interface StreamWrapperInterface

interface StreamWrapperInterface extends PhpStreamWrapperInterface {

  /**
   * Stream wrapper bit flags that are the basis for composite types.
   *
   * Note that 0x0002 is skipped, because it was the value of a constant that
   * has since been removed.
   */

  /**
   * A filter that matches all wrappers.
   */
  const ALL = 0x0;

  /**
   * Refers to a local file system location.
   */
  const LOCAL = 0x1;

  /**
   * Wrapper is readable (almost always true).
   */
  const READ = 0x4;

  /**
   * Wrapper is writable.
   */
  const WRITE = 0x8;

  /**
   * Exposed in the UI and potentially web accessible.
   */
  const VISIBLE = 0x10;

  /**
   * Composite stream wrapper bit flags that are usually used as the types.
   */

  /**
   * Defines the stream wrapper bit flag for a hidden file.
   *
   * This is not visible in the UI or accessible via web, but readable and
   * writable; for instance, the temporary directory for file uploads.
   */
  const HIDDEN = 0xc;

  /**
   * Hidden, readable and writable using local files.
   */
  const LOCAL_HIDDEN = 0xd;

  /**
   * Visible, readable and writable.
   */
  const WRITE_VISIBLE = 0x1c;

  /**
   * Visible and read-only.
   */
  const READ_VISIBLE = 0x14;

  /**
   * The default 'type' flag.
   *
   * This does not include StreamWrapperInterface::LOCAL, because PHP grants a
   * greater trust level to local files (for example, they can be used in an
   * "include" statement, regardless of the "allow_url_include" setting), so
   * stream wrappers need to explicitly opt-in to this.
   */
  const NORMAL = 0x1c;

  /**
   * Visible, readable and writable using local files.
   */
  const LOCAL_NORMAL = 0x1d;

  /**
   * Returns the type of stream wrapper.
   *
   * @return int
   */
  public static function getType();

  /**
   * Returns the name of the stream wrapper for use in the UI.
   *
   * @return string|\Drupal\Core\StringTranslation\TranslatableMarkup
   *   The stream wrapper name.
   */
  public function getName();

  /**
   * Returns the description of the stream wrapper for use in the UI.
   *
   * @return string|\Drupal\Core\StringTranslation\TranslatableMarkup
   *   The stream wrapper description.
   */
  public function getDescription();

  /**
   * Sets the absolute stream resource URI.
   *
   * This allows you to set the URI. Generally is only called by the factory
   * method.
   *
   * @param string $uri
   *   A string containing the URI that should be used for this instance.
   */
  public function setUri($uri);

  /**
   * Returns the stream resource URI.
   *
   * @return string
   *   Returns the current URI of the instance.
   */
  public function getUri();

  /**
   * Returns a web accessible URL for the resource.
   *
   * This function should return a URL that can be embedded in a web page
   * and accessed from a browser. For example, the external URL of
   * "youtube://random_string" might be
   * "http://www.youtube.com/watch?v=random_string".
   *
   * @return string
   *   Returns a string containing a web accessible URL for the resource.
   */
  public function getExternalUrl();

  /**
   * Returns canonical, absolute path of the resource.
   *
   * Implementation placeholder. PHP's realpath() does not support stream
   * wrappers. We provide this as a default so that individual wrappers may
   * implement their own solutions.
   *
   * @return string
   *   Returns a string with absolute pathname on success (implemented
   *   by core wrappers), or FALSE on failure or if the registered
   *   wrapper does not provide an implementation.
   */
  public function realpath();

  /**
   * Gets the name of the directory from a given path.
   *
   * This method is usually accessed through
   * \Drupal\Core\File\FileSystemInterface::dirname(), which wraps around the
   * normal PHP dirname() function, which does not support stream wrappers.
   *
   * @param string $uri
   *   An optional URI.
   *
   * @return string
   *   A string containing the directory name, or FALSE if not applicable.
   *
   * @see \Drupal\Core\File\FileSystemInterface::dirname()
   */
  public function dirname($uri = NULL);

}