File uuid.php

1:	<?php
2:
3:	namespace nightmare;
4:
5:	class uuid
6:	{
7:	public static function v4()
8:	{
9:	$b = random_bytes(16);
10:	$b[6] = chr(ord($b[6]) & 0x0f \| 0x40);
11:	$b[8] = chr(ord($b[8]) & 0x3f \| 0x80);
12:
13:	$hex = bin2hex($b);
14:
15:	return sprintf(
16:	'%s%s-%s-%s-%s-%s%s%s',
17:	substr($hex, 0, 4),
18:	substr($hex, 4, 4),
19:	substr($hex, 8, 4),
20:	substr($hex, 12, 4),
21:	substr($hex, 16, 4),
22:	substr($hex, 20, 4),
23:	substr($hex, 24, 4),
24:	substr($hex, 28, 4)
25:	);
26:	}
27:
28:	// uuidv7 see https://www.rfc-editor.org/rfc/rfc9562#name-uuid-version-7
29:	public static function v7()
30:	{
31:	// 1) Lấy timestamp mili-giây từ Unix Epoch (UTC)
32:	$unix_ms = (int) (microtime(true) * 1000);
33:
34:	// 2) 48-bit timestamp big-endian -> 6 byte
35:	// N = 32-bit big-endian, n = 16-bit big-endian
36:	$time_bytes = pack('Nn', $unix_ms >> 16, $unix_ms & 0xFFFF);
37:
38:	// 3) 10 byte ngẫu nhiên (crypto-safe)
39:	$rand_bytes = random_bytes(10);
40:
41:	// 4) Ghép thành 16 byte
42:	$bytes = $time_bytes . $rand_bytes;
43:
44:	// 5) Set version 7 (0111) vào high nibble của byte thứ 7 (index 6)
45:	$bytes[6] = chr((ord($bytes[6]) & 0x0F) \| 0x70);
46:
47:	// 6) Set variant RFC 4122 -> 10xxxxxx vào byte thứ 9 (index 8)
48:	$bytes[8] = chr((ord($bytes[8]) & 0x3F) \| 0x80);
49:
50:	// 7) Chuyển sang dạng string 8-4-4-4-12
51:	$hex = bin2hex($bytes);
52:
53:	return sprintf(
54:	'%s-%s-%s-%s-%s',
55:	substr($hex, 0, 8),
56:	substr($hex, 8, 4),
57:	substr($hex, 12, 4),
58:	substr($hex, 16, 4),
59:	substr($hex, 20),
60:	);
61:	}
62:	}
63: