perf: use fast api for op_now (#15643)

1 files changed, 19 insertions, 0 deletions

diff --git a/cli/bench/op_now.js b/cli/bench/op_now.js
new file mode 100644
index 000000000..edce96fed
--- /dev/null
+++ b/cli/bench/op_now.js
@@ -0,0 +1,19 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+const queueMicrotask = globalThis.queueMicrotask || process.nextTick;
+let [total, count] = typeof Deno !== "undefined"
+  ? Deno.args
+  : [process.argv[2], process.argv[3]];
+
+total = total ? parseInt(total, 0) : 50;
+count = count ? parseInt(count, 10) : 10000000;
+
+function bench(fun) {
+  const start = Date.now();
+  for (let i = 0; i < count; i++) fun();
+  const elapsed = Date.now() - start;
+  const rate = Math.floor(count / (elapsed / 1000));
+  console.log(`time ${elapsed} ms rate ${rate}`);
+  if (--total) queueMicrotask(() => bench(fun));
+}
+
+bench(() => performance.now());