gecko-dev/toolkit/components/contentprefs/ContentPrefServiceChild.jsm

182 строки
5.4 KiB
JavaScript

/* vim: set ts=2 sw=2 sts=2 et tw=80: */
/* 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";
var EXPORTED_SYMBOLS = [ "ContentPrefServiceChild" ];
const {Services} = ChromeUtils.import("resource://gre/modules/Services.jsm");
const {ContentPref, _methodsCallableFromChild, cbHandleCompletion, cbHandleError, cbHandleResult, safeCallback} = ChromeUtils.import("resource://gre/modules/ContentPrefUtils.jsm");
// We only need one bit of information out of the context.
function contextArg(context) {
return (context && context.usePrivateBrowsing) ?
{ usePrivateBrowsing: true } :
null;
}
function NYI() {
throw new Error("Do not add any new users of these functions");
}
function CallbackCaller(callback) {
this._callback = callback;
}
CallbackCaller.prototype = {
handleResult(contentPref) {
cbHandleResult(this._callback,
new ContentPref(contentPref.domain,
contentPref.name,
contentPref.value));
},
handleError(result) {
cbHandleError(this._callback, result);
},
handleCompletion(reason) {
cbHandleCompletion(this._callback, reason);
},
};
var ContentPrefServiceChild = {
QueryInterface: ChromeUtils.generateQI([ Ci.nsIContentPrefService2 ]),
// Map from pref name -> set of observers
_observers: new Map(),
_getRandomId() {
return Cc["@mozilla.org/uuid-generator;1"]
.getService(Ci.nsIUUIDGenerator).generateUUID().toString();
},
// Map from random ID string -> CallbackCaller, per request
_requests: new Map(),
init() {
Services.cpmm.addMessageListener("ContentPrefs:HandleResult", this);
Services.cpmm.addMessageListener("ContentPrefs:HandleError", this);
Services.cpmm.addMessageListener("ContentPrefs:HandleCompletion", this);
Services.obs.addObserver(this, "xpcom-shutdown");
},
observe() {
Services.obs.removeObserver(this, "xpcom-shutdown");
delete this._observers;
delete this._requests;
},
receiveMessage(msg) {
let data = msg.data;
let callback;
switch (msg.name) {
case "ContentPrefs:HandleResult":
callback = this._requests.get(data.requestId);
callback.handleResult(data.contentPref);
break;
case "ContentPrefs:HandleError":
callback = this._requests.get(data.requestId);
callback.handleError(data.error);
break;
case "ContentPrefs:HandleCompletion":
callback = this._requests.get(data.requestId);
this._requests.delete(data.requestId);
callback.handleCompletion(data.reason);
break;
case "ContentPrefs:NotifyObservers": {
let observerList = this._observers.get(data.name);
if (!observerList)
break;
for (let observer of observerList) {
safeCallback(observer, data.callback, data.args);
}
break;
}
}
},
_callFunction(call, args, callback) {
let requestId = this._getRandomId();
let data = { call, args, requestId };
Services.cpmm.sendAsyncMessage("ContentPrefs:FunctionCall", data);
this._requests.set(requestId, new CallbackCaller(callback));
},
getCachedByDomainAndName: NYI,
getCachedBySubdomainAndName: NYI,
getCachedGlobal: NYI,
addObserverForName(name, observer) {
let set = this._observers.get(name);
if (!set) {
set = new Set();
if (this._observers.size === 0) {
// This is the first observer of any kind. Start listening for changes.
Services.cpmm.addMessageListener("ContentPrefs:NotifyObservers", this);
}
// This is the first observer for this name. Start listening for changes
// to it.
Services.cpmm.sendAsyncMessage("ContentPrefs:AddObserverForName", { name });
this._observers.set(name, set);
}
set.add(observer);
},
removeObserverForName(name, observer) {
let set = this._observers.get(name);
if (!set)
return;
set.delete(observer);
if (set.size === 0) {
// This was the last observer for this name. Stop listening for changes.
Services.cpmm.sendAsyncMessage("ContentPrefs:RemoveObserverForName", { name });
this._observers.delete(name);
if (this._observers.size === 0) {
// This was the last observer for this process. Stop listing for all
// changes.
Services.cpmm.removeMessageListener("ContentPrefs:NotifyObservers", this);
}
}
},
extractDomain: NYI,
};
function forwardMethodToParent(method, signature, ...args) {
// Ignore superfluous arguments
args = args.slice(0, signature.length);
// Process context argument for forwarding
let contextIndex = signature.indexOf("context");
if (contextIndex > -1) {
args[contextIndex] = contextArg(args[contextIndex]);
}
// Take out the callback argument, if present.
let callbackIndex = signature.indexOf("callback");
let callback = null;
if (callbackIndex > -1 && args.length > callbackIndex) {
callback = args.splice(callbackIndex, 1)[0];
}
this._callFunction(method, args, callback);
}
for (let [method, signature] of _methodsCallableFromChild) {
ContentPrefServiceChild[method] = forwardMethodToParent.bind(ContentPrefServiceChild, method, signature);
}
ContentPrefServiceChild.init();