Bug 1137222 - Submit subsession-specific value for simpleMeasurements.activeTicks. r=gfritzsche

toolkit/components/telemetry/TelemetrySession.jsm

@@ -727,6 +727,7 @@ this.TelemetrySession = Object.freeze({
     Impl._previousSubsessionId = null;
     Impl._subsessionCounter = 0;
     Impl._profileSubsessionCounter = 0;
+    Impl._subsessionStartActiveTicks = 0;
     this.uninstall();
     return this.setup();
   },
@@ -804,6 +805,8 @@ let Impl = {
   _profileSubsessionCounter: 0,
   // Date of the last session split
   _subsessionStartDate: null,
+  // The active ticks counted when the subsession starts
+  _subsessionStartActiveTicks: 0,
   // A task performing delayed initialization of the chrome process
   _delayedInitTask: null,
   // The deferred promise resolved when the initialization task completes.
@@ -816,10 +819,12 @@ let Impl = {
   /**
    * Gets a series of simple measurements (counters). At the moment, this
    * only returns startup data from nsIAppStartup.getStartupInfo().
+   * @param {Boolean} isSubsession True if this is a subsession, false otherwise.
+   * @param {Boolean} clearSubsession True if a new subsession is being started, false otherwise.
    *
    * @return simple measurements as a dictionary.
    */
-  getSimpleMeasurements: function getSimpleMeasurements(forSavedSession) {
+  getSimpleMeasurements: function getSimpleMeasurements(forSavedSession, isSubsession, clearSubsession) {
     this._log.trace("getSimpleMeasurements");
 
     let si = Services.startup.getStartupInfo();
@@ -909,7 +914,16 @@ let Impl = {
 
       let sr = drs.getSessionRecorder();
       if (sr) {
-        ret.activeTicks = sr.activeTicks;
+        let activeTicks = sr.activeTicks;
+        if (isSubsession) {
+          activeTicks = sr.activeTicks - this._subsessionStartActiveTicks;
+        }
+
+        if (clearSubsession) {
+          this._subsessionStartActiveTicks = activeTicks;
+        }
+
+        ret.activeTicks = activeTicks;
       }
     }
 
@@ -1340,9 +1354,13 @@ let Impl = {
     this._log.trace("getSessionPayload - reason: " + reason + ", clearSubsession: " + clearSubsession);
 #if defined(MOZ_WIDGET_GONK) || defined(MOZ_WIDGET_ANDROID)
     clearSubsession = false;
+    const isSubsession = false;
+#else
+    const isSubsession = !this._isClassicReason(reason);
 #endif
 
-    let measurements = this.getSimpleMeasurements(reason == REASON_SAVED_SESSION);
+    let measurements =
+      this.getSimpleMeasurements(reason == REASON_SAVED_SESSION, isSubsession, clearSubsession);
     let info = !IS_CONTENT_PROCESS ? this.getMetadata(reason) : null;
     let payload = this.assemblePayloadWithMeasurements(measurements, info, reason, clearSubsession);
 

toolkit/components/telemetry/tests/unit/test_TelemetrySession.js

@@ -664,7 +664,7 @@ add_task(function* test_saveLoadPing() {
   }
 });
 
-add_task(function* test_checkSubsession() {
+add_task(function* test_checkSubsessionHistograms() {
   if (gIsAndroid) {
     // We don't support subsessions yet on Android.
     return;
@@ -852,6 +852,55 @@ add_task(function* test_checkSubsession() {
   Assert.equal(subsession.keyedHistograms[KEYED_ID]["b"].sum, 1);
 });
 
+add_task(function* test_checkSubsessionData() {
+  if (gIsAndroid || !SESSION_RECORDER_EXPECTED) {
+    // We don't support subsessions yet on Android. Also bail out if we
+    // can't use the session recorder.
+    return;
+  }
+
+  // Keep track of the active ticks count if the session recorder is available.
+  let sessionRecorder = gDatareportingService.getSessionRecorder();
+  let activeTicksAtSubsessionStart = sessionRecorder.activeTicks;
+  let expectedActiveTicks = activeTicksAtSubsessionStart;
+
+  incrementActiveTicks = () => {
+    sessionRecorder.incrementActiveTicks();
+    ++expectedActiveTicks;
+  }
+
+  yield TelemetrySession.reset();
+
+  // Both classic and subsession payload data should be the same on the first subsession.
+  incrementActiveTicks();
+  let classic = TelemetrySession.getPayload();
+  let subsession = TelemetrySession.getPayload("environment-change");
+  Assert.equal(classic.simpleMeasurements.activeTicks, expectedActiveTicks,
+               "Classic pings must count active ticks since the beginning of the session.");
+  Assert.equal(subsession.simpleMeasurements.activeTicks, expectedActiveTicks,
+               "Subsessions must count active ticks as classic pings on the first subsession.");
+
+  // Start a new subsession and check that the active ticks are correctly reported.
+  incrementActiveTicks();
+  activeTicksAtSubsessionStart = sessionRecorder.activeTicks;
+  classic = TelemetrySession.getPayload();
+  subsession = TelemetrySession.getPayload("environment-change", true);
+  Assert.equal(classic.simpleMeasurements.activeTicks, expectedActiveTicks,
+               "Classic pings must count active ticks since the beginning of the session.");
+  Assert.equal(subsession.simpleMeasurements.activeTicks, expectedActiveTicks,
+               "Pings must not loose the tick count when starting a new subsession.");
+
+  // Get a new subsession payload without clearing the subsession.
+  incrementActiveTicks();
+  classic = TelemetrySession.getPayload();
+  subsession = TelemetrySession.getPayload("environment-change");
+  Assert.equal(classic.simpleMeasurements.activeTicks, expectedActiveTicks,
+               "Classic pings must count active ticks since the beginning of the session.");
+  Assert.equal(subsession.simpleMeasurements.activeTicks,
+               expectedActiveTicks - activeTicksAtSubsessionStart,
+               "Subsessions must count active ticks since the last new subsession.");
+});
+
 add_task(function* test_dailyCollection() {
   if (gIsAndroid) {
     // We don't do daily collections yet on Android.