function VariantTrait::getVariant

Returns the variant identifier, according to RFC 4122, for the given bytes

The following values may be returned:

`0` -- Reserved, NCS backward compatibility.
`2` -- The variant specified in RFC 4122.
`6` -- Reserved, Microsoft Corporation backward compatibility.
`7` -- Reserved for future definition.

@link https://tools.ietf.org/html/rfc4122#section-4.1.1 RFC 4122, § 4.1.1: Variant

Return value

int The variant identifier, according to RFC 4122

2 calls to VariantTrait::getVariant()

Fields::isCorrectVariant in vendor/ramsey/uuid/src/Guid/Fields.php
Fields::isCorrectVariant in vendor/ramsey/uuid/src/Rfc4122/Fields.php

File

vendor/ramsey/uuid/src/Rfc4122/VariantTrait.php, line 55

Class

VariantTrait: Provides common functionality for handling the variant, as defined by RFC 4122

Namespace

Ramsey\Uuid\Rfc4122

Code

public function getVariant() : int {
    if (strlen($this->getBytes()) !== 16) {
        throw new InvalidBytesException('Invalid number of bytes');
    }
    if ($this->isMax() || $this->isNil()) {
        // RFC 4122 defines these special types of UUID, so we will consider
        // them as belonging to the RFC 4122 variant.
        return Uuid::RFC_4122;
    }
    
    /** @var int[] $parts */
    $parts = unpack('n*', $this->getBytes());
    // $parts[5] is a 16-bit, unsigned integer containing the variant bits
    // of the UUID. We convert this integer into a string containing a
    // binary representation, padded to 16 characters. We analyze the first
    // three characters (three most-significant bits) to determine the
    // variant.
    $binary = str_pad(decbin($parts[5]), 16, '0', STR_PAD_LEFT);
    $msb = substr($binary, 0, 3);
    if ($msb === '111') {
        return Uuid::RESERVED_FUTURE;
    }
    elseif ($msb === '110') {
        return Uuid::RESERVED_MICROSOFT;
    }
    elseif (str_starts_with($msb, '10')) {
        return Uuid::RFC_4122;
    }
    return Uuid::RESERVED_NCS;
}