/// <summary>
/// Fires when an error has occured; contains the exception and the errors operational severity
/// </summary>
private void OnSessionError(object owner, DtmErrorArgs args)
{
// in case window is closed; should call disconnect in a forms closing event
if (_dtmServer.IsConnected)
{
Console.WriteLine(CON_TITLE + "Severity:" + (DtmErrorSeverityFlags)args.Severity + "Message: " + args.Message);
}
}
/// <summary>
/// Sends a packet with increasing wait times.
/// <para>After 4 attempts fires a SessionError.</para>
/// </summary>
///
/// <param name="PacketStream">The packet to send</param>
private void Throttle(MemoryStream PacketStream)
{
int maxwait = 10;
for (int i = 0; i < 4; i++)
{
try
{
Wait(maxwait);
_clientSocket.SendAsync(PacketStream);
break;
}
catch (CryptoSocketException ce)
{
SocketException se = ce.InnerException as SocketException;
if (se.SocketErrorCode == SocketError.WouldBlock ||
se.SocketErrorCode == SocketError.IOPending ||
se.SocketErrorCode == SocketError.NoBufferSpaceAvailable)
{
// buffer is full
maxwait *= 2;
}
else
{
// possible connection dropped, alert app
if (SessionError != null)
{
DtmErrorArgs args = new DtmErrorArgs(ce, DtmErrorSeverityFlags.Connection);
SessionError(this, args);
}
}
}
}
// all attempts have failed
if (maxwait > 160)
{
// possible connection dropped, alert app
if (SessionError != null)
{
DtmErrorArgs args = new DtmErrorArgs(new SocketException((int)SocketError.HostUnreachable), DtmErrorSeverityFlags.Connection);
SessionError(this, args);
}
}
}
private void Transmit(DtmPacketFlags PacketType, short PacketFlag, long OptionFlag = 0, MemoryStream Payload = null)
{
lock (_sndLock)
{
long pldLen = Payload == null ? 0 : Payload.Length;
// create a new packet: packet flag, payload size, sequence, and state flag
MemoryStream pktStm = new DtmPacketStruct(PacketType, pldLen, _sndSequence, PacketFlag, OptionFlag).ToStream();
// add payload
if (Payload != null)
{
// copy to output
pktStm.Seek(0, SeekOrigin.End);
Payload.WriteTo(pktStm);
pktStm.Seek(0, SeekOrigin.Begin);
}
// store in the file packet buffer
_sndBuffer.Push(_sndSequence, pktStm);
// increment file send counter
_sndSequence++;
// transmit to remote client
if (_clientSocket.IsConnected)
{
try
{
_clientSocket.SendAsync(pktStm);
}
catch (CryptoSocketException ce)
{
SocketException se = ce.InnerException as SocketException;
if (se.SocketErrorCode == SocketError.WouldBlock ||
se.SocketErrorCode == SocketError.IOPending ||
se.SocketErrorCode == SocketError.NoBufferSpaceAvailable)
{
// buffer is full, throttle down
Throttle(pktStm);
}
else
{
// possible connection dropped, alert app
if (SessionError != null)
{
DtmErrorArgs args = new DtmErrorArgs(ce, DtmErrorSeverityFlags.Connection);
SessionError(this, args);
}
}
}
catch (Exception ex)
{
// possible connection dropped, alert app
if (SessionError != null)
{
DtmErrorArgs args = new DtmErrorArgs(ex, DtmErrorSeverityFlags.Connection);
SessionError(this, args);
}
}
// notify app
if (PacketSent != null)
{
PacketSent(this, new DtmPacketArgs((short)DtmTransferFlags.DataChunk, pldLen));
}
}
}
}
