@header("content-Type: text/html; charset=UTF-8");
  require('includes/configure.php');
  //include database tables
  require('includes/database_table.php'); 
   // set php_self in the local scope
  if (!isset($PHP_SELF)) $PHP_SELF = basename($_SERVER['SCRIPT_FILENAME']);
   // include the database class
  require(DIR_WS_CLASSES . 'db_mysql_class.php');
  $db=new DbCom();
  // make a connection to the database... now
  $db->connect(DB_SERVER, DB_SERVER_USERNAME, DB_SERVER_PASSWORD, DB_DATABASE);
  $db->query("set names utf8");


   $session = new session($db);
    session_start();
       $_SESSION['webid']=117;
      $_SESSION['username']='duanjianbo';
   

   
   class session { 
    var $db; 
    function session(&$db) { 
        $this->db = &$db;
        session_module_name('user'); 
        session_set_save_handler( 
            array(&$this, 'open'), 
            array(&$this, 'close'), 
            array(&$this, 'read'), 
            array(&$this, 'write'), 
            array(&$this, 'destroy'), 
            array(&$this, 'gc') 
        ); 
        session_start(); 
    } 
  
    function unserializes($data_value) { 
        $vars = preg_split( 
            '/([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*)\|/', 
            $data_value, -1, PREG_SPLIT_NO_EMPTY | 
            PREG_SPLIT_DELIM_CAPTURE 
        ); 
        for ($i = 0; isset($vars[$i]); $i++) { 
            $result[$vars[$i++]] = unserialize($vars[$i]); 
        } 
        return $result; 
    } 

    function open($path, $name) { 
        return true; 
    } 
    function close() { 
        return true; 
    } 
   function read($SessionKey){
   
        $sql = "SELECT uid FROM sessions WHERE session_id = '".$SessionKey."' limit 1"; 
        $query =$this->db->query($sql);
        if($row=$this->db->fetch_array($query)){
          return $row['uid'];
        }else{
           
            $this->db->query("insert into `sessions` set `session_id` = '$SessionKey'"); 
            return ""; 
        }
         
   } 
    function write($SessionKey, $VArray) { 
      require_once(DIR_WS_CLASSES . 'db_mysql_class.php');
      $db1=new DbCom();
      // make a connection to the database... now
      $db1->connect(DB_SERVER, DB_SERVER_USERNAME, DB_SERVER_PASSWORD, DB_DATABASE);
      $db1->query("set names utf8");//这里为什么之前的$this->db的对象改变了
       $SessionArray = addslashes($VArray);
       $data=$this->unserializes($VArray);
        $this->db=$db1;
        $sql = "update `sessions` set "; 
        if(isset($data['webid'])){
        $sql .= "uid = '".$data['webid']."', " ;
        }
        $sql.="`last_visit` = null " 
              . "where `session_id` = '$SessionKey'"; 
        $this->db->query($sql); 
        return true; 
    } 
  function destroy($SessionKey) { 
     $this->db->query("delete from `sessions` where `session_id` = '$SessionKey'"); 
     return true; 
   } 
   function gc($lifetime) {
       $this->db->query("delete from `sessions` where unix_timestamp(now()) - unix_timestamp(`last_visit`) > $lifetime");
       return true;
   } 

  
}