SimpleSAML_Session::getSessionFromRequest PHP Method

    public static function getSessionFromRequest()
    {
        // check if we already have initialized the session
        if (isset(self::$instance)) {
            return self::$instance;
        }
        // check if we have stored a session stored with the session handler
        $session = null;
        try {
            $session = self::getSession();
        } catch (Exception $e) {
            /*
             * For some reason, we were unable to initialize this session. Note that this error might be temporary, and
             * it's possible that we can recover from it in subsequent requests, so we should not try to create a new
             * session here. Therefore, use just a transient session and throw the exception for someone else to handle
             * it.
             */
            SimpleSAML\Logger::error('Error loading session: ' . $e->getMessage());
            self::useTransientSession();
            if ($e instanceof SimpleSAML_Error_Exception) {
                $cause = $e->getCause();
                if ($cause instanceof Exception) {
                    throw $cause;
                }
            }
            throw $e;
        }
        // if getSession() found it, use it
        if ($session !== null) {
            return self::load($session);
        }
        /*
         * We didn't have a session loaded when we started, but we have it now. At this point, getSession() failed but
         * it must have triggered the creation of a session at some point during the process (e.g. while logging an
         * error message). This means we don't need to create a new session again, we can use the one that's loaded now
         * instead.
         */
        if (self::$instance !== null) {
            return self::$instance;
        }
        // try to create a new session
        try {
            self::load(new SimpleSAML_Session());
        } catch (\SimpleSAML\Error\CannotSetCookie $e) {
            // can't create a regular session because we can't set cookies. Use transient.
            $c = SimpleSAML_Configuration::getInstance();
            self::useTransientSession();
            if ($e->getCode() === \SimpleSAML\Error\CannotSetCookie::SECURE_COOKIE) {
                throw new \SimpleSAML\Error\CriticalConfigurationError($e->getMessage(), null, $c->toArray());
            }
            SimpleSAML\Logger::error('Error creating session: ' . $e->getMessage());
        }
        // we must have a session now, either regular or transient
        return self::$instance;
    }

 public function process(&$state)
 {
     assert('is_array($state)');
     if (empty($state['Expire']) || empty($state['Authority'])) {
         return;
     }
     $now = time();
     $delta = $state['Expire'] - $now;
     $globalConfig = SimpleSAML_Configuration::getInstance();
     $sessionDuration = $globalConfig->getInteger('session.duration', 8 * 60 * 60);
     /* Extend only if half of session duration already passed */
     if ($delta >= $sessionDuration * 0.5) {
         return;
     }
     /* Update authority expire time */
     $session = SimpleSAML_Session::getSessionFromRequest();
     $session->setAuthorityExpire($state['Authority']);
     /* Update session cookies duration */
     /* If remember me is active */
     $rememberMeExpire = $session->getRememberMeExpire();
     if (!empty($state['RememberMe']) && $rememberMeExpire !== NULL && $globalConfig->getBoolean('session.rememberme.enable', FALSE)) {
         $session->setRememberMeExpire();
         return;
     }
     /* Or if session lifetime is more than zero */
     $sessionHandler = SimpleSAML_SessionHandler::getSessionHandler();
     $cookieParams = $sessionHandler->getCookieParams();
     if ($cookieParams['lifetime'] > 0) {
         $session->updateSessionCookies();
     }
 }