rocksdb/utilities/cassandra/merge_operator.h
Sagar Vemuri 132306fbf0 Remove PartialMerge implementation from Cassandra merge operator
Summary:
`PartialMergeMulti` implementation is enough for Cassandra, and `PartialMerge` is not required. Implementing both will just duplicate the code.
As per https://github.com/facebook/rocksdb/blob/master/include/rocksdb/merge_operator.h#L130-L135 :

```
  // The default implementation of PartialMergeMulti will use this function
  // as a helper, for backward compatibility.  Any successor class of
  // MergeOperator should either implement PartialMerge or PartialMergeMulti,
  // although implementing PartialMergeMulti is suggested as it is in general
  // more effective to merge multiple operands at a time instead of two
  // operands at a time.
```
Closes https://github.com/facebook/rocksdb/pull/2737

Reviewed By: scv119

Differential Revision: D5633073

Pulled By: sagar0

fbshipit-source-id: ef4fa102c22fec6a0175ed12f5c44c15afe3c8ca
2017-08-15 14:59:34 -07:00

32 lines
1.1 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 cassandra {
/**
* A MergeOperator for rocksdb that implements Cassandra row value merge.
*/
class CassandraValueMergeOperator : public MergeOperator {
public:
static std::shared_ptr<MergeOperator> CreateSharedInstance();
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;
};
} // namespace cassandra
} // namespace rocksdb