/**
* Checks if there are not too many login attempts using specified username in the specified number of seconds until now.
* @param string $username
* @param integer $count_limit number of login attempts
* @param integer $time_limit number of seconds
* @return boolean
*/
public static function hasTooManyFailedAttempts($username, $count_limit = 5, $time_limit = 1800)
{
$since = new DateTime();
$since->sub(new DateInterval("PT{$time_limit}S"));
$subquery = UserLoginAttempt::model()->dbConnection->createCommand()->select('is_successful')->from(UserLoginAttempt::model()->tableName())->where('username = :username AND performed_on > :since')->order('performed_on DESC')->limit($count_limit)->getText();
return $count_limit <= (int) UserLoginAttempt::model()->dbConnection->createCommand()->select('COUNT(NOT is_successful OR NULL)')->from("({$subquery}) AS t")->queryScalar(array(':username' => $username, ':since' => $since->format('Y-m-d H:i:s')));
}