Bug 1361855 - Filter TAB_COUNT histogram to record only on 5 minute intervals; r=Gijs

MozReview-Commit-ID: F5mI1eiffWN

--HG--
extra : rebase_source : 477b4c7df0c6c7dec0fad0648ff069037fc8e696

browser/modules/BrowserUsageTelemetry.jsm

@@ -9,6 +9,7 @@ this.EXPORTED_SYMBOLS = [
   "BrowserUsageTelemetry",
   "URLBAR_SELECTED_RESULT_TYPES",
   "URLBAR_SELECTED_RESULT_METHODS",
+  "MINIMUM_TAB_COUNT_INTERVAL_MS",
  ];
 
 const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
@@ -84,6 +85,10 @@ const URLBAR_SELECTED_RESULT_METHODS = {
   click: 2,
 };
 
+
+const MINIMUM_TAB_COUNT_INTERVAL_MS = 5 * 60 * 1000; // 5 minutes, in ms
+
+
 function getOpenTabsAndWinsCounts() {
   let tabCount = 0;
   let winCount = 0;
@@ -317,6 +322,7 @@ let urlbarListener = {
 
 let BrowserUsageTelemetry = {
   init() {
+    this._lastRecordTabCount = 0;
     urlbarListener.init();
     this._setupAfterRestore();
   },
@@ -645,7 +651,14 @@ let BrowserUsageTelemetry = {
     win.addEventListener("load", onLoad);
   },
 
-  _recordTabCount(tabCount = getTabCount()) {
-    Services.telemetry.getHistogramById("TAB_COUNT").add(tabCount);
-  },
+  _recordTabCount(tabCount) {
+    let currentTime = Date.now();
+    if (currentTime > this._lastRecordTabCount + MINIMUM_TAB_COUNT_INTERVAL_MS) {
+      if (tabCount === undefined) {
+        tabCount = getTabCount();
+      }
+      Services.telemetry.getHistogramById("TAB_COUNT").add(tabCount);
+      this._lastRecordTabCount = currentTime;
+    }
+  }
 };

browser/modules/test/browser/browser_UsageTelemetry.js

@@ -10,6 +10,9 @@ const UNFILTERED_URI_COUNT = "browser.engagement.unfiltered_uri_count";
 
 const TELEMETRY_SUBSESSION_TOPIC = "internal-telemetry-after-subsession-split";
 
+XPCOMUtils.defineLazyModuleGetter(this, "MINIMUM_TAB_COUNT_INTERVAL_MS",
+                                  "resource:///modules/BrowserUsageTelemetry.jsm");
+
 // Reset internal URI counter in case URIs were opened by other tests.
 Services.obs.notifyObservers(null, TELEMETRY_SUBSESSION_TOPIC);
 
@@ -280,28 +283,68 @@ add_task(async function test_tabsHistogram() {
   checkTabCountHistogram(tabCountHist.snapshot(), [0, 0], "TAB_COUNT telemetry - initial tab counts")
 
   // Add a new tab and check that the count is right.
+  BrowserUsageTelemetry._lastRecordTabCount = 0;
   openedTabs.push(await BrowserTestUtils.openNewForegroundTab(gBrowser, "about:blank"));
   checkTabCountHistogram(tabCountHist.snapshot(), [0, 0, 1], "TAB_COUNT telemetry - opening tabs");
 
   // Open a different page and check the counts.
+  BrowserUsageTelemetry._lastRecordTabCount = 0;
   let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, "about:blank");
   openedTabs.push(tab);
+  BrowserUsageTelemetry._lastRecordTabCount = 0;
   await BrowserTestUtils.loadURI(tab.linkedBrowser, "http://example.com/");
   await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
   checkTabCountHistogram(tabCountHist.snapshot(), [0, 0, 1, 2], "TAB_COUNT telemetry - loading page");
 
   // Open another tab
+  BrowserUsageTelemetry._lastRecordTabCount = 0;
   openedTabs.push(await BrowserTestUtils.openNewForegroundTab(gBrowser, "about:blank"));
   checkTabCountHistogram(tabCountHist.snapshot(), [0, 0, 1, 2, 1], "TAB_COUNT telemetry - opening more tabs");
 
   // Add a new window and then some tabs in it. A new window starts with one tab.
+  BrowserUsageTelemetry._lastRecordTabCount = 0;
   let win = await BrowserTestUtils.openNewBrowserWindow();
   checkTabCountHistogram(tabCountHist.snapshot(), [0, 0, 1, 2, 1, 1], "TAB_COUNT telemetry - opening window");
 
-  openedTabs.push(await BrowserTestUtils.openNewForegroundTab(win.gBrowser, "about:blank"));
-  openedTabs.push(await BrowserTestUtils.openNewForegroundTab(win.gBrowser, "about:blank"));
-  openedTabs.push(await BrowserTestUtils.openNewForegroundTab(win.gBrowser, "about:blank"));
-  checkTabCountHistogram(tabCountHist.snapshot(), [0, 0, 1, 2, 1, 1, 1, 1, 1], "TAB_COUNT telemetry - opening more tabs in another window");
+  // Do not trigger a recount if _lastRecordTabCount is recent on new tab
+  BrowserUsageTelemetry._lastRecordTabCount = Date.now() - (MINIMUM_TAB_COUNT_INTERVAL_MS / 2);
+  {
+    let oldLastRecordTabCount = BrowserUsageTelemetry._lastRecordTabCount;
+    openedTabs.push(await BrowserTestUtils.openNewForegroundTab(win.gBrowser, "about:blank"));
+    checkTabCountHistogram(tabCountHist.snapshot(), [0, 0, 1, 2, 1, 1, 0], "TAB_COUNT telemetry - new tab, recount event ignored");
+    ok(BrowserUsageTelemetry._lastRecordTabCount == oldLastRecordTabCount, "TAB_COUNT telemetry - _lastRecordTabCount unchanged");
+  }
+
+  // Trigger a recount if _lastRecordTabCount has passed on new tab
+  BrowserUsageTelemetry._lastRecordTabCount = Date.now() - (MINIMUM_TAB_COUNT_INTERVAL_MS + 1000);
+  {
+    let oldLastRecordTabCount = BrowserUsageTelemetry._lastRecordTabCount;
+    openedTabs.push(await BrowserTestUtils.openNewForegroundTab(win.gBrowser, "about:blank"));
+    checkTabCountHistogram(tabCountHist.snapshot(), [0, 0, 1, 2, 1, 1, 0, 1], "TAB_COUNT telemetry - new tab, recount event included");
+    ok(BrowserUsageTelemetry._lastRecordTabCount != oldLastRecordTabCount, "TAB_COUNT telemetry - _lastRecordTabCount updated");
+    ok(BrowserUsageTelemetry._lastRecordTabCount > Date.now() - MINIMUM_TAB_COUNT_INTERVAL_MS, "TAB_COUNT telemetry - _lastRecordTabCount invariant");
+  }
+
+  // Do not trigger a recount if _lastRecordTabCount is recent on page load
+  BrowserUsageTelemetry._lastRecordTabCount = Date.now() - (MINIMUM_TAB_COUNT_INTERVAL_MS / 2);
+  {
+    let oldLastRecordTabCount = BrowserUsageTelemetry._lastRecordTabCount;
+    await BrowserTestUtils.loadURI(tab.linkedBrowser, "http://example.com/");
+    await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+    checkTabCountHistogram(tabCountHist.snapshot(), [0, 0, 1, 2, 1, 1, 0, 1], "TAB_COUNT telemetry - page load, recount event ignored");
+    ok(BrowserUsageTelemetry._lastRecordTabCount == oldLastRecordTabCount, "TAB_COUNT telemetry - _lastRecordTabCount unchanged");
+  }
+
+  // Trigger a recount if _lastRecordTabCount has passed on page load
+  BrowserUsageTelemetry._lastRecordTabCount = Date.now() - (MINIMUM_TAB_COUNT_INTERVAL_MS + 1000);
+  {
+    let oldLastRecordTabCount = BrowserUsageTelemetry._lastRecordTabCount;
+    await BrowserTestUtils.loadURI(tab.linkedBrowser, "http://example.com/");
+    await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+    checkTabCountHistogram(tabCountHist.snapshot(), [0, 0, 1, 2, 1, 1, 0, 2], "TAB_COUNT telemetry - page load, recount event included");
+    ok(BrowserUsageTelemetry._lastRecordTabCount != oldLastRecordTabCount, "TAB_COUNT telemetry - _lastRecordTabCount updated");
+    ok(BrowserUsageTelemetry._lastRecordTabCount > Date.now() - MINIMUM_TAB_COUNT_INTERVAL_MS, "TAB_COUNT telemetry - _lastRecordTabCount invariant");
+  }
 
   // Remove all the extra windows and tabs.
   for (let openTab of openedTabs) {