/// <summary>
/// Serializes the network frame into datagrams.
/// </summary>
/// <param name="networkFrame">Network frame.</param>
/// <returns>List of datagrams.</returns>
/// <exception cref="ArgumentException">
/// The <paramref name="networkFrame"/> is invalid.
/// </exception>
public IEnumerable <byte[]> Serialize(NetworkFrame networkFrame)
{
if (!ValidateFrame(networkFrame))
{
throw new ArgumentException("The network frame is invalid", nameof(networkFrame));
}
int index = 0, packetNumber = 0, frameSize = networkFrame.DataSegments.Sum(e => e.Count);
int segment = 0, segmentOffset = 0;
var packets = new List <byte[]>();
var taskBytes = Encoding.UTF8.GetBytes(networkFrame.Task);
var flowBytes = Encoding.UTF8.GetBytes(networkFrame.Flow);
Array.Resize(ref taskBytes, TaskIdSize);
Array.Resize(ref flowBytes, FlowIdSize);
while (index < frameSize)
{
var dataSize = Math.Min(PacketDataMaxSize, frameSize - index);
var packet = new byte[PacketHeaderSize + dataSize];
using var stream = new MemoryStream(packet);
using var writer = new EndianBinaryWriter(stream);
writer.Write(ProtocolVersion);
writer.Write((ushort)0);
writer.Write((ushort)packet.Length);
writer.Write((ushort)packetNumber++);
writer.Write((uint)index);
writer.Write(networkFrame.Id);
writer.Write((uint)frameSize);
writer.Write(networkFrame.Number);
writer.Write(networkFrame.Interpretation);
writer.Write(taskBytes);
writer.Write(flowBytes);
while (segment < networkFrame.DataSegments.Length && dataSize > 0)
{
while (segmentOffset >= networkFrame.DataSegments[segment].Count)
{
++segment;
segmentOffset = 0;
}
var copySize = Math.Min(dataSize, networkFrame.DataSegments[segment].Count - segmentOffset);
writer.Write(networkFrame.DataSegments[segment].Slice(segmentOffset, copySize));
segmentOffset += copySize;
index += copySize;
dataSize -= copySize;
}
writer.Seek(1, SeekOrigin.Begin);
writer.Write(Checksum.Crc16(packet));
packets.Add(packet);
}
return(packets);
}
public int TestCrc16(string asciiString)
{
var bytes = Encoding.ASCII.GetBytes(asciiString);
return(Checksum.Crc16(bytes));
}
