Source: lib/net/data_uri_plugin.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.net.DataUriPlugin');
  20. goog.require('shaka.log');
  21. goog.require('shaka.net.NetworkingEngine');
  22. goog.require('shaka.util.AbortableOperation');
  23. goog.require('shaka.util.Error');
  24. goog.require('shaka.util.StringUtils');
  25. goog.require('shaka.util.Uint8ArrayUtils');
  28. /**
  29.  * @namespace
  30.  * @summary A networking plugin to handle data URIs.
  31.  * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/data_URIs
  32.  * @param {string} uri
  33.  * @param {shaka.extern.Request} request
  34.  * @param {shaka.net.NetworkingEngine.RequestType} requestType
  35.  * @param {shaka.extern.ProgressUpdated} progressUpdated Called when a
  36.  *   progress event happened.
  37.  * @return {!shaka.extern.IAbortableOperation.<shaka.extern.Response>}
  38.  * @export
  39.  */
  40. shaka.net.DataUriPlugin = function(uri, request, requestType, progressUpdated) {
  41.   try {
  42.     let parsed = shaka.net.DataUriPlugin.parse(uri);
  44.     /** @type {shaka.extern.Response} */
  45.     let response = {
  46.       uri: uri,
  47.       originalUri: uri,
  48.       data: parsed.data,
  49.       headers: {
  50.         'content-type': parsed.contentType,
  51.       },
  52.     };
  54.     return shaka.util.AbortableOperation.completed(response);
  55.   } catch (error) {
  56.     return shaka.util.AbortableOperation.failed(error);
  57.   }
  58. };
  61. /**
  62.  * @param {string} uri
  63.  * @return {{data: ArrayBuffer, contentType: string}}
  64.  */
  65. shaka.net.DataUriPlugin.parse = function(uri) {
  66.   // Extract the scheme.
  67.   let parts = uri.split(':');
  68.   if (parts.length < 2 || parts[0] != 'data') {
  69.     shaka.log.error('Bad data URI, failed to parse scheme');
  70.     throw new shaka.util.Error(
  71.         shaka.util.Error.Severity.CRITICAL,
  72.         shaka.util.Error.Category.NETWORK,
  73.         shaka.util.Error.Code.MALFORMED_DATA_URI,
  74.         uri);
  75.   }
  76.   let path = parts.slice(1).join(':');
  78.   // Extract the encoding and MIME type (required but can be empty).
  79.   let infoAndData = path.split(',');
  80.   if (infoAndData.length < 2) {
  81.     shaka.log.error('Bad data URI, failed to extract encoding and MIME type');
  82.     throw new shaka.util.Error(
  83.         shaka.util.Error.Severity.CRITICAL,
  84.         shaka.util.Error.Category.NETWORK,
  85.         shaka.util.Error.Code.MALFORMED_DATA_URI,
  86.         uri);
  87.   }
  88.   let info = infoAndData[0];
  89.   let dataStr = window.decodeURIComponent(infoAndData.slice(1).join(','));
  91.   // The MIME type is always the first thing in the semicolon-separated list
  92.   // of type parameters.  It may be blank.
  93.   const typeInfoList = info.split(';');
  94.   const contentType = typeInfoList[0];
  96.   // Check for base64 encoding, which is always the last in the
  97.   // semicolon-separated list if present.
  98.   let base64Encoded = false;
  99.   if (typeInfoList.length > 1 &&
  100.       typeInfoList[typeInfoList.length - 1] == 'base64') {
  101.     base64Encoded = true;
  102.     typeInfoList.pop();
  103.   }
  105.   // Convert the data.
  106.   /** @type {ArrayBuffer} */
  107.   let data;
  108.   if (base64Encoded) {
  109.     data = shaka.util.Uint8ArrayUtils.fromBase64(dataStr).buffer;
  110.   } else {
  111.     data = shaka.util.StringUtils.toUTF8(dataStr);
  112.   }
  114.   return {data, contentType};
  115. };
  118. shaka.net.NetworkingEngine.registerScheme('data', shaka.net.DataUriPlugin);