116 lines
3.1 KiB
PHP
116 lines
3.1 KiB
PHP
<?php
|
|
|
|
/**
|
|
* This file is part of the ramsey/uuid library
|
|
*
|
|
* For the full copyright and license information, please view the LICENSE
|
|
* file that was distributed with this source code.
|
|
*
|
|
* @copyright Copyright (c) Ben Ramsey <ben@benramsey.com>
|
|
* @license http://opensource.org/licenses/MIT MIT
|
|
*/
|
|
|
|
declare(strict_types=1);
|
|
|
|
namespace Ramsey\Uuid\Generator;
|
|
|
|
use Ramsey\Uuid\Converter\NumberConverterInterface;
|
|
use Ramsey\Uuid\Exception\InvalidArgumentException;
|
|
|
|
use function bin2hex;
|
|
use function explode;
|
|
use function hex2bin;
|
|
use function microtime;
|
|
use function str_pad;
|
|
use function substr;
|
|
|
|
use const STR_PAD_LEFT;
|
|
|
|
/**
|
|
* CombGenerator generates COMBs (combined UUID/timestamp)
|
|
*
|
|
* The CombGenerator, when used with the StringCodec (and, by proxy, the
|
|
* TimestampLastCombCodec) or the TimestampFirstCombCodec, combines the current
|
|
* timestamp with a UUID (hence the name "COMB"). The timestamp either appears
|
|
* as the first or last 48 bits of the COMB, depending on the codec used.
|
|
*
|
|
* By default, COMBs will have the timestamp set as the last 48 bits of the
|
|
* identifier.
|
|
*
|
|
* ``` php
|
|
* $factory = new UuidFactory();
|
|
*
|
|
* $factory->setRandomGenerator(new CombGenerator(
|
|
* $factory->getRandomGenerator(),
|
|
* $factory->getNumberConverter()
|
|
* ));
|
|
*
|
|
* $comb = $factory->uuid4();
|
|
* ```
|
|
*
|
|
* To generate a COMB with the timestamp as the first 48 bits, set the
|
|
* TimestampFirstCombCodec as the codec.
|
|
*
|
|
* ``` php
|
|
* $factory->setCodec(new TimestampFirstCombCodec($factory->getUuidBuilder()));
|
|
* ```
|
|
*
|
|
* @link https://www.informit.com/articles/printerfriendly/25862 The Cost of GUIDs as Primary Keys
|
|
*/
|
|
class CombGenerator implements RandomGeneratorInterface
|
|
{
|
|
public const TIMESTAMP_BYTES = 6;
|
|
|
|
public function __construct(
|
|
private RandomGeneratorInterface $generator,
|
|
private NumberConverterInterface $numberConverter
|
|
) {
|
|
}
|
|
|
|
/**
|
|
* @throws InvalidArgumentException if $length is not a positive integer
|
|
* greater than or equal to CombGenerator::TIMESTAMP_BYTES
|
|
*
|
|
* @inheritDoc
|
|
*/
|
|
public function generate(int $length): string
|
|
{
|
|
if ($length < self::TIMESTAMP_BYTES) {
|
|
throw new InvalidArgumentException(
|
|
'Length must be a positive integer greater than or equal to ' . self::TIMESTAMP_BYTES
|
|
);
|
|
}
|
|
|
|
$hash = '';
|
|
if (self::TIMESTAMP_BYTES > 0 && $length > self::TIMESTAMP_BYTES) {
|
|
$hash = $this->generator->generate($length - self::TIMESTAMP_BYTES);
|
|
}
|
|
|
|
$lsbTime = str_pad(
|
|
$this->numberConverter->toHex($this->timestamp()),
|
|
self::TIMESTAMP_BYTES * 2,
|
|
'0',
|
|
STR_PAD_LEFT
|
|
);
|
|
|
|
return (string) hex2bin(
|
|
str_pad(
|
|
bin2hex($hash),
|
|
$length - self::TIMESTAMP_BYTES,
|
|
'0'
|
|
)
|
|
. $lsbTime
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Returns current timestamp a string integer, precise to 0.00001 seconds
|
|
*/
|
|
private function timestamp(): string
|
|
{
|
|
$time = explode(' ', microtime(false));
|
|
|
|
return $time[1] . substr($time[0], 2, 5);
|
|
}
|
|
}
|