The Tor Browser: dom/alarm/AlarmService.jsm@97036ab72558 (annotated)

dom/alarm/AlarmService.jsm@97036ab72558 (annotated)

dom/alarm/AlarmService.jsm

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* 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";
 /* static functions */
 const DEBUG = false;
 function debug(aStr) {
   if (DEBUG)
     dump("AlarmService: " + aStr + "\n");
 }
 const { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/AlarmDB.jsm");
 this.EXPORTED_SYMBOLS = ["AlarmService"];
 XPCOMUtils.defineLazyGetter(this, "appsService", function() {
   return Cc["@mozilla.org/AppsService;1"].getService(Ci.nsIAppsService);
 });
 XPCOMUtils.defineLazyServiceGetter(this, "ppmm",
                                    "@mozilla.org/parentprocessmessagemanager;1",
                                    "nsIMessageListenerManager");
 XPCOMUtils.defineLazyGetter(this, "messenger", function() {
   return Cc["@mozilla.org/system-message-internal;1"].getService(Ci.nsISystemMessagesInternal);
 });
 XPCOMUtils.defineLazyGetter(this, "powerManagerService", function() {
   return Cc["@mozilla.org/power/powermanagerservice;1"].getService(Ci.nsIPowerManagerService);
 });
 /**
  * AlarmService provides an API to schedule alarms using the device's RTC.
  *
  * AlarmService is primarily used by the mozAlarms API (navigator.mozAlarms)
  * which uses IPC to communicate with the service.
  *
  * AlarmService can also be used by Gecko code by importing the module and then
  * using AlarmService.add() and AlarmService.remove(). Only Gecko code running
  * in the parent process should do this.
  */
 this.AlarmService = {
   init: function init() {
     debug("init()");
     Services.obs.addObserver(this, "profile-change-teardown", false);
     Services.obs.addObserver(this, "webapps-clear-data",false);
     this._currentTimezoneOffset = (new Date()).getTimezoneOffset();
     let alarmHalService =
       this._alarmHalService = Cc["@mozilla.org/alarmHalService;1"]
                               .getService(Ci.nsIAlarmHalService);
     alarmHalService.setAlarmFiredCb(this._onAlarmFired.bind(this));
     alarmHalService.setTimezoneChangedCb(this._onTimezoneChanged.bind(this));
     // Add the messages to be listened to.
     this._messages = ["AlarmsManager:GetAll",
                       "AlarmsManager:Add",
                       "AlarmsManager:Remove"];
     this._messages.forEach(function addMessage(msgName) {
       ppmm.addMessageListener(msgName, this);
     }.bind(this));
     // Set the indexeddb database.
     this._db = new AlarmDB();
     this._db.init();
     // Variable to save alarms waiting to be set.
     this._alarmQueue = [];
     this._restoreAlarmsFromDb();
   },
   // Getter/setter to access the current alarm set in system.
   _alarm: null,
   get _currentAlarm() {
     return this._alarm;
   },
   set _currentAlarm(aAlarm) {
     this._alarm = aAlarm;
     if (!aAlarm) {
       return;
     }
     let alarmTimeInMs = this._getAlarmTime(aAlarm);
     let ns = (alarmTimeInMs % 1000) * 1000000;
     if (!this._alarmHalService.setAlarm(alarmTimeInMs / 1000, ns)) {
       throw Components.results.NS_ERROR_FAILURE;
     }
   },
   receiveMessage: function receiveMessage(aMessage) {
     debug("receiveMessage(): " + aMessage.name);
     let json = aMessage.json;
     // To prevent the hacked child process from sending commands to parent
     // to schedule alarms, we need to check its permission and manifest URL.
     if (this._messages.indexOf(aMessage.name) != -1) {
       if (!aMessage.target.assertPermission("alarms")) {
         debug("Got message from a child process with no 'alarms' permission.");
         return null;
       }
       if (!aMessage.target.assertContainApp(json.manifestURL)) {
         debug("Got message from a child process containing illegal manifest URL.");
         return null;
       }
     }
     let mm = aMessage.target.QueryInterface(Ci.nsIMessageSender);
     switch (aMessage.name) {
       case "AlarmsManager:GetAll":
         this._db.getAll(
           json.manifestURL,
           function getAllSuccessCb(aAlarms) {
             debug("Callback after getting alarms from database: " +
                   JSON.stringify(aAlarms));
             this._sendAsyncMessage(mm, "GetAll", true, json.requestId, aAlarms);
           }.bind(this),
           function getAllErrorCb(aErrorMsg) {
             this._sendAsyncMessage(mm, "GetAll", false, json.requestId, aErrorMsg);
           }.bind(this)
         );
         break;
       case "AlarmsManager:Add":
         // Prepare a record for the new alarm to be added.
         let newAlarm = {
           date: json.date,
           ignoreTimezone: json.ignoreTimezone,
           data: json.data,
           pageURL: json.pageURL,
           manifestURL: json.manifestURL
         };
         this.add(newAlarm, null,
           // Receives the alarm ID as the last argument.
           this._sendAsyncMessage.bind(this, mm, "Add", true, json.requestId),
           // Receives the error message as the last argument.
           this._sendAsyncMessage.bind(this, mm, "Add", false, json.requestId)
         );
         break;
       case "AlarmsManager:Remove":
         this.remove(json.id, json.manifestURL);
         break;
       default:
         throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
         break;
     }
   },
   _sendAsyncMessage: function _sendAsyncMessage(aMessageManager, aMessageName,
                                                 aSuccess, aRequestId, aData) {
     debug("_sendAsyncMessage()");
     if (!aMessageManager) {
       debug("Invalid message manager: null");
       throw Components.results.NS_ERROR_FAILURE;
     }
     let json = null;
     switch (aMessageName)
     {
       case "Add":
         json = aSuccess ?
           { requestId: aRequestId, id: aData } :
           { requestId: aRequestId, errorMsg: aData };
         break;
       case "GetAll":
         json = aSuccess ?
           { requestId: aRequestId, alarms: aData } :
           { requestId: aRequestId, errorMsg: aData };
         break;
       default:
         throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
         break;
     }
     aMessageManager.sendAsyncMessage("AlarmsManager:" + aMessageName +
                                      ":Return:" + (aSuccess ? "OK" : "KO"), json);
   },
   _removeAlarmFromDb: function _removeAlarmFromDb(aId, aManifestURL,
                                                   aRemoveSuccessCb) {
     debug("_removeAlarmFromDb()");
     // If the aRemoveSuccessCb is undefined or null, set a dummy callback for
     // it which is needed for _db.remove().
     if (!aRemoveSuccessCb) {
       aRemoveSuccessCb = function removeSuccessCb() {
         debug("Remove alarm from DB successfully.");
       };
     }
     this._db.remove(
       aId,
       aManifestURL,
       aRemoveSuccessCb,
       function removeErrorCb(aErrorMsg) {
         throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
       }
     );
   },
   /**
    * Create a copy of the alarm that does not expose internal fields to
    * receivers and sticks to the public |respectTimezone| API rather than the
    * boolean |ignoreTimezone| field.
    */
   _publicAlarm: function _publicAlarm(aAlarm) {
     let alarm = {
       "id":              aAlarm.id,
       "date":            aAlarm.date,
       "respectTimezone": aAlarm.ignoreTimezone ?
                            "ignoreTimezone" : "honorTimezone",
       "data":            aAlarm.data
     };
     return alarm;
   },
   _fireSystemMessage: function _fireSystemMessage(aAlarm) {
     debug("Fire system message: " + JSON.stringify(aAlarm));
     let manifestURI = Services.io.newURI(aAlarm.manifestURL, null, null);
     let pageURI = Services.io.newURI(aAlarm.pageURL, null, null);
     messenger.sendMessage("alarm", this._publicAlarm(aAlarm),
                           pageURI, manifestURI);
   },
   _notifyAlarmObserver: function _notifyAlarmObserver(aAlarm) {
     debug("_notifyAlarmObserver()");
     if (aAlarm.manifestURL) {
       this._fireSystemMessage(aAlarm);
     } else if (typeof aAlarm.alarmFiredCb === "function") {
       aAlarm.alarmFiredCb(this._publicAlarm(aAlarm));
     }
   },
   _onAlarmFired: function _onAlarmFired() {
     debug("_onAlarmFired()");
     if (this._currentAlarm) {
       this._removeAlarmFromDb(this._currentAlarm.id, null);
       this._notifyAlarmObserver(this._currentAlarm);
       this._currentAlarm = null;
     }
     // Reset the next alarm from the queue.
     let alarmQueue = this._alarmQueue;
     while (alarmQueue.length > 0) {
       let nextAlarm = alarmQueue.shift();
       let nextAlarmTime = this._getAlarmTime(nextAlarm);
       // If the next alarm has been expired, directly notify the observer.
       // it instead of setting it.
       if (nextAlarmTime <= Date.now()) {
         this._removeAlarmFromDb(nextAlarm.id, null);
         this._notifyAlarmObserver(nextAlarm);
       } else {
         this._currentAlarm = nextAlarm;
         break;
       }
     }
     this._debugCurrentAlarm();
   },
   _onTimezoneChanged: function _onTimezoneChanged(aTimezoneOffset) {
     debug("_onTimezoneChanged()");
     this._currentTimezoneOffset = aTimezoneOffset;
     this._restoreAlarmsFromDb();
   },
   _restoreAlarmsFromDb: function _restoreAlarmsFromDb() {
     debug("_restoreAlarmsFromDb()");
     this._db.getAll(
       null,
       function getAllSuccessCb(aAlarms) {
         debug("Callback after getting alarms from database: " +
               JSON.stringify(aAlarms));
         // Clear any alarms set or queued in the cache.
         let alarmQueue = this._alarmQueue;
         alarmQueue.length = 0;
         this._currentAlarm = null;
         // Only restore the alarm that's not yet expired; otherwise, remove it
         // from the database and notify the observer.
         aAlarms.forEach(function addAlarm(aAlarm) {
           if (this._getAlarmTime(aAlarm) > Date.now()) {
             alarmQueue.push(aAlarm);
           } else {
             this._removeAlarmFromDb(aAlarm.id, null);
             this._notifyAlarmObserver(aAlarm);
           }
         }.bind(this));
         // Set the next alarm from queue.
         if (alarmQueue.length) {
           alarmQueue.sort(this._sortAlarmByTimeStamps.bind(this));
           this._currentAlarm = alarmQueue.shift();
         }
         this._debugCurrentAlarm();
       }.bind(this),
       function getAllErrorCb(aErrorMsg) {
         throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
       }
     );
   },
   _getAlarmTime: function _getAlarmTime(aAlarm) {
     // Avoid casting a Date object to a Date again to
     // preserve milliseconds. See bug 810973.
     let alarmTime;
     if (aAlarm.date instanceof Date) {
       alarmTime = aAlarm.date.getTime();
     } else {
       alarmTime = (new Date(aAlarm.date)).getTime();
     }
     // For an alarm specified with "ignoreTimezone", it must be fired respect
     // to the user's timezone.  Supposing an alarm was set at 7:00pm at Tokyo,
     // it must be gone off at 7:00pm respect to Paris' local time when the user
     // is located at Paris.  We can adjust the alarm UTC time by calculating
     // the difference of the orginal timezone and the current timezone.
     if (aAlarm.ignoreTimezone) {
        alarmTime += (this._currentTimezoneOffset - aAlarm.timezoneOffset) * 60000;
     }
     return alarmTime;
   },
   _sortAlarmByTimeStamps: function _sortAlarmByTimeStamps(aAlarm1, aAlarm2) {
     return this._getAlarmTime(aAlarm1) - this._getAlarmTime(aAlarm2);
   },
   _debugCurrentAlarm: function _debugCurrentAlarm() {
     debug("Current alarm: " + JSON.stringify(this._currentAlarm));
     debug("Alarm queue: " + JSON.stringify(this._alarmQueue));
   },
   /**
    *
    * Add a new alarm. This will set the RTC to fire at the selected date and
    * notify the caller. Notifications are delivered via System Messages if the
    * alarm is added on behalf of a app. Otherwise aAlarmFiredCb is called.
    *
    * @param object aNewAlarm
    *        Should contain the following literal properties:
    *          - |date| date: when the alarm should timeout.
    *          - |ignoreTimezone| boolean: See [1] for the details.
    *          - |manifestURL| string: Manifest of app on whose behalf the alarm
    *                                  is added.
    *          - |pageURL| string: The page in the app that receives the system
    *                              message.
    *          - |data| object [optional]: Data that can be stored in DB.
    * @param function aAlarmFiredCb
    *        Callback function invoked when the alarm is fired.
    *        It receives a single argument, the alarm object.
    *        May be null.
    * @param function aSuccessCb
    *        Callback function to receive an alarm ID (number).
    * @param function aErrorCb
    *        Callback function to receive an error message (string).
    * @returns void
    *
    * Notes:
    * [1] https://wiki.mozilla.org/WebAPI/AlarmAPI#Proposed_API
    */
   add: function(aNewAlarm, aAlarmFiredCb, aSuccessCb, aErrorCb) {
     debug("add(" + aNewAlarm.date + ")");
     aSuccessCb = aSuccessCb || function() {};
     aErrorCb = aErrorCb || function() {};
     if (!aNewAlarm) {
       aErrorCb("alarm is null");
       return;
     }
     if (!aNewAlarm.date) {
       aErrorCb("alarm.date is null");
       return;
     }
     aNewAlarm['timezoneOffset'] = this._currentTimezoneOffset;
     this._db.add(
       aNewAlarm,
       function addSuccessCb(aNewId) {
         debug("Callback after adding alarm in database.");
         aNewAlarm['id'] = aNewId;
         // Now that the alarm has been added to the database, we can tack on
         // the non-serializable callback to the in-memory object.
         aNewAlarm['alarmFiredCb'] = aAlarmFiredCb;
         // If there is no alarm being set in system, set the new alarm.
         if (this._currentAlarm == null) {
           this._currentAlarm = aNewAlarm;
           this._debugCurrentAlarm();
           aSuccessCb(aNewId);
           return;
         }
         // If the new alarm is earlier than the current alarm, swap them and
         // push the previous alarm back to queue.
         let alarmQueue = this._alarmQueue;
         let aNewAlarmTime = this._getAlarmTime(aNewAlarm);
         let currentAlarmTime = this._getAlarmTime(this._currentAlarm);
         if (aNewAlarmTime < currentAlarmTime) {
           alarmQueue.unshift(this._currentAlarm);
           this._currentAlarm = aNewAlarm;
           this._debugCurrentAlarm();
           aSuccessCb(aNewId);
           return;
         }
         // Push the new alarm in the queue.
         alarmQueue.push(aNewAlarm);
         alarmQueue.sort(this._sortAlarmByTimeStamps.bind(this));
         this._debugCurrentAlarm();
         aSuccessCb(aNewId);
       }.bind(this),
       function addErrorCb(aErrorMsg) {
         aErrorCb(aErrorMsg);
       }.bind(this)
     );
   },
   /*
    * Remove the alarm associated with an ID.
    *
    * @param number aAlarmId
    *        The ID of the alarm to be removed.
    * @param string aManifestURL
    *        Manifest URL for application which added the alarm. (Optional)
    * @returns void
    */
   remove: function(aAlarmId, aManifestURL) {
     debug("remove(" + aAlarmId + ", " + aManifestURL + ")");
     this._removeAlarmFromDb(
       aAlarmId,
       aManifestURL,
       function removeSuccessCb() {
         debug("Callback after removing alarm from database.");
         // If there are no alarms set, nothing to do.
         if (!this._currentAlarm) {
           debug("No alarms set.");
           return;
         }
         // Check if the alarm to be removed is in the queue and whether it
         // belongs to the requesting app.
         let alarmQueue = this._alarmQueue;
         if (this._currentAlarm.id != aAlarmId ||
             this._currentAlarm.manifestURL != aManifestURL) {
           for (let i = 0; i < alarmQueue.length; i++) {
             if (alarmQueue[i].id == aAlarmId &&
                 alarmQueue[i].manifestURL == aManifestURL) {
               alarmQueue.splice(i, 1);
               break;
             }
           }
           this._debugCurrentAlarm();
           return;
         }
         // The alarm to be removed is the current alarm reset the next alarm
         // from queue if any.
         if (alarmQueue.length) {
           this._currentAlarm = alarmQueue.shift();
           this._debugCurrentAlarm();
           return;
         }
         // No alarm waiting to be set in the queue.
         this._currentAlarm = null;
         this._debugCurrentAlarm();
       }.bind(this)
     );
   },
   observe: function(aSubject, aTopic, aData) {
     switch (aTopic) {
       case "profile-change-teardown":
         this.uninit();
         break;
       case "webapps-clear-data":
         let params =
           aSubject.QueryInterface(Ci.mozIApplicationClearPrivateDataParams);
         if (!params) {
           debug("Error! Fail to remove alarms for an uninstalled app.");
           return;
         }
         // Only remove alarms for apps.
         if (params.browserOnly) {
           return;
         }
         let manifestURL = appsService.getManifestURLByLocalId(params.appId);
         if (!manifestURL) {
           debug("Error! Fail to remove alarms for an uninstalled app.");
           return;
         }
         this._db.getAll(
           manifestURL,
           function getAllSuccessCb(aAlarms) {
             aAlarms.forEach(function removeAlarm(aAlarm) {
               this.remove(aAlarm.id, manifestURL);
             }, this);
           }.bind(this),
           function getAllErrorCb(aErrorMsg) {
             throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
           }
         );
         break;
     }
   },
   uninit: function uninit() {
     debug("uninit()");
     Services.obs.removeObserver(this, "profile-change-teardown");
     Services.obs.removeObserver(this, "webapps-clear-data");
     this._messages.forEach(function(aMsgName) {
       ppmm.removeMessageListener(aMsgName, this);
     }.bind(this));
     ppmm = null;
     if (this._db) {
       this._db.close();
     }
     this._db = null;
     this._alarmHalService = null;
   }
 }
 AlarmService.init();

The Tor Browser / annotate

dom/alarm/AlarmService.jsm@97036ab72558 (annotated)

dom/alarm/AlarmService.jsm