From 050ca394096d22330bf5519aad2c59f84be7a0c2 Mon Sep 17 00:00:00 2001
From: Marcos Casagrande <marcoscvp90@gmail.com>
Date: Sat, 12 Aug 2023 20:29:00 +0200
Subject: [PATCH] perf(ext/request): optimize validate and normalize HTTP
 method (#20143)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This PR optimizes `Request` constructor init method step. It doubles the
speed for known lowercased methods. I also added `PATCH` to known
methods

**this patch**

```
benchmark                   time (avg)        iter/s             (min … max)       p75       p99      p995
---------------------------------------------------------------------------- -----------------------------
method: GET                  1.49 µs/iter     669,336.9     (1.35 µs … 2.02 µs)   1.54 µs   2.02 µs   2.02 µs
method: PATCH                1.85 µs/iter     540,921.5     (1.65 µs … 2.02 µs)   1.91 µs   2.02 µs   2.02 µs
method: get                  1.49 µs/iter     669,067.9     (1.28 µs … 1.69 µs)   1.55 µs   1.69 µs   1.69 µs
```

**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
---------------------------------------------------------------------------- -----------------------------
method: GET                   1.5 µs/iter     665,232.3      (1.3 µs … 2.02 µs)   1.54 µs   2.02 µs   2.02 µs
method: PATCH                2.47 µs/iter     404,052.7     (2.06 µs … 4.05 µs)   2.51 µs   4.05 µs   4.05 µs
method: get                     3 µs/iter     333,277.2     (2.72 µs … 4.04 µs)   3.05 µs   4.04 µs   4.04 µs
```

```js
Deno.bench("method: GET", () => {
  const r = new Request("https://deno.land", {
    method: "GET",
  });
});

Deno.bench("method: PATCH", () => {
  const r = new Request("https://deno.land", {
    method: "PATCH",
    body: '{"foo": "bar"}',
  });
});

Deno.bench("method: get", () => {
  const r = new Request("https://deno.land", {
    method: "get",
  });
});
```
---
 ext/fetch/23_request.js | 45 ++++++++++++++++++++---------------------
 1 file changed, 22 insertions(+), 23 deletions(-)

diff --git a/ext/fetch/23_request.js b/ext/fetch/23_request.js
index cfdce01d3ea6bb..5232cc13c96c97 100644
--- a/ext/fetch/23_request.js
+++ b/ext/fetch/23_request.js
@@ -202,31 +202,29 @@ function cloneInnerRequest(request, skipBody = false) {
   };
 }
 
-/**
- * @param {string} m
- * @returns {boolean}
- */
-function isKnownMethod(m) {
-  return (
-    m === "DELETE" ||
-    m === "GET" ||
-    m === "HEAD" ||
-    m === "OPTIONS" ||
-    m === "POST" ||
-    m === "PUT"
-  );
-}
+// method => normalized method
+const KNOWN_METHODS = {
+  "DELETE": "DELETE",
+  "delete": "DELETE",
+  "GET": "GET",
+  "get": "GET",
+  "HEAD": "HEAD",
+  "head": "HEAD",
+  "OPTIONS": "OPTIONS",
+  "options": "OPTIONS",
+  "PATCH": "PATCH",
+  "patch": "PATCH",
+  "POST": "POST",
+  "post": "POST",
+  "PUT": "PUT",
+  "put": "PUT",
+};
+
 /**
  * @param {string} m
  * @returns {string}
  */
 function validateAndNormalizeMethod(m) {
-  // Fast path for well-known methods
-  if (isKnownMethod(m)) {
-    return m;
-  }
-
-  // Regular path
   if (RegExpPrototypeExec(HTTP_TOKEN_CODE_POINT_RE, m) === null) {
     throw new TypeError("Method is not valid.");
   }
@@ -325,9 +323,10 @@ class Request {
 
     // 25.
     if (init.method !== undefined) {
-      let method = init.method;
-      method = validateAndNormalizeMethod(method);
-      request.method = method;
+      const method = init.method;
+      // fast path: check for known methods
+      request.method = KNOWN_METHODS[method] ??
+        validateAndNormalizeMethod(method);
     }
 
     // 26.