rocksdb/utilities/merge_operators/string_append/stringappend2.h
Deon Nicholas ad48c3c262 Benchmarking for Merge Operator
Summary:
Updated db_bench and utilities/merge_operators.h to allow for dynamic benchmarking
of merge operators in db_bench. Added a new test (--benchmarks=mergerandom), which performs
a bunch of random Merge() operations over random keys. Also added a "--merge_operator=" flag
so that the tester can easily benchmark different merge operators. Currently supports
the PutOperator and UInt64Add operator. Support for stringappend or list append may come later.

Test Plan:
	1. make db_bench
	2. Test the PutOperator (simulating Put) as follows:
./db_bench --benchmarks=fillrandom,readrandom,updaterandom,readrandom,mergerandom,readrandom --merge_operator=put
--threads=2

3. Test the UInt64AddOperator (simulating numeric addition) similarly:
./db_bench --value_size=8 --benchmarks=fillrandom,readrandom,updaterandom,readrandom,mergerandom,readrandom
--merge_operator=uint64add --threads=2

Reviewers: haobo, dhruba, zshao, MarkCallaghan

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11535
2013-08-15 17:13:07 -07:00

51 lines
1.8 KiB
C++

/**
* A TEST MergeOperator for rocksdb/leveldb 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
*/
#include "leveldb/merge_operator.h"
#include "leveldb/slice.h"
namespace leveldb {
class StringAppendTESTOperator : public MergeOperator {
public:
StringAppendTESTOperator(char delim_char); /// Constructor with delimiter
virtual bool Merge(const Slice& key,
const Slice* existing_value,
const std::deque<std::string>& operand_sequence,
std::string* new_value,
Logger* logger) const override;
virtual bool PartialMerge(const Slice& key,
const Slice& left_operand,
const Slice& right_operand,
std::string* new_value,
Logger* logger) const override;
virtual const char* Name() const override;
private:
// A version of PartialMerge that actually performs "partial merging".
// Use this to simulate the exact behaviour of the StringAppendOperator.
bool _AssocPartialMerge(const Slice& key,
const Slice& left_operand,
const Slice& right_operand,
std::string* new_value,
Logger* logger) const;
char delim_; // The delimiter is inserted between elements
};
} // namespace leveldb