ChatterBox.Client.Presentation.Shared.Services.NtpService.OnNTPTimeReceived C# (CSharp) Method

OnNTPTimeReceived() public method

Event hander when receiving response from the ntp server.
public OnNTPTimeReceived ( Windows socket, Windows eventArguments ) : void
socket Windows The udp socket object which triggered this event
eventArguments Windows event information
return void
        void OnNTPTimeReceived(Windows.Networking.Sockets.DatagramSocket socket, Windows.Networking.Sockets.DatagramSocketMessageReceivedEventArgs eventArguments)
        {
            int currentRTT = (int)ntpResponseMonitor.ElapsedMilliseconds;

            Debug.WriteLine($"NtpSync: current RTT {currentRTT}");


            ntpResponseMonitor.Stop();

            if (currentNtpQueryCount < MaxNtpRTTProbeQuery)
            {
                //we only trace 'min' RTT within the RTT probe attempts
                if (minNtpRTT == -1 || minNtpRTT > currentRTT)
                {

                    minNtpRTT = currentRTT;

                    if (minNtpRTT == 0)
                        minNtpRTT = 1; //in case we got response so  fast, consider it to be 1ms.
                }


                averageNtpRTT = (averageNtpRTT * (currentNtpQueryCount - 1) + currentRTT) / currentNtpQueryCount;

                if (averageNtpRTT < 1)
                {
                    averageNtpRTT = 1;
                }

                RunOnUiThread(() =>
                {
                    ntpQueryTimer.Stop();
                    ntpRTTIntervalTimer.Start();
                });

                return;

            }

            //if currentRTT is good enough, e.g.: closer to minRTT, then, we don't have to continue to query.
            if (currentRTT > (averageNtpRTT + minNtpRTT) / 2)
            {
                RunOnUiThread(() =>
                {
                    ntpQueryTimer.Stop();
                    ntpRTTIntervalTimer.Start();
                });

                return;
            }


            byte[] ntpData = new byte[48];

            eventArguments.GetDataReader().ReadBytes(ntpData);

            //Offset to get to the "Transmit Timestamp" field (time at which the reply 
            //departed the server for the client, in 64-bit timestamp format."
            const byte serverReplyTime = 40;

            //Get the seconds part
            ulong intPart = BitConverter.ToUInt32(ntpData, serverReplyTime);

            //Get the seconds fraction
            ulong fractPart = BitConverter.ToUInt32(ntpData, serverReplyTime + 4);

            //Convert From big-endian to little-endian
            intPart = SwapEndianness(intPart);
            fractPart = SwapEndianness(fractPart);

            ulong milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000L);

            RunOnUiThread(() =>
            {
                OnNTPTimeAvailable?.Invoke((long)milliseconds + currentRTT / 2);
            });

            socket.Dispose();
            ReportNtpSyncStatus(true, currentRTT);
        }