From 1428c9c94c22a33e9cba4b11a70738f7af3a0274 Mon Sep 17 00:00:00 2001
From: David Luis <95457148+babiabeo@users.noreply.github.com>
Date: Sat, 10 Aug 2024 13:48:05 +0700
Subject: [PATCH] perf(uuid): make `uuidToBytes()` up to 2.5x faster (#5670)

perf(uuid): make `uuidToBytes` up to 2.5x faster
---
 uuid/_common.ts | 36 +++++++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

diff --git a/uuid/_common.ts b/uuid/_common.ts
index 820375663..83a9d058e 100644
--- a/uuid/_common.ts
+++ b/uuid/_common.ts
@@ -45,9 +45,35 @@ export function bytesToUuid(bytes: number[] | Uint8Array): string {
  * @param uuid Value that gets converted.
  */
 export function uuidToBytes(uuid: string): Uint8Array {
-  const bytes = uuid
-    .replaceAll("-", "")
-    .match(/.{1,2}/g)!
-    .map((byte) => parseInt(byte, 16));
-  return new Uint8Array(bytes);
+  const bytes = new Uint8Array(16);
+  let i = 0;
+
+  for (const str of uuid.split("-")) {
+    const hex = parseInt(str, 16);
+    switch (str.length) {
+      case 4: {
+        bytes[i++] = (hex >>> 8) & 0xff;
+        bytes[i++] = hex & 0xff;
+        break;
+      }
+      case 8: {
+        bytes[i++] = (hex >>> 24) & 0xff;
+        bytes[i++] = (hex >>> 16) & 0xff;
+        bytes[i++] = (hex >>> 8) & 0xff;
+        bytes[i++] = hex & 0xff;
+        break;
+      }
+      case 12: {
+        bytes[i++] = (hex / 0x10000000000) & 0xff;
+        bytes[i++] = (hex / 0x100000000) & 0xff;
+        bytes[i++] = (hex >>> 24) & 0xff;
+        bytes[i++] = (hex >>> 16) & 0xff;
+        bytes[i++] = (hex >>> 8) & 0xff;
+        bytes[i++] = hex & 0xff;
+        break;
+      }
+    }
+  }
+
+  return bytes;
 }