DrupalVerifiedStorageFile.php

<?php

namespace Drupal\Core\Config;

use Drupal\Core\Config\DrupalConfigVerifiedStorage;

/**
 * Represents an SQL-based configuration storage object.
 */
class DrupalVerifiedStorageFile extends DrupalConfigVerifiedStorage {

  /**
   * Implements DrupalConfigVerifiedStorage::read().
   */
  public function read() {
    $file = config_get_config_directory() . '/' . $this->name . '.xml';
    return file_get_contents($file);
  }

  /**
   * Implements DrupalConfigVerifiedStorageInterface::writeToActive().
   */
  public function writeToActive($data) {
    return $this->writeToFile($data);
  }

  /**
   * @todo
   */
  public function deleteFromActive() {
  }

  /**
   * Implements DrupalConfigVerifiedStorageInterface::getNamesWithPrefix().
   */
  static public function getNamesWithPrefix($prefix = '') {
    config_get_signed_file_storage_names_with_prefix($prefix);
  }
}