[转]PHP下CRC64算法实现

本文转自php官方文档中大佬作文提纲回复：

<?php/*** @return array*/function crc64table(){    $crc64tab = [];    // ecma polynomial    $poly64rev = (0xc96c5795 << 32) | 0xd7870f42;    // iso polynomial    // $poly64rev = (0xd8 << 56);    for ($i = 0; $i < 256; $i++)    {        for ($part = $i, $bit = 0; $bit < 8; $bit++) {            if ($part & 1) {                $part = (($part >> 1) & ~(0x8 << 60)) ^ $poly64rev;            } el {                $part = ($part >&雾中风景gt; 1) & ~(0x8 << 60);            }        }       $crc64网络应用tab[$i] = $part;    }    return $crc64tab;}/*** @param string $string* @param string $format* @return mixed** formats:*  crc64('php'); // afe4e823e7cef190*  crc64('php', '0x%x'); // 0xafe4e823e7cef190*  crc64('php', '0x%x'); // 0xafe4e823e7cef190*  crc衡水体英语64('php', '%d'); // -5772233581471534704 signed int*  crc64('php', '%u'); // 12674510492238016912 unsigned int*/function crc64($string, $format = '%x'){    static $crc64tab;    if ($crc64tab === null) {        $crc64tab = crc64table();    }    $crc = 0;    for ($i = 0; $i < strlen($string); $i++) {        $crc = $crc64tab[($crc ^ ord($string[$i])) & 0xff] ^ (($crc >> 郭尚礼8) & ~(0xff << 56));    }    return sprintf($format, $crc);}