lines
1.8 KiB
C++
52 lines
1.8 KiB
C++
/**
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* A TEST MergeOperator for rocksdb that implements string append.
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* It is built using the MergeOperator interface rather than the simpler
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* AssociativeMergeOperator interface. This is useful for testing/benchmarking.
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* While the two operators are semantically the same, all production code
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* should use the StringAppendOperator defined in stringappend.{h,cc}. The
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* operator defined in the present file is primarily for testing.
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*
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* @author Deon Nicholas (dnicholas@fb.com)
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* Copyright 2013 Facebook
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*/
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#pragma once
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#include <deque>
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#include <string>
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#include "rocksdb/merge_operator.h"
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#include "rocksdb/slice.h"
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namespace rocksdb {
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class StringAppendTESTOperator : public MergeOperator {
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public:
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// Constructor with delimiter
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explicit StringAppendTESTOperator(char delim_char);
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virtual bool FullMerge(const Slice& key,
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const Slice* existing_value,
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const std::deque<std::string>& operand_sequence,
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std::string* new_value,
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Logger* logger) const override;
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virtual bool PartialMergeMulti(const Slice& key,
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const std::deque<Slice>& operand_list,
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std::string* new_value, Logger* logger) const
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override;
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virtual const char* Name() const override;
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private:
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// A version of PartialMerge that actually performs "partial merging".
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// Use this to simulate the exact behaviour of the StringAppendOperator.
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bool _AssocPartialMergeMulti(const Slice& key,
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const std::deque<Slice>& operand_list,
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std::string* new_value, Logger* logger) const;
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char delim_; // The delimiter is inserted between elements
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};
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} // namespace rocksdb
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