class CachedStorageTest

class CachedStorageTest extends ConfigStorageTestBase {
  
  /**
   * The cache backend the cached storage is using.
   *
   * @var \Drupal\Core\Cache\CacheBackendInterface
   */
  protected $cache;
  
  /**
   * The file storage the cached storage is using.
   *
   * @var \Drupal\Core\Config\FileStorage
   */
  protected $fileStorage;
  
  /**
   * {@inheritdoc}
   */
  protected function setUp() : void {
    parent::setUp();
    // Create a directory.
    $dir = PublicStream::basePath() . '/config';
    $this->fileStorage = new FileStorage($dir);
    $this->storage = new CachedStorage($this->fileStorage, \Drupal::service('cache.config'));
    $this->cache = \Drupal::service('cache_factory')->get('config');
    // ::listAll() verifications require other configuration data to exist.
    $this->storage
      ->write('system.performance', []);
  }
  
  /**
   * {@inheritdoc}
   */
  public function testInvalidStorage() {
    $this->markTestSkipped('No-op as this test does not make sense');
  }
  
  /**
   * {@inheritdoc}
   */
  protected function read($name) {
    $data = $this->cache
      ->get($name);
    // Cache misses fall through to the underlying storage.
    return $data ? $data->data : $this->fileStorage
      ->read($name);
  }
  
  /**
   * {@inheritdoc}
   */
  protected function insert($name, $data) {
    $this->fileStorage
      ->write($name, $data);
    $this->cache
      ->set($name, $data);
  }
  
  /**
   * {@inheritdoc}
   */
  protected function update($name, $data) {
    $this->fileStorage
      ->write($name, $data);
    $this->cache
      ->set($name, $data);
  }
  
  /**
   * {@inheritdoc}
   */
  protected function delete($name) {
    $this->cache
      ->delete($name);
    unlink($this->fileStorage
      ->getFilePath($name));
  }

}