セッションをデータベースに書き込むPHPクラス

class session_handler {
 protected $maxlifetime = null;
 protected $dbHandle = null;
 public $config = null;
 public static function init($args) {
 return new self($args);
 }
 public function __construct($args) {
  $this->config = $args;
 $this->maxlifetime = get_cfg_var("session.gc_maxlifetime");
 session_set_save_handler(
 array($this, "open"),
 array($this, "close" ),
 array($this, "read"),
 array($this, "write"),
 array($this, "destroy"),
 array($this, "gc"));
 }< ;/p>
 public function open() {
 $this->link = mysqli_connect(
 $this->config['host'],
 $this->config['user'],
 $this->config[ 'パスワード'],
 $this->config['データベース']);
 mysqli_set_charset($this->link, "utf8");
 $sql = '存在しない場合はテーブルを作成 `%s` (
 `session_id` varchar(255) NOT NULL,
 `session_data` text,
 `session_expires` char(10) NOT NULL,
 PRIMARY KEY (`session_id`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;';
 $sql = sprintf($sql, $this->config['table']);
 mysqli_query($this->link, $sql);
 return true;
 }
< p> public function close() {
 return true;
 }
  public function read($session_id) {
 if(empty($session_id)) return null;
  $sql = 'SELECT `session_data` AS `data` FROM `%s` WHERE `session_id` = "%s" AND `session_expires` > "%u"';
 $sql = sprintf($sql,
 mysqli_real_escape_string($this->link, $this->config['table']),
 mysqli_real_escape_string($this->link, $session_id ),
 time());
  $result = mysqli_query($this->link, $sql);
 $row = mysqli_fetch_assoc($result);
 return $row['data'];
 }
 public function write($session_id, $session_data) {
 if(empty($session_id)) return null;
  $newExpires = time() + $this->maxlifetime;
 $sql = 'REPLACE INTO `%s` SET `session_id` = "%s", `session_data` = "%s", `session_expires` = "% u"';
 $sql = sprintf($sql,
 mysqli_real_escape_string($this->link, $this->config['table']),
 mysqli_real_escape_string($this->link, $session_id),
 mysqli_real_escape_string($this->link, $session_data),
 $newExpires);
  $result = mysqli_query($this->link, $sql);
 return mysqli_affected_rows($this->link);
}
 public function destroy($session_id) {
 $sql = 'DELETE FROM `%s` WHERE `session_id` = "%s"';
 $sql = sprintf($sql,
 mysqli_real_escape_string($this->link, $ this->config['table']),
 mysqli_real_escape_string($this->link, $session_id));
 $result = mysqli_query($this->link, $sql);
 return mysqli_affected_rows($this ->link);
}
 public function gc() {
 $sql = 'DELETE FROM `%s` WHERE `session_expires` < "%u"';
 $sql = sprintf($sql,
 mysqli_real_escape_string($this->link, $this->config['table']),
 time());
   $result = mysqli_query($this->link, $sql);
 return mysqli_affected_rows($this->link);
}
}
class session {
 public static $collection = null;
  public static function open($clean = false, $token = false) {
 if($clean) ob_end_clean();
 if($token) session_id($token);
 session_start();
 self::$collection = $_SESSION;
 }
 public static function id() {
 $num_args = func_num_args();
 if($num_args) {
 $args = func_get_arg(0);
 return session_id($args);
 }else{
 return session_id();
 }
 }
 public static function get($name) {
 return isset($_SESSION[$name]) ? $_SESSION[$name] : null;
 }
 public static function set($name, $value) {
 $_SESSION[$name] = $value;
 return true;
 }
 public static function delete($name) {
 if(!isset($_SESSION[$name])) return null;
 unset($_SESSION[$name]);
 return true;
 }
 public static function destroy() {
 session_destroy();
 }
}
$config = array(
"host"=> "127.0.0.1",
"user"=> ; "root",
"password"=> "123456",
"database"=> "utf8",
"table"=>
session_handler::init($config);
session::open();
session::set("profile", array("id"=> 1, "user"=> "haowei", "vip -level"=> 6));