public ArraySegment <byte> Encode(MqttBasePacket packet)
{
if (packet == null)
{
throw new ArgumentNullException(nameof(packet));
}
// Leave enough head space for max header size (fixed + 4 variable remaining length = 5 bytes)
_packetWriter.Reset(5);
_packetWriter.Seek(5);
var fixedHeader = EncodePacket(packet, _packetWriter);
var remainingLength = (uint)(_packetWriter.Length - 5);
var remainingLengthSize = MqttPacketWriter.GetLengthOfVariableInteger(remainingLength);
var headerSize = FixedHeaderSize + remainingLengthSize;
var headerOffset = 5 - headerSize;
// Position cursor on correct offset on beginning of array (has leading 0x0)
_packetWriter.Seek(headerOffset);
_packetWriter.Write(fixedHeader);
_packetWriter.WriteVariableLengthInteger(remainingLength);
var buffer = _packetWriter.GetBuffer();
return(new ArraySegment <byte>(buffer, headerOffset, _packetWriter.Length - headerOffset));
}