randomsequence.php

<?php
namespace Bitrix\Main\Type;
class RandomSequence
{
    private $mz = 0;
    private $mw = 0;
 
    public function __construct($seed = "")
    {
        $md = md5($seed);
        $this->mz = crc32(mb_substr($md, 0, 16));
        $this->mw = crc32(mb_substr($md, -16));
    }
 
    public function getNext()
    {
        $this->mz = 36969 * ($this->mz & 65535) + ($this->mz >> 16);
        if($this->mz > 0x7FFFFFFF)
            $this->mz = -(0xFFFFFFFF - $this->mz + 1);
 
        $this->mw = 18000 * ($this->mw & 65535) + ($this->mw >> 16);
        if($this->mw > 0x7FFFFFFF)
            $this->mw = -(0xFFFFFFFF - $this->mw + 1);
 
        //return ($this->mz << 16) + $this->mw;
 
        $r = ($this->mz << 16) & 0xFFFF0000;
        if($r > 0x7FFFFFFF)
            $r = -(0xFFFFFFFF - $r + 1);
 
        $r += $this->mw;
        if($r > 0x7FFFFFFF)
            $r = -(0xFFFFFFFF - $r + 1);
 
        return ($r & 0xFFFFFFFF);
    }
 
    public function rand($min, $max)
    {
        if ($min >= $max)
            throw new \Bitrix\Main\NotSupportedException("max parameter must be greater than min.");
 
        $r = sprintf("%u", $this->getNext()) / sprintf("%u", 0xffffffff);
        return intval($min + $r * ($max - $min + 1));
    }
 
    public function randString($length = 10)
    {
        static $allChars = "abcdefghijklnmopqrstuvwxyzABCDEFGHIJKLNMOPQRSTUVWXYZ0123456789";
        $result = "";
        for ($i = 0; $i < $length; $i++)
        {
            $result .= $allChars[$this->rand(0, 61)];
        }
        return $result;
    }
}