Created
June 20, 2019 16:21
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A UUID to short ID (SID) convertor based on CRC64 to Base36
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<?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; | |
} else { | |
$part = ($part >> 1) & ~(0x8 << 60); | |
} | |
} | |
$crc64tab[$i] = $part; | |
} | |
return $crc64tab; | |
} | |
/** | |
* @param string $string | |
* @param string $format | |
* @return mixed | |
* | |
* Formats: | |
* crc64('php'); // afe4e823e7cef190 | |
* crc64('php', '0x%x'); // 0xafe4e823e7cef190 | |
* crc64('php', '0x%X'); // 0xAFE4E823E7CEF190 | |
* crc64('php', '%d'); // -5772233581471534704 signed int | |
* crc64('php', '%u'); // 12674510492238016912 unsigned int | |
*/ | |
function crc64($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] ^ (($crc >> 8) & ~(0xff << 56)); | |
} | |
return sprintf($format, $crc); | |
} | |
include 'vendor/autoload.php'; | |
$uuid = strtoupper(str_replace('-', '', \Ramsey\Uuid\Uuid::uuid4()->toString())); | |
var_dump($uuid); | |
$crc = crc64($uuid, '%X'); | |
var_dump($crc); | |
$hex = substr($crc, 0, 5); | |
$sid = strtoupper(base_convert($hex, 16, 36)); | |
var_dump($sid); |
Author
dalabarge
commented
Jun 20, 2019
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