public static unsafe void ReadAckPacket(NetworkPipelineContext context, PacketHeader header)
{
SharedContext *reliable = (SharedContext *)context.internalSharedProcessBuffer.GetUnsafePtr();
// Store receive timestamp for our acked sequence ID with remote processing time
StoreReceiveTimestamp(context.internalSharedProcessBuffer, header.AckedSequenceId, context.timestamp, header.ProcessingTime);
// Check the distance of the acked seqId in the header, if it's too far away from last acked packet we
// can't process it and add it to the ack mask
if (!SequenceHelpers.GreaterThan16(header.AckedSequenceId, (ushort)reliable->SentPackets.Acked))
{
// No new acks;
return;
}
reliable->SentPackets.Acked = header.AckedSequenceId;
reliable->SentPackets.AckMask = header.AckMask;
}
/// <summary>
/// Read header data and update reliability tracking information in the shared context.
/// - If the packets sequence ID is lower than the last received ID+1, then it's stale
/// - If the packets sequence ID is higher, then we'll process it and update tracking info in the shared context
/// </summary>
/// <param name="context">Pipeline context, the reliability shared state is used here.</param>
/// <param name="header">Packet header of a new received packet.</param>
/// <returns>Sequence ID of the received packet.</returns>
public static unsafe int Read(NetworkPipelineContext context, PacketHeader header)
{
SharedContext *reliable = (SharedContext *)context.internalSharedProcessBuffer.GetUnsafePtr();
reliable->stats.PacketsReceived++;
if (SequenceHelpers.StalePacket(
header.SequenceId,
(ushort)(reliable->ReceivedPackets.Sequence + 1),
(ushort)reliable->WindowSize))
{
reliable->stats.PacketsStale++;
return((int)ErrorCodes.Stale_Packet);
}
var window = reliable->WindowSize - 1;
if (SequenceHelpers.GreaterThan16((ushort)(header.SequenceId + 1), (ushort)reliable->ReceivedPackets.Sequence))
{
int distance = SequenceHelpers.AbsDistance(header.SequenceId, (ushort)reliable->ReceivedPackets.Sequence);
for (var i = 0; i < Math.Min(distance, window); ++i)
{
if ((reliable->ReceivedPackets.AckMask & 1 << (window - i)) == 0)
{
reliable->stats.PacketsDropped++;
}
}
if (distance > window)
{
reliable->stats.PacketsDropped += distance - window;
reliable->ReceivedPackets.AckMask = 1;
}
else
{
reliable->ReceivedPackets.AckMask <<= distance;
reliable->ReceivedPackets.AckMask |= 1;
}
reliable->ReceivedPackets.Sequence = header.SequenceId;
}
else if (SequenceHelpers.LessThan16(header.SequenceId, (ushort)reliable->ReceivedPackets.Sequence))
{
int distance = SequenceHelpers.AbsDistance(header.SequenceId, (ushort)reliable->ReceivedPackets.Sequence);
// If this is a resent packet the distance will seem very big and needs to be calculated again with adjustment for wrapping
if (distance >= ushort.MaxValue - reliable->WindowSize)
{
distance = reliable->ReceivedPackets.Sequence - header.SequenceId;
}
var ackBit = 1 << distance;
if ((ackBit & reliable->ReceivedPackets.AckMask) != 0)
{
reliable->stats.PacketsDuplicated++;
return((int)ErrorCodes.Duplicated_Packet);
}
reliable->stats.PacketsOutOfOrder++;
reliable->ReceivedPackets.AckMask |= (uint)ackBit;
}
// Store receive timestamp for remote sequence ID we just received
StoreRemoteReceiveTimestamp(context.internalSharedProcessBuffer, header.SequenceId, context.timestamp);
ReadAckPacket(context, header);
return(header.SequenceId);
}