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> data, out int processed)
{
var span = data.Span;
var tkptLength = BinaryPrimitives.ReadUInt16BigEndian(span.Slice(2, 2));
if (data.Length < tkptLength)
{
processed = 0;
return(null);
}
var result = new DataTransferDatagram
{
Tkpt = new TpktDatagram
{
Sync1 = span[0],
Sync2 = span[1],
Length = tkptLength
},
Li = span[4],
PduType = span[5],
TpduNr = span[6]
};
var length = result.Tkpt.Length - Rfc1006ProtocolContext.DataHeaderSize;
result.Payload = data.Slice(Rfc1006ProtocolContext.DataHeaderSize, length);
processed = result.Tkpt.Length;
return(result);
}
public static Memory <byte> TranslateToMemory(DataTransferDatagram datagram, Memory <byte> buffer)
{
var span = buffer.Span;
span[0] = datagram.Tkpt.Sync1;
span[1] = datagram.Tkpt.Sync2;
BinaryPrimitives.WriteUInt16BigEndian(span.Slice(2, 2), datagram.Tkpt.Length);
span[4] = datagram.Li;
span[5] = datagram.PduType;
span[6] = datagram.TpduNr;
datagram.Payload.CopyTo(buffer.Slice(7));
return(buffer);
}
public static Memory <byte> TranslateToMemory(DataTransferDatagram datagram)
{
var length = datagram.Tkpt.Length;
var result = new Memory <byte>(new byte[length]); // check if we could use ArrayBuffer
var span = result.Span;
span[0] = datagram.Tkpt.Sync1;
span[1] = datagram.Tkpt.Sync2;
BinaryPrimitives.WriteUInt16BigEndian(span.Slice(2, 2), datagram.Tkpt.Length);
span[4] = datagram.Li;
span[5] = datagram.PduType;
span[6] = datagram.TpduNr;
datagram.Payload.CopyTo(result.Slice(7));
return(result);
}
public static DataTransferDatagram TranslateFromMemory(Memory <byte> data, out int processed)
{
var span = data.Span;
var result = new DataTransferDatagram
{
Tkpt = new TpktDatagram
{
Sync1 = span[0],
Sync2 = span[1],
Length = BinaryPrimitives.ReadUInt16BigEndian(span.Slice(2, 2))
},
Li = span[4],
PduType = span[5],
TpduNr = span[6]
};
var length = result.Tkpt.Length - 7;
result.Payload = data.Slice(7, length);
processed = result.Tkpt.Length;
return(result);
}
public static ushort GetRawDataLength(DataTransferDatagram datagram) => datagram.Tkpt.Length;
