gecko-dev/dom/datastore/DataStoreChangeNotifier.jsm

133 lines
4.0 KiB
JavaScript

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