Bug 1717080 - Create a micro benchmark for Intl.PluralRules; r=nordzilla

Differential Revision: https://phabricator.services.mozilla.com/D118205

intl/benchmarks/perftest.ini

@@ -1,2 +1,3 @@
 [perftest_dateTimeFormat.js]
 [perftest_locale.js]
+[perftest_pluralRules.js]

intl/benchmarks/perftest_pluralRules.js

@@ -0,0 +1,119 @@
+/* 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/. */
+// @ts-check
+
+var perfMetadata = {
+  owner: "Internationalization Team",
+  name: "Intl.PluralRules",
+  description: "Test the speed of the Intl.PluralRules implementation.",
+  options: {
+    default: {
+      perfherder: true,
+      perfherder_metrics: [
+        {
+          name: "Intl.PluralRules constructor iterations",
+          unit: "iterations",
+        },
+        { name: "Intl.PluralRules constructor accumulatedTime", unit: "ms" },
+        { name: "Intl.PluralRules constructor perCallTime", unit: "ms" },
+
+        {
+          name: "Intl.PluralRules.prototype.select iterations",
+          unit: "iterations",
+        },
+        {
+          name: "Intl.PluralRules.prototype.select accumulatedTime",
+          unit: "ms",
+        },
+        {
+          name: "Intl.PluralRules.prototype.select perCallTime",
+          unit: "ms",
+        },
+
+        {
+          name: "Intl.PluralRules pluralCategories iterations",
+          unit: "iterations",
+        },
+        {
+          name: "Intl.PluralRules pluralCategories accumulatedTime",
+          unit: "ms",
+        },
+        {
+          name: "Intl.PluralRules pluralCategories perCallTime",
+          unit: "ms",
+        },
+      ],
+      verbose: true,
+    },
+  },
+  tags: ["intl", "ecma402"],
+};
+
+add_task(function measure_pluralrules() {
+  const measureConstructor = measureIterations("Intl.PluralRules constructor");
+  const measureSelect = measureIterations("Intl.PluralRules.prototype.select");
+  const measurePluralCategories = measureIterations(
+    "Intl.PluralRules pluralCategories"
+  );
+
+  // Re-use the config between runs.
+
+  const fieldOptions = {
+    type: ["cardinal", "ordinal"],
+  };
+
+  const config = {};
+  function randomizeConfig(name, chance) {
+    const option = fieldOptions[name];
+    if (prng() < chance) {
+      config[name] = option[Math.floor(option.length * prng())];
+    } else {
+      delete config[name];
+    }
+  }
+
+  // Split each step of the benchmark into separate JS functions so that performance
+  // profiles are easy to analyze.
+
+  function benchmarkPluralRulesConstructor() {
+    for (let i = 0; i < 1000; i++) {
+      // Create a random configuration powered by a pseudo-random number generator. This
+      // way the configurations will be the same between 2 different runs.
+      const locale = pickRepresentativeLocale();
+      randomizeConfig("type", 0.5);
+
+      // Measure the constructor.
+      measureConstructor.start();
+      const pr = new Intl.PluralRules(locale, config);
+      measureConstructor.stop();
+
+      benchmarkSelectOperation(pr);
+      benchmarkPluralCategories(pr);
+    }
+  }
+
+  function benchmarkSelectOperation(pr) {
+    // Measure the select operation.
+    for (let j = 0; j < 1000; j++) {
+      // TODO: We may want to extend this to non-integer values in the future.
+      const num = Math.floor(prng() * 10000);
+      measureSelect.start();
+      pr.select(num);
+      measureSelect.stop();
+    }
+  }
+
+  function benchmarkPluralCategories(pr) {
+    measurePluralCategories.start();
+    pr.resolvedOptions().pluralCategories;
+    measurePluralCategories.stop();
+  }
+
+  benchmarkPluralRulesConstructor();
+  measureConstructor.reportMetrics();
+  measureSelect.reportMetrics();
+  measurePluralCategories.reportMetrics();
+
+  ok(true);
+});

intl/benchmarks/xpcshell.ini

@@ -9,3 +9,6 @@ skip-if = true
 
 [perftest_locale.js]
 skip-if = true
+
+[perftest_pluralRules.js]
+skip-if = true