shaka-player/lib/net/data_uri_plugin.js

DASH/EME video player library

/*! @license
 * Shaka Player
 * Copyright 2016 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

goog.provide('shaka.net.DataUriPlugin');

goog.require('shaka.log');
goog.require('shaka.net.NetworkingEngine');
goog.require('shaka.util.AbortableOperation');
goog.require('shaka.util.Error');
goog.require('shaka.util.StringUtils');
goog.require('shaka.util.Uint8ArrayUtils');


/**
 * @summary A networking plugin to handle data URIs.
 * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/data_URIs
 * @export
 */
shaka.net.DataUriPlugin = class {
  /**
   * @param {string} uri
   * @param {shaka.extern.Request} request
   * @param {shaka.net.NetworkingEngine.RequestType} requestType
   * @param {shaka.extern.ProgressUpdated} progressUpdated Called when a
   *   progress event happened.
   * @return {!shaka.extern.IAbortableOperation.<shaka.extern.Response>}
   * @export
   */
  static parse(uri, request, requestType, progressUpdated) {
    try {
      const parsed = shaka.net.DataUriPlugin.parseRaw(uri);

      /** @type {shaka.extern.Response} */
      const response = {
        uri: uri,
        originalUri: uri,
        data: parsed.data,
        headers: {
          'content-type': parsed.contentType,
        },
        originalRequest: request,
      };

      return shaka.util.AbortableOperation.completed(response);
    } catch (error) {
      return shaka.util.AbortableOperation.failed(error);
    }
  }

  /**
   * @param {string} uri
   * @return {{data: BufferSource, contentType: string}}
   */
  static parseRaw(uri) {
    // Extract the scheme.
    const parts = uri.split(':');
    if (parts.length < 2 || parts[0] != 'data') {
      shaka.log.error('Bad data URI, failed to parse scheme');
      throw new shaka.util.Error(
          shaka.util.Error.Severity.CRITICAL,
          shaka.util.Error.Category.NETWORK,
          shaka.util.Error.Code.MALFORMED_DATA_URI,
          uri);
    }
    const path = parts.slice(1).join(':');

    // Extract the encoding and MIME type (required but can be empty).
    const infoAndData = path.split(',');
    if (infoAndData.length < 2) {
      shaka.log.error('Bad data URI, failed to extract encoding and MIME type');
      throw new shaka.util.Error(
          shaka.util.Error.Severity.CRITICAL,
          shaka.util.Error.Category.NETWORK,
          shaka.util.Error.Code.MALFORMED_DATA_URI,
          uri);
    }
    const info = infoAndData[0];
    const dataStr = window.decodeURIComponent(infoAndData.slice(1).join(','));

    // The MIME type is always the first thing in the semicolon-separated list
    // of type parameters.  It may be blank.
    const typeInfoList = info.split(';');
    const contentType = typeInfoList[0];

    // Check for base64 encoding, which is always the last in the
    // semicolon-separated list if present.
    let base64Encoded = false;
    if (typeInfoList.length > 1 &&
        typeInfoList[typeInfoList.length - 1] == 'base64') {
      base64Encoded = true;
      typeInfoList.pop();
    }

    // Convert the data.
    /** @type {BufferSource} */
    let data;
    if (base64Encoded) {
      data = shaka.util.Uint8ArrayUtils.fromBase64(dataStr);
    } else {
      data = shaka.util.StringUtils.toUTF8(dataStr);
    }

    return {data: data, contentType};
  }
};


shaka.net.NetworkingEngine.registerScheme(
    'data', shaka.net.DataUriPlugin.parse);