static function packHexString(&$buffer, $str)
{
if (!preg_match("/^(0x)?([a-f0-9]+)\$/", $str, $match)) {
throw new \Exception("Invalid hex string format");
}
$str = $match[2];
$len = strlen($str);
if ($len % 2 != 0) {
throw new \Exception("Hex string should have an even number of nibbles");
}
for ($x = 0; $x < $len; $x += 2) {
Buffer::packInt8u($buffer, "0x" . substr($str, $x, 2));
}
return true;
}
