/**
* Preload the next message
*
* @return void
*/
private function preloadNextMessage()
{
try {
$this->msg = new Message($this->getMessage());
if ($this->msg->compression() != Encoder::COMPRESSION_NONE) {
$this->internalIterator = $this->msg->payload();
$this->internalIterator->rewind();
$this->msg = null;
} else {
$this->internalIterator = null;
}
$this->valid = TRUE;
} catch (Exception\OutOfRange $e) {
$this->valid = FALSE;
}
}
/**
* Pack message
*
* Internal method for packing message into kafka wire format.
*
* @param Message $message
* @param Mixed $overrideCompression Null or \Kafka\Kafka::COMPRESSION_NONE
* or
* \Kafka\Kafka::COMPRESSION_GZIP, etc.
*
* @throws \Kafka\Exception
*/
protected function packMessage(Message $message, $overrideCompression = null)
{
$compression = $overrideCompression === null ? $message->compression() : $overrideCompression;
switch ($compression) {
case \Kafka\Kafka::COMPRESSION_NONE:
$compressedPayload = $message->payload();
break;
case \Kafka\Kafka::COMPRESSION_GZIP:
$compressedPayload = gzencode($message->payload());
break;
case \Kafka\Kafka::COMPRESSION_SNAPPY:
throw new \Kafka\Kafka_Exception("Snappy compression not yet implemented in php\n client");
break;
default:
throw new \Kafka\Kafka_Exception("Unknown kafka compression codec {$compression}");
break;
}
// for reach message using MAGIC_1 format which includes compression
// attribute byte
$messageBoundsSize = 1 + 1 + 4 + strlen($compressedPayload);
$data = pack('N', $messageBoundsSize);
//int
$data .= pack('C', \Kafka\Kafka::MAGIC_1);
//byte
$data .= pack('C', $compression);
//byte
$data .= pack('N', crc32($compressedPayload));
//int
$data .= $compressedPayload;
//unbounded string
return $data;
}