public static IEnumerable <DataTransferDatagram> Build(Rfc1006ProtocolContext context, Memory <byte> rawPayload)
{
var result = new List <DataTransferDatagram>();
var payload = rawPayload;
do
{
var frame = payload.Slice(0, Math.Min(payload.Length, context.FrameSizeSending));
payload = payload.Slice(frame.Length);
var current = new DataTransferDatagram
{
_payload = MemoryPool <byte> .Shared.Rent(frame.Length)
};
current.Payload = current._payload.Memory.Slice(0, frame.Length);
frame.CopyTo(current.Payload);
if (payload.Length > 0)
{
current.TpduNr = 0x00;
}
current.Tkpt.Length = Convert.ToUInt16(frame.Length + Rfc1006ProtocolContext.DataHeaderSize);
result.Add(current);
} while (payload.Length > 0);
return(result);
}
public static DataTransferDatagram TranslateFromMemory(Memory <byte> buffer,
Rfc1006ProtocolContext context,
out bool needMoteData,
out int processed)
{
var datagram = TranslateFromMemory(buffer, out processed);
if (datagram != null)
{
if (datagram.TpduNr == EndOfTransmition)
{
if (context.FrameBuffer.Any())
{
ApplyPayloadFromFrameBuffer(context.FrameBuffer, datagram);
}
needMoteData = false;
return(datagram);
}
else if (!datagram.Payload.IsEmpty)
{
AddPayloadToFrameBuffer(context.FrameBuffer, datagram);
}
}
needMoteData = true;
return(datagram);
}
public void CalcLength(Rfc1006ProtocolContext context, out byte li, out ushort length)
{
const int optionsMinLength = 7;
const int TpduCrWithoutProperties = 6;
var tmp = Convert.ToUInt16(optionsMinLength + context.SourceTsap.Length + context.DestTsap.Length + TpduCrWithoutProperties);
length = (ushort)(tmp + TpktHeaderSize + 1); // add 1 because li is without li
li = Convert.ToByte(tmp);
}
public static ConnectionRequestDatagram BuildCr(Rfc1006ProtocolContext context)
{
context.CalcLength(context, out var li, out var length);
var result = new ConnectionRequestDatagram
{
Li = li,
SizeTpduReceiving = context.SizeTpduReceiving,
SourceTsapLength = Convert.ToByte(context.SourceTsap.Length),
SourceTsap = context.SourceTsap,
DestTsapLength = Convert.ToByte(context.DestTsap.Length),
DestTsap = context.DestTsap
};
result.Tkpt.Length = length;
return(result);
}
public ConnectionConfirmedDatagram BuildCc(Rfc1006ProtocolContext context, ConnectionRequestDatagram req)
{
context.CalcLength(context, out byte li, out ushort length);
context.SizeTpduSending = req.SizeTpduReceiving;
var result = new ConnectionConfirmedDatagram
{
Li = li,
SizeTpduReceiving = context.SizeTpduReceiving,
SourceTsapLength = req.DestTsapLength,
SourceTsap = req.SourceTsap,
DestTsapLength = req.DestTsapLength,
DestTsap = req.DestTsap
};
result.Tkpt.Length = length;
return(result);
}
public static DataTransferDatagram TranslateFromMemory(Memory <byte> buffer,
Rfc1006ProtocolContext context,
out bool needMoteData,
out int processed)
{
var datagram = TranslateFromMemory(buffer, out processed);
if (datagram.TpduNr == EndOfTransmition)
{
Memory <byte> payload = Memory <byte> .Empty;
if (context.FrameBuffer.Any())
{
context.FrameBuffer.Add(new Tuple <Memory <byte>, int>(datagram.Payload, datagram.Payload.Length));
var length = context.FrameBuffer.Sum(x => x.Item1.Length);
payload = new byte[length];
var index = 0;
foreach (var item in context.FrameBuffer)
{
item.Item1.Slice(0, item.Item2).CopyTo(payload.Slice(index));
if (!ReferenceEquals(datagram.Payload, item.Item1))
{
ArrayPool <byte> .Shared.Return(item.Item1.ToArray());
}
index += item.Item2;
}
datagram.Payload = payload;
context.FrameBuffer.Clear();
}
needMoteData = false;
return(datagram);
}
else if (!datagram.Payload.IsEmpty)
{
Memory <byte> copy = ArrayPool <byte> .Shared.Rent(datagram.Payload.Length);
datagram.Payload.CopyTo(copy);
context.FrameBuffer.Add(new Tuple <Memory <byte>, int>(copy, datagram.Payload.Length));
}
needMoteData = true;
return(datagram);
}
