private void HandleFragmentationMessageTerminated(object sender, FragmentationMessageTerminatedEventArgs args)
{
if (sender is InboundFragmentationMessage)
{
if ((args.FinalState != FragmentationMessageState.Final) || (args.FinalStatus != Status.Success))
{
// do nothing.
return;
}
InboundFragmentationMessage inMsg = sender as InboundFragmentationMessage;
Frame receivedMessage = inMsg.RetrieveData();
if (receivedMessage != null)
{
DataIndicationHandler handler = _dataIndicationHandler;
if (handler != null)
{
handler.Invoke(this, inMsg.Source, inMsg.Destination, receivedMessage);
}
else
{
Frame.Release(ref receivedMessage);
}
}
}
else if (sender is OutboundFragmentationMessage)
{
OutboundFragmentationMessage outMsg, newOutMsg;
lock (_lock)
{
outMsg = sender as OutboundFragmentationMessage;
ushort previousDestination = outMsg.Destination;
_transmissionCharacteristicStorage.UpdateTransmissionCharacteristic(outMsg.Destination, outMsg.TimeoutForResending,
outMsg.MaxFragmentsBeforeAck);
// remove active message from repository
_outboundAssociations.RemoveFragmentationMessage(outMsg);
// try to start new message (if possible)
DataRequestItem newItem;
newOutMsg = null;
if (_dataRequestQueueSet.Dequeue(previousDestination, out newItem))
{
newOutMsg = CreateNewOutboundMessage(newItem);
}
}
// after releasing the lock, call method in FragmentationMessage class.
outMsg.NotifySender(args.FinalState, args.FinalStatus);
outMsg.Dispose();
if (newOutMsg != null)
{
newOutMsg.SendNextDataFragment(true);
}
}
}
public void HandleLowerLayerDataIndication(object sender, ushort originatorShortAddr, ushort targetShortAddr, Frame sdu)
{
FragmentationMessage fragMsg = null;
FragmentHeader header;
lock (_lock)
{
if ((!_started) || (sdu.LengthDataUsed < 2))
{
Frame.Release(ref sdu);
return;
}
// extract fragment header.
header = FragmentHeader.Decode(sdu.ReadUInt16(0));
sdu.DeleteFromFront(2);
FragmentationMessageAssociationSet associations;
switch (header.Type)
{
case FragmentType.DATA:
associations = _inboundAssociations;
if (associations == null)
{
Frame.Release(ref sdu);
return;
}
fragMsg = (InboundFragmentationMessage)associations.GetFragmentationMessage(originatorShortAddr, targetShortAddr);
if (fragMsg != null)
{
// there is already one message with this peer. Check freshness.
if (fragMsg.MessageNumber != header.MessageSeqNumber)
{
int sqnOld = (int)fragMsg.MessageNumber;
int sqnNew = (int)header.MessageSeqNumber;
int diff = (sqnNew > sqnOld) ? sqnNew - sqnOld : sqnNew - sqnOld + 256;
if ((header.MessageSeqNumber == 0) || (diff < 128))
{
// data received is most recent.
fragMsg.Dispose();
fragMsg = null;
}
else
{
// data received is old stuff.
Frame.Release(ref sdu);
return;
}
}
}
if (fragMsg == null)
{
// new message must be started
fragMsg = new InboundFragmentationMessage(originatorShortAddr, targetShortAddr,
header.MessageSeqNumber, _lowerLayerDataRequest, _lowerMtu, _lowerHead, _lowerTail, _timer);
fragMsg.FragmentationMessageTerminated += this.HandleFragmentationMessageTerminated;
associations.SetFragmentationMessage(originatorShortAddr, targetShortAddr, fragMsg);
}
break;
case FragmentType.ACK:
associations = _outboundAssociations;
if (associations == null)
{
Frame.Release(ref sdu);
return;
}
fragMsg = (OutboundFragmentationMessage)associations.GetFragmentationMessage(targetShortAddr, originatorShortAddr);
if ((fragMsg == null) || (fragMsg.MessageNumber != header.MessageSeqNumber))
{
//no one waiting for this segment. Discard.
#if DEBUG
Trace.Print("No one waiting for this segment. Discard.");
#endif
Frame.Release(ref sdu);
return;
}
break;
default:
break;
}
}
// release the lock before calling method in FragmentMessage class
if (fragMsg != null)
{
fragMsg.HandleReceivedFragment(header, ref sdu);
}
}
public void HandleLowerLayerDataIndication(object sender, ushort originatorShortAddr, ushort targetShortAddr, Frame sdu)
{
FragmentationMessage fragMsg = null;
FragmentHeader header;
lock (_lock)
{
if ((!_started) || (sdu.LengthDataUsed < 2))
{
Frame.Release(ref sdu);
return;
}
// extract fragment header.
header = FragmentHeader.Decode(sdu.ReadUInt16(0));
sdu.DeleteFromFront(2);
FragmentationMessageAssociationSet associations;
switch (header.Type)
{
case FragmentType.DATA:
associations = _inboundAssociations;
if (associations == null)
{
Frame.Release(ref sdu);
return;
}
fragMsg = (InboundFragmentationMessage)associations.GetFragmentationMessage(originatorShortAddr, targetShortAddr);
if (fragMsg != null)
{
// there is already one message with this peer. Check freshness.
if (fragMsg.MessageNumber != header.MessageSeqNumber)
{
int sqnOld = (int)fragMsg.MessageNumber;
int sqnNew = (int)header.MessageSeqNumber;
int diff = (sqnNew > sqnOld) ? sqnNew - sqnOld : sqnNew - sqnOld + 256;
if ((header.MessageSeqNumber == 0) || (diff < 128))
{
// data received is most recent.
fragMsg.Dispose();
fragMsg = null;
}
else
{
// data received is old stuff.
Frame.Release(ref sdu);
return;
}
}
}
if (fragMsg == null)
{
// new message must be started
fragMsg = new InboundFragmentationMessage(originatorShortAddr, targetShortAddr,
header.MessageSeqNumber, _lowerLayerDataRequest, _lowerMtu, _lowerHead, _lowerTail, _timer);
fragMsg.FragmentationMessageTerminated += this.HandleFragmentationMessageTerminated;
associations.SetFragmentationMessage(originatorShortAddr, targetShortAddr, fragMsg);
}
break;
case FragmentType.ACK:
associations = _outboundAssociations;
if (associations == null)
{
Frame.Release(ref sdu);
return;
}
fragMsg = (OutboundFragmentationMessage)associations.GetFragmentationMessage(targetShortAddr, originatorShortAddr);
if ((fragMsg == null) || (fragMsg.MessageNumber != header.MessageSeqNumber))
{
//no one waiting for this segment. Discard.
#if DEBUG
Trace.Print("No one waiting for this segment. Discard.");
#endif
Frame.Release(ref sdu);
return;
}
break;
default:
break;
}
}
// release the lock before calling method in FragmentMessage class
if (fragMsg != null)
{
fragMsg.HandleReceivedFragment(header, ref sdu);
}
}