Source: lib/offline/offline_scheme.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.offline.OfflineScheme');
  20. goog.require('goog.asserts');
  21. goog.require('shaka.net.NetworkingEngine');
  22. goog.require('shaka.offline.OfflineUri');
  23. goog.require('shaka.offline.StorageMuxer');
  24. goog.require('shaka.util.AbortableOperation');
  25. goog.require('shaka.util.Error');
  26. goog.require('shaka.util.IDestroyable');
  29. /**
  30.  * @namespace
  31.  * @summary A plugin that handles requests for offline content.
  32.  * @param {string} uri
  33.  * @param {shakaExtern.Request} request
  34.  * @param {shaka.net.NetworkingEngine.RequestType=} requestType
  35.  * @return {!shakaExtern.IAbortableOperation.<shakaExtern.Response>}
  36.  * @export
  37.  */
  38. shaka.offline.OfflineScheme = function(uri, request, requestType) {
  39.   let offlineUri = shaka.offline.OfflineUri.parse(uri);
  41.   if (offlineUri && offlineUri.isManifest()) {
  42.     return shaka.offline.OfflineScheme.getManifest_(uri);
  43.   }
  45.   if (offlineUri && offlineUri.isSegment()) {
  46.     return shaka.offline.OfflineScheme.getSegment_(
  47.         offlineUri.key(), offlineUri);
  48.   }
  50.   return shaka.util.AbortableOperation.failed(
  51.       new shaka.util.Error(
  52.           shaka.util.Error.Severity.CRITICAL,
  53.           shaka.util.Error.Category.NETWORK,
  54.           shaka.util.Error.Code.MALFORMED_OFFLINE_URI,
  55.           uri));
  56. };
  59. /**
  60.  * @param {string} uri
  61.  * @return {!shakaExtern.IAbortableOperation.<shakaExtern.Response>}
  62.  * @private
  63.  */
  64. shaka.offline.OfflineScheme.getManifest_ = function(uri) {
  65.   /** @type {shakaExtern.Response} */
  66.   let response = {
  67.     uri: uri,
  68.     data: new ArrayBuffer(0),
  69.     headers: {'content-type': 'application/x-offline-manifest'}
  70.   };
  72.   return shaka.util.AbortableOperation.completed(response);
  73. };
  76. /**
  77.  * @param {number} id
  78.  * @param {!shaka.offline.OfflineUri} uri
  79.  * @return {!shakaExtern.IAbortableOperation.<shakaExtern.Response>}
  80.  * @private
  81.  */
  82. shaka.offline.OfflineScheme.getSegment_ = function(id, uri) {
  83.   goog.asserts.assert(
  84.       uri.isSegment(),
  85.       'Only segment uri\'s should be given to getSegment');
  87.   let muxer = new shaka.offline.StorageMuxer();
  89.   let promise = shaka.util.IDestroyable.with([muxer], async () => {
  90.     await muxer.init();
  91.     let cell = await muxer.getCell(uri.mechanism(), uri.cell());
  92.     let segments = await cell.getSegments([uri.key()]);
  93.     let segment = segments[0];
  94.     return {
  95.       uri: uri,
  96.       data: segment.data,
  97.       headers: {}
  98.     };
  99.   });
  101.   // TODO: Support abort() in OfflineScheme.
  102.   return shaka.util.AbortableOperation.notAbortable(promise);
  103. };
  106. shaka.net.NetworkingEngine.registerScheme(
  107.     'offline', shaka.offline.OfflineScheme);