8f52972cf9
Summary: An arbitrary string can be used as a delimiter in StringAppend merge operator flavor. In particular, it allows using an empty string, combining binary values for the same key byte-to-byte one next to another. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8536 Reviewed By: mrambacher Differential Revision: D29962120 Pulled By: zhichao-cao fbshipit-source-id: 4ef5d846a47835cf428a11200409e30e2dbffc4f
58 lines
2.1 KiB
C++
58 lines
2.1 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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#pragma once
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#include "rocksdb/merge_operator.h"
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#include <stdio.h>
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#include <memory>
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#include <string>
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namespace ROCKSDB_NAMESPACE {
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class MergeOperators {
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public:
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static std::shared_ptr<MergeOperator> CreatePutOperator();
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static std::shared_ptr<MergeOperator> CreateDeprecatedPutOperator();
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static std::shared_ptr<MergeOperator> CreateUInt64AddOperator();
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static std::shared_ptr<MergeOperator> CreateStringAppendOperator();
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static std::shared_ptr<MergeOperator> CreateStringAppendOperator(char delim_char);
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static std::shared_ptr<MergeOperator> CreateStringAppendOperator(
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const std::string& delim);
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static std::shared_ptr<MergeOperator> CreateStringAppendTESTOperator();
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static std::shared_ptr<MergeOperator> CreateMaxOperator();
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static std::shared_ptr<MergeOperator> CreateBytesXOROperator();
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static std::shared_ptr<MergeOperator> CreateSortOperator();
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// Will return a different merge operator depending on the string.
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// TODO: Hook the "name" up to the actual Name() of the MergeOperators?
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static std::shared_ptr<MergeOperator> CreateFromStringId(
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const std::string& name) {
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if (name == "put") {
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return CreatePutOperator();
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} else if (name == "put_v1") {
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return CreateDeprecatedPutOperator();
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} else if ( name == "uint64add") {
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return CreateUInt64AddOperator();
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} else if (name == "stringappend") {
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return CreateStringAppendOperator();
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} else if (name == "stringappendtest") {
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return CreateStringAppendTESTOperator();
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} else if (name == "max") {
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return CreateMaxOperator();
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} else if (name == "bytesxor") {
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return CreateBytesXOROperator();
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} else if (name == "sortlist") {
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return CreateSortOperator();
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} else {
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// Empty or unknown, just return nullptr
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return nullptr;
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}
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}
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};
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} // namespace ROCKSDB_NAMESPACE
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