rocksdb/utilities/cassandra/merge_operator.h
sdong fdf882ded2 Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433

Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.

Differential Revision: D19977691

fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
2020-02-20 12:09:57 -08:00

45 lines
1.5 KiB
C++

// Copyright (c) 2017-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#include "rocksdb/merge_operator.h"
#include "rocksdb/slice.h"
namespace ROCKSDB_NAMESPACE {
namespace cassandra {
/**
* A MergeOperator for rocksdb that implements Cassandra row value merge.
*/
class CassandraValueMergeOperator : public MergeOperator {
public:
explicit CassandraValueMergeOperator(int32_t gc_grace_period_in_seconds,
size_t operands_limit = 0)
: gc_grace_period_in_seconds_(gc_grace_period_in_seconds),
operands_limit_(operands_limit) {}
virtual bool FullMergeV2(const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const override;
virtual bool PartialMergeMulti(const Slice& key,
const std::deque<Slice>& operand_list,
std::string* new_value,
Logger* logger) const override;
virtual const char* Name() const override;
virtual bool AllowSingleOperand() const override { return true; }
virtual bool ShouldMerge(const std::vector<Slice>& operands) const override {
return operands_limit_ > 0 && operands.size() >= operands_limit_;
}
private:
int32_t gc_grace_period_in_seconds_;
size_t operands_limit_;
};
} // namespace cassandra
} // namespace ROCKSDB_NAMESPACE