1 files changed, 339 insertions, 0 deletions
diff --git a/toolkit/components/timermanager/nsUpdateTimerManager.js b/toolkit/components/timermanager/nsUpdateTimerManager.js
new file mode 100644
index 000000000..d7fc15960
--- /dev/null
+++ b/toolkit/components/timermanager/nsUpdateTimerManager.js
@@ -0,0 +1,339 @@
+/* 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/. */
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm", this);
+Components.utils.import("resource://gre/modules/Services.jsm", this);
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+const PREF_APP_UPDATE_LASTUPDATETIME_FMT  = "app.update.lastUpdateTime.%ID%";
+const PREF_APP_UPDATE_TIMERMINIMUMDELAY   = "app.update.timerMinimumDelay";
+const PREF_APP_UPDATE_TIMERFIRSTINTERVAL  = "app.update.timerFirstInterval";
+const PREF_APP_UPDATE_LOG                 = "app.update.log";
+
+const CATEGORY_UPDATE_TIMER               = "update-timer";
+
+XPCOMUtils.defineLazyGetter(this, "gLogEnabled", function tm_gLogEnabled() {
+  return getPref("getBoolPref", PREF_APP_UPDATE_LOG, false);
+});
+
+/**
+ *  Gets a preference value, handling the case where there is no default.
+ *  @param   func
+ *           The name of the preference function to call, on nsIPrefBranch
+ *  @param   preference
+ *           The name of the preference
+ *  @param   defaultValue
+ *           The default value to return in the event the preference has
+ *           no setting
+ *  @returns The value of the preference, or undefined if there was no
+ *           user or default value.
+ */
+function getPref(func, preference, defaultValue) {
+  try {
+    return Services.prefs[func](preference);
+  } catch (e) {
+  }
+  return defaultValue;
+}
+
+/**
+ *  Logs a string to the error console.
+ *  @param   string
+ *           The string to write to the error console.
+ */
+function LOG(string) {
+  if (gLogEnabled) {
+    dump("*** UTM:SVC " + string + "\n");
+    Services.console.logStringMessage("UTM:SVC " + string);
+  }
+}
+
+/**
+ *  A manager for timers. Manages timers that fire over long periods of time
+ *  (e.g. days, weeks, months).
+ *  @constructor
+ */
+function TimerManager() {
+  Services.obs.addObserver(this, "xpcom-shutdown", false);
+}
+TimerManager.prototype = {
+  /**
+   * The Checker Timer
+   */
+  _timer: null,
+
+  /**
+   * The Checker Timer minimum delay interval as specified by the
+   * app.update.timerMinimumDelay pref. If the app.update.timerMinimumDelay
+   * pref doesn't exist this will default to 120000.
+   */
+  _timerMinimumDelay: null,
+
+  /**
+   * The set of registered timers.
+   */
+  _timers: { },
+
+  /**
+   * See nsIObserver.idl
+   */
+  observe: function TM_observe(aSubject, aTopic, aData) {
+    // Prevent setting the timer interval to a value of less than 30 seconds.
+    var minInterval = 30000;
+    // Prevent setting the first timer interval to a value of less than 10
+    // seconds.
+    var minFirstInterval = 10000;
+    switch (aTopic) {
+      case "utm-test-init":
+        // Enforce a minimum timer interval of 500 ms for tests and fall through
+        // to profile-after-change to initialize the timer.
+        minInterval = 500;
+        minFirstInterval = 500;
+      case "profile-after-change":
+        this._timerMinimumDelay = Math.max(1000 * getPref("getIntPref", PREF_APP_UPDATE_TIMERMINIMUMDELAY, 120),
+                                           minInterval);
+        // Prevent the timer delay between notifications to other consumers from
+        // being greater than 5 minutes which is 300000 milliseconds.
+        this._timerMinimumDelay = Math.min(this._timerMinimumDelay, 300000);
+        // Prevent the first interval from being less than the value of minFirstInterval
+        let firstInterval = Math.max(getPref("getIntPref", PREF_APP_UPDATE_TIMERFIRSTINTERVAL,
+                                             30000), minFirstInterval);
+        // Prevent the first interval from being greater than 2 minutes which is
+        // 120000 milliseconds.
+        firstInterval = Math.min(firstInterval, 120000);
+        // Cancel the timer if it has already been initialized. This is primarily
+        // for tests.
+        this._canEnsureTimer = true;
+        this._ensureTimer(firstInterval);
+        break;
+      case "xpcom-shutdown":
+        Services.obs.removeObserver(this, "xpcom-shutdown");
+
+        // Release everything we hold onto.
+        this._cancelTimer();
+        for (var timerID in this._timers) {
+          delete this._timers[timerID];
+        }
+        this._timers = null;
+        break;
+    }
+  },
+
+  /**
+   * Called when the checking timer fires.
+   *
+   * We only fire one notification each time, so that the operations are
+   * staggered. We don't want too many to happen at once, which could
+   * negatively impact responsiveness.
+   *
+   * @param   timer
+   *          The checking timer that fired.
+   */
+  notify: function TM_notify(timer) {
+    var nextDelay = null;
+    function updateNextDelay(delay) {
+      if (nextDelay === null || delay < nextDelay) {
+        nextDelay = delay;
+      }
+    }
+
+    // Each timer calls tryFire(), which figures out which is the one that
+    // wanted to be called earliest. That one will be fired; the others are
+    // skipped and will be done later.
+    var now = Math.round(Date.now() / 1000);
+
+    var callbackToFire = null;
+    var earliestIntendedTime = null;
+    var skippedFirings = false;
+    var lastUpdateTime = null;
+    function tryFire(callback, intendedTime) {
+      var selected = false;
+      if (intendedTime <= now) {
+        if (intendedTime < earliestIntendedTime ||
+            earliestIntendedTime === null) {
+          callbackToFire = callback;
+          earliestIntendedTime = intendedTime;
+          selected = true;
+        } else if (earliestIntendedTime !== null) {
+          skippedFirings = true;
+        }
+      }
+      // We do not need to updateNextDelay for the timer that actually fires;
+      // we'll update right after it fires, with the proper intended time.
+      // Note that we might select one, then select another later (with an
+      // earlier intended time); it is still ok that we did not update for
+      // the first one, since if we have skipped firings, the next delay
+      // will be the minimum delay anyhow.
+      if (!selected) {
+        updateNextDelay(intendedTime - now);
+      }
+    }
+
+    var catMan = Cc["@mozilla.org/categorymanager;1"].
+                 getService(Ci.nsICategoryManager);
+    var entries = catMan.enumerateCategory(CATEGORY_UPDATE_TIMER);
+    while (entries.hasMoreElements()) {
+      let entry = entries.getNext().QueryInterface(Ci.nsISupportsCString).data;
+      let value = catMan.getCategoryEntry(CATEGORY_UPDATE_TIMER, entry);
+      let [cid, method, timerID, prefInterval, defaultInterval, maxInterval] = value.split(",");
+
+      defaultInterval = parseInt(defaultInterval);
+      // cid and method are validated below when calling notify.
+      if (!timerID || !defaultInterval || isNaN(defaultInterval)) {
+        LOG("TimerManager:notify - update-timer category registered" +
+            (cid ? " for " + cid : "") + " without required parameters - " +
+             "skipping");
+        continue;
+      }
+
+      let interval = getPref("getIntPref", prefInterval, defaultInterval);
+      // Allow the update-timer category to specify a maximum value to prevent
+      // values larger than desired.
+      maxInterval = parseInt(maxInterval);
+      if (maxInterval && !isNaN(maxInterval)) {
+        interval = Math.min(interval, maxInterval);
+      }
+      let prefLastUpdate = PREF_APP_UPDATE_LASTUPDATETIME_FMT.replace(/%ID%/,
+                                                                      timerID);
+      // Initialize the last update time to 0 when the preference isn't set so
+      // the timer will be notified soon after a new profile's first use.
+      lastUpdateTime = getPref("getIntPref", prefLastUpdate, 0);
+
+      // If the last update time is greater than the current time then reset
+      // it to 0 and the timer manager will correct the value when it fires
+      // next for this consumer.
+      if (lastUpdateTime > now) {
+        lastUpdateTime = 0;
+      }
+
+      if (lastUpdateTime == 0) {
+        Services.prefs.setIntPref(prefLastUpdate, lastUpdateTime);
+      }
+
+      tryFire(function () {
+        try {
+          Components.classes[cid][method](Ci.nsITimerCallback).notify(timer);
+          LOG("TimerManager:notify - notified " + cid);
+        } catch (e) {
+          LOG("TimerManager:notify - error notifying component id: " +
+              cid + " ,error: " + e);
+        }
+        lastUpdateTime = now;
+        Services.prefs.setIntPref(prefLastUpdate, lastUpdateTime);
+        updateNextDelay(lastUpdateTime + interval - now);
+      }, lastUpdateTime + interval);
+    }
+
+    for (let _timerID in this._timers) {
+      let timerID = _timerID; // necessary for the closure to work properly
+      let timerData = this._timers[timerID];
+      // If the last update time is greater than the current time then reset
+      // it to 0 and the timer manager will correct the value when it fires
+      // next for this consumer.
+      if (timerData.lastUpdateTime > now) {
+        let prefLastUpdate = PREF_APP_UPDATE_LASTUPDATETIME_FMT.replace(/%ID%/, timerID);
+        timerData.lastUpdateTime = 0;
+        Services.prefs.setIntPref(prefLastUpdate, timerData.lastUpdateTime);
+      }
+      tryFire(function () {
+        if (timerData.callback && timerData.callback.notify) {
+          try {
+            timerData.callback.notify(timer);
+            LOG("TimerManager:notify - notified timerID: " + timerID);
+          } catch (e) {
+            LOG("TimerManager:notify - error notifying timerID: " + timerID +
+                ", error: " + e);
+          }
+        } else {
+          LOG("TimerManager:notify - timerID: " + timerID + " doesn't " +
+              "implement nsITimerCallback - skipping");
+        }
+        lastUpdateTime = now;
+        timerData.lastUpdateTime = lastUpdateTime;
+        let prefLastUpdate = PREF_APP_UPDATE_LASTUPDATETIME_FMT.replace(/%ID%/, timerID);
+        Services.prefs.setIntPref(prefLastUpdate, lastUpdateTime);
+        updateNextDelay(timerData.lastUpdateTime + timerData.interval - now);
+      }, timerData.lastUpdateTime + timerData.interval);
+    }
+
+    if (callbackToFire) {
+      callbackToFire();
+    }
+
+    if (nextDelay !== null) {
+      if (skippedFirings) {
+        timer.delay = this._timerMinimumDelay;
+      } else {
+        timer.delay = Math.max(nextDelay * 1000, this._timerMinimumDelay);
+      }
+      this.lastTimerReset = Date.now();
+    } else {
+      this._cancelTimer();
+    }
+  },
+
+  /**
+   * Starts the timer, if necessary, and ensures that it will fire soon enough
+   * to happen after time |interval| (in milliseconds).
+   */
+  _ensureTimer: function (interval) {
+    if (!this._canEnsureTimer) {
+      return;
+    }
+    if (!this._timer) {
+      this._timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+      this._timer.initWithCallback(this, interval,
+                                   Ci.nsITimer.TYPE_REPEATING_SLACK);
+      this.lastTimerReset = Date.now();
+    } else if (Date.now() + interval < this.lastTimerReset + this._timer.delay) {
+      this._timer.delay = Math.max(this.lastTimerReset + interval - Date.now(), 0);
+    }
+  },
+
+  /**
+   * Stops the timer, if it is running.
+   */
+  _cancelTimer: function () {
+    if (this._timer) {
+      this._timer.cancel();
+      this._timer = null;
+    }
+  },
+
+  /**
+   * See nsIUpdateTimerManager.idl
+   */
+  registerTimer: function TM_registerTimer(id, callback, interval) {
+    LOG("TimerManager:registerTimer - id: " + id);
+    if (id in this._timers && callback != this._timers[id].callback) {
+      LOG("TimerManager:registerTimer - Ignoring second registration for " + id);
+      return;
+    }
+    let prefLastUpdate = PREF_APP_UPDATE_LASTUPDATETIME_FMT.replace(/%ID%/, id);
+    // Initialize the last update time to 0 when the preference isn't set so
+    // the timer will be notified soon after a new profile's first use.
+    let lastUpdateTime = getPref("getIntPref", prefLastUpdate, 0);
+    let now = Math.round(Date.now() / 1000);
+    if (lastUpdateTime > now) {
+      lastUpdateTime = 0;
+    }
+    if (lastUpdateTime == 0) {
+      Services.prefs.setIntPref(prefLastUpdate, lastUpdateTime);
+    }
+    this._timers[id] = {callback: callback,
+                        interval: interval,
+                        lastUpdateTime: lastUpdateTime};
+
+    this._ensureTimer(interval * 1000);
+  },
+
+  classID: Components.ID("{B322A5C0-A419-484E-96BA-D7182163899F}"),
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIUpdateTimerManager,
+                                         Ci.nsITimerCallback,
+                                         Ci.nsIObserver])
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([TimerManager]);