tor-browser

commit b1b84d814fc4fdc453893b3bd8b9c82750c54f76
parent f58038979749b7bb225c931a870d73dd8ed947e0
Author: Chris H-C <chutten@mozilla.com>
Date:   Mon,  8 Dec 2025 21:42:51 +0000

Bug 1999541 - Implement Nimbus-controlled shutoff switch for "main" ping histograms r=TravisLong

We keep the existing recording and clearing behaviour,
we just refuse to include them in the ping any more.

Differential Revision: https://phabricator.services.mozilla.com/D274466

Diffstat:
M
toolkit/components/nimbus/FeatureManifest.yaml
 | 
6
++++++
M
toolkit/components/telemetry/pings/TelemetrySession.sys.mjs
 | 
20
++++++++++++++++++--
M
toolkit/components/telemetry/tests/unit/test_MainPingDisablement.js
 | 
41
++++++++++++++++++++++++++++++++++++++++-

3 files changed, 64 insertions(+), 3 deletions(-)
diff --git a/toolkit/components/nimbus/FeatureManifest.yaml b/toolkit/components/nimbus/FeatureManifest.yaml
@@ -2763,6 +2763,12 @@ legacyTelemetry:
         `browser.engagement.active_ticks`.
         These scalars will continue to be reported as normal, even if all
         others are disabled by this variable.
+    disableMainPingHgrams:
+      type: boolean
+      description: |
+        If true, histograms will not be included in "main" pings.
+        Data will still be recorded locally,
+        it will merely not be included in "main" pings when they are submitted.
 
 browserLowMemoryPrefs:
   description: Prefs which control the browser's behaviour under low memory.
diff --git a/toolkit/components/telemetry/pings/TelemetrySession.sys.mjs b/toolkit/components/telemetry/pings/TelemetrySession.sys.mjs
@@ -464,19 +464,35 @@ var Impl = {
   },
 
   getHistograms: function getHistograms(clearSubsession) {
-    return Services.telemetry.getSnapshotForHistograms(
+    const snapshot = Services.telemetry.getSnapshotForHistograms(
       "main",
       clearSubsession,
       !this._testing
     );
+    if (
+      lazy.NimbusFeatures.legacyTelemetry.getVariable("disableMainPingHgrams")
+    ) {
+      this._log.trace("getHistograms - Main ping histograms are disabled.");
+      return {};
+    }
+    return snapshot;
   },
 
   getKeyedHistograms(clearSubsession) {
-    return Services.telemetry.getSnapshotForKeyedHistograms(
+    const snapshot = Services.telemetry.getSnapshotForKeyedHistograms(
       "main",
       clearSubsession,
       !this._testing
     );
+    if (
+      lazy.NimbusFeatures.legacyTelemetry.getVariable("disableMainPingHgrams")
+    ) {
+      this._log.trace(
+        "getKeyedHistograms - Main ping histograms are disabled."
+      );
+      return {};
+    }
+    return snapshot;
   },
 
   /**
diff --git a/toolkit/components/telemetry/tests/unit/test_MainPingDisablement.js b/toolkit/components/telemetry/tests/unit/test_MainPingDisablement.js
@@ -55,7 +55,6 @@ add_task(async function test_scalarDisablement() {
 
   info("2. Ensure we can disable scalars, leaving important ones intact.");
   const { cleanup } = await NimbusTestUtils.setupTest();
-  registerCleanupFunction(cleanup);
 
   let nimbusCleanup = await NimbusTestUtils.enrollWithFeatureConfig({
     featureId: NimbusFeatures.legacyTelemetry.featureId,
@@ -74,4 +73,44 @@ add_task(async function test_scalarDisablement() {
   Assert.ok(!(LAST_SHUTDOWN_SCALAR in filtered.processes.parent.scalars));
 
   await nimbusCleanup();
+  await cleanup();
+});
+
+add_task(async function test_hgramDisablement() {
+  const ARCHIVE_HGRAM = "TELEMETRY_ARCHIVE_DIRECTORIES_COUNT";
+  const SEND_KEYED_HGRAM = "TELEMETRY_SEND_FAILURE_TYPE_PER_PING";
+  // Let's check both normal and keyed.
+  Glean.telemetry.archiveDirectoriesCount.accumulateSingleSample(42);
+  Glean.telemetry.sendFailureTypePerPing.get("some-ping", "eOK").add(1);
+
+  info("1. Ensure histogram data is reported normally to begin with.");
+
+  let payload = TelemetrySession.getPayload(
+    "reason",
+    /*clearSubsession*/ false
+  );
+
+  Assert.ok(ARCHIVE_HGRAM in payload.histograms);
+  Assert.ok(SEND_KEYED_HGRAM in payload.keyedHistograms);
+
+  info("2. Ensure we can disable histograms.");
+  const { cleanup } = await NimbusTestUtils.setupTest();
+
+  let nimbusCleanup = await NimbusTestUtils.enrollWithFeatureConfig({
+    featureId: NimbusFeatures.legacyTelemetry.featureId,
+    value: {
+      disableMainPingHgrams: true,
+    },
+  });
+
+  let filtered = TelemetrySession.getPayload(
+    "reason",
+    /*clearSubsession*/ false
+  );
+
+  Assert.ok(!(ARCHIVE_HGRAM in filtered.histograms));
+  Assert.ok(!(SEND_KEYED_HGRAM in filtered.keyedHistograms));
+
+  await nimbusCleanup();
+  await cleanup();
 });