Bug 1890582 - Collect telemetry for time spent on purging bounce tracker storage r=pbz,anti-tracking-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D207876

toolkit/components/antitracking/bouncetrackingprotection/BounceTrackingProtection.cpp

@@ -660,6 +660,26 @@ nsresult BounceTrackingProtection::ClearExpiredUserInteractions(
 NS_IMPL_ISUPPORTS(BounceTrackingProtection::ClearDataCallback,
                   nsIClearDataCallback);
 
+BounceTrackingProtection::ClearDataCallback::ClearDataCallback(
+    ClearDataMozPromise::Private* aPromise, const nsACString& aHost)
+    : mHost(aHost), mClearDurationTimer(0), mPromise(aPromise) {
+  MOZ_ASSERT(!aHost.IsEmpty(), "Host must not be empty");
+  if (!StaticPrefs::privacy_bounceTrackingProtection_enableDryRunMode()) {
+    // Only collect timing information when actually performing the deletion
+    mClearDurationTimer =
+        glean::bounce_tracking_protection::purge_duration.Start();
+    MOZ_ASSERT(mClearDurationTimer);
+  }
+};
+
+BounceTrackingProtection::ClearDataCallback::~ClearDataCallback() {
+  mPromise->Reject(0, __func__);
+  if (mClearDurationTimer) {
+    glean::bounce_tracking_protection::purge_duration.Cancel(
+        std::move(mClearDurationTimer));
+  }
+}
+
 // nsIClearDataCallback implementation
 NS_IMETHODIMP BounceTrackingProtection::ClearDataCallback::OnDataDeleted(
     uint32_t aFailedFlags) {
@@ -670,7 +690,17 @@ NS_IMETHODIMP BounceTrackingProtection::ClearDataCallback::OnDataDeleted(
             ("%s: Cleared %s", __FUNCTION__, mHost.get()));
     mPromise->Resolve(std::move(mHost), __func__);
   }
+  RecordClearDurationTelemetry();
   return NS_OK;
 }
 
+void BounceTrackingProtection::ClearDataCallback::
+    RecordClearDurationTelemetry() {
+  if (mClearDurationTimer) {
+    glean::bounce_tracking_protection::purge_duration.StopAndAccumulate(
+        std::move(mClearDurationTimer));
+    mClearDurationTimer = 0;
+  }
+}
+
 }  // namespace mozilla

toolkit/components/antitracking/bouncetrackingprotection/BounceTrackingProtection.h

@@ -6,6 +6,7 @@
 
 #include "mozilla/Logging.h"
 #include "mozilla/MozPromise.h"
+#include "mozilla/glean/GleanMetrics.h"
 #include "nsIBounceTrackingProtection.h"
 #include "nsIClearDataService.h"
 
@@ -82,13 +83,16 @@ class BounceTrackingProtection final : public nsIBounceTrackingProtection {
     NS_DECL_NSICLEARDATACALLBACK
 
     explicit ClearDataCallback(ClearDataMozPromise::Private* aPromise,
-                               const nsACString& aHost)
-        : mHost(aHost), mPromise(aPromise){};
+                               const nsACString& aHost);
 
    private:
-    virtual ~ClearDataCallback() { mPromise->Reject(0, __func__); }
+    virtual ~ClearDataCallback();
 
     nsCString mHost;
+
+    void RecordClearDurationTelemetry();
+
+    glean::TimerId mClearDurationTimer;
     RefPtr<ClearDataMozPromise::Private> mPromise;
   };
 };

toolkit/components/antitracking/bouncetrackingprotection/metrics.yaml

@@ -0,0 +1,33 @@
+# 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/.
+
+# Adding a new metric? We have docs for that!
+# https://firefox-source-docs.mozilla.org/toolkit/components/glean/user/new_definitions_file.html
+
+---
+$schema: moz://mozilla.org/schemas/glean/metrics/2-0-0
+$tags:
+  - 'Core :: Privacy: Anti-Tracking'
+
+bounce.tracking.protection:
+  purge_duration:
+    type: timing_distribution
+    description: >
+      For every purge that is scheduled, we call the ClearDataService to
+      purge persistent storage for each detected bounce tracker. This may
+      do some blocking work on main thread and dispatch some cleanups to
+      other threads.
+      Collect telemetry on how long it takes to clear in the wild to
+      determine whether we need to improve performance here.
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1890582
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1890582#c4
+    data_sensitivity:
+      - technical
+    notification_emails:
+      - pbz@mozilla.com
+      - bvandersloot@mozilla.com
+      - manuel@mozilla.com
+    expires: 130

toolkit/components/antitracking/bouncetrackingprotection/test/browser/browser.toml

@@ -30,3 +30,5 @@ support-files = [
 ["browser_bouncetracking_stateful_storage.js"]
 
 ["browser_bouncetracking_stateful_web_worker.js"]
+
+["browser_bouncetracking_telemetry_purge_duration.js"]

toolkit/components/antitracking/bouncetrackingprotection/test/browser/browser_bouncetracking_telemetry_purge_duration.js

@@ -0,0 +1,66 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+let bounceTrackingProtection;
+
+async function test_purge_duration(isDryRunMode) {
+  await SpecialPowers.pushPrefEnv({
+    set: [["privacy.bounceTrackingProtection.enableDryRunMode", isDryRunMode]],
+  });
+
+  is(
+    Glean.bounceTrackingProtection.purgeDuration.testGetValue(),
+    null,
+    "Histogram should not exist initially."
+  );
+
+  info("Run server bounce with cookie.");
+  await runTestBounce({
+    bounceType: "server",
+    setState: "cookie-server",
+    postBounceCallback: () => {
+      is(
+        Glean.bounceTrackingProtection.purgeDuration.testGetValue(),
+        null,
+        "Histogram should still be empty after bounce, because we haven't purged yet."
+      );
+    },
+  });
+
+  let events = Glean.bounceTrackingProtection.purgeDuration.testGetValue();
+  if (isDryRunMode) {
+    is(events, null, "Should not collect purge timining in dry mode");
+  } else {
+    is(events.count, 1, "Histogram should contain one value.");
+  }
+
+  // Cleanup
+  Services.fog.testResetFOG();
+  await SpecialPowers.popPrefEnv();
+  bounceTrackingProtection.clearAll();
+}
+
+add_setup(async function () {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["privacy.bounceTrackingProtection.requireStatefulBounces", true],
+      ["privacy.bounceTrackingProtection.bounceTrackingGracePeriodSec", 0],
+    ],
+  });
+  bounceTrackingProtection = Cc[
+    "@mozilla.org/bounce-tracking-protection;1"
+  ].getService(Ci.nsIBounceTrackingProtection);
+
+  // Clear telemetry before test.
+  Services.fog.testResetFOG();
+});
+
+add_task(async function test_purge_duration_dry_mode() {
+  await test_purge_duration(true);
+});
+
+add_task(async function test_purge_duration_enabled() {
+  await test_purge_duration(false);
+});

toolkit/components/glean/metrics_index.py

@@ -35,6 +35,7 @@ gecko_metrics = [
     "netwerk/protocol/http/metrics.yaml",
     "security/certverifier/metrics.yaml",
     "security/manager/ssl/metrics.yaml",
+    "toolkit/components/antitracking/bouncetrackingprotection/metrics.yaml",
     "toolkit/components/cookiebanners/metrics.yaml",
     "toolkit/components/extensions/metrics.yaml",
     "toolkit/components/formautofill/metrics.yaml",