rocksdb/utilities/merge_operators/string_append/stringappend2.h
mrambacher d057e8326d Make MergeOperator+CompactionFilter/Factory into Customizable Classes (#8481)
Summary:
- Changed MergeOperator, CompactionFilter, and CompactionFilterFactory into Customizable classes.
 - Added Options/Configurable/Object Registration for TTL and Cassandra variants
 - Changed the StringAppend MergeOperators to accept a string delimiter rather than a simple char.  Made the delimiter into a configurable option
 - Added tests for new functionality

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8481

Reviewed By: zhichao-cao

Differential Revision: D30136050

Pulled By: mrambacher

fbshipit-source-id: 271d1772835935b6773abaf018ee71e42f9491af
2021-08-06 08:27:25 -07:00

53 lines
2.0 KiB
C++

// Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
/**
* A TEST MergeOperator for rocksdb that implements string append.
* It is built using the MergeOperator interface rather than the simpler
* AssociativeMergeOperator interface. This is useful for testing/benchmarking.
* While the two operators are semantically the same, all production code
* should use the StringAppendOperator defined in stringappend.{h,cc}. The
* operator defined in the present file is primarily for testing.
*
* @author Deon Nicholas (dnicholas@fb.com)
* Copyright 2013 Facebook
*/
#pragma once
#include <deque>
#include <string>
#include "rocksdb/merge_operator.h"
#include "rocksdb/slice.h"
namespace ROCKSDB_NAMESPACE {
class StringAppendTESTOperator : public MergeOperator {
public:
// Constructor with delimiter
explicit StringAppendTESTOperator(char delim_char);
explicit StringAppendTESTOperator(const std::string& delim);
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;
static const char* kClassName() { return "StringAppendTESTOperator"; }
static const char* kNickName() { return "stringappendtest"; }
const char* Name() const override { return kClassName(); }
const char* NickName() const override { return kNickName(); }
private:
// A version of PartialMerge that actually performs "partial merging".
// Use this to simulate the exact behaviour of the StringAppendOperator.
bool _AssocPartialMergeMulti(const Slice& key,
const std::deque<Slice>& operand_list,
std::string* new_value, Logger* logger) const;
std::string delim_; // The delimiter is inserted between elements
};
} // namespace ROCKSDB_NAMESPACE