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//
// Copyright (C) 2014 The Android Open Source Project
//
// 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 UPDATE_ENGINE_UPDATE_MANAGER_PRNG_H_
#define UPDATE_ENGINE_UPDATE_MANAGER_PRNG_H_
#include <random>
#include <base/logging.h>
namespace chromeos_update_manager {
// A thread-safe, unsecure, 32-bit pseudo-random number generator based on
// std::mt19937.
class PRNG {
public:
// Initializes the generator with the passed |seed| value.
explicit PRNG(uint32_t seed) : gen_(seed) {}
// Returns a random unsigned 32-bit integer.
uint32_t Rand() { return gen_(); }
// Returns a random integer uniformly distributed in the range [min, max].
int RandMinMax(int min, int max) {
DCHECK_LE(min, max);
return std::uniform_int_distribution<>(min, max)(gen_);
}
private:
// A pseudo-random number generator.
std::mt19937 gen_;
DISALLOW_COPY_AND_ASSIGN(PRNG);
};
} // namespace chromeos_update_manager
#endif // UPDATE_ENGINE_UPDATE_MANAGER_PRNG_H_