60 lines
2.4 KiB
C
60 lines
2.4 KiB
C
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/*------------------------------------------------------------------------------*
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* Architecture & Implementation of DBMS *
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*------------------------------------------------------------------------------*
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* Copyright 2022 Databases and Information Systems Group TU Dortmund *
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* Visit us at *
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* http://dbis.cs.tu-dortmund.de/cms/en/home/ *
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* *
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR *
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* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, *
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR *
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* OTHER DEALINGS IN THE SOFTWARE. *
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* *
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* Authors: *
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* Maximilian Berens <maximilian.berens@tu-dortmund.de> *
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* Roland Kühn <roland.kuehn@cs.tu-dortmund.de> *
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* Jan Mühlig <jan.muehlig@tu-dortmund.de> *
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*------------------------------------------------------------------------------*
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*/
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#pragma once
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#include <array>
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#include <cstdint>
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namespace beedb::util
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{
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/**
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* Random generator for cheap pseudo random numbers.
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*/
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class RandomGenerator
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{
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public:
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RandomGenerator() noexcept;
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explicit RandomGenerator(std::uint32_t seed) noexcept;
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/**
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* @return Next pseudo random number.
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*/
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std::int32_t next() noexcept;
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/**
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* @param max_value Max value.
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* @return Next pseudo random number in range (0,max_value].
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*/
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std::uint32_t next(const std::uint64_t max_value) noexcept
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{
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return next() % max_value;
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}
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private:
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std::array<std::uint32_t, 7> _register;
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std::uint32_t _multiplier = 0;
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std::uint32_t _ic_state = 0;
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const std::uint32_t _addend = 0;
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};
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} // namespace beedb::util
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