rocksdb/utilities/merge_operators/max_operator.h

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// Copyright (c) 2011-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).
//
// Merge operator that picks the maximum operand, Comparison is based on
// Slice::compare
#pragma once
#include "rocksdb/merge_operator.h"
namespace ROCKSDB_NAMESPACE {
class Logger;
class Slice;
class MaxOperator : public MergeOperator {
public:
static const char* kClassName() { return "MaxOperator"; }
static const char* kNickName() { return "max"; }
const char* Name() const override { return kClassName(); }
const char* NickName() const override { return kNickName(); }
bool FullMergeV2(const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const override;
bool PartialMerge(const Slice& /*key*/, const Slice& left_operand,
const Slice& right_operand, std::string* new_value,
Logger* /*logger*/) const override;
bool PartialMergeMulti(const Slice& /*key*/,
const std::deque<Slice>& operand_list,
std::string* new_value,
Logger* /*logger*/) const override;
};
} // namespace ROCKSDB_NAMESPACE