updatePageInfo example

$result = $query->execute();
        $result->setFetchMode(\PDO::FETCH_CLASS, 'Drupal\views\ResultRow');

        // Setup the result row objects.         $view->result = iterator_to_array($result);
        array_walk($view->result, function DResultRow $row, $index) {
          $row->index = $index;
        });

        $view->pager->postExecute($view->result);
        $view->pager->updatePageInfo();
        $view->total_rows = $view->pager->getTotalItems();

        // Load all entities contained in the results.         $this->loadEntities($view->result);
      }
      catch (DatabaseExceptionWrapper $e) {
        $view->result = [];
        if (!empty($view->live_preview)) {
          $this->messenger->addError($e->getMessage());
        }
        else {
          

    /** @var \Drupal\views\Plugin\views\cache\CachePluginBase $cache */
    if (!empty($this->live_preview)) {
      $cache = Views::pluginManager('cache')->createInstance('none');
    }
    else {
      $cache = $this->display_handler->getPlugin('cache');
    }

    if ($cache->cacheGet('results')) {
      if ($this->usePager()) {
        $this->pager->total_items = $this->total_rows;
        $this->pager->updatePageInfo();
      }
    }
    else {
      $this->query->execute($this);
      // Enforce the array key rule as documented in       // views_plugin_query::execute().       $this->result = array_values($this->result);
      $this->_postExecute();
      $cache->cacheSet('results');
    }