rocksdb/utilities/cassandra/merge_operator.h
Pengchao Wang 825a22c00c garbage collect tombstones in merge operator
Summary:
Remove cassandra tombstone when reaching the max compaction level (full merge). if all columns collected key will be removed in next compaction via compaction filter
Closes https://github.com/facebook/rocksdb/pull/2791

Reviewed By: sagar0

Differential Revision: D5722465

Pulled By: wpc

fbshipit-source-id: 61e9898a5686551653a16383255aeaab3197e65e
2017-08-31 10:11:54 -07:00

38 lines
1.2 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:
explicit CassandraValueMergeOperator(int32_t gc_grace_period_in_seconds)
: gc_grace_period_in_seconds_(gc_grace_period_in_seconds) {}
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; }
private:
int32_t gc_grace_period_in_seconds_;
};
} // namespace cassandra
} // namespace rocksdb