1 files changed, 16 insertions, 0 deletions
diff --git a/cli/js/web/performance.ts b/cli/js/web/performance.ts
new file mode 100644
index 000000000..cb4daa846
--- /dev/null
+++ b/cli/js/web/performance.ts
@@ -0,0 +1,16 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import { now as opNow } from "../ops/timers.ts";
+
+export class Performance {
+  /** Returns a current time from Deno's start in milliseconds.
+   *
+   * Use the flag --allow-hrtime return a precise value.
+   *
+   *       const t = performance.now();
+   *       console.log(`${t} ms since start!`);
+   */
+  now(): number {
+    const res = opNow();
+    return res.seconds * 1e3 + res.subsecNanos / 1e6;
+  }
+}