1 files changed, 105 insertions, 0 deletions
diff --git a/toolkit/components/terminator/nsTerminatorTelemetry.js b/toolkit/components/terminator/nsTerminatorTelemetry.js
new file mode 100644
index 000000000..ed017da78
--- /dev/null
+++ b/toolkit/components/terminator/nsTerminatorTelemetry.js
@@ -0,0 +1,105 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80 filetype=javascript: */
+/* 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";
+
+/**
+ * Read the data saved by nsTerminator during shutdown and feed it to the
+ * relevant telemetry histograms.
+ */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+const Cr = Components.results;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "OS",
+  "resource://gre/modules/osfile.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Promise",
+  "resource://gre/modules/Promise.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Task",
+  "resource://gre/modules/Task.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "setTimeout",
+  "resource://gre/modules/Timer.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Services",
+  "resource://gre/modules/Services.jsm");
+
+function nsTerminatorTelemetry() {}
+
+var HISTOGRAMS = {
+  "quit-application": "SHUTDOWN_PHASE_DURATION_TICKS_QUIT_APPLICATION",
+  "profile-change-teardown": "SHUTDOWN_PHASE_DURATION_TICKS_PROFILE_CHANGE_TEARDOWN",
+  "profile-before-change":  "SHUTDOWN_PHASE_DURATION_TICKS_PROFILE_BEFORE_CHANGE",
+  "xpcom-will-shutdown": "SHUTDOWN_PHASE_DURATION_TICKS_XPCOM_WILL_SHUTDOWN",
+};
+
+nsTerminatorTelemetry.prototype = {
+  classID: Components.ID("{3f78ada1-cba2-442a-82dd-d5fb300ddea7}"),
+
+  _xpcom_factory: XPCOMUtils.generateSingletonFactory(nsTerminatorTelemetry),
+
+  // nsISupports
+
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver]),
+
+  // nsIObserver
+
+  observe: function DS_observe(aSubject, aTopic, aData)
+  {
+    Task.spawn(function*() {
+      //
+      // This data is hardly critical, reading it can wait for a few seconds.
+      //
+      yield new Promise(resolve => setTimeout(resolve, 3000));
+
+      let PATH = OS.Path.join(OS.Constants.Path.localProfileDir,
+        "ShutdownDuration.json");
+      let raw;
+      try {
+        raw = yield OS.File.read(PATH, { encoding: "utf-8" });
+      } catch (ex) {
+        if (!ex.becauseNoSuchFile) {
+          throw ex;
+        }
+        return;
+      }
+      // Let other errors be reported by Promise's error-reporting.
+
+      // Clean up
+      OS.File.remove(PATH);
+      OS.File.remove(PATH + ".tmp");
+
+      let data = JSON.parse(raw);
+      for (let k of Object.keys(data)) {
+        let id = HISTOGRAMS[k];
+        try {
+          let histogram = Services.telemetry.getHistogramById(id);
+          if (!histogram) {
+            throw new Error("Unknown histogram " + id);
+          }
+
+          histogram.add(Number.parseInt(data[k]));
+        } catch (ex) {
+          // Make sure that the error is reported and causes test failures,
+          // but otherwise, ignore it.
+          Promise.reject(ex);
+          continue;
+        }
+      }
+
+      // Inform observers that we are done.
+      Services.obs.notifyObservers(null,
+        "shutdown-terminator-telemetry-updated",
+        "");
+    });
+  },
+};
+
+// Module
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([nsTerminatorTelemetry]);