From 627499177f3a69646c352dede4926db12b03002e Mon Sep 17 00:00:00 2001
From: Marcos Casagrande <marcoscvp90@gmail.com>
Date: Sun, 20 Aug 2023 11:30:57 +0200
Subject: [PATCH] perf(ext/event): optimize addEventListener options converter
 (#20203)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This PR optimizes `addEventListener` by replacing
`webidl.createDictionaryConverter("AddEventListenerOptions", ...)` with
a custom options parsing function to avoid the overhead of `webidl`
methods

**this PR**

```
cpu: 13th Gen Intel(R) Core(TM) i9-13900H
runtime: deno 1.36.1 (x86_64-unknown-linux-gnu)

benchmark                                           time (avg)        iter/s             (min … max)       p75       p99      p995
---------------------------------------------------------------------------------------------------- -----------------------------
addEventListener options converter (undefined)       4.87 ns/iter 205,248,660.8     (4.7 ns … 13.18 ns)   4.91 ns    5.4 ns    5.6 ns
addEventListener options converter (signal)         13.02 ns/iter  76,782,031.2   (11.74 ns … 18.84 ns)  13.08 ns  16.22 ns  16.57 ns
```

**main**
```
cpu: 13th Gen Intel(R) Core(TM) i9-13900H
runtime: deno 1.36.1 (x86_64-unknown-linux-gnu)

benchmark                                           time (avg)        iter/s             (min … max)       p75       p99      p995
---------------------------------------------------------------------------------------------------- -----------------------------
addEventListener options converter (undefined)     108.36 ns/iter   9,228,688.6  (103.5 ns … 129.88 ns) 109.69 ns 115.61 ns 125.28 ns
addEventListener options converter (signal)        134.03 ns/iter   7,460,878.1 (129.14 ns … 144.54 ns) 135.68 ns 141.13 ns  144.1 ns
```

```js
const tg = new EventTarget();
const signal = new AbortController().signal;

Deno.bench("addEventListener options converter (undefined)", () => {
  tg.addEventListener("foo", null); // null callback to only bench options converter
});

Deno.bench("addEventListener options converter (signal)", () => {
  tg.addEventListener("foo", null, { signal });
});
```

Towards https://github.com/denoland/deno/issues/20167
---
 ext/web/02_event.js | 62 +++++++++++++++------------------------------
 1 file changed, 21 insertions(+), 41 deletions(-)

diff --git a/ext/web/02_event.js b/ext/web/02_event.js
index 4d3f23a022..2be8003674 100644
--- a/ext/web/02_event.js
+++ b/ext/web/02_event.js
@@ -896,44 +896,28 @@ function getDefaultTargetData() {
   };
 }
 
-// This is lazy loaded because there is a circular dependency with AbortSignal.
-let addEventListenerOptionsConverter;
-
-function lazyAddEventListenerOptionsConverter() {
-  addEventListenerOptionsConverter ??= webidl.createDictionaryConverter(
-    "AddEventListenerOptions",
-    [
-      {
-        key: "capture",
-        defaultValue: false,
-        converter: webidl.converters.boolean,
-      },
-      {
-        key: "passive",
-        defaultValue: false,
-        converter: webidl.converters.boolean,
-      },
-      {
-        key: "once",
-        defaultValue: false,
-        converter: webidl.converters.boolean,
-      },
-      {
-        key: "signal",
-        converter: webidl.converters.AbortSignal,
-      },
-    ],
-  );
-}
-
-webidl.converters.AddEventListenerOptions = (V, prefix, context, opts) => {
-  if (webidl.type(V) !== "Object" || V === null) {
-    V = { capture: Boolean(V) };
+function addEventListenerOptionsConverter(V, prefix) {
+  if (webidl.type(V) !== "Object") {
+    return { capture: !!V, once: false, passive: false };
   }
 
-  lazyAddEventListenerOptionsConverter();
-  return addEventListenerOptionsConverter(V, prefix, context, opts);
-};
+  const options = {
+    capture: !!V.capture,
+    once: !!V.once,
+    passive: !!V.passive,
+  };
+
+  const signal = V.signal;
+  if (signal !== undefined) {
+    options.signal = webidl.converters.AbortSignal(
+      signal,
+      prefix,
+      "'signal' of 'AddEventListenerOptions' (Argument 3)",
+    );
+  }
+
+  return options;
+}
 
 class EventTarget {
   constructor() {
@@ -952,11 +936,7 @@ class EventTarget {
 
     webidl.requiredArguments(arguments.length, 2, prefix);
 
-    options = webidl.converters.AddEventListenerOptions(
-      options,
-      prefix,
-      "Argument 3",
-    );
+    options = addEventListenerOptionsConverter(options, prefix);
 
     if (callback === null) {
       return;