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<?php |
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namespace Savvot\Random; |
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/** |
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* Static helper class. |
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* Provides uniform way to create RNG objects from different generators and states |
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* |
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* @package Savvot\Random |
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* @author SavvoT <[email protected]> |
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*/ |
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class Random |
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{ |
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const MT = '\Savvot\Random\MtRand'; |
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const XORSHIFT = '\Savvot\Random\XorShiftRand'; |
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const HASH = '\Savvot\Random\HashRand'; |
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/** |
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* Creates RNG from specified class and initializes it with given seed |
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* |
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* @param string $seed Seed to initialize generator's state. Defaults to null (auto) |
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* @param string $rngClass Generator's class. Must be the child of AbstractRand. Defaults to XorShiftRand |
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* @return AbstractRand Newly created PRNG |
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* @throws RandException if generator class is invalid |
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*/ |
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public static function create($seed = null, $rngClass = self::XORSHIFT) |
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{ |
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if (!is_subclass_of($rngClass, '\Savvot\Random\AbstractRand')) { |
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throw new RandException('PRNG class must extend AbstractRand'); |
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} |
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return new $rngClass($seed); |
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} |
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/** |
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* Creates RNG from previously saved state |
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* |
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* @param array $state State array created with getState() method |
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* @return AbstractRand Newly created PRNG |
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* @throws RandException if specified state is invalid |
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*/ |
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public static function createFromState(array $state) |
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{ |
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if (!isset($state['class'])) { |
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throw new RandException('Invalid state'); |
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} |
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$class = $state['class']; |
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if (!is_subclass_of($class, '\Savvot\Random\AbstractRand')) { |
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throw new RandException('Invalid RNG class in state'); |
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} |
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/** @var \Savvot\Random\AbstractRand $prng */ |
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$prng = new $class; |
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$prng->setState($state); |
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return $prng; |
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} |
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} |
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savvot /
random
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