foundationdb/flow/DeterministicRandom.h

/*
 * DeterministicRandom.h
 *
 * This source file is part of the FoundationDB open source project
 *
 * Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef FLOW_DETERIMINISTIC_RANDOM_H
#define FLOW_DETERIMINISTIC_RANDOM_H
#pragma once

#include <cinttypes>
#include "flow/IRandom.h"
#include "flow/Error.h"
#include "flow/Trace.h"
#include "flow/FastRef.h"

#include <random>

class DeterministicRandom : public IRandom, public ReferenceCounted<DeterministicRandom> {
private:
	std::mt19937 random;
	uint64_t next;
	bool useRandLog;

	uint64_t gen64();

public:
	DeterministicRandom(uint32_t seed, bool useRandLog = false);
	double random01() override;
	int randomInt(int min, int maxPlusOne) override;
	int64_t randomInt64(int64_t min, int64_t maxPlusOne) override;
	uint32_t randomUInt32() override;
	uint64_t randomUInt64() override;
	uint32_t randomSkewedUInt32(uint32_t min, uint32_t maxPlusOne) override;
	UID randomUniqueID() override;
	char randomAlphaNumeric() override;
	std::string randomAlphaNumeric(int length) override;
	uint64_t peek() const override;
	void addref() override;
	void delref() override;
};

#endif