repl: add benchmarks

benchmark/repl/completion.js

@@ -0,0 +1,53 @@
+'use strict';
+
+const common = require('../common.js');
+const repl = require('node:repl');
+const { PassThrough, Writable } = require('node:stream');
+
+const bench = common.createBenchmark(main, {
+  n: [5e3],
+  query: [
+    'cons',
+    'console.lo',
+    'Buffer.prototype.wri',
+    "require('f",
+  ],
+  useGlobal: [0, 1],
+});
+
+function main({ n, query, useGlobal }) {
+  const input = new PassThrough();
+  const output = new Writable({ write(c, e, cb) { cb(); } });
+  const server = new repl.REPLServer({
+    input,
+    output,
+    terminal: false,
+    useGlobal: !!useGlobal,
+  });
+
+  // Inspector callbacks do not keep the event loop alive on their own.
+  const keepAlive = setInterval(() => {}, 0x7fffffff);
+  let remaining = n;
+
+  function complete() {
+    server.complete(query, onComplete);
+  }
+
+  function onComplete(err) {
+    if (err) {
+      throw err;
+    }
+
+    if (--remaining === 0) {
+      bench.end(n);
+      clearInterval(keepAlive);
+      server.close();
+      return;
+    }
+
+    setImmediate(complete);
+  }
+
+  bench.start();
+  setImmediate(complete);
+}

benchmark/repl/creation.js

@@ -0,0 +1,39 @@
+'use strict';
+
+const common = require('../common.js');
+const repl = require('node:repl');
+const { PassThrough, Writable } = require('node:stream');
+
+const bench = common.createBenchmark(main, {
+  n: [500],
+  preview: [0, 1],
+  terminal: [0, 1],
+  useGlobal: [0, 1],
+}, {
+  combinationFilter: ({ preview, terminal }) => !!terminal || !preview,
+});
+
+function main({ n, preview, terminal, useGlobal }) {
+  const inputs = Array.from({ length: n }, () => new PassThrough());
+  const outputs = Array.from(
+    { length: n },
+    () => new Writable({ write(c, e, cb) { cb(); } }),
+  );
+  const servers = new Array(n);
+
+  bench.start();
+  for (let i = 0; i < n; i++) {
+    servers[i] = new repl.REPLServer({
+      input: inputs[i],
+      output: outputs[i],
+      preview: !!preview,
+      terminal: !!terminal,
+      useGlobal: !!useGlobal,
+    });
+  }
+  bench.end(n);
+
+  for (const server of servers) {
+    server.close();
+  }
+}

benchmark/repl/evaluate.js

@@ -0,0 +1,57 @@
+'use strict';
+
+const common = require('../common.js');
+const repl = require('node:repl');
+const { PassThrough, Writable } = require('node:stream');
+
+const bench = common.createBenchmark(main, {
+  n: [2e4],
+  code: [
+    '1 + 1',
+    '({ answer: 42 })',
+    'Promise.resolve(42)',
+    'await Promise.resolve(42)',
+  ],
+  mode: ['sloppy', 'strict'],
+  useGlobal: [0, 1],
+});
+
+function main({ n, code, mode, useGlobal }) {
+  const input = new PassThrough();
+  const output = new Writable({ write(c, e, cb) { cb(); } });
+  const server = new repl.REPLServer({
+    input,
+    output,
+    replMode: mode === 'strict' ?
+      repl.REPL_MODE_STRICT :
+      repl.REPL_MODE_SLOPPY,
+    terminal: false,
+    useGlobal: !!useGlobal,
+  });
+
+  // Inspector callbacks do not keep the event loop alive on their own.
+  const keepAlive = setInterval(() => {}, 0x7fffffff);
+  let remaining = n;
+
+  function evaluate() {
+    server.eval(`${code}\n`, server.context, 'repl', onEvaluate);
+  }
+
+  function onEvaluate(err) {
+    if (err) {
+      throw err;
+    }
+
+    if (--remaining === 0) {
+      bench.end(n);
+      clearInterval(keepAlive);
+      server.close();
+      return;
+    }
+
+    setImmediate(evaluate);
+  }
+
+  bench.start();
+  setImmediate(evaluate);
+}

benchmark/repl/process-lines.js

@@ -0,0 +1,52 @@
+'use strict';
+
+const common = require('../common.js');
+const repl = require('node:repl');
+const { PassThrough, Writable } = require('node:stream');
+
+const bench = common.createBenchmark(main, {
+  n: [1e4],
+  code: [
+    '1 + 1\n',
+    'Promise.resolve(42)\n',
+  ],
+  mode: ['sloppy', 'strict'],
+  terminal: [0, 1],
+  useGlobal: [0, 1],
+});
+
+function main({ n, code: inputCode, mode, terminal, useGlobal }) {
+  const input = new PassThrough();
+  const output = new Writable({ write(c, e, cb) { cb(); } });
+  const server = new repl.REPLServer({
+    input,
+    output,
+    replMode: mode === 'strict' ?
+      repl.REPL_MODE_STRICT :
+      repl.REPL_MODE_SLOPPY,
+    terminal: !!terminal,
+    useGlobal: !!useGlobal,
+  });
+  const originalEval = server.eval;
+  // TTY input dispatch can briefly have no other active event loop handles.
+  const keepAlive = setInterval(() => {}, 0x7fffffff);
+  let remaining = n;
+
+  // eslint-disable-next-line node-core/func-name-matching
+  server.eval = function REPLEval(code, context, file, callback) {
+    originalEval(code, context, file, function onEvaluate() {
+      const result = Reflect.apply(callback, this, arguments);
+      if (--remaining === 0) {
+        bench.end(n);
+        clearInterval(keepAlive);
+        server.close();
+      } else {
+        setImmediate(() => input.write(inputCode));
+      }
+      return result;
+    });
+  };
+
+  bench.start();
+  input.write(inputCode);
+}

benchmark/repl/reset-context.js

@@ -0,0 +1,26 @@
+'use strict';
+
+const common = require('../common.js');
+const repl = require('node:repl');
+const { PassThrough, Writable } = require('node:stream');
+
+const bench = common.createBenchmark(main, {
+  n: [1e3],
+});
+
+function main({ n }) {
+  const input = new PassThrough();
+  const output = new Writable({ write(c, e, cb) { cb(); } });
+  const server = new repl.REPLServer({
+    input,
+    output,
+    terminal: false,
+  });
+
+  bench.start();
+  for (let i = 0; i < n; i++) {
+    server.resetContext();
+  }
+  bench.end(n);
+  server.close();
+}

test/benchmark/test-benchmark-repl.js

@@ -0,0 +1,7 @@
+'use strict';
+
+require('../common');
+
+const runBenchmark = require('../common/benchmark');
+
+runBenchmark('repl', { NODEJS_BENCHMARK_ZERO_ALLOWED: 1 });