/**
  * @see SessionFactory::create()
  */
 public function create()
 {
     // get spider information
     $spider = $this->isSpider(UserUtil::getUserAgent());
     if ($spider) {
         if (($session = $this->getExistingSpiderSession($spider['spiderID'])) !== null) {
             if (!$session->isCorrupt()) {
                 return $session;
             }
         }
     }
     // create new session hash
     $sessionID = StringUtil::getRandomID();
     // check cookies for userID & password
     require_once WCF_DIR . 'lib/system/auth/UserAuth.class.php';
     $user = UserAuth::getInstance()->loginAutomatically(true, $this->userClassName);
     if ($user === null) {
         // no valid user found
         // create guest user
         $user = new $this->guestClassName();
     }
     // update user session
     $user->update();
     if ($user->userID != 0) {
         // user is no guest
         // delete all other sessions of this user
         Session::deleteSessions($user->userID, true, false);
     }
     $requestMethod = !empty($_SERVER['REQUEST_METHOD']) ? $_SERVER['REQUEST_METHOD'] : '';
     // insert session into database
     $sql = "INSERT INTO \twcf" . WCF_N . "_session\n\t\t\t\t\t(sessionID, packageID, userID, ipAddress, userAgent,\n\t\t\t\t\tlastActivityTime, requestURI, requestMethod,\n\t\t\t\t\tusername" . ($spider ? ", spiderID" : "") . ")\n\t\t\tVALUES\t\t('" . $sessionID . "',\n\t\t\t\t\t" . PACKAGE_ID . ",\n\t\t\t\t\t" . $user->userID . ",\n\t\t\t\t\t'" . escapeString(UserUtil::getIpAddress()) . "',\n\t\t\t\t\t'" . escapeString(UserUtil::getUserAgent()) . "',\n\t\t\t\t\t" . TIME_NOW . ",\n\t\t\t\t\t'" . escapeString(UserUtil::getRequestURI()) . "',\n\t\t\t\t\t'" . escapeString($requestMethod) . "',\n\t\t\t\t\t'" . ($spider ? escapeString($spider['spiderName']) : escapeString($user->username)) . "'\n\t\t\t\t\t" . ($spider ? ", " . $spider['spiderID'] : "") . ")";
     WCF::getDB()->sendQuery($sql);
     // save user data
     $serializedUserData = '';
     if (ENABLE_SESSION_DATA_CACHE && get_class(WCF::getCache()->getCacheSource()) == 'MemcacheCacheSource') {
         require_once WCF_DIR . 'lib/system/cache/source/MemcacheAdapter.class.php';
         MemcacheAdapter::getInstance()->getMemcache()->set('session_userdata_-' . $sessionID, $user);
     } else {
         $serializedUserData = serialize($user);
         try {
             $sql = "INSERT INTO \twcf" . WCF_N . "_session_data\n\t\t\t\t\t\t\t(sessionID, userData)\n\t\t\t\t\tVALUES \t\t('" . $sessionID . "',\n\t\t\t\t\t\t\t'" . escapeString($serializedUserData) . "')";
             WCF::getDB()->sendQuery($sql);
         } catch (DatabaseException $e) {
             // horizon update workaround
             $sql = "UPDATE \twcf" . WCF_N . "_session\n\t\t\t\t\tSET\tuserData = '" . escapeString($serializedUserData) . "'\n\t\t\t\t\tWHERE\tsessionID = '" . $sessionID . "'";
             WCF::getDB()->sendQuery($sql);
         }
     }
     // return new session object
     return new $this->sessionClassName(null, array('sessionID' => $sessionID, 'packageID' => PACKAGE_ID, 'userID' => $user->userID, 'ipAddress' => UserUtil::getIpAddress(), 'userAgent' => UserUtil::getUserAgent(), 'lastActivityTime' => TIME_NOW, 'requestURI' => UserUtil::getRequestURI(), 'requestMethod' => $requestMethod, 'userData' => $serializedUserData, 'sessionVariables' => '', 'username' => $spider ? $spider['spiderName'] : $user->username, 'spiderID' => $spider ? $spider['spiderID'] : 0, 'isNew' => true));
 }
 /**
  * Deletes users.
  * Returns the number of deleted users.
  *
  * @param	array		$userIDs
  * @return	integer
  */
 public static function deleteUsers($userIDs)
 {
     if (count($userIDs) == 0) {
         return 0;
     }
     $userIDsStr = implode(',', $userIDs);
     // delete options from this user
     $sql = "DELETE \tFROM wcf" . WCF_N . "_user_option_value\n\t\t\tWHERE \tuserID IN (" . $userIDsStr . ")";
     WCF::getDB()->sendQuery($sql);
     // delete user from user table
     $sql = "DELETE \tFROM wcf" . WCF_N . "_user\n\t\t\tWHERE \tuserID IN (" . $userIDsStr . ")";
     WCF::getDB()->sendQuery($sql);
     // delete user to groups
     $sql = "DELETE \tFROM wcf" . WCF_N . "_user_to_groups\n\t\t\tWHERE \tuserID IN (" . $userIDsStr . ")";
     WCF::getDB()->sendQuery($sql);
     // delete user to languages
     $sql = "DELETE \tFROM wcf" . WCF_N . "_user_to_languages\n\t\t\tWHERE \tuserID IN (" . $userIDsStr . ")";
     WCF::getDB()->sendQuery($sql);
     // delete sessions
     Session::deleteSessions($userIDs);
     return count($userIDs);
 }