events: improve arrayClone performance

PR-URL: https://github.com/nodejs/node/pull/33774
Reviewed-By: Robert Nagy <ronagy@icloud.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Zeyu Yang <himself65@outlook.com>

benchmark/events/ee-emit.js

@@ -10,6 +10,7 @@ const bench = common.createBenchmark(main, {
 
 function main({ n, argc, listeners }) {
   const ee = new EventEmitter();
+  ee.setMaxListeners(listeners + 1);
 
   for (let k = 0; k < listeners; k += 1)
     ee.on('dummy', () => {});

benchmark/events/ee-listeners-many.js

@@ -1,22 +0,0 @@
-'use strict';
-const common = require('../common.js');
-const EventEmitter = require('events').EventEmitter;
-
-const bench = common.createBenchmark(main, { n: [5e6] });
-
-function main({ n }) {
-  const ee = new EventEmitter();
-  ee.setMaxListeners(101);
-
-  for (let k = 0; k < 50; k += 1) {
-    ee.on('dummy0', () => {});
-    ee.on('dummy1', () => {});
-  }
-
-  bench.start();
-  for (let i = 0; i < n; i += 1) {
-    const dummy = (i % 2 === 0) ? 'dummy0' : 'dummy1';
-    ee.listeners(dummy);
-  }
-  bench.end(n);
-}

benchmark/events/ee-listeners.js

@@ -2,20 +2,34 @@
 const common = require('../common.js');
 const EventEmitter = require('events').EventEmitter;
 
-const bench = common.createBenchmark(main, { n: [5e6] });
+const bench = common.createBenchmark(main, {
+  n: [5e6],
+  listeners: [5, 50],
+  raw: ['true', 'false']
+});
 
-function main({ n }) {
+function main({ n, listeners, raw }) {
   const ee = new EventEmitter();
+  ee.setMaxListeners(listeners * 2 + 1);
 
-  for (let k = 0; k < 5; k += 1) {
+  for (let k = 0; k < listeners; k += 1) {
     ee.on('dummy0', () => {});
     ee.on('dummy1', () => {});
   }
 
-  bench.start();
-  for (let i = 0; i < n; i += 1) {
-    const dummy = (i % 2 === 0) ? 'dummy0' : 'dummy1';
-    ee.listeners(dummy);
+  if (raw === 'true') {
+    bench.start();
+    for (let i = 0; i < n; i += 1) {
+      const dummy = (i % 2 === 0) ? 'dummy0' : 'dummy1';
+      ee.rawListeners(dummy);
+    }
+    bench.end(n);
+  } else {
+    bench.start();
+    for (let i = 0; i < n; i += 1) {
+      const dummy = (i % 2 === 0) ? 'dummy0' : 'dummy1';
+      ee.listeners(dummy);
+    }
+    bench.end(n);
   }
-  bench.end(n);
 }