1 files changed, 0 insertions, 234 deletions
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;
-    }
-  }
-};