Subversion-Projekte lars-tiefland.laravel_shop

<?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 Brick\Math\BigInteger;

use DateTimeImmutable;

use DateTimeInterface;

use Ramsey\Uuid\Type\Hexadecimal;

use function hash;

use function pack;

use function str_pad;

use function strlen;

use function substr;

use function substr_replace;

use function unpack;

use const PHP_INT_SIZE;

use const STR_PAD_LEFT;

/**

 * UnixTimeGenerator generates bytes that combine a 48-bit timestamp in

 * milliseconds since the Unix Epoch with 80 random bits

 *

 * Code and concepts within this class are borrowed from the symfony/uid package

 * and are used under the terms of the MIT license distributed with symfony/uid.

 *

 * symfony/uid is copyright (c) Fabien Potencier.

 *

 * @link https://symfony.com/components/Uid Symfony Uid component

 * @link https://github.com/symfony/uid/blob/4f9f537e57261519808a7ce1d941490736522bbc/UuidV7.php Symfony UuidV7 class

 * @link https://github.com/symfony/uid/blob/6.2/LICENSE MIT License

 */

class UnixTimeGenerator implements TimeGeneratorInterface

{

    private static string $time = '';

    private static ?string $seed = null;

    private static int $seedIndex = 0;

    /** @var int[] */

    private static array $rand = [];

    /** @var int[] */

    private static array $seedParts;

    public function __construct(

        private RandomGeneratorInterface $randomGenerator,

        private int $intSize = PHP_INT_SIZE

    ) {

    }

    /**

     * @param Hexadecimal|int|string|null $node Unused in this generator

     * @param int|null $clockSeq Unused in this generator

     * @param DateTimeInterface $dateTime A date-time instance to use when

     *     generating bytes

     *

     * @inheritDoc

     */

    public function generate($node = null, ?int $clockSeq = null, ?DateTimeInterface $dateTime = null): string

    {

        $time = ($dateTime ?? new DateTimeImmutable('now'))->format('Uv');

        if ($time > self::$time || ($dateTime !== null && $time !== self::$time)) {

            $this->randomize($time);

        } else {

            $time = $this->increment();

        }

        if ($this->intSize >= 8) {

            $time = substr(pack('J', (int) $time), -6);

        } else {

            $time = str_pad(BigInteger::of($time)->toBytes(false), 6, "\x00", STR_PAD_LEFT);

        }

        /** @var non-empty-string */

        return $time . pack('n*', self::$rand[1], self::$rand[2], self::$rand[3], self::$rand[4], self::$rand[5]);

    }

    private function randomize(string $time): void

    {

        if (self::$seed === null) {

            $seed = $this->randomGenerator->generate(16);

            self::$seed = $seed;

        } else {

            $seed = $this->randomGenerator->generate(10);

        }

        /** @var int[] $rand */

        $rand = unpack('n*', $seed);

        $rand[1] &= 0x03ff;

        self::$rand = $rand;

        self::$time = $time;

    }

    /**

     * Special thanks to Nicolas Grekas for sharing the following information:

     *

     * Within the same ms, we increment the rand part by a random 24-bit number.

     *

     * Instead of getting this number from random_bytes(), which is slow, we get

     * it by sha512-hashing self::$seed. This produces 64 bytes of entropy,

     * which we need to split in a list of 24-bit numbers. unpack() first splits

     * them into 16 x 32-bit numbers; we take the first byte of each of these

     * numbers to get 5 extra 24-bit numbers. Then, we consume those numbers

     * one-by-one and run this logic every 21 iterations.

     *

     * self::$rand holds the random part of the UUID, split into 5 x 16-bit

     * numbers for x86 portability. We increment this random part by the next

     * 24-bit number in the self::$seedParts list and decrement

     * self::$seedIndex.

     *

     * @link https://twitter.com/nicolasgrekas/status/1583356938825261061 Tweet from Nicolas Grekas

     */

    private function increment(): string

    {

        if (self::$seedIndex === 0 && self::$seed !== null) {

            self::$seed = hash('sha512', self::$seed, true);

            /** @var int[] $s */

            $s = unpack('l*', self::$seed);

            $s[] = ($s[1] >> 8 & 0xff0000) | ($s[2] >> 16 & 0xff00) | ($s[3] >> 24 & 0xff);

            $s[] = ($s[4] >> 8 & 0xff0000) | ($s[5] >> 16 & 0xff00) | ($s[6] >> 24 & 0xff);

            $s[] = ($s[7] >> 8 & 0xff0000) | ($s[8] >> 16 & 0xff00) | ($s[9] >> 24 & 0xff);

            $s[] = ($s[10] >> 8 & 0xff0000) | ($s[11] >> 16 & 0xff00) | ($s[12] >> 24 & 0xff);

            $s[] = ($s[13] >> 8 & 0xff0000) | ($s[14] >> 16 & 0xff00) | ($s[15] >> 24 & 0xff);

            self::$seedParts = $s;

            self::$seedIndex = 21;

        }

        self::$rand[5] = 0xffff & $carry = self::$rand[5] + (self::$seedParts[self::$seedIndex--] & 0xffffff);

        self::$rand[4] = 0xffff & $carry = self::$rand[4] + ($carry >> 16);

        self::$rand[3] = 0xffff & $carry = self::$rand[3] + ($carry >> 16);

        self::$rand[2] = 0xffff & $carry = self::$rand[2] + ($carry >> 16);

        self::$rand[1] += $carry >> 16;

        if (0xfc00 & self::$rand[1]) {

            $time = self::$time;

            $mtime = (int) substr($time, -9);

            if ($this->intSize >= 8 || strlen($time) < 10) {

                $time = (string) ((int) $time + 1);

            } elseif ($mtime === 999999999) {

                $time = (1 + (int) substr($time, 0, -9)) . '000000000';

            } else {

                $mtime++;

                $time = substr_replace($time, str_pad((string) $mtime, 9, '0', STR_PAD_LEFT), -9);

            }

            $this->randomize($time);

        }

        return self::$time;

    }

}