UUIDv7 in PHP

uuidv7.php

<?php

// uuidv7 see https://www.rfc-editor.org/rfc/rfc9562#name-uuid-version-7
function uuidv7() {
	// current timestamp in ms
	$timestamp = intval(microtime(true) * 1000);

	return sprintf(
		'%02x%02x%02x%02x-%02x%02x-%04x-%04x-%012x',
		// first 48 bits are timestamp based
		($timestamp >> 40) & 0xFF,
		($timestamp >> 32) & 0xFF,
		($timestamp >> 24) & 0xFF,
		($timestamp >> 16) & 0xFF,
		($timestamp >> 8) & 0xFF,
		$timestamp & 0xFF,

		// 16 bits: 4 bits for version (7) and 12 bits for rand_a
		mt_rand(0, 0x0FFF) | 0x7000,

		// 16 bits: 4 bits for variant where 2 bits are fixed 10 and next 2 are random to get (8-9, a-b)
		// next 12 are random
		mt_rand(0, 0x3FFF) | 0x8000,

		// random 48 bits
		mt_rand(0, 0xFFFFFFFFFFFF),
	);
}

for ($i = 0; $i < 2000000; $i++) {
	$uuid = uuidv7();
	// echo $uuid . PHP_EOL;
	if (!preg_match("/^[0-9a-f]{8}-[0-9a-f]{4}-7[0-9a-f]{3}-[8-9a-b][0-9a-f]{3}-[0-9a-f]{12}$/m", $uuid)) {
		echo $uuid . ' not valid uuidv7';
	}
}

test online