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https://github.com/facebook/rocksdb.git
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bb38cd03a9
Summary: Now that RocksDB supports conditional merging during point lookups (introduced in #2923), Cassandra value merge operator can be updated to pass in a limit. The limit needs to be passed in from the Cassandra code. Closes https://github.com/facebook/rocksdb/pull/2947 Differential Revision: D5938454 Pulled By: sagar0 fbshipit-source-id: d64a72d53170d8cf202b53bd648475c3952f7d7f
45 lines
1.5 KiB
C++
45 lines
1.5 KiB
C++
// Copyright (c) 2017-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 "rocksdb/merge_operator.h"
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#include "rocksdb/slice.h"
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namespace rocksdb {
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namespace cassandra {
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/**
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* A MergeOperator for rocksdb that implements Cassandra row value merge.
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*/
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class CassandraValueMergeOperator : public MergeOperator {
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public:
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explicit CassandraValueMergeOperator(int32_t gc_grace_period_in_seconds,
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size_t operands_limit = 0)
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: gc_grace_period_in_seconds_(gc_grace_period_in_seconds),
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operands_limit_(operands_limit) {}
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virtual bool FullMergeV2(const MergeOperationInput& merge_in,
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MergeOperationOutput* merge_out) 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,
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Logger* logger) const override;
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virtual const char* Name() const override;
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virtual bool AllowSingleOperand() const override { return true; }
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virtual bool ShouldMerge(const std::vector<Slice>& operands) const override {
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return operands_limit_ > 0 && operands.size() >= operands_limit_;
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}
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private:
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int32_t gc_grace_period_in_seconds_;
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size_t operands_limit_;
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};
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} // namespace cassandra
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} // namespace rocksdb
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