Redirect to the last changed node of a type with elegant cache

Controller.php

<?php

/**
 * @file
 * Contains \Drupal\faf_videos\Controller.
 */

namespace Drupal\faf_videos;

use Drupal\Core\Cache\Cache;
use Drupal\Core\Cache\CacheBackendInterface;
use Drupal\Core\Controller\ControllerBase;
use Drupal\Core\Entity\Query\QueryFactory;

class Controller extends ControllerBase {

  /**
   * The entity query factory.
   *
   * @var \Drupal\Core\Entity\Query\QueryFactory
   */
  protected $queryFactory;

  /**
   * The cache backend.
   *
   * @var \Drupal\Core\Cache\CacheBackendInterface
   */
  protected $cache;

  /**
   * Constructs a \Drupal\Core\Menu\DefaultMenuLinkTreeManipulators object.
   *
   * @param \Drupal\Core\Entity\Query\QueryFactory $query_factory
   *   The entity query factory.
   */
  public function __construct(QueryFactory $query_factory, CacheBackendInterface $cache) {
    $this->queryFactory = $query_factory;
    $this->cache = $cache;
  }

  /**
   * /videos controller endpoint. Redirects to the last changed video.
   */
  public function last() {
    $cid = 'faf_video:last';
    // Retrieve value from cache if it's in.
    if ($cache = $this->cache->get($cid)) {
      $nid = $cache->data;
    }
    // Find the last changed video nid as it's not in cache.
    else {
      $query = $this->queryFactory->get('node');
      $last_video = $query->condition('type', 'video')
        ->sort('changed', 'DESC')
        ->range(0, 1)
        ->execute();
      $nid = key($last_video);

      // Save the value in cache using the node_list tag to auto invalidate
      // when a node is saved.
      $this->cache->set($cid, $nid, Cache::PERMANENT, ['node_list']);
    }

    // If no video is found, return 404.
    if (empty($nid)) {
      throw new NotFoundHttpException();
    }

    // Redirect to the found video.
    return $this->redirect('entity.node.canonical', ['node' => $nid]);
  }

}

faf_videos.services.yml

services:
  faf_videos.controller:
    class: Drupal\faf_videos\Controller
    arguments: ['@entity.query', '@cache.default']