PHP GUID和UUID生成类

 <?php
 
class Guid
{
 /**
 * 系统当前时间
 */
 private static function  _curTimeMillis() {  
 list($usec,  $sec)  =  explode("  ",microtime());
 return  $sec.substr($usec,  2,  3);  
 }
 
 /**
 * 客户端相关信息
 */
 private static function  _getHost() {
 $name = empty($_SERVER["HTTP_USER_AGENT"]) ? 'localhost' : $_SERVER["HTTP_USER_AGENT"];
 return strtolower($name . '/' . self::_clientIp());
 }
 
 /**
 * 客户端IP
 */
 private static function _clientIp() {
 $ip = (@$_SERVER['HTTP_REALIP'])
 ? $_SERVER['HTTP_REALIP']
 : ((@$_SERVER['HTTP_X_FORWARDED_FOR'])
 ? $_SERVER['HTTP_X_FORWARDED_FOR']
 : @$_SERVER['REMOTE_ADDR']);
 
 if (empty($ip))    $ip = '0.0.0.0';
 return $ip;
 }
 
 /**
 * 随机数
 */
 private static function  _random() {
 $tmp  =  rand(0,1) ? '-' : '';
 return  $tmp.rand(1000,  9999).rand(1000,  9999).rand(1000,  9999).rand(100,  999).rand(100,  999);  
 }
 
 /**
 * 生成GUID字符串
 * (长度：32 + 4)
 * 三段：一段是微秒,  一段是地址,  一段是随机数
 */
 public static function  toString() {
 if (function_exists('com_create_guid')) {
 return com_create_guid();
 } else {
 $string = md5(self::_getHost() . ':' . self::_curTimeMillis() . ':' . self::_random());
 $raw  =  strtoupper($string);
 return  substr($raw,0,8).'-'.substr($raw,8,4).'-'.substr($raw,12,4).'-'.substr($raw,16,4).'-'.substr($raw,20);
 }
 }
}
 
------------------------------------------------
class Uuid
{
 private $_yearCode = array('A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T');
 const START_YEAR = 2011;
 
 /**
 * 组成结构：年份(1个字符)，月份(1个字符[十六进制])，日(2个字符)，时间戳(后5字符)，微秒(6个字符)，随机数(3个字符) ＝ 18个字符
 */
 public static function make() {
 return    $this->_yearCode[intval(date('Y')) - self::START_YEAR].
 strtoupper(dechex(date('m'))) . date('d') .
 substr(time(), -5) . substr(microtime(), 2, 6) . sprintf('%02d', rand(0, 99));
 }
}