The Tor Browser: dom/downloads/src/DownloadsIPC.jsm@b8a032363ba2 (annotated)

dom/downloads/src/DownloadsIPC.jsm@b8a032363ba2 (annotated)

dom/downloads/src/DownloadsIPC.jsm

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* 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";
 const Cc = Components.classes;
 const Ci = Components.interfaces;
 const Cu = Components.utils;
 this.EXPORTED_SYMBOLS = ["DownloadsIPC"];
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/Promise.jsm");
 XPCOMUtils.defineLazyServiceGetter(this, "cpmm",
                                    "@mozilla.org/childprocessmessagemanager;1",
                                    "nsIMessageSender");
 /**
   * This module lives in the child process and receives the ipc messages
   * from the parent. It saves the download's state and redispatch changes
   * to DOM objects using an observer notification.
   *
   * This module needs to be loaded once and only once per process.
   */
 function debug(aStr) {
 #ifdef MOZ_DEBUG
   dump("-*- DownloadsIPC.jsm : " + aStr + "\n");
 #endif
 }
 const ipcMessages = ["Downloads:Added",
                      "Downloads:Removed",
                      "Downloads:Changed",
                      "Downloads:GetList:Return",
                      "Downloads:ClearAllDone:Return",
                      "Downloads:Remove:Return",
                      "Downloads:Pause:Return",
                      "Downloads:Resume:Return"];
 this.DownloadsIPC = {
   downloads: {},
   init: function() {
     debug("init");
     Services.obs.addObserver(this, "xpcom-shutdown", false);
     ipcMessages.forEach((aMessage) => {
       cpmm.addMessageListener(aMessage, this);
     });
     // We need to get the list of current downloads.
     this.ready = false;
     this.getListPromises = [];
     this.clearAllPromises = [];
     this.downloadPromises = {};
     cpmm.sendAsyncMessage("Downloads:GetList", {});
     this._promiseId = 0;
   },
   notifyChanges: function(aId) {
     // TODO: use the subject instead of stringifying.
     if (this.downloads[aId]) {
       debug("notifyChanges notifying changes for " + aId);
       Services.obs.notifyObservers(null, "downloads-state-change-" + aId,
                                    JSON.stringify(this.downloads[aId]));
     } else {
       debug("notifyChanges failed for " + aId)
     }
   },
   _updateDownloadsArray: function(aDownloads) {
     this.downloads = [];
     // We actually have an array of downloads.
     aDownloads.forEach((aDownload) => {
       this.downloads[aDownload.id] = aDownload;
     });
   },
   receiveMessage: function(aMessage) {
     let download = aMessage.data;
     debug("message: " + aMessage.name);
     switch(aMessage.name) {
       case "Downloads:GetList:Return":
         this._updateDownloadsArray(download);
         if (!this.ready) {
           this.getListPromises.forEach(aPromise =>
                                        aPromise.resolve(this.downloads));
           this.getListPromises.length = 0;
         }
         this.ready = true;
         break;
       case "Downloads:ClearAllDone:Return":
         this._updateDownloadsArray(download);
         this.clearAllPromises.forEach(aPromise =>
                                       aPromise.resolve(this.downloads));
         this.clearAllPromises.length = 0;
         break;
       case "Downloads:Added":
         this.downloads[download.id] = download;
         this.notifyChanges(download.id);
         break;
       case "Downloads:Removed":
         if (this.downloads[download.id]) {
           this.downloads[download.id] = download;
           this.notifyChanges(download.id);
           delete this.downloads[download.id];
         }
         break;
       case "Downloads:Changed":
         // Only update properties that actually changed.
         let cached = this.downloads[download.id];
         if (!cached) {
           debug("No download found for " + download.id);
           return;
         }
         let props = ["totalBytes", "currentBytes", "url", "path", "state",
                      "contentType", "startTime"];
         let changed = false;
         props.forEach((aProp) => {
           if (download[aProp] && (download[aProp] != cached[aProp])) {
             cached[aProp] = download[aProp];
             changed = true;
           }
         });
         // Updating the error property. We always get a 'state' change as
         // well.
         cached.error = download.error;
         if (changed) {
           this.notifyChanges(download.id);
         }
         break;
       case "Downloads:Remove:Return":
       case "Downloads:Pause:Return":
       case "Downloads:Resume:Return":
         if (this.downloadPromises[download.promiseId]) {
           if (!download.error) {
             this.downloadPromises[download.promiseId].resolve(download);
           } else {
             this.downloadPromises[download.promiseId].reject(download);
           }
           delete this.downloadPromises[download.promiseId];
         }
         break;
     }
   },
   /**
     * Returns a promise that is resolved with the list of current downloads.
     */
   getDownloads: function() {
     debug("getDownloads()");
     let deferred = Promise.defer();
     if (this.ready) {
       debug("Returning existing list.");
       deferred.resolve(this.downloads);
     } else {
       this.getListPromises.push(deferred);
     }
     return deferred.promise;
   },
   /**
     * Returns a promise that is resolved with the list of current downloads.
     */
   clearAllDone: function() {
     debug("clearAllDone");
     let deferred = Promise.defer();
     this.clearAllPromises.push(deferred);
     cpmm.sendAsyncMessage("Downloads:ClearAllDone", {});
     return deferred.promise;
   },
   promiseId: function() {
     return this._promiseId++;
   },
   remove: function(aId) {
     debug("remove " + aId);
     let deferred = Promise.defer();
     let pId = this.promiseId();
     this.downloadPromises[pId] = deferred;
     cpmm.sendAsyncMessage("Downloads:Remove",
                           { id: aId, promiseId: pId });
     return deferred.promise;
   },
   pause: function(aId) {
     debug("pause " + aId);
     let deferred = Promise.defer();
     let pId = this.promiseId();
     this.downloadPromises[pId] = deferred;
     cpmm.sendAsyncMessage("Downloads:Pause",
                           { id: aId, promiseId: pId });
     return deferred.promise;
   },
   resume: function(aId) {
     debug("resume " + aId);
     let deferred = Promise.defer();
     let pId = this.promiseId();
     this.downloadPromises[pId] = deferred;
     cpmm.sendAsyncMessage("Downloads:Resume",
                           { id: aId, promiseId: pId });
     return deferred.promise;
   },
   observe: function(aSubject, aTopic, aData) {
     if (aTopic == "xpcom-shutdown") {
       ipcMessages.forEach((aMessage) => {
         cpmm.removeMessageListener(aMessage, this);
       });
     }
   }
 };
 DownloadsIPC.init();

The Tor Browser / annotate

dom/downloads/src/DownloadsIPC.jsm@b8a032363ba2 (annotated)

dom/downloads/src/DownloadsIPC.jsm