UniqueID.php

<?php
// vim: set et sw=4 ts=4 sts=4 fdm=marker ff=unix fenc=utf8

 * UniqueID 生成唯一的id
 可用于在分布式服务器下生成唯一的id。

 * @author shaojianyi <issuoow@gmail.com> 
 */
class UniqueID {
    public $u1;
    public $u2;
    public $u3;
    public $u4;

    public function __construct(){
        $this->u1 = $_SERVER['UNIQUE_ID'];
        $this->u2 = $this->get_ip();
        $this->u3 = microtime();
        $this->u4 = rand(0,999999);
    }
    /**
     * get_ip 
     * @return string 
     */
    public function get_ip (){
        return isset($_SERVER['HTTP_X_FORWARDED_FOR']) ? $_SERVER['HTTP_X_FORWARDED_FOR'] : $_SERVER['REMOTE_ADDR'];
    }

    public function get(){
        return md5($this->u1 . $this->u2 . $this->u3 . $this->u4);
    }
}
?>