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-rw-r--r--application/basilisk/components/sessionstore/StartupPerformance.jsm234
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diff --git a/application/basilisk/components/sessionstore/StartupPerformance.jsm b/application/basilisk/components/sessionstore/StartupPerformance.jsm
deleted file mode 100644
index d1b77a237..000000000
--- a/application/basilisk/components/sessionstore/StartupPerformance.jsm
+++ /dev/null
@@ -1,234 +0,0 @@
-/* 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 = ["StartupPerformance"];
-
-const { utils: Cu, classes: Cc, interfaces: Ci } = Components;
-
-Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);
-
-XPCOMUtils.defineLazyModuleGetter(this, "Services",
- "resource://gre/modules/Services.jsm");
-XPCOMUtils.defineLazyModuleGetter(this, "console",
- "resource://gre/modules/Console.jsm");
-XPCOMUtils.defineLazyModuleGetter(this, "setTimeout",
- "resource://gre/modules/Timer.jsm");
-XPCOMUtils.defineLazyModuleGetter(this, "clearTimeout",
- "resource://gre/modules/Timer.jsm");
-XPCOMUtils.defineLazyModuleGetter(this, "Promise",
- "resource://gre/modules/Promise.jsm");
-
-const COLLECT_RESULTS_AFTER_MS = 10000;
-
-const OBSERVED_TOPICS = ["sessionstore-restoring-on-startup", "sessionstore-initiating-manual-restore"];
-
-this.StartupPerformance = {
- /**
- * Once we have finished restoring initial tabs, we broadcast on this topic.
- */
- RESTORED_TOPIC: "sessionstore-finished-restoring-initial-tabs",
-
- // Instant at which we have started restoration (notification "sessionstore-restoring-on-startup")
- _startTimeStamp: null,
-
- // Latest instant at which we have finished restoring a tab (DOM event "SSTabRestored")
- _latestRestoredTimeStamp: null,
-
- // A promise resolved once we have finished restoring all the startup tabs.
- _promiseFinished: null,
-
- // Function `resolve()` for `_promiseFinished`.
- _resolveFinished: null,
-
- // A timer
- _deadlineTimer: null,
-
- // `true` once the timer has fired
- _hasFired: false,
-
- // `true` once we are restored
- _isRestored: false,
-
- // Statistics on the session we need to restore.
- _totalNumberOfEagerTabs: 0,
- _totalNumberOfTabs: 0,
- _totalNumberOfWindows: 0,
-
- init: function() {
- for (let topic of OBSERVED_TOPICS) {
- Services.obs.addObserver(this, topic, false);
- }
- },
-
- /**
- * Return the timestamp at which we finished restoring the latest tab.
- *
- * This information is not really interesting until we have finished restoring
- * tabs.
- */
- get latestRestoredTimeStamp() {
- return this._latestRestoredTimeStamp;
- },
-
- /**
- * `true` once we have finished restoring startup tabs.
- */
- get isRestored() {
- return this._isRestored;
- },
-
- // Called when restoration starts.
- // Record the start timestamp, setup the timer and `this._promiseFinished`.
- // Behavior is unspecified if there was already an ongoing measure.
- _onRestorationStarts: function(isAutoRestore) {
- this._latestRestoredTimeStamp = this._startTimeStamp = Date.now();
- this._totalNumberOfEagerTabs = 0;
- this._totalNumberOfTabs = 0;
- this._totalNumberOfWindows = 0;
-
- // While we may restore several sessions in a single run of the browser,
- // that's a very unusual case, and not really worth measuring, so let's
- // stop listening for further restorations.
-
- for (let topic of OBSERVED_TOPICS) {
- Services.obs.removeObserver(this, topic);
- }
-
- Services.obs.addObserver(this, "sessionstore-single-window-restored", false);
- this._promiseFinished = new Promise(resolve => {
- this._resolveFinished = resolve;
- });
- this._promiseFinished.then(() => {
- try {
- this._isRestored = true;
- Services.obs.notifyObservers(null, this.RESTORED_TOPIC, "");
-
- if (this._latestRestoredTimeStamp == this._startTimeStamp) {
- // Apparently, we haven't restored any tab.
- return;
- }
-
- // Once we are done restoring tabs, update Telemetry.
- let histogramName = isAutoRestore ?
- "FX_SESSION_RESTORE_AUTO_RESTORE_DURATION_UNTIL_EAGER_TABS_RESTORED_MS" :
- "FX_SESSION_RESTORE_MANUAL_RESTORE_DURATION_UNTIL_EAGER_TABS_RESTORED_MS";
- let histogram = Services.telemetry.getHistogramById(histogramName);
- let delta = this._latestRestoredTimeStamp - this._startTimeStamp;
- histogram.add(delta);
-
- Services.telemetry.getHistogramById("FX_SESSION_RESTORE_NUMBER_OF_EAGER_TABS_RESTORED").add(this._totalNumberOfEagerTabs);
- Services.telemetry.getHistogramById("FX_SESSION_RESTORE_NUMBER_OF_TABS_RESTORED").add(this._totalNumberOfTabs);
- Services.telemetry.getHistogramById("FX_SESSION_RESTORE_NUMBER_OF_WINDOWS_RESTORED").add(this._totalNumberOfWindows);
-
- // Reset
- this._startTimeStamp = null;
- } catch (ex) {
- console.error("StartupPerformance: error after resolving promise", ex);
- }
- });
- },
-
- _startTimer: function() {
- if (this._hasFired) {
- return;
- }
- if (this._deadlineTimer) {
- clearTimeout(this._deadlineTimer);
- }
- this._deadlineTimer = setTimeout(() => {
- try {
- this._resolveFinished();
- } catch (ex) {
- console.error("StartupPerformance: Error in timeout handler", ex);
- } finally {
- // Clean up.
- this._deadlineTimer = null;
- this._hasFired = true;
- this._resolveFinished = null;
- Services.obs.removeObserver(this, "sessionstore-single-window-restored");
- }
- }, COLLECT_RESULTS_AFTER_MS);
- },
-
- observe: function(subject, topic, details) {
- try {
- switch (topic) {
- case "sessionstore-restoring-on-startup":
- this._onRestorationStarts(true);
- break;
- case "sessionstore-initiating-manual-restore":
- this._onRestorationStarts(false);
- break;
- case "sessionstore-single-window-restored": {
- // Session Restore has just opened a window with (initially empty) tabs.
- // Some of these tabs will be restored eagerly, while others will be
- // restored on demand. The process becomes usable only when all windows
- // have finished restored their eager tabs.
- //
- // While it would be possible to track the restoration of each tab
- // from within SessionRestore to determine exactly when the process
- // becomes usable, experience shows that this is too invasive. Rather,
- // we employ the following heuristic:
- // - we maintain a timer of `COLLECT_RESULTS_AFTER_MS` that we expect
- // will be triggered only once all tabs have been restored;
- // - whenever we restore a new window (hence a bunch of eager tabs),
- // we postpone the timer to ensure that the new eager tabs have
- // `COLLECT_RESULTS_AFTER_MS` to be restored;
- // - whenever a tab is restored, we update
- // `this._latestRestoredTimeStamp`;
- // - after `COLLECT_RESULTS_AFTER_MS`, we collect the final version
- // of `this._latestRestoredTimeStamp`, and use it to determine the
- // entire duration of the collection.
- //
- // Note that this heuristic may be inaccurate if a user clicks
- // immediately on a restore-on-demand tab before the end of
- // `COLLECT_RESULTS_AFTER_MS`. We assume that this will not
- // affect too much the results.
- //
- // Reset the delay, to give the tabs a little (more) time to restore.
- this._startTimer();
-
- this._totalNumberOfWindows += 1;
-
- // Observe the restoration of all tabs. We assume that all tabs of this
- // window will have been restored before `COLLECT_RESULTS_AFTER_MS`.
- // The last call to `observer` will let us determine how long it took
- // to reach that point.
- let win = subject;
-
- let observer = (event) => {
- // We don't care about tab restorations that are due to
- // a browser flipping from out-of-main-process to in-main-process
- // or vice-versa. We only care about restorations that are due
- // to the user switching to a lazily restored tab, or for tabs
- // that are restoring eagerly.
- if (!event.detail.isRemotenessUpdate) {
- this._latestRestoredTimeStamp = Date.now();
- this._totalNumberOfEagerTabs += 1;
- }
- };
- win.gBrowser.tabContainer.addEventListener("SSTabRestored", observer);
- this._totalNumberOfTabs += win.gBrowser.tabContainer.itemCount;
-
- // Once we have finished collecting the results, clean up the observers.
- this._promiseFinished.then(() => {
- if (!win.gBrowser.tabContainer) {
- // May be undefined during shutdown and/or some tests.
- return;
- }
- win.gBrowser.tabContainer.removeEventListener("SSTabRestored", observer);
- });
- }
- break;
- default:
- throw new Error(`Unexpected topic ${topic}`);
- }
- } catch (ex) {
- console.error("StartupPerformance error", ex, ex.stack);
- throw ex;
- }
- }
-};