class FileUsageBase

abstract class FileUsageBase implements FileUsageInterface {
    
    /**
     * The config factory.
     *
     * @var \Drupal\Core\Config\ConfigFactoryInterface
     */
    protected $configFactory;
    
    /**
     * Creates a FileUsageBase object.
     *
     * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
     *   The config factory.
     */
    public function __construct(ConfigFactoryInterface $config_factory) {
        $this->configFactory = $config_factory;
    }
    
    /**
     * {@inheritdoc}
     */
    public function add(FileInterface $file, $module, $type, $id, $count = 1) {
        // Make sure that a used file is permanent.
        if (!$file->isPermanent()) {
            $file->setPermanent();
            $file->save();
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function delete(FileInterface $file, $module, $type = NULL, $id = NULL, $count = 1) {
        // Do not actually mark files as temporary when the behavior is disabled.
        if (!$this->configFactory
            ->get('file.settings')
            ->get('make_unused_managed_files_temporary')) {
            return;
        }
        // If there are no more remaining usages of this file, mark it as temporary,
        // which result in a delete through system_cron().
        $usage = \Drupal::service('file.usage')->listUsage($file);
        if (empty($usage)) {
            $file->setTemporary();
            $file->save();
        }
    }

}