michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict"
michael@0: 
michael@0: const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = ["DataStoreChangeNotifier"];
michael@0: 
michael@0: function debug(s) {
michael@0:   //dump('DEBUG DataStoreChangeNotifier: ' + s + '\n');
michael@0: }
michael@0: 
michael@0: // DataStoreServiceInternal should not be converted into a lazy getter as it
michael@0: // runs code during initialization.
michael@0: Cu.import('resource://gre/modules/DataStoreServiceInternal.jsm');
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: Cu.import("resource://gre/modules/Services.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyServiceGetter(this, "ppmm",
michael@0:                                    "@mozilla.org/parentprocessmessagemanager;1",
michael@0:                                    "nsIMessageBroadcaster");
michael@0: 
michael@0: this.DataStoreChangeNotifier = {
michael@0:   children: [],
michael@0:   messages: [ "DataStore:Changed", "DataStore:RegisterForMessages",
michael@0:               "DataStore:UnregisterForMessages",
michael@0:               "child-process-shutdown" ],
michael@0: 
michael@0:   init: function() {
michael@0:     debug("init");
michael@0: 
michael@0:     this.messages.forEach((function(msgName) {
michael@0:       ppmm.addMessageListener(msgName, this);
michael@0:     }).bind(this));
michael@0: 
michael@0:     Services.obs.addObserver(this, 'xpcom-shutdown', false);
michael@0:   },
michael@0: 
michael@0:   observe: function(aSubject, aTopic, aData) {
michael@0:     debug("observe");
michael@0: 
michael@0:     switch (aTopic) {
michael@0:       case 'xpcom-shutdown':
michael@0:         this.messages.forEach((function(msgName) {
michael@0:           ppmm.removeMessageListener(msgName, this);
michael@0:         }).bind(this));
michael@0: 
michael@0:         Services.obs.removeObserver(this, 'xpcom-shutdown');
michael@0:         ppmm = null;
michael@0:         break;
michael@0: 
michael@0:       default:
michael@0:         debug("Wrong observer topic: " + aTopic);
michael@0:         break;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   broadcastMessage: function broadcastMessage(aData) {
michael@0:     debug("Broadast");
michael@0:     this.children.forEach(function(obj) {
michael@0:       if (obj.store == aData.store && obj.owner == aData.owner) {
michael@0:         obj.mm.sendAsyncMessage("DataStore:Changed:Return:OK", aData);
michael@0:       }
michael@0:     });
michael@0:   },
michael@0: 
michael@0: 
michael@0:   receiveMessage: function(aMessage) {
michael@0:     debug("receiveMessage");
michael@0: 
michael@0:     // No check has to be done when the message is 'child-process-shutdown'
michael@0:     // because at this point the target is already disconnected from
michael@0:     // nsFrameMessageManager, so that assertAppHasStatus will always fail.
michael@0:     let prefName = 'dom.testing.datastore_enabled_for_hosted_apps';
michael@0:     if (aMessage.name != 'child-process-shutdown' &&
michael@0:         (Services.prefs.getPrefType(prefName) == Services.prefs.PREF_INVALID ||
michael@0:          !Services.prefs.getBoolPref(prefName)) &&
michael@0:         !aMessage.target.assertAppHasStatus(Ci.nsIPrincipal.APP_STATUS_CERTIFIED)) {
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     switch (aMessage.name) {
michael@0:       case "DataStore:Changed":
michael@0:         this.broadcastMessage(aMessage.data);
michael@0:         break;
michael@0: 
michael@0:       case "DataStore:RegisterForMessages":
michael@0:         debug("Register!");
michael@0: 
michael@0:         for (let i = 0; i < this.children.length; ++i) {
michael@0:           if (this.children[i].mm == aMessage.target &&
michael@0:               this.children[i].store == aMessage.data.store &&
michael@0:               this.children[i].owner == aMessage.data.owner) {
michael@0:             debug("Register on existing index: " + i);
michael@0:             ++this.children[i].count;
michael@0:             return;
michael@0:           }
michael@0:         }
michael@0: 
michael@0:         this.children.push({ mm: aMessage.target,
michael@0:                              store: aMessage.data.store,
michael@0:                              owner: aMessage.data.owner,
michael@0:                              count: 1 });
michael@0:         break;
michael@0: 
michael@0:       case "child-process-shutdown":
michael@0:       case "DataStore:UnregisterForMessages":
michael@0:         debug("Unregister");
michael@0: 
michael@0:         for (let i = 0; i < this.children.length;) {
michael@0:           if (this.children[i].mm == aMessage.target) {
michael@0:             debug("Unregister index: " + i);
michael@0:             if (!--this.children[i].count) {
michael@0:               debug("Unregister delete index: " + i);
michael@0:               this.children.splice(i, 1);
michael@0:             }
michael@0:             break;
michael@0:           } else {
michael@0:             ++i;
michael@0:           }
michael@0:         }
michael@0:         break;
michael@0: 
michael@0:       default:
michael@0:         debug("Wrong message: " + aMessage.name);
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: DataStoreChangeNotifier.init();