test: refactor test-readline-async-iterators into a benchmark

PR-URL: https://github.com/nodejs/node/pull/49237
Fixes: https://github.com/nodejs/node/issues/49224
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

benchmark/readline/readline-iterable.js

@@ -5,6 +5,7 @@ const { Readable } = require('stream');
 
 const bench = common.createBenchmark(main, {
   n: [1e1, 1e2, 1e3, 1e4, 1e5, 1e6],
+  type: ['old', 'new'],
 });
 
 const loremIpsum = `Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed
@@ -21,6 +22,37 @@ Condimentum mattis pellentesque id nibh tortor id aliquet lectus proin.
 Diam in arcu cursus euismod quis viverra nibh.
 Rest of line`;
 
+function oldWay() {
+  const readable = new Readable({
+    objectMode: true,
+    read: () => {
+      this.resume();
+    },
+    destroy: (err, cb) => {
+      this.off('line', lineListener);
+      this.off('close', closeListener);
+      this.close();
+      cb(err);
+    },
+  });
+  const lineListener = (input) => {
+    if (!readable.push(input)) {
+      // TODO(rexagod): drain to resume flow
+      this.pause();
+    }
+  };
+  const closeListener = () => {
+    readable.push(null);
+  };
+  const errorListener = (err) => {
+    readable.destroy(err);
+  };
+  this.on('error', errorListener);
+  this.on('line', lineListener);
+  this.on('close', closeListener);
+  return readable[Symbol.asyncIterator]();
+}
+
 function getLoremIpsumStream(repetitions) {
   const readable = Readable({
     objectMode: true,
@@ -32,7 +64,7 @@ function getLoremIpsumStream(repetitions) {
   return readable;
 }
 
-async function main({ n }) {
+async function main({ n, type }) {
   bench.start();
   let lineCount = 0;
 
@@ -40,8 +72,10 @@ async function main({ n }) {
     input: getLoremIpsumStream(n),
   });
 
+  const readlineIterable = type === 'old' ? oldWay.call(iterable) : iterable;
+
   // eslint-disable-next-line no-unused-vars
-  for await (const _ of iterable) {
+  for await (const _ of readlineIterable) {
     lineCount++;
   }
   bench.end(lineCount);

test/parallel/test-readline-async-iterators.js

@@ -73,115 +73,6 @@ async function testMutual() {
   }
 }
 
-async function testPerformance() {
-  const loremIpsum = `Lorem ipsum dolor sit amet, consectetur adipiscing elit,
-sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
-Dui accumsan sit amet nulla facilisi morbi tempus iaculis urna.
-Eget dolor morbi non arcu risus quis varius quam quisque.
-Lacus viverra vitae congue eu consequat ac felis donec.
-Amet porttitor eget dolor morbi non arcu.
-Velit ut tortor pretium viverra suspendisse.
-Mauris nunc congue nisi vitae suscipit tellus.
-Amet nisl suscipit adipiscing bibendum est ultricies integer.
-Sit amet dictum sit amet justo donec enim diam.
-Condimentum mattis pellentesque id nibh tortor id aliquet lectus proin.
-Diam in arcu cursus euismod quis viverra nibh.
-`;
-
-  const REPETITIONS = 10000;
-  const SAMPLE = 100;
-  const THRESHOLD = 81;
-
-  function getLoremIpsumStream() {
-    const readable = Readable({
-      objectMode: true,
-    });
-    let i = 0;
-    readable._read = () => readable.push(
-      i++ >= REPETITIONS ? null : loremIpsum
-    );
-    return readable;
-  }
-
-  function oldWay() {
-    const readable = new Readable({
-      objectMode: true,
-      read: () => {
-        this.resume();
-      },
-      destroy: (err, cb) => {
-        this.off('line', lineListener);
-        this.off('close', closeListener);
-        this.close();
-        cb(err);
-      },
-    });
-    const lineListener = (input) => {
-      if (!readable.push(input)) {
-        // TODO(rexagod): drain to resume flow
-        this.pause();
-      }
-    };
-    const closeListener = () => {
-      readable.push(null);
-    };
-    const errorListener = (err) => {
-      readable.destroy(err);
-    };
-    this.on('error', errorListener);
-    this.on('line', lineListener);
-    this.on('close', closeListener);
-    return readable[Symbol.asyncIterator]();
-  }
-
-  function getAvg(mean, x, n) {
-    return (mean * n + x) / (n + 1);
-  }
-
-  let totalTimeOldWay = 0;
-  let totalTimeNewWay = 0;
-  let totalCharsOldWay = 0;
-  let totalCharsNewWay = 0;
-  const linesOldWay = [];
-  const linesNewWay = [];
-
-  for (let time = 0; time < SAMPLE; time++) {
-    const rlOldWay = readline.createInterface({
-      input: getLoremIpsumStream(),
-    });
-    let currenttotalTimeOldWay = Date.now();
-    for await (const line of oldWay.call(rlOldWay)) {
-      totalCharsOldWay += line.length;
-      if (time === 0) {
-        linesOldWay.push(line);
-      }
-    }
-    currenttotalTimeOldWay = Date.now() - currenttotalTimeOldWay;
-    totalTimeOldWay = getAvg(totalTimeOldWay, currenttotalTimeOldWay, SAMPLE);
-
-    const rlNewWay = readline.createInterface({
-      input: getLoremIpsumStream(),
-    });
-    let currentTotalTimeNewWay = Date.now();
-    for await (const line of rlNewWay) {
-      totalCharsNewWay += line.length;
-      if (time === 0) {
-        linesNewWay.push(line);
-      }
-    }
-    currentTotalTimeNewWay = Date.now() - currentTotalTimeNewWay;
-    totalTimeNewWay = getAvg(totalTimeNewWay, currentTotalTimeNewWay, SAMPLE);
-  }
-
-  assert.strictEqual(totalCharsOldWay, totalCharsNewWay);
-  assert.strictEqual(linesOldWay.length, linesNewWay.length);
-  linesOldWay.forEach((line, index) =>
-    assert.strictEqual(line, linesNewWay[index])
-  );
-  const percentage = totalTimeNewWay * 100 / totalTimeOldWay;
-  assert.ok(percentage <= THRESHOLD, `Failed: ${totalTimeNewWay} isn't lesser than ${THRESHOLD}% of ${totalTimeOldWay}. Actual percentage: ${percentage.toFixed(2)}%`);
-}
-
 async function testSlowStreamForLeaks() {
   const message = 'a\nb\nc\n';
   const DELAY = 1;
@@ -225,6 +116,5 @@ async function testSlowStreamForLeaks() {
 
 testSimple()
   .then(testMutual)
-  .then(testPerformance)
   .then(testSlowStreamForLeaks)
   .then(common.mustCall());