/**
* Encode a DomainName field
*
* @param \LibDNS\Records\Types\DomainName $domainName
* @param \LibDNS\Encoder\EncodingContext $encodingContext
* @return string
*/
private function encodeDomainName(DomainName $domainName, EncodingContext $encodingContext)
{
$packetIndex = $encodingContext->getPacket()->getLength() + 12;
$labelRegistry = $encodingContext->getLabelRegistry();
$result = '';
$labels = $domainName->getLabels();
if ($encodingContext->useCompression()) {
do {
$part = implode('.', $labels);
$index = $labelRegistry->lookupIndex($part);
if ($index === null) {
$labelRegistry->register($part, $packetIndex);
$label = array_shift($labels);
$length = strlen($label);
$result .= chr($length) . $label;
$packetIndex += $length + 1;
} else {
$result .= pack('n', 0b1100000000000000 | $index);
break;
}
} while ($labels);
if (!$labels) {
$result .= "";
}
} else {
foreach ($labels as $label) {
$result .= chr(strlen($label)) . $label;
}
$result .= "";
}
return $result;
}
