import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

toolkit/components/contentprefs/ContentPrefServiceChild.jsm

@@ -0,0 +1,182 @@
+/* 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";
+
+this.EXPORTED_SYMBOLS = [ "ContentPrefServiceChild" ];
+
+const Ci = Components.interfaces;
+const Cc = Components.classes;
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/ContentPrefUtils.jsm");
+Cu.import("resource://gre/modules/ContentPrefStore.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: function(contentPref) {
+    cbHandleResult(this._callback,
+                   new ContentPref(contentPref.domain,
+                                   contentPref.name,
+                                   contentPref.value));
+  },
+
+  handleError: function(result) {
+    cbHandleError(this._callback, result);
+  },
+
+  handleCompletion: function(reason) {
+    cbHandleCompletion(this._callback, reason);
+  },
+};
+
+var ContentPrefServiceChild = {
+  QueryInterface: XPCOMUtils.generateQI([ Ci.nsIContentPrefService2 ]),
+
+  // Map from pref name -> set of observers
+  _observers: new Map(),
+
+  _mm: Cc["@mozilla.org/childprocessmessagemanager;1"]
+         .getService(Ci.nsIMessageSender),
+
+  _getRandomId: function() {
+    return Cc["@mozilla.org/uuid-generator;1"]
+             .getService(Ci.nsIUUIDGenerator).generateUUID().toString();
+  },
+
+  // Map from random ID string -> CallbackCaller, per request
+  _requests: new Map(),
+
+  init: function() {
+    this._mm.addMessageListener("ContentPrefs:HandleResult", this);
+    this._mm.addMessageListener("ContentPrefs:HandleError", this);
+    this._mm.addMessageListener("ContentPrefs:HandleCompletion", this);
+  },
+
+  receiveMessage: function(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: function(call, args, callback) {
+    let requestId = this._getRandomId();
+    let data = { call: call, args: args, requestId: requestId };
+
+    this._mm.sendAsyncMessage("ContentPrefs:FunctionCall", data);
+
+    this._requests.set(requestId, new CallbackCaller(callback));
+  },
+
+  getCachedByDomainAndName: NYI,
+  getCachedBySubdomainAndName: NYI,
+  getCachedGlobal: NYI,
+
+  addObserverForName: function(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.
+        this._mm.addMessageListener("ContentPrefs:NotifyObservers", this);
+      }
+
+      // This is the first observer for this name. Start listening for changes
+      // to it.
+      this._mm.sendAsyncMessage("ContentPrefs:AddObserverForName", { name: name });
+      this._observers.set(name, set);
+    }
+
+    set.add(observer);
+  },
+
+  removeObserverForName: function(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.
+      this._mm.sendAsyncMessage("ContentPrefs:RemoveObserverForName", { name: name });
+
+      this._observers.delete(name);
+      if (this._observers.size === 0) {
+        // This was the last observer for this process. Stop listing for all
+        // changes.
+        this._mm.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();