From d856bfd336137e1bcf81a0db9e8ad2b418ba711e Mon Sep 17 00:00:00 2001
From: Divy Srivastava <dj.srivastava23@gmail.com>
Date: Mon, 1 May 2023 10:39:30 +0530
Subject: perf(ext/web): fast path for ws events (#18905)

- Do not use `ReflectHas` in `isNode`.
- Avoid copying handler array when handlers.length == 1
- Avoid searching for path target when path.length == 1

```
Linux divy-2 5.19.0-1022-gcp #24~22.04.1-Ubuntu SMP Sun Apr 23 09:51:08 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
32GiB System memory
Intel(R) Xeon(R) CPU @ 3.10GHz

# main + https://github.com/denoland/deno/pull/18904
Msg/sec: 89326.750000
Msg/sec: 90320.000000
Msg/sec: 89576.250000

# this patch
Msg/sec: 97250.000000
Msg/sec: 97125.500000
Msg/sec: 97964.500000
```
---
 ext/web/02_event.js | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

(limited to 'ext/web')

diff --git a/ext/web/02_event.js b/ext/web/02_event.js
index 6a5db3464..0372293cf 100644
--- a/ext/web/02_event.js
+++ b/ext/web/02_event.js
@@ -482,7 +482,7 @@ function getRoot(eventTarget) {
 function isNode(
   eventTarget,
 ) {
-  return Boolean(eventTarget && ReflectHas(eventTarget, "nodeType"));
+  return eventTarget?.nodeType !== undefined;
 }
 
 // https://dom.spec.whatwg.org/#concept-shadow-including-inclusive-ancestor
@@ -734,8 +734,12 @@ function innerInvokeEventListeners(
     return found;
   }
 
+  let handlers = targetListeners[type];
+
   // Copy event listeners before iterating since the list can be modified during the iteration.
-  const handlers = ArrayPrototypeSlice(targetListeners[type]);
+  if (handlers.length > 1) {
+    handlers = ArrayPrototypeSlice(targetListeners[type]);
+  }
 
   for (let i = 0; i < handlers.length; i++) {
     const listener = handlers[i];
@@ -804,12 +808,19 @@ function innerInvokeEventListeners(
  * Ref: https://dom.spec.whatwg.org/#concept-event-listener-invoke */
 function invokeEventListeners(tuple, eventImpl) {
   const path = getPath(eventImpl);
-  const tupleIndex = ArrayPrototypeIndexOf(path, tuple);
-  for (let i = tupleIndex; i >= 0; i--) {
-    const t = path[i];
+  if (path.length === 1) {
+    const t = path[0];
     if (t.target) {
       setTarget(eventImpl, t.target);
-      break;
+    }
+  } else {
+    const tupleIndex = ArrayPrototypeIndexOf(path, tuple);
+    for (let i = tupleIndex; i >= 0; i--) {
+      const t = path[i];
+      if (t.target) {
+        setTarget(eventImpl, t.target);
+        break;
+      }
     }
   }
 
-- 
cgit v1.2.3