private DownloadPacket receive(CommunicationPacket p)
{
UInt64 realSerial = CommunicationFacade.ComputeRealNumber(p.SerialNumber, this.required, UInt16.MaxValue, (uint)Sizes.WINDOW_SIZE);
DownloadPacket toReturn = new DownloadPacket(p.Data, p.ConnectionNumber, p.Flags, realSerial);;
Logger.WriteLine($"Downloader recive packet with serial={toReturn.SerialNumber}");
return(toReturn);
}
public void AcceptFile()
{
try
{
byte[] empty = new byte[] { };
IPriorityQueue <DownloadPacket, UInt64> queue = new SimplePriorityQueue <DownloadPacket, UInt64>();
//TODO add priority queue
while (true)
{
DownloadPacket pack = this.receive(CommunicationFacade.Receive(this.socket));
pack = this.validatePacket(pack);
if (pack.Flags == (byte)Flag.FIN)
{
Logger.WriteLine("All data arrive", ConsoleColor.Cyan);
CommunicationFacade.Send(this.socket, new CommunicationPacket(this.connectionNumber, 0, Convert.ToUInt16(this.required & UInt16.MaxValue), (byte)Flag.FIN, empty));
return;
}
queue.Enqueue(pack, pack.SerialNumber);
//Attach into priority queue
while (queue.Count > 0 && queue.First.SerialNumber <= this.required)
{
DownloadPacket toProccess = queue.Dequeue();
if (toProccess.SerialNumber < this.required)
{
continue;
}
Logger.WriteLine($"Accepted packet {toProccess.SerialNumber}");
this.outFile.Write(toProccess.Data);
this.required += (uint)toProccess.Data.Length;
if (toProccess.Data.Length != 255)
{
Logger.WriteLine("Last packet arrive, waiting to FIN packet", ConsoleColor.Cyan);
this.waitingToFin = true;
}
}
Logger.WriteLine($"Waiting for packet {this.required}");
CommunicationFacade.Send(this.socket, new CommunicationPacket(this.connectionNumber, 0, Convert.ToUInt16(this.required & UInt16.MaxValue), 0, empty));
}
}
catch (CommunicationException)
{
Logger.WriteLine("Occurs error during communication", ConsoleColor.Yellow);
throw new TerminateException();
}
catch (InvalidPacketException e)
{
Logger.WriteLine($"Obtained invalid packet: {e.Message}", ConsoleColor.Yellow);
CommunicationFacade.Send(this.socket, new CommunicationPacket(this.connectionNumber, 0, Convert.ToUInt16(this.required & UInt16.MaxValue), (byte)Flag.RST, new byte[] { }));
throw new TerminateException();
}
}
private DownloadPacket validatePacket(DownloadPacket p)
{
if (p.ConnectionNumber != this.connectionNumber)
{
throw new InvalidPacketException($"Connection number not match, required: {this.connectionNumber:X} accepted: {p.ConnectionNumber:X}");
}
if (p.Flags > 0 && p.Flags != (byte)Flag.FIN && p.Flags != (byte)Flag.SYN && p.Flags != (byte)Flag.RST)
{
throw new InvalidPacketException($"Invalid packet, obtained {Convert.ToString(p.Flags, 2)}");
}
if (!waitingToFin)
{
UInt64 i = 0;
UInt64 max = (UInt64)Sizes.WINDOW_PACKETS * 4;
for (i = 0; i < max; i++)
{
if (p.SerialNumber + i * (UInt64)Sizes.MAX_DATA == this.required || p.SerialNumber + i * (UInt64)Sizes.MAX_DATA == this.required + (UInt64)Sizes.WINDOW_SIZE)
{
break;
}
}
if (i == max)
{
throw new InvalidPacketException($"Invalid packet serial, min required: {this.required} max required: {this.required + (uint)Sizes.WINDOW_SIZE}, obtained: {p.SerialNumber}");
}
}
if (p.Flags == (byte)Flag.FIN && p.Data.Length > 0)
{
throw new InvalidPacketException("Packet with FIN contains data");
}
if (p.Flags == (byte)Flag.RST)
{
throw new CommunicationException();
}
return(p);
}
private void EnviarPeticionDescargaBGWorker(object sender, DoWorkEventArgs e)
{
ActualizarTextboxInfoEstadoDescarga(String.Format("Enviando petición de descarga: {0}", (String)e.Argument));
string text = (String)e.Argument;
string[] palabras = text.Split(':');
string nombreArchivo = palabras[0];
string para = palabras[1];
DownloadPacket packet = new DownloadPacket();
packet.nombreArchivo = nombreArchivo;
packet.nombreNodoDestino = para;
packet.comando = "_PETICION_DESCARGA_";
if (EnviandoDescarga != null)
{
EnviandoDescarga(this, new DescargaChangedEventArgs(packet));
ActualizarTextboxInfoEstadoDescarga(String.Format("Petición de descarga enviada con éxito.", (String)e.Argument));
}
}
private void EnviarBusquedaRecursoBGWorker(object sender, DoWorkEventArgs e)
{
ActualizarTextboxInfoEstadoDescarga(String.Format("Enviando busqueda: {0}.", (String)e.Argument));
if (EnviandoBusqueda != null)
{
DownloadPacket packet = new DownloadPacket();
packet.nombreArchivo = (String)e.Argument;
packet.nombreNodoDestino = "*"; //busqueda enviada a todos los nodos conectados (*)
packet.comando = "_BUSQUEDA_";
if (EnviandoBusqueda != null)
{
EnviandoBusqueda(this, new DescargaChangedEventArgs(packet));
ActualizarTextboxInfoEstadoDescarga(String.Format("Buscando...\n"));
}
else
{
ActualizarTextboxInfoEstadoDescarga("Error de envío. Por favor, inténtelo de nuevo. Si el error persiste, reinicie la aplicación.");
}
}
}
