defender-security / vendor / ramsey / uuid / src / Generator / CombGenerator.php

CombGenerator.php in Defender Security – Malware Scanner, Login Security & Firewall 5.6.0, at vendor/ramsey/uuid/src/Generator/CombGenerator.php

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1	<?php
2
3	/**
4	* This file is part of the ramsey/uuid library
5	*
6	* For the full copyright and license information, please view the LICENSE
7	* file that was distributed with this source code.
8	*
9	* @copyright Copyright (c) Ben Ramsey <[email protected]>
10	* @license http://opensource.org/licenses/MIT MIT
11	*/
12
13	declare(strict_types=1);
14
15	namespace Ramsey\Uuid\Generator;
16
17	use Ramsey\Uuid\Converter\NumberConverterInterface;
18	use Ramsey\Uuid\Exception\InvalidArgumentException;
19
20	use function bin2hex;
21	use function explode;
22	use function hex2bin;
23	use function microtime;
24	use function str_pad;
25	use function substr;
26
27	use const STR_PAD_LEFT;
28
29	/**
30	* CombGenerator generates COMBs (combined UUID/timestamp)
31	*
32	* The CombGenerator, when used with the StringCodec (and, by proxy, the
33	* TimestampLastCombCodec) or the TimestampFirstCombCodec, combines the current
34	* timestamp with a UUID (hence the name "COMB"). The timestamp either appears
35	* as the first or last 48 bits of the COMB, depending on the codec used.
36	*
37	* By default, COMBs will have the timestamp set as the last 48 bits of the
38	* identifier.
39	*
40	* ``` php
41	* $factory = new UuidFactory();
42	*
43	* $factory->setRandomGenerator(new CombGenerator(
44	* $factory->getRandomGenerator(),
45	* $factory->getNumberConverter()
46	* ));
47	*
48	* $comb = $factory->uuid4();
49	* ```
50	*
51	* To generate a COMB with the timestamp as the first 48 bits, set the
52	* TimestampFirstCombCodec as the codec.
53	*
54	* ``` php
55	* $factory->setCodec(new TimestampFirstCombCodec($factory->getUuidBuilder()));
56	* ```
57	*
58	* @link https://www.informit.com/articles/printerfriendly/25862 The Cost of GUIDs as Primary Keys
59	*/
60	class CombGenerator implements RandomGeneratorInterface
61	{
62	public const TIMESTAMP_BYTES = 6;
63
64	/**
65	* @var RandomGeneratorInterface
66	*/
67	private $randomGenerator;
68
69	/**
70	* @var NumberConverterInterface
71	*/
72	private $converter;
73
74	public function __construct(
75	RandomGeneratorInterface $generator,
76	NumberConverterInterface $numberConverter
77	) {
78	$this->converter = $numberConverter;
79	$this->randomGenerator = $generator;
80	}
81
82	/**
83	* @throws InvalidArgumentException if $length is not a positive integer
84	* greater than or equal to CombGenerator::TIMESTAMP_BYTES
85	*
86	* @inheritDoc
87	*/
88	public function generate(int $length): string
89	{
90	if ($length < self::TIMESTAMP_BYTES \|\| $length < 0) {
91	throw new InvalidArgumentException(
92	'Length must be a positive integer greater than or equal to ' . self::TIMESTAMP_BYTES
93	);
94	}
95
96	$hash = '';
97	if (self::TIMESTAMP_BYTES > 0 && $length > self::TIMESTAMP_BYTES) {
98	$hash = $this->randomGenerator->generate($length - self::TIMESTAMP_BYTES);
99	}
100
101	$lsbTime = str_pad(
102	$this->converter->toHex($this->timestamp()),
103	self::TIMESTAMP_BYTES * 2,
104	'0',
105	STR_PAD_LEFT
106	);
107
108	return (string) hex2bin(
109	str_pad(
110	bin2hex($hash),
111	$length - self::TIMESTAMP_BYTES,
112	'0'
113	)
114	. $lsbTime
115	);
116	}
117
118	/**
119	* Returns current timestamp a string integer, precise to 0.00001 seconds
120	*/
121	private function timestamp(): string
122	{
123	$time = explode(' ', microtime(false));
124
125	return $time[1] . substr($time[0], 2, 5);
126	}
127	}
128