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<?php |
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|
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/** |
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* This file is part of the ramsey/uuid library |
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* |
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* For the full copyright and license information, please view the LICENSE |
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* file that was distributed with this source code. |
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* |
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* @copyright Copyright (c) Ben Ramsey <[email protected]> |
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* @license http://opensource.org/licenses/MIT MIT |
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*/ |
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|
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declare(strict_types=1); |
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|
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namespace Ramsey\Uuid\Rfc4122; |
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|
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use Ramsey\Uuid\Exception\InvalidBytesException; |
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use Ramsey\Uuid\Uuid; |
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|
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use function decbin; |
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use function str_pad; |
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use function strlen; |
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use function strpos; |
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use function substr; |
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use function unpack; |
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|
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use const STR_PAD_LEFT; |
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|
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/** |
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* Provides common functionality for handling the variant, as defined by RFC 4122 |
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* |
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* @psalm-immutable |
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*/ |
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trait VariantTrait |
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{ |
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/** |
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* Returns the bytes that comprise the fields |
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*/ |
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abstract public function getBytes(): string; |
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|
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/** |
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* Returns the variant identifier, according to RFC 4122, for the given bytes |
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* |
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* The following values may be returned: |
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* |
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* - `0` -- Reserved, NCS backward compatibility. |
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* - `2` -- The variant specified in RFC 4122. |
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* - `6` -- Reserved, Microsoft Corporation backward compatibility. |
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* - `7` -- Reserved for future definition. |
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* |
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* @link https://tools.ietf.org/html/rfc4122#section-4.1.1 RFC 4122, § 4.1.1: Variant |
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* |
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* @return int The variant identifier, according to RFC 4122 |
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*/ |
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public function getVariant(): int |
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{ |
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if (strlen($this->getBytes()) !== 16) { |
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throw new InvalidBytesException('Invalid number of bytes'); |
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} |
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|
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/** @var array $parts */ |
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$parts = unpack('n*', $this->getBytes()); |
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|
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// $parts[5] is a 16-bit, unsigned integer containing the variant bits |
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// of the UUID. We convert this integer into a string containing a |
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// binary representation, padded to 16 characters. We analyze the first |
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// three characters (three most-significant bits) to determine the |
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// variant. |
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$binary = str_pad( |
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decbin((int) $parts[5]), |
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16, |
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'0', |
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STR_PAD_LEFT |
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); |
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|
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$msb = substr($binary, 0, 3); |
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|
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if ($msb === '111') { |
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$variant = Uuid::RESERVED_FUTURE; |
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} elseif ($msb === '110') { |
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$variant = Uuid::RESERVED_MICROSOFT; |
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} elseif (strpos($msb, '10') === 0) { |
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$variant = Uuid::RFC_4122; |
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} else { |
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$variant = Uuid::RESERVED_NCS; |
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} |
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|
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return $variant; |
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} |
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} |
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|
