// writes as many enqued as as can fit into datagram
private void WriteEnquedAcksToDatagram(Datagram datagram, int index)
{
while (enqueudAcks.Count > 0 && (datagram.MaxSize - (index - datagram.Offset)) > Const.FALCON_PACKET_HEADER_SIZE)
{
AckDetail ack = enqueudAcks.Dequeue();
FalconHelper.WriteAck(ack, datagram.BackingBuffer, index);
index += Const.FALCON_PACKET_HEADER_SIZE;
}
datagram.Resize(index - datagram.Offset);
}
internal void EnqueueSend(PacketType type, Packet packet)
{
// NOTE: packet may be null in the case of Falcon system messages.
if (packet != null && packet.BytesWritten > FalconPeer.MaxPayloadSize)
{
throw new InvalidOperationException(String.Format("Packet size: {0}, greater than max: {1}", packet.BytesWritten, FalconPeer.MaxPayloadSize));
}
bool isFalconHeaderWritten = currentDatagramTotalBufferOffset > currentDatagram.Offset;
if (isFalconHeaderWritten)
{
if (packet != null && (packet.BytesWritten + Const.ADDITIONAL_PACKET_HEADER_SIZE) > (currentDatagram.Count - (currentDatagramTotalBufferOffset - currentDatagram.Offset))) // i.e. cannot fit
{
// enqueue the current args and get a new one
EnqueueCurrentDatagram();
isFalconHeaderWritten = false;
}
}
if (!isFalconHeaderWritten)
{
// write the falcon header
FalconHelper.WriteFalconHeader(currentDatagram.BackingBuffer,
currentDatagram.Offset,
type,
channelType,
seqCount,
packet == null ? (ushort)0 : (ushort)packet.BytesWritten);
currentDatagramTotalBufferOffset += Const.FALCON_PACKET_HEADER_SIZE;
}
else
{
// TODO limit max additional to 100 so receive channel can distinguish ordinal seq
// write additional header
FalconHelper.WriteAdditionalFalconHeader(currentDatagram.BackingBuffer,
currentDatagramTotalBufferOffset,
type,
channelType,
packet == null ? (ushort)0 : (ushort)packet.BytesWritten);
currentDatagramTotalBufferOffset += Const.ADDITIONAL_PACKET_HEADER_SIZE;
}
if (packet != null)
{
//---------------------------------------------------------------------------------------------------
packet.CopyBytes(0, currentDatagram.BackingBuffer, currentDatagramTotalBufferOffset, packet.BytesWritten);
//---------------------------------------------------------------------------------------------------
currentDatagramTotalBufferOffset += packet.BytesWritten;
}
}
// returns true if caller should continue adding any additional packets in datagram
internal bool TryAddReceivedPacket(
ushort seq,
SendOptions opts,
PacketType type,
byte[] buffer,
int index,
int payloadSize,
bool isFirstPacketInDatagram)
{
// If we are not the keep alive master, i.e. this remote peer is, and this packet was
// sent reliably reset ellpasedMilliseondsAtLastRealiablePacket[Received].
if (IsKeepAliveMaster && ((opts & SendOptions.Reliable) == SendOptions.Reliable))
{
ellapasedSecondsSinceLastRealiablePacket = 0.0f;
}
switch (type)
{
case PacketType.Application:
case PacketType.KeepAlive:
case PacketType.AcceptJoin:
{
bool wasAppPacketAdded;
ReceiveChannel channel = noneReceiveChannel;
switch (opts)
{
case SendOptions.InOrder: channel = inOrderReceiveChannel; break;
case SendOptions.Reliable: channel = reliableReceiveChannel; break;
case SendOptions.ReliableInOrder: channel = reliableInOrderReceiveChannel; break;
}
if (!channel.TryAddReceivedPacket(seq, type, buffer, index, payloadSize, isFirstPacketInDatagram, out wasAppPacketAdded))
{
return(false);
}
if (wasAppPacketAdded)
{
unreadPacketCount++;
}
return(true);
}
case PacketType.ACK:
{
// Look for the oldest datagram with the same seq AND channel type
// seq is for which we ASSUME the ACK is for.
int datagramIndex;
Datagram sentDatagramAwaitingAck = null;
for (datagramIndex = 0; datagramIndex < sentDatagramsAwaitingACK.Count; datagramIndex++)
{
Datagram datagram = sentDatagramsAwaitingACK[datagramIndex];
if (datagram.Sequence == seq && datagram.SendOptions == opts)
{
sentDatagramAwaitingAck = datagram;
break;
}
}
if (sentDatagramAwaitingAck == null)
{
// Possible reasons:
// 1) ACK has arrived too late and the datagram must have already been removed.
// 2) ACK duplicated and has already been processed
// 3) ACK was unsolicited (i.e. malicious or buggy peer)
// NOTE: If ACK "piggy-backed" on a reliable datagram that was re-sent
// that datagram if recieved more than once would have been dropped
// when processing the first Application packet so should never
// get to here.
localPeer.Log(LogLevel.Warning, "Datagram for ACK not found - too late?");
}
else
{
// recieving our first ACK from this peer means they have Accepted us
if (!hasAccepted)
{
hasAccepted = true;
}
// remove datagram
sentDatagramsAwaitingACK.RemoveAt(datagramIndex);
// Update QoS
// ----------
//
// If the datagram was not re-sent update latency, otherwise we do not
// know which send this ACK is for so cannot determine latency.
//
// Also update re-sends sample if datagram was not re-sent with: not
// re-sent. If was re-sent sample would have already been updated when
// re-sent.
if (sentDatagramAwaitingAck.ResentCount == 0)
{
TimeSpan rtt = localPeer.Stopwatch.Elapsed - sentDatagramAwaitingAck.EllapsedAtSent;
qualityOfService.UpdateLatency(rtt);
qualityOfService.UpdateResentSample(false);
localPeer.Log(LogLevel.Debug, String.Format("ACK from: {0}, channel: {1}, seq: {2}, RTT: {3}s", PeerName, opts.ToString(), seq.ToString(), rtt.TotalSeconds.ToString()));
localPeer.Log(LogLevel.Debug, String.Format("Latency now: {0}s", qualityOfService.RoudTripTime.TotalSeconds.ToString()));
}
else
{
localPeer.Log(LogLevel.Info, String.Format("ACK for re-sent datagram: {0}, channel: {1}, seq: {2}", PeerName, opts.ToString(), seq.ToString()));
}
// return datagram
sendDatagramsPool.Return(sentDatagramAwaitingAck);
}
return(true);
}
case PacketType.Ping:
{
return(Pong());
}
case PacketType.Pong:
{
if (localPeer.HasPingsAwaitingPong)
{
PingDetail detail = localPeer.PingsAwaitingPong.Find(pd => pd.PeerIdPingSentTo == Id);
if (detail != null)
{
localPeer.RaisePongReceived(this, TimeSpan.FromSeconds(detail.EllapsedSeconds));
localPeer.RemovePingAwaitingPongDetail(detail);
}
}
return(true);
}
case PacketType.JoinRequest:
{
if (hasAccepted)
{
// If peer has accepted must be is joining again (possible when did not
// say Bye and has restarted again before timed out). Drop this
// instance of peer and process Accept next update so both peers on
// the same page, i.e. that we are starting a new connection.
//
byte[] datagram = new byte[Const.FALCON_PACKET_HEADER_SIZE + payloadSize];
FalconHelper.WriteFalconHeader(datagram, 0, PacketType.JoinRequest, SendOptions.None, (ushort)seq, (ushort)payloadSize);
if (payloadSize > 0)
{
Buffer.BlockCopy(buffer, index, datagram, Const.FALCON_PACKET_HEADER_SIZE, payloadSize);
}
localPeer.RemovePeerOnNextUpdate(this);
localPeer.EnqueuePacketToProcessOnNextUpdate(this.EndPoint, datagram);
return(false);
}
return(Accept());
}
case PacketType.DiscoverRequest:
{
DiscoverReply();
return(true);
}
case PacketType.DiscoverReply:
{
// do nothing, DiscoveryReply only relevant when peer not added
return(true);
}
case PacketType.Bye:
{
localPeer.Log(LogLevel.Info, String.Format("Bye received from: {0}.", PeerName));
localPeer.RemovePeerOnNextUpdate(this);
return(false);
}
default:
{
localPeer.Log(LogLevel.Error, String.Format("Datagram dropped - unexpected type: {0}, received from authenticated peer: {1}.", type, PeerName));
return(false);
}
}
}
