mirror of https://github.com/facebook/rocksdb.git
36 lines
1.2 KiB
C++
36 lines
1.2 KiB
C++
// Copyright (c) 2011-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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//
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// A 'model' merge operator with uint64 addition semantics
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// Implemented as an AssociativeMergeOperator for simplicity and example.
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#pragma once
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#include "rocksdb/merge_operator.h"
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#include "utilities/merge_operators.h"
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namespace ROCKSDB_NAMESPACE {
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class Logger;
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class Slice;
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class UInt64AddOperator : public AssociativeMergeOperator {
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public:
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static const char* kClassName() { return "UInt64AddOperator"; }
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static const char* kNickName() { return "uint64add"; }
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const char* Name() const override { return kClassName(); }
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const char* NickName() const override { return kNickName(); }
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bool Merge(const Slice& /*key*/, const Slice* existing_value,
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const Slice& value, std::string* new_value,
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Logger* logger) const override;
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private:
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// Takes the string and decodes it into a uint64_t
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// On error, prints a message and returns 0
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uint64_t DecodeInteger(const Slice& value, Logger* logger) const;
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};
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} // namespace ROCKSDB_NAMESPACE
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