tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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e10s.js (3184B)

      1 /* This Source Code Form is subject to the terms of the Mozilla Public
      2 * License, v. 2.0. If a copy of the MPL was not distributed with this
      3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      4 
      5 "use strict";
      6 
      7 // The prefix used for RDM messages in content.
      8 // see: devtools/client/responsive/browser/content.js
      9 const MESSAGE_PREFIX = "ResponsiveMode:";
     10 const REQUEST_DONE_SUFFIX = ":Done";
     11 
     12 /**
     13 * Registers a message `listener` that is called every time messages of
     14 * specified `message` is emitted on the given message manager.
     15 *
     16 * @param {nsIMessageListenerManager} mm
     17 *    The Message Manager
     18 * @param {string} message
     19 *    The message. It will be prefixed with the constant `MESSAGE_PREFIX`
     20 * @param {Function} listener
     21 *    The listener function that processes the message.
     22 */
     23 function on(mm, message, listener) {
     24  mm.addMessageListener(MESSAGE_PREFIX + message, listener);
     25 }
     26 exports.on = on;
     27 
     28 /**
     29 * Removes a message `listener` for the specified `message` on the given
     30 * message manager.
     31 *
     32 * @param {nsIMessageListenerManager} mm
     33 *    The Message Manager
     34 * @param {string} message
     35 *    The message. It will be prefixed with the constant `MESSAGE_PREFIX`
     36 * @param {Function} listener
     37 *    The listener function that processes the message.
     38 */
     39 function off(mm, message, listener) {
     40  mm.removeMessageListener(MESSAGE_PREFIX + message, listener);
     41 }
     42 exports.off = off;
     43 
     44 /**
     45 * Resolves a promise the next time the specified `message` is sent over the
     46 * given message manager.
     47 *
     48 * @param {nsIMessageListenerManager} mm
     49 *    The Message Manager
     50 * @param {string} message
     51 *    The message. It will be prefixed with the constant `MESSAGE_PREFIX`
     52 * @returns {Promise}
     53 *    A promise that is resolved when the given message is emitted.
     54 */
     55 function once(mm, message) {
     56  return new Promise(resolve => {
     57    on(mm, message, function onMessage({ data }) {
     58      off(mm, message, onMessage);
     59      resolve(data);
     60    });
     61  });
     62 }
     63 exports.once = once;
     64 
     65 /**
     66 * Asynchronously emit a `message` to the listeners of the given message
     67 * manager.
     68 *
     69 * @param {nsIMessageListenerManager} mm
     70 *    The Message Manager
     71 * @param {string} message
     72 *    The message. It will be prefixed with the constant `MESSAGE_PREFIX`.
     73 * @param {object} data
     74 *    A JSON object containing data to be delivered to the listeners.
     75 */
     76 function emit(mm, message, data) {
     77  mm.sendAsyncMessage(MESSAGE_PREFIX + message, data);
     78 }
     79 exports.emit = emit;
     80 
     81 /**
     82 * Asynchronously send a "request" over the given message manager, and returns
     83 * a promise that is resolved when the request is complete.
     84 *
     85 * @param {nsIMessageListenerManager} mm
     86 *    The Message Manager
     87 * @param {string} message
     88 *    The message. It will be prefixed with the constant `MESSAGE_PREFIX`, and
     89 *    also suffixed with `REQUEST_DONE_SUFFIX` for the reply.
     90 * @param {object} data
     91 *    A JSON object containing data to be delivered to the listeners.
     92 * @returns {Promise}
     93 *    A promise that is resolved when the request is done.
     94 */
     95 function request(mm, message, data) {
     96  const done = once(mm, message + REQUEST_DONE_SUFFIX);
     97 
     98  emit(mm, message, data);
     99 
    100  return done;
    101 }
    102 exports.request = request;