token.class.php

<?php

class Token
{
    private $mmc;
    private $cache_time; 

    function __construct()
    {
        $this->cache_time = 60 * 60 * 24;
    	
        //初始化memcache
    	
        if( defined('SAE_APPNAME') ){
            $this->mmc = memcache_init();
        }else{
            $this->mmc = new memcache;
            $this->mmc->connect("127.0.0.1", 11211);
        }

        if($this->mmc == false)
            die('Memcache Init Failed');    
        
    }

    /**
     *  缓存用户的Token及UID
     *  key     用户的Token(随机Hash)
     *  value   用户的身份标识
     */
     
    public function set_user_token($key,$value)
    {
    	$time = $this->cache_time;
    	$mmc = $this->mmc;

    	memcache_set($mmc,$key,$value,0,$time);
    }
    
    /**
     *  通过Token获取用户的身份标识
     *  key        用户的Token(随机Hash)
     *  @return    用户的身份标识
     */

    public function get_user_uid($key)
    {   
    	$mmc = $this->mmc;

    	$uid = memcache_get($mmc,$key);

    	return $uid;
    }
    
    /**
     *  延长Token的有效期
     *  key   用户的Token(随机Hash)
     */

    public function prolong_user_token($key)
    {   
    	$mmc = $this->mmc;

    	$uid = memcache_get($mmc,$key);

    	//删除老的cache
    	$this->delete_user_cache($key);

    	//新增新的cache
    	$this->set_user_token($key,$uid);
    }
    
    /**
     *  删除用户的Token缓存
     *  key   用户的Token(随机Hash)
     */

    public function delete_user_cache($key)
    {   
    	$mmc = $this->mmc;

    	memcache_delete($mmc,$key);
    }
    
    /**
     *  生成一个随机Token
     *  string   字符串
     *  salt     撒盐
     */
    
    public function ttpassv2($string, $salt = '')
    {
        return substr(md5(md5($string) . 'key' . $salt), 0, 30);
    }
}
?>