toolkit/modules/ResponsivenessMonitor.sys.mjs

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 export function ResponsivenessMonitor(intervalMS = 100) {
   6   this._intervalMS = intervalMS;
   7   this._prevTimestamp = Date.now();
   8   this._accumulatedDelay = 0;
   9   this._timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
  10   this._timer.initWithCallback(
  11     this,
  12     this._intervalMS,
  13     Ci.nsITimer.TYPE_REPEATING_SLACK
  14   );
  15 }
  16
  17 ResponsivenessMonitor.prototype = {
  18   QueryInterface: ChromeUtils.generateQI(["nsINamed", "nsITimerCallback"]),
  19
  20   name: "ResponsivenessMonitor",
  21
  22   notify() {
  23     let now = Date.now();
  24     this._accumulatedDelay += Math.max(
  25       0,
  26       now - this._prevTimestamp - this._intervalMS
  27     );
  28     this._prevTimestamp = now;
  29   },
  30
  31   abort() {
  32     if (this._timer) {
  33       this._timer.cancel();
  34       this._timer = null;
  35     }
  36   },
  37
  38   finish() {
  39     this.abort();
  40     return this._accumulatedDelay;
  41   },
  42 };