Add bench suite of common Deno functions (#9878)

cli/bench/deno_common.js

@@ -0,0 +1,53 @@
+// Run with: deno run -A ./cli/bench/deno_common.js
+function benchSync(name, n, innerLoop) {
+  const t1 = Date.now();
+  for (let i = 0; i < n; i++) {
+    innerLoop(i);
+  }
+  const t2 = Date.now();
+  const dt = (t2 - t1) / 1e3;
+  const r = n / dt;
+  console.log(
+    `${name}:${" ".repeat(20 - name.length)}\t` +
+      `n = ${n}, dt = ${dt.toFixed(3)}s, r = ${r.toFixed(0)}/s`,
+  );
+}
+
+function benchUrlParse() {
+  benchSync("url_parse", 5e4, (i) => {
+    new URL(`http://www.google.com/${i}`);
+  });
+}
+
+function benchNow() {
+  benchSync("now", 5e5, () => {
+    performance.now();
+  });
+}
+
+function benchWriteNull() {
+  // Not too large since we want to measure op-overhead not sys IO
+  const dataChunk = new Uint8Array(100);
+  const file = Deno.openSync("/dev/null", { write: true });
+  benchSync("write_null", 5e5, () => {
+    Deno.writeSync(file.rid, dataChunk);
+  });
+  Deno.close(file.rid);
+}
+
+function benchReadZero() {
+  const buf = new Uint8Array(100);
+  const file = Deno.openSync("/dev/zero");
+  benchSync("read_zero", 5e5, () => {
+    Deno.readSync(file.rid, buf);
+  });
+  Deno.close(file.rid);
+}
+
+function main() {
+  benchUrlParse();
+  benchNow();
+  benchWriteNull();
+  benchReadZero();
+}
+main();