PHP_INT_MAX) { return null; } $cmap = self::CMAP; $base = strlen($cmap); $shortcode = ''; while ($id) { $id = ($id - ($r = $id % $base)) / $base; $shortcode = $cmap[$r].$shortcode; } return $shortcode; } public static function decode($short = false) { if (! $short) { return; } $id = 0; foreach (str_split($short) as $needle) { $pos = strpos(self::CMAP, $needle); $id = ($id * 64) + $pos; } return $id; } }