Bug 1803363 - Record metrics related to the amount of DNR rules enabled during DNR rule evaluation. r=robwu

Differential Revision: https://phabricator.services.mozilla.com/D174026

toolkit/components/extensions/ExtensionDNR.sys.mjs

@@ -1808,6 +1808,8 @@ class RequestEvaluator {
 }
 
 const NetworkIntegration = {
+  maxEvaluatedRulesCount: 0,
+
   register() {
     // We register via WebRequest.jsm to ensure predictable ordering of DNR and
     // WebRequest behavior.
@@ -1852,6 +1854,14 @@ const NetworkIntegration = {
           );
         }
       }
+      const evaluateRulesCount = ruleManagers.reduce(
+        (sum, ruleManager) => sum + ruleManager.getRulesCount(),
+        0
+      );
+      if (evaluateRulesCount > this.maxEvaluatedRulesCount) {
+        Glean.extensionsApisDnr.evaluateRulesCountMax.set(evaluateRulesCount);
+        this.maxEvaluatedRulesCount = evaluateRulesCount;
+      }
     }
     // Cache for later. In case of redirects, _dnrMatchedRules may exist for
     // the pre-redirect HTTP channel, and is overwritten here again.
@@ -1980,6 +1990,7 @@ class RuleManager {
     this.hasBlockPermission = extension.hasPermission("declarativeNetRequest");
     this.hasRulesWithTabIds = false;
     this.hasRulesWithAllowAllRequests = false;
+    this.totalRulesCount = 0;
   }
 
   get availableStaticRuleCount() {
@@ -2002,7 +2013,10 @@ class RuleManager {
   }
 
   setSessionRules(validatedSessionRules) {
+    let oldRulesCount = this.sessionRules.rules.length;
+    let newRulesCount = validatedSessionRules.length;
     this.sessionRules.rules = validatedSessionRules;
+    this.totalRulesCount += newRulesCount - oldRulesCount;
     this.hasRulesWithTabIds = !!this.sessionRules.rules.find(rule => {
       return rule.condition.tabIds || rule.condition.excludedTabIds;
     });
@@ -2011,7 +2025,10 @@ class RuleManager {
   }
 
   setDynamicRules(validatedDynamicRules) {
+    let oldRulesCount = this.dynamicRules.rules.length;
+    let newRulesCount = validatedDynamicRules.length;
     this.dynamicRules.rules = validatedDynamicRules;
+    this.totalRulesCount += newRulesCount - oldRulesCount;
     this.#updateAllowAllRequestRules();
   }
 
@@ -2030,7 +2047,12 @@ class RuleManager {
         this.makeRuleset(id, idx + PRECEDENCE_STATIC_RULESETS_BASE, rules)
       );
     }
+    const countRules = rulesets =>
+      rulesets.reduce((sum, ruleset) => sum + ruleset.rules.length, 0);
+    const oldRulesCount = countRules(this.enabledStaticRules);
+    const newRulesCount = countRules(rulesets);
     this.enabledStaticRules = rulesets;
+    this.totalRulesCount += newRulesCount - oldRulesCount;
     this.#updateAllowAllRequestRules();
   }
 
@@ -2042,6 +2064,10 @@ class RuleManager {
     return this.dynamicRules.rules;
   }
 
+  getRulesCount() {
+    return this.totalRulesCount;
+  }
+
   #updateAllowAllRequestRules() {
     const filterAAR = rule => rule.action.type === "allowAllRequests";
     this.hasRulesWithAllowAllRequests =

toolkit/components/extensions/metrics.yaml

@@ -146,3 +146,19 @@ extensions.apis.dnr:
       - https://bugzilla.mozilla.org/show_bug.cgi?id=1803363#c11
     data_sensitivity:
       - technical
+
+  evaluate_rules_count_max:
+    type: quantity
+    unit: rules
+    expires: 120
+    description: |
+      Max amount of DNR rules being evaluated.
+    lifetime: ping
+    notification_emails:
+      - addons-dev-internal@mozilla.com
+    bugs:
+      - https://bugzilla.mozilla.org/1803363/
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1803363#c11
+    data_sensitivity:
+      - technical

toolkit/components/extensions/test/xpcshell/test_ext_dnr_static_rules.js

@@ -1627,12 +1627,13 @@ add_task(async function test_static_rules_telemetry() {
   info("Verify telemetry recorded on rules evaluation");
   extension.sendMessage("updateEnabledRulesets", {
     enableRulesetIds: ["ruleset1"],
+    disableRulesetIds: ["ruleset2"],
   });
   await extension.awaitMessage("updateEnabledRulesets:done");
-  await assertDNRGetEnabledRulesets(extension, ["ruleset1", "ruleset2"]);
+  await assertDNRGetEnabledRulesets(extension, ["ruleset1"]);
 
   assertDNRTelemetryMetricsNoSamples(
-    ["evaluateRulesTime"],
+    ["evaluateRulesTime", "evaluateRulesCountMax"],
     "before any request have been intercepted"
   );
 
@@ -1643,11 +1644,23 @@ add_task(async function test_static_rules_telemetry() {
   );
 
   assertDNRTelemetryMetricsNoSamples(
-    ["evaluateRulesTime"],
+    ["evaluateRulesTime", "evaluateRulesCountMax"],
     "after restricted request have been intercepted (but no rules evaluated)"
   );
 
   const page = await ExtensionTestUtils.loadContentPage("http://example.com");
+  const callPageFetch = async () => {
+    Assert.equal(
+      await page.spawn([], () => {
+        return this.content.fetch("http://example.com/").then(
+          res => res.text(),
+          err => err.message
+        );
+      }),
+      "NetworkError when attempting to fetch resource.",
+      "DNR should have blocked test request to example.com"
+    );
+  };
 
   // Expect one sample recorded on evaluating rules for the
   // top level navigation.
@@ -1657,18 +1670,16 @@ add_task(async function test_static_rules_telemetry() {
     expectedEvaluateRulesTimeSamples,
     "evaluateRulesTime should be collected after evaluated rulesets"
   );
-
-  Assert.equal(
-    await page.spawn([], () => {
-      return this.content.fetch("http://example.com/").then(
-        res => res.text(),
-        err => err.message
-      );
-    }),
-    "NetworkError when attempting to fetch resource.",
-    "DNR should have blocked test request to example.com"
+  // Expect 1 rule with only one ruleset enabled.
+  let expectedEvaluateRulesCountMax = 1;
+  assertDNRTelemetryMetricsGetValueEq(
+    ["evaluateRulesCountMax"],
+    expectedEvaluateRulesCountMax,
+    "evaluateRulesCountMax should be collected after evaluated rulesets"
   );
 
+  await callPageFetch();
+
   // Expect one new sample reported on evaluating rules for the
   // top level navigation.
   expectedEvaluateRulesTimeSamples += 1;
@@ -1678,6 +1689,36 @@ add_task(async function test_static_rules_telemetry() {
     "evaluateRulesTime should be collected after evaluated rulesets"
   );
 
+  extension.sendMessage("updateEnabledRulesets", {
+    enableRulesetIds: ["ruleset2"],
+  });
+  await extension.awaitMessage("updateEnabledRulesets:done");
+  await assertDNRGetEnabledRulesets(extension, ["ruleset1", "ruleset2"]);
+
+  await callPageFetch();
+
+  // Expect two rules with both rulesets enabled.
+  expectedEvaluateRulesCountMax += 1;
+  assertDNRTelemetryMetricsGetValueEq(
+    ["evaluateRulesCountMax"],
+    expectedEvaluateRulesCountMax,
+    "evaluateRulesCountMax should have been increased"
+  );
+
+  extension.sendMessage("updateEnabledRulesets", {
+    disableRulesetIds: ["ruleset2"],
+  });
+  await extension.awaitMessage("updateEnabledRulesets:done");
+  await assertDNRGetEnabledRulesets(extension, ["ruleset1"]);
+
+  await callPageFetch();
+
+  assertDNRTelemetryMetricsGetValueEq(
+    ["evaluateRulesCountMax"],
+    expectedEvaluateRulesCountMax,
+    "evaluateRulesCountMax should have not been decreased"
+  );
+
   await page.close();
 
   await extension.unload();