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('shaka.net.NetworkingEngine');
  21. goog.require('shaka.offline.OfflineUtils');
  22. goog.require('shaka.util.Error');
  25. /**
  26.  * @namespace
  27.  * @summary A plugin that handles requests for offline content.
  28.  * @param {string} uri
  29.  * @param {shakaExtern.Request} request
  30.  * @return {!Promise.<shakaExtern.Response>}
  31.  * @export
  32.  */
  33. shaka.offline.OfflineScheme = function(uri, request) {
  34.   var manifestParts = /^offline:([0-9]+)$/.exec(uri);
  35.   if (manifestParts) {
  36.     /** @type {shakaExtern.Response} */
  37.     var response = {
  38.       uri: uri,
  39.       data: new ArrayBuffer(0),
  40.       headers: {'content-type': 'application/x-offline-manifest'}
  41.     };
  42.     return Promise.resolve(response);
  43.   }
  45.   var segmentParts = /^offline:[0-9]+\/[0-9]+\/([0-9]+)$/.exec(uri);
  46.   if (segmentParts) {
  47.     var segmentId = Number(segmentParts[1]);
  48.     var scheme = shaka.offline.OfflineUtils.DB_SCHEME;
  49.     var storageEngine = shaka.offline.OfflineUtils.createStorageEngine();
  51.     if (!storageEngine) {
  52.       return Promise.reject(new shaka.util.Error(
  53.           shaka.util.Error.Severity.CRITICAL,
  54.           shaka.util.Error.Category.STORAGE,
  55.           shaka.util.Error.Code.STORAGE_NOT_SUPPORTED));
  56.     }
  58.     return storageEngine.init(scheme)
  59.         .then(function() { return storageEngine.get('segment', segmentId); })
  60.         .then(function(segment) {
  61.           return storageEngine.destroy().then(function() {
  62.             if (!segment) {
  63.               throw new shaka.util.Error(
  64.                   shaka.util.Error.Severity.CRITICAL,
  65.                   shaka.util.Error.Category.STORAGE,
  66.                   shaka.util.Error.Code.REQUESTED_ITEM_NOT_FOUND, segmentId);
  67.             }
  68.             return {uri: uri, data: segment.data, headers: {}};
  69.           });
  70.         });
  71.   }
  73.   return Promise.reject(new shaka.util.Error(
  74.       shaka.util.Error.Severity.CRITICAL,
  75.       shaka.util.Error.Category.NETWORK,
  76.       shaka.util.Error.Code.MALFORMED_OFFLINE_URI, uri));
  77. };
  80. shaka.net.NetworkingEngine.registerScheme(
  81.     'offline', shaka.offline.OfflineScheme);