UUID version 4
, (*1)
Implementation of the RFC 4122 UUID version 4 (variant 1) data type. UUID stands for Universally Unique Identifier., (*2)
Table of Contents
Why
We already have comprehensive UUID libraries in PHP, eg. ramsey/uuid., (*3)
My goal was to create a minimalistic implementation of the version 4 UUID spec. UUIDv4-s are randomly generated which makes implementation trivial as it requires nothing other than a random external seed value., (*4)
The decision to only implement version 4 resulted in a tiny functional library capturing the UUIDv4 data type that can be understood in minutes. Creation happens using a pure function that takes the random seed and is trivially testable., (*5)
Requirements
PHP 7.1+, (*6)
Installation
$ composer require pwm/uuid-v4
Usage
Creating a UUIDv4 data type from a valid string:, (*7)
$uuidV4String = '30313233-3435-4637-b839-616263646566';
$uuidV4 = new UuidV4($uuidV4String); // the data type
assert($uuidV4 instanceof UuidV4);
assert($uuidV4String === (string)$uuidV4);
Creating a random UUIDv4 from a 16 byte random seed:, (*8)
$uuidV4 = UuidV4::createFrom(random_bytes(16));
assert($uuidV4 instanceof UuidV4);
Creating from the same seed produces the same UUIDv4:, (*9)
$seed = random_bytes(16);
assert((string)UuidV4::createFrom($seed) === (string)UuidV4::createFrom($seed));
How it works
UUID version 4 is defined in RFC 4122 as a sequence of 128 bits, where 6 bits are fixed (4 for the version, 2 for the variant) leaving 122 randomly generated bits for entropy., (*10)
UuidV4 is a simple data type that can only be created from valid UUIDv4 strings. It comes with a createFrom() function that facilitates the creation of random UUIDv4-s from 16 byte random seeds. It is to be used with PHP's random_bytes() function., (*11)
Tests
$ vendor/bin/phpunit
$ composer phpcs
$ composer phpstan
$ composer infection
Changelog
Click here, (*12)
Licence
MIT, (*13)
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