class FileStorageFactory

class FileStorageFactory {
    
    /**
     * Returns a FileStorage object working with the active config directory.
     *
     * @return \Drupal\Core\Config\FileStorage FileStorage
     *
     * @deprecated in drupal:8.0.0 and is removed from drupal:9.0.0. Drupal core
     * no longer creates an active directory.
     */
    public static function getActive() {
        return new FileStorage(config_get_config_directory(CONFIG_ACTIVE_DIRECTORY));
    }
    
    /**
     * Returns a FileStorage object working with the sync config directory.
     *
     * @return \Drupal\Core\Config\FileStorage FileStorage
     *
     * @throws \Exception
     *   In case the sync directory does not exist or is not defined in
     *   $settings['config_sync_directory'].
     */
    public static function getSync() {
        $directory = Settings::get('config_sync_directory', FALSE);
        if ($directory === FALSE) {
            // @todo: throw a more specific exception.
            // @see https://www.drupal.org/node/2696103
            throw new \Exception('The config sync directory is not defined in $settings["config_sync_directory"]');
        }
        return new FileStorage($directory);
    }

}