Source: lib/util/i_destroyable.js

  1. /**
  2.  * @license
  3.  * Copyright 2016 Google Inc.
  4.  *
  5.  * Licensed under the Apache License, Version 2.0 (the "License");
  6.  * you may not use this file except in compliance with the License.
  7.  * You may obtain a copy of the License at
  8.  *
  9.  *     http://www.apache.org/licenses/LICENSE-2.0
  10.  *
  11.  * Unless required by applicable law or agreed to in writing, software
  12.  * distributed under the License is distributed on an "AS IS" BASIS,
  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14.  * See the License for the specific language governing permissions and
  15.  * limitations under the License.
  16.  */
  18. goog.provide('shaka.util.IDestroyable');
  22. /**
  23.  * An interface to standardize how objects are destroyed.
  24.  * @interface
  25.  * @exportInterface
  26.  */
  27. shaka.util.IDestroyable = function() {};
  30. /**
  31.  * Destroys the object, releasing all resources and shutting down all
  32.  * operations.  Returns a Promise which is resolved when destruction is
  33.  * complete.  This Promise should never be rejected.
  34.  *
  35.  * @return {!Promise}
  36.  * @exportInterface
  37.  */
  38. shaka.util.IDestroyable.prototype.destroy = function() {};
  41. /**
  42.  * A helper function that will destroy a group of destroyable object once the
  43.  * callback (and its promises) complete. The destroyable object will be
  44.  * destroyed regardless of whether or not the callback (and its promises) get
  45.  * resolved or rejected.
  46.  *
  47.  * @param {!Array.<!shaka.util.IDestroyable>} objs A list of destroyable object
  48.  *                                                 that should be destroyed
  49.  *                                                 after the callback completes.
  50.  * @param {function():!Promise<T>|function():T} callback
  51.  * @return {!Promise.<T>}
  52.  * @template T
  53.  */
  54. shaka.util.IDestroyable.with = function(objs, callback) {
  55.   let cleanup = () => {
  56.     return Promise.all(objs.map((obj) => obj.destroy()));
  57.   };
  59.   return Promise.resolve(callback()).then(
  60.     (r) => cleanup().then(() => r),
  61.     (e) => cleanup().then(() => { throw e; }));
  62. };