<?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\Converter\Time;
use Ramsey\Uuid\Converter\TimeConverterInterface;
use Ramsey\Uuid\Math\BrickMathCalculator;
use Ramsey\Uuid\Math\CalculatorInterface;
use Ramsey\Uuid\Type\Hexadecimal;
use Ramsey\Uuid\Type\Integer as IntegerObject;
use Ramsey\Uuid\Type\Time;
use function count;
use function dechex;
use function explode;
use function is_float;
use function is_int;
use function str_pad;
use function strlen;
use function substr;
use const STR_PAD_LEFT;
use const STR_PAD_RIGHT;
/**
* PhpTimeConverter uses built-in PHP functions and standard math operations
* available to the PHP programming language to provide facilities for
* converting parts of time into representations that may be used in UUIDs
*
* @psalm-immutable
*/
class PhpTimeConverter implements TimeConverterInterface
{
/**
* The number of 100-nanosecond intervals from the Gregorian calendar epoch
* to the Unix epoch.
*/
private const GREGORIAN_TO_UNIX_INTERVALS = 0x01b21dd213814000;
/**
* The number of 100-nanosecond intervals in one second.
*/
private const SECOND_INTERVALS = 10000000;
/**
* The number of 100-nanosecond intervals in one microsecond.
*/
private const MICROSECOND_INTERVALS = 10;
/**
* @var CalculatorInterface
*/
private $calculator;
/**
* @var TimeConverterInterface
*/
private $fallbackConverter;
/**
* @var int
*/
private $phpPrecision;
public function __construct(
?CalculatorInterface $calculator = null,
?TimeConverterInterface $fallbackConverter = null
) {
if ($calculator === null) {
$calculator = new BrickMathCalculator();
}
if ($fallbackConverter === null) {
$fallbackConverter = new GenericTimeConverter($calculator);
}
$this->calculator = $calculator;
$this->fallbackConverter = $fallbackConverter;
$this->phpPrecision = (int) ini_get('precision');
}
public function calculateTime(string $seconds, string $microseconds): Hexadecimal
{
$seconds = new IntegerObject($seconds);
$microseconds = new IntegerObject($microseconds);
// Calculate the count of 100-nanosecond intervals since the Gregorian
// calendar epoch for the given seconds and microseconds.
$uuidTime = ((int) $seconds->toString() * self::SECOND_INTERVALS)
+ ((int) $microseconds->toString() * self::MICROSECOND_INTERVALS)
+ self::GREGORIAN_TO_UNIX_INTERVALS;
// Check to see whether we've overflowed the max/min integer size.
// If so, we will default to a different time converter.
/** @psalm-suppress RedundantCondition */
if (!is_int($uuidTime)) {
return $this->fallbackConverter->calculateTime(
$seconds->toString(),
$microseconds->toString()
);
}
return new Hexadecimal(str_pad(dechex($uuidTime), 16, '0', STR_PAD_LEFT));
}
public function convertTime(Hexadecimal $uuidTimestamp): Time
{
$timestamp = $this->calculator->toInteger($uuidTimestamp);
// Convert the 100-nanosecond intervals into seconds and microseconds.
$splitTime = $this->splitTime(
((int) $timestamp->toString() - self::GREGORIAN_TO_UNIX_INTERVALS)
/ self::SECOND_INTERVALS
);
if (count($splitTime) === 0) {
return $this->fallbackConverter->convertTime($uuidTimestamp);
}
return new Time($splitTime['sec'], $splitTime['usec']);
}
/**
* @param int|float $time The time to split into seconds and microseconds
*
* @return string[]
*/
private function splitTime($time): array
{
$split = explode('.', (string) $time, 2);
// If the $time value is a float but $split only has 1 element, then the
// float math was rounded up to the next second, so we want to return
// an empty array to allow use of the fallback converter.
if (is_float($time) && count($split) === 1) {
return [];
}
if (count($split) === 1) {
return [
'sec' => $split[0],
'usec' => '0',
];
}
// If the microseconds are less than six characters AND the length of
// the number is greater than or equal to the PHP precision, then it's
// possible that we lost some precision for the microseconds. Return an
// empty array, so that we can choose to use the fallback converter.
if (strlen($split[1]) < 6 && strlen((string) $time) >= $this->phpPrecision) {
return [];
}
$microseconds = $split[1];
// Ensure the microseconds are no longer than 6 digits. If they are,
// truncate the number to the first 6 digits and round up, if needed.
if (strlen($microseconds) > 6) {
$roundingDigit = (int) substr($microseconds, 6, 1);
$microseconds = (int) substr($microseconds, 0, 6);
if ($roundingDigit >= 5) {
$microseconds++;
}
}
return [
'sec' => $split[0],
'usec' => str_pad((string) $microseconds, 6, '0', STR_PAD_RIGHT),
];
}
}