<?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 <[email protected]>
* @license http://opensource.org/licenses/MIT MIT
*/
declare(strict_types=1);
namespace Ramsey\Uuid\Codec;
use Ramsey\Uuid\Exception\InvalidUuidStringException;
use Ramsey\Uuid\UuidInterface;
use function bin2hex;
use function sprintf;
use function substr;
use function substr_replace;
/**
* TimestampFirstCombCodec encodes and decodes COMBs, with the timestamp as the
* first 48 bits
*
* In contrast with the TimestampLastCombCodec, the TimestampFirstCombCodec
* adds the timestamp to the first 48 bits of the COMB. To generate a
* timestamp-first COMB, set the TimestampFirstCombCodec as the codec, along
* with the CombGenerator as the random generator.
*
* ``` php
* $factory = new UuidFactory();
*
* $factory->setCodec(new TimestampFirstCombCodec($factory->getUuidBuilder()));
*
* $factory->setRandomGenerator(new CombGenerator(
* $factory->getRandomGenerator(),
* $factory->getNumberConverter()
* ));
*
* $timestampFirstComb = $factory->uuid4();
* ```
*
* @link https://www.informit.com/articles/printerfriendly/25862 The Cost of GUIDs as Primary Keys
*
* @psalm-immutable
*/
class TimestampFirstCombCodec extends StringCodec
{
/**
* @psalm-return non-empty-string
* @psalm-suppress MoreSpecificReturnType we know that the retrieved `string` is never empty
* @psalm-suppress LessSpecificReturnStatement we know that the retrieved `string` is never empty
*/
public function encode(UuidInterface $uuid): string
{
$bytes = $this->swapBytes($uuid->getFields()->getBytes());
return sprintf(
'%08s-%04s-%04s-%04s-%012s',
bin2hex(substr($bytes, 0, 4)),
bin2hex(substr($bytes, 4, 2)),
bin2hex(substr($bytes, 6, 2)),
bin2hex(substr($bytes, 8, 2)),
bin2hex(substr($bytes, 10))
);
}
/**
* @psalm-return non-empty-string
* @psalm-suppress MoreSpecificReturnType we know that the retrieved `string` is never empty
* @psalm-suppress LessSpecificReturnStatement we know that the retrieved `string` is never empty
*/
public function encodeBinary(UuidInterface $uuid): string
{
/** @phpstan-ignore-next-line PHPStan complains that this is not a non-empty-string. */
return $this->swapBytes($uuid->getFields()->getBytes());
}
/**
* @throws InvalidUuidStringException
*
* @inheritDoc
*/
public function decode(string $encodedUuid): UuidInterface
{
$bytes = $this->getBytes($encodedUuid);
return $this->getBuilder()->build($this, $this->swapBytes($bytes));
}
public function decodeBytes(string $bytes): UuidInterface
{
return $this->getBuilder()->build($this, $this->swapBytes($bytes));
}
/**
* Swaps bytes according to the timestamp-first COMB rules
*/
private function swapBytes(string $bytes): string
{
$first48Bits = substr($bytes, 0, 6);
$last48Bits = substr($bytes, -6);
$bytes = substr_replace($bytes, $last48Bits, 0, 6);
$bytes = substr_replace($bytes, $first48Bits, -6);
return $bytes;
}
}