From 44e1551ee1d25d18035f7b8d206b99a326250189 Mon Sep 17 00:00:00 2001
From: mei23 <m@m544.net>
Date: Sat, 13 Apr 2024 21:56:43 +0900
Subject: [PATCH] UUID v7

---
 src/misc/id/uuid7.ts                     | 67 ++++++++++++++++++++++++
 src/remote/activitypub/renderer/index.ts |  2 +-
 src/tools/dev/_uuid.ts                   |  5 ++
 3 files changed, 73 insertions(+), 1 deletion(-)
 create mode 100644 src/misc/id/uuid7.ts
 create mode 100644 src/tools/dev/_uuid.ts

diff --git a/src/misc/id/uuid7.ts b/src/misc/id/uuid7.ts
new file mode 100644
index 000000000000..a22dbe8adbd8
--- /dev/null
+++ b/src/misc/id/uuid7.ts
@@ -0,0 +1,67 @@
+// draft-ietf-uuidrev-rfc4122bis-14
+// https://www.ietf.org/archive/id/draft-ietf-uuidrev-rfc4122bis-14.html
+// 5.7. UUID Version 7
+// without OPTIONAL sub-millisecond timestamp fraction
+// without OPTIONAL carefully seeded counter
+
+export function uuid7() {
+	// 48bit(12char) UNIX timestamp (ms)
+	const timestamp = Date.now().toString(16).padStart(12, '0').slice(-12);
+	// 4bit(1char) version
+	const ver = '7';
+	// 12bit(3char) rand_a
+	const randA = getRandomHex(3);
+
+	// 64bit(16char) var + rand_b
+
+	//  最初の2charのうち最初の2bitは10
+	const x2 = getRandomHex(2);
+	let n = parseInt(x2, 16) & 0b0011_1111 | 0b1000_0000;
+	const randB1 = n.toString(16).padStart(2, '0');
+
+	//  残り14char
+	const randB2 = getRandomHex(14);
+	
+	const combined = timestamp + ver + randA + randB1 + randB2;
+	const splited = `${combined.substring(0, 8)}-${combined.substring(8, 12)}-${combined.substring(12, 16)}-${combined.substring(16, 20)}-${combined.substring(20)}`;
+	return splited;
+}
+
+function getRandomHex(len: number) {
+	const jo = Math.floor(len / 2);
+	const yo = len % 2;
+	
+	let result = '';
+	for (let i = 0; i < jo; i++) {
+		result += getRandom2CharInHex();
+	}
+
+	if (yo > 0) result += getRandom2CharInHex().substring(1);
+
+	return result;
+}
+
+function getRandom2CharInHex(): string {
+	return getRandomByte().toString(16).padStart(2, '0').slice(-2);
+}
+
+const getRandomByte = getRandomByteNode;
+
+
+// WebCrypto版 (未使用、Nodeはv19以降)
+function getRandomByteWeb(): number {
+	if (typeof globalThis.crypto?.getRandomValues !== 'undefined') {
+		const a = new Uint8Array(1);
+		globalThis.crypto.getRandomValues(a);
+		return a[0];
+	} else {
+		return Math.min(Math.floor(Math.random() * 256), 255);
+	}
+}
+
+import * as crypto from 'crypto';
+
+function getRandomByteNode(): number {
+	return crypto.randomBytes(1).readUInt8(0)
+}
+
diff --git a/src/remote/activitypub/renderer/index.ts b/src/remote/activitypub/renderer/index.ts
index efce8ebadae3..309f98110d27 100644
--- a/src/remote/activitypub/renderer/index.ts
+++ b/src/remote/activitypub/renderer/index.ts
@@ -1,5 +1,5 @@
 import config from '../../../config';
-import { v4 as uuid } from 'uuid';
+import { uuid7 as uuid } from '../../../misc/id/uuid7';
 import { IActivity } from '../type';
 import { LdSignature } from '../misc/ld-signature';
 import { ILocalUser } from '../../../models/user';
diff --git a/src/tools/dev/_uuid.ts b/src/tools/dev/_uuid.ts
new file mode 100644
index 000000000000..535a78cbaad9
--- /dev/null
+++ b/src/tools/dev/_uuid.ts
@@ -0,0 +1,5 @@
+import { uuid7 } from '../../misc/id/uuid7';
+
+for(let i = 0; i < 16; i++) {
+	console.log(uuid7());
+}