/// <summary>
/// Attempts to match each echo packet with the oldest, available send packet
/// </summary>
public override void MatchPackets()
{
// Console.WriteLine("this is in first match");
// Initialize the Send Packet Queue
var sendQ = new Queue <Tuple <CougarPacket, int> >();
// Match every Echo Packet to the First, Available Send Packet
for (int ndx = 0; ndx < ConnectionPackets.Count; ++ndx)
{
// Gather the current packet
var current = ConnectionPackets[ndx];
// determine TCP type
switch (current.Type)
{
// Add the packet to the Queue if it's a Send
case TCPType.SEND:
// add the packet and the send packet number to the queue
sendQ.Enqueue(Tuple.Create <CougarPacket, int>(current, SendIndex++));
// add the packet to a list for external use
SendPackets.Add(current);
break;
// Match the packet to the first packet in the Queue if it's an Echo
case TCPType.ECHO:
// add the packet to a list of echo packets for external use
EchoPackets.Add(current);
EchoIndex++;
// if there is a send packet to match
if (sendQ.Count > 0)
{
// take the first send packet out of the queue
var sendTuple = sendQ.Dequeue();
var send = sendTuple.Item1;
// parse the send and echos packets' timestamps
DateTime.TryParse(current.TimeStamp, out DateTime echoT);
DateTime.TryParse(send.TimeStamp, out DateTime sendT);
// calculate the round trip time
// RTT = echoT - sendT
var rtt = CalculateRoundTripTime(echoT, sendT);
RoundTripTimes.Add(rtt);
// Format a string declaring the Send and Echo Match
PairedMatches.Add(NumberOfMatches++, String.Format("(S#{0}, Packet#{1}), (E#{2}, Packet#{3}), RTT = {4}", sendTuple.Item2, send.PacketNumber, EchoIndex, current.PacketNumber, rtt));
}
break;
}
}
}
public override void MatchPackets()
{
//Console.WriteLine("this is greedy");
// bool correctMatch = true;
var sendQ = new Queue <Tuple <CougarPacket, int> >();
bool firstPacket = true;
//for every packet
for (int ndx = 0; ndx < ConnectionPackets.Count; ++ndx)
{
var current = ConnectionPackets[ndx];
//determine the type
switch (current.Type)
{
// if it is a send packet
case TCPType.SEND:
DateTime lastTime = new DateTime();
SendIndex++;
SendPackets.Add(current);
// if this will be the first packet in the queue
if (firstPacket)
{
// "initialize" the value for last packet's time to this packet's
DateTime.TryParse(current.TimeStamp, out lastTime);
// clear flag for the next run
firstPacket = false;
}
// parse the current packet's time stamp
DateTime.TryParse(current.TimeStamp, out DateTime currentTime);
// calculate time elapsed between send packets
double tg = currentTime.Subtract(lastTime).TotalSeconds;
// reset queue and flags if beyond threshold amount
if (tg > Threshold)
{
sendQ.Clear();
firstPacket = true;
}
// add the packet to the queue if within threshold
else
{
sendQ.Enqueue(Tuple.Create <CougarPacket, int>(current, SendIndex));
}
break;
// if it is an echo packet
case TCPType.ECHO:
EchoIndex++;
if (sendQ.Count > 0)
{
// gather the first send packet from the queue
var sendTuple = sendQ.Dequeue();
var send = sendTuple.Item1;
EchoPackets.Add(current);
// determine whether they match, or not
if ((current.SeqNum >= send.AckNum) && (current.AckNum > send.SeqNum)) // && correctMatch)
{
// if they match, calculate the Round Trip Time
// RTT = TimeOfEcho - TimeOfSend
DateTime.TryParse(current.TimeStamp, out DateTime echoT);
DateTime.TryParse(send.TimeStamp, out DateTime sendT);
var rtt = CalculateRoundTripTime(echoT, sendT);
RoundTripTimes.Add(rtt);
// Format a string declaring the Send and Echo Match
PairedMatches.Add(NumberOfMatches++, String.Format("(S#{0}, Packet#{1}), (E#{2}, Packet#{3}), RTT = {4}", sendTuple.Item2, send.PacketNumber, EchoIndex, current.PacketNumber, rtt));
}
}
// else
// correctMatch = false;
break;
}
}
}