1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/downloads/src/DownloadsIPC.jsm Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,223 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +"use strict";
1.9 +
1.10 +const Cc = Components.classes;
1.11 +const Ci = Components.interfaces;
1.12 +const Cu = Components.utils;
1.13 +
1.14 +this.EXPORTED_SYMBOLS = ["DownloadsIPC"];
1.15 +
1.16 +Cu.import("resource://gre/modules/XPCOMUtils.jsm");
1.17 +Cu.import("resource://gre/modules/Services.jsm");
1.18 +Cu.import("resource://gre/modules/Promise.jsm");
1.19 +
1.20 +XPCOMUtils.defineLazyServiceGetter(this, "cpmm",
1.21 + "@mozilla.org/childprocessmessagemanager;1",
1.22 + "nsIMessageSender");
1.23 +
1.24 +/**
1.25 + * This module lives in the child process and receives the ipc messages
1.26 + * from the parent. It saves the download's state and redispatch changes
1.27 + * to DOM objects using an observer notification.
1.28 + *
1.29 + * This module needs to be loaded once and only once per process.
1.30 + */
1.31 +
1.32 +function debug(aStr) {
1.33 +#ifdef MOZ_DEBUG
1.34 + dump("-*- DownloadsIPC.jsm : " + aStr + "\n");
1.35 +#endif
1.36 +}
1.37 +
1.38 +const ipcMessages = ["Downloads:Added",
1.39 + "Downloads:Removed",
1.40 + "Downloads:Changed",
1.41 + "Downloads:GetList:Return",
1.42 + "Downloads:ClearAllDone:Return",
1.43 + "Downloads:Remove:Return",
1.44 + "Downloads:Pause:Return",
1.45 + "Downloads:Resume:Return"];
1.46 +
1.47 +this.DownloadsIPC = {
1.48 + downloads: {},
1.49 +
1.50 + init: function() {
1.51 + debug("init");
1.52 + Services.obs.addObserver(this, "xpcom-shutdown", false);
1.53 + ipcMessages.forEach((aMessage) => {
1.54 + cpmm.addMessageListener(aMessage, this);
1.55 + });
1.56 +
1.57 + // We need to get the list of current downloads.
1.58 + this.ready = false;
1.59 + this.getListPromises = [];
1.60 + this.clearAllPromises = [];
1.61 + this.downloadPromises = {};
1.62 + cpmm.sendAsyncMessage("Downloads:GetList", {});
1.63 + this._promiseId = 0;
1.64 + },
1.65 +
1.66 + notifyChanges: function(aId) {
1.67 + // TODO: use the subject instead of stringifying.
1.68 + if (this.downloads[aId]) {
1.69 + debug("notifyChanges notifying changes for " + aId);
1.70 + Services.obs.notifyObservers(null, "downloads-state-change-" + aId,
1.71 + JSON.stringify(this.downloads[aId]));
1.72 + } else {
1.73 + debug("notifyChanges failed for " + aId)
1.74 + }
1.75 + },
1.76 +
1.77 + _updateDownloadsArray: function(aDownloads) {
1.78 + this.downloads = [];
1.79 + // We actually have an array of downloads.
1.80 + aDownloads.forEach((aDownload) => {
1.81 + this.downloads[aDownload.id] = aDownload;
1.82 + });
1.83 + },
1.84 +
1.85 + receiveMessage: function(aMessage) {
1.86 + let download = aMessage.data;
1.87 + debug("message: " + aMessage.name);
1.88 + switch(aMessage.name) {
1.89 + case "Downloads:GetList:Return":
1.90 + this._updateDownloadsArray(download);
1.91 +
1.92 + if (!this.ready) {
1.93 + this.getListPromises.forEach(aPromise =>
1.94 + aPromise.resolve(this.downloads));
1.95 + this.getListPromises.length = 0;
1.96 + }
1.97 + this.ready = true;
1.98 + break;
1.99 + case "Downloads:ClearAllDone:Return":
1.100 + this._updateDownloadsArray(download);
1.101 + this.clearAllPromises.forEach(aPromise =>
1.102 + aPromise.resolve(this.downloads));
1.103 + this.clearAllPromises.length = 0;
1.104 + break;
1.105 + case "Downloads:Added":
1.106 + this.downloads[download.id] = download;
1.107 + this.notifyChanges(download.id);
1.108 + break;
1.109 + case "Downloads:Removed":
1.110 + if (this.downloads[download.id]) {
1.111 + this.downloads[download.id] = download;
1.112 + this.notifyChanges(download.id);
1.113 + delete this.downloads[download.id];
1.114 + }
1.115 + break;
1.116 + case "Downloads:Changed":
1.117 + // Only update properties that actually changed.
1.118 + let cached = this.downloads[download.id];
1.119 + if (!cached) {
1.120 + debug("No download found for " + download.id);
1.121 + return;
1.122 + }
1.123 + let props = ["totalBytes", "currentBytes", "url", "path", "state",
1.124 + "contentType", "startTime"];
1.125 + let changed = false;
1.126 +
1.127 + props.forEach((aProp) => {
1.128 + if (download[aProp] && (download[aProp] != cached[aProp])) {
1.129 + cached[aProp] = download[aProp];
1.130 + changed = true;
1.131 + }
1.132 + });
1.133 +
1.134 + // Updating the error property. We always get a 'state' change as
1.135 + // well.
1.136 + cached.error = download.error;
1.137 +
1.138 + if (changed) {
1.139 + this.notifyChanges(download.id);
1.140 + }
1.141 + break;
1.142 + case "Downloads:Remove:Return":
1.143 + case "Downloads:Pause:Return":
1.144 + case "Downloads:Resume:Return":
1.145 + if (this.downloadPromises[download.promiseId]) {
1.146 + if (!download.error) {
1.147 + this.downloadPromises[download.promiseId].resolve(download);
1.148 + } else {
1.149 + this.downloadPromises[download.promiseId].reject(download);
1.150 + }
1.151 + delete this.downloadPromises[download.promiseId];
1.152 + }
1.153 + break;
1.154 + }
1.155 + },
1.156 +
1.157 + /**
1.158 + * Returns a promise that is resolved with the list of current downloads.
1.159 + */
1.160 + getDownloads: function() {
1.161 + debug("getDownloads()");
1.162 + let deferred = Promise.defer();
1.163 + if (this.ready) {
1.164 + debug("Returning existing list.");
1.165 + deferred.resolve(this.downloads);
1.166 + } else {
1.167 + this.getListPromises.push(deferred);
1.168 + }
1.169 + return deferred.promise;
1.170 + },
1.171 +
1.172 + /**
1.173 + * Returns a promise that is resolved with the list of current downloads.
1.174 + */
1.175 + clearAllDone: function() {
1.176 + debug("clearAllDone");
1.177 + let deferred = Promise.defer();
1.178 + this.clearAllPromises.push(deferred);
1.179 + cpmm.sendAsyncMessage("Downloads:ClearAllDone", {});
1.180 + return deferred.promise;
1.181 + },
1.182 +
1.183 + promiseId: function() {
1.184 + return this._promiseId++;
1.185 + },
1.186 +
1.187 + remove: function(aId) {
1.188 + debug("remove " + aId);
1.189 + let deferred = Promise.defer();
1.190 + let pId = this.promiseId();
1.191 + this.downloadPromises[pId] = deferred;
1.192 + cpmm.sendAsyncMessage("Downloads:Remove",
1.193 + { id: aId, promiseId: pId });
1.194 + return deferred.promise;
1.195 + },
1.196 +
1.197 + pause: function(aId) {
1.198 + debug("pause " + aId);
1.199 + let deferred = Promise.defer();
1.200 + let pId = this.promiseId();
1.201 + this.downloadPromises[pId] = deferred;
1.202 + cpmm.sendAsyncMessage("Downloads:Pause",
1.203 + { id: aId, promiseId: pId });
1.204 + return deferred.promise;
1.205 + },
1.206 +
1.207 + resume: function(aId) {
1.208 + debug("resume " + aId);
1.209 + let deferred = Promise.defer();
1.210 + let pId = this.promiseId();
1.211 + this.downloadPromises[pId] = deferred;
1.212 + cpmm.sendAsyncMessage("Downloads:Resume",
1.213 + { id: aId, promiseId: pId });
1.214 + return deferred.promise;
1.215 + },
1.216 +
1.217 + observe: function(aSubject, aTopic, aData) {
1.218 + if (aTopic == "xpcom-shutdown") {
1.219 + ipcMessages.forEach((aMessage) => {
1.220 + cpmm.removeMessageListener(aMessage, this);
1.221 + });
1.222 + }
1.223 + }
1.224 +};
1.225 +
1.226 +DownloadsIPC.init();
