/// <summary>
/// Processes the body of the message.
/// </summary>
/// <param name="state">Instance of <see cref="T:NavtelecomProtocol.SessionState" />.</param>
/// <param name="reader"><see cref="T:SharpStructures.BinaryListReader" /> linked to an NTCB message body.</param>
/// <param name="writer"><see cref="T:SharpStructures.MemoryBufferWriter" /> with data to be sent to the client.</param>
public void ProcessBody(SessionState state, BinaryListReader reader, MemoryBufferWriter writer)
{
if (!reader.ReadBytes(MessageIdentifier.Length).Select(x => (char)x).SequenceEqual(MessageIdentifier))
{
throw new ArgumentException("NTCB identity message prefix does not match.");
}
if (reader.ReadByte() != ProtocolIdentifier)
{
throw new ArgumentException("Unknown NTCB protocol identifier.");
}
state.ProtocolVersion = reader.ReadByte();
state.StructVersion = reader.ReadByte();
var dataSize = reader.ReadByte();
state.FieldMask = new bool[dataSize];
var maskBytes = reader.ReadBytes(BinaryUtilities.GetByteCountFromBitCount(dataSize));
for (var i = 0; i < dataSize; ++i)
{
var targetByte = maskBytes[i >> 3];
var mask = 1 << (7 - i & 7);
state.FieldMask[i] = (targetByte & mask) != 0;
}
writer.Write(BinaryUtilities.StringToBytes("*<FLEX"));
writer.Write(ProtocolIdentifier);
writer.Write(state.ProtocolVersion);
writer.Write(state.StructVersion);
}