benchmark: add fs warmup to writefile-promises

PR-URL: #59215 Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com> Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

Author: brunocroh

benchmark/fs/writefile-promises.js

@@ -39,8 +39,17 @@ function main({ encodingType, duration, concurrent, size }) {
  let writes = 0;
  let waitConcurrent = 0;
 
- const startedAt = Date.now();
- const endAt = startedAt + (duration * 1000);
+ let startedAt = Date.now();
+ let endAt = startedAt + duration * 1000;
+
+ // fs warmup
+ for (let i = 0; i < concurrent; i++) write();
+
+ writes = 0;
+ waitConcurrent = 0;
+
+ startedAt = Date.now();
+ endAt = startedAt + duration * 1000;
 
  bench.start();
 
@@ -59,7 +68,8 @@ function main({ encodingType, duration, concurrent, size }) {
  }
 
  function write() {
- fs.promises.writeFile(`${filename}-${filesWritten++}`, chunk, encoding)
+ fs.promises
+ .writeFile(`${filename}-${filesWritten++}`, chunk, encoding)
  .then(() => afterWrite())
  .catch((err) => afterWrite(err));
  }
@@ -72,7 +82,7 @@ function main({ encodingType, duration, concurrent, size }) {
  writes++;
  const benchEnded = Date.now() >= endAt;
 
- if (benchEnded && (++waitConcurrent) === concurrent) {
+ if (benchEnded && ++waitConcurrent === concurrent) {
  stop();
  } else if (!benchEnded) {
  write();