The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this file,

  * You can obtain one at http://mozilla.org/MPL/2.0/. */

 "use strict";

 this.EXPORTED_SYMBOLS = ["LanguageDetector"];

 Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");

 XPCOMUtils.defineLazyModuleGetter(this, "Promise",

                                   "resource://gre/modules/Promise.jsm");

 const WORKER_URL = "resource:///modules/translation/cld-worker.js";

 let detectionQueue = [];

 let workerReady = false;

 let pendingStrings = [];

 XPCOMUtils.defineLazyGetter(this, "worker", () => {

   let worker = new Worker(WORKER_URL);

   worker.onmessage = function(aMsg) {

     if (aMsg.data == "ready") {

       workerReady = true;

       for (let string of pendingStrings)

         worker.postMessage(string);

       pendingStrings = [];

     }

     else

       detectionQueue.shift().resolve(aMsg.data);

   }

   return worker;

 });

 this.LanguageDetector = {

   /**

    * Detect the language of a given string

    *

    * @returns {Promise}

    * @resolves When detection is finished, with a object containing

    * these fields:

    *  - 'language' (string with a language code)

    *  - 'confident' (boolean).

    */

   detectLanguage: function(aString) {

     let deferred = Promise.defer();

     detectionQueue.push(deferred);

     if (worker && workerReady)

       worker.postMessage(aString);

     else

       pendingStrings.push(aString);

     return deferred.promise;

   }

 };