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.Error');
  23. goog.require('shaka.util.StringUtils');
  24. goog.require('shaka.util.Uint8ArrayUtils');
  27. /**
  28.  * @namespace
  29.  * @summary A networking plugin to handle data URIs.
  30.  * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/data_URIs
  31.  * @param {string} uri
  32.  * @param {shakaExtern.Request} request
  33.  * @return {!Promise.<shakaExtern.Response>}
  34.  * @export
  35.  */
  36. shaka.net.DataUriPlugin = function(uri, request) {
  37.   return new Promise(function(resolve, reject) {
  38.     var parsed = shaka.net.DataUriPlugin.parse(uri);
  40.     /** @type {shakaExtern.Response} */
  41.     var response = {
  42.       uri: uri,
  43.       data: parsed.data,
  44.       headers: {
  45.         'content-type': parsed.contentType
  46.       }
  47.     };
  49.     resolve(response);
  50.   });
  51. };
  54. /**
  55.  * @param {string} uri
  56.  * @return {{data: ArrayBuffer, contentType: string}}
  57.  */
  58. shaka.net.DataUriPlugin.parse = function(uri) {
  59.   // Extract the scheme.
  60.   var parts = uri.split(':');
  61.   if (parts.length < 2 || parts[0] != 'data') {
  62.     shaka.log.error('Bad data URI, failed to parse scheme');
  63.     throw new shaka.util.Error(
  64.         shaka.util.Error.Severity.CRITICAL,
  65.         shaka.util.Error.Category.NETWORK,
  66.         shaka.util.Error.Code.MALFORMED_DATA_URI,
  67.         uri);
  68.   }
  69.   var path = parts.slice(1).join(':');
  71.   // Extract the encoding and MIME type (required but can be empty).
  72.   var infoAndData = path.split(',');
  73.   if (infoAndData.length < 2) {
  74.     shaka.log.error('Bad data URI, failed to extract encoding and MIME type');
  75.     throw new shaka.util.Error(
  76.         shaka.util.Error.Severity.CRITICAL,
  77.         shaka.util.Error.Category.NETWORK,
  78.         shaka.util.Error.Code.MALFORMED_DATA_URI,
  79.         uri);
  80.   }
  81.   var info = infoAndData[0];
  82.   var dataStr = window.decodeURIComponent(infoAndData.slice(1).join(','));
  84.   // Extract the encoding (optional).
  85.   var typeAndEncoding = info.split(';');
  86.   var encoding = null;
  87.   if (typeAndEncoding.length > 1)
  88.     encoding = typeAndEncoding[1];
  90.   // Convert the data.
  91.   /** @type {ArrayBuffer} */
  92.   var data;
  93.   if (encoding == 'base64') {
  94.     data = shaka.util.Uint8ArrayUtils.fromBase64(dataStr).buffer;
  95.   } else if (encoding) {
  96.     shaka.log.error('Bad data URI, unknown encoding');
  97.     throw new shaka.util.Error(
  98.         shaka.util.Error.Severity.CRITICAL,
  99.         shaka.util.Error.Category.NETWORK,
  100.         shaka.util.Error.Code.UNKNOWN_DATA_URI_ENCODING,
  101.         uri);
  102.   } else {
  103.     data = shaka.util.StringUtils.toUTF8(dataStr);
  104.   }
  106.   return {data: data, contentType: typeAndEncoding[0]};
  107. };
  110. shaka.net.NetworkingEngine.registerScheme('data', shaka.net.DataUriPlugin);