Calculate speed per sec and time left of sending a file using sockets tcp c#

Question

How can I calculate the speed per sec, and the time left in sec? I've tried to use:

void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) {
    long prevSum = 0;
    while (fileTransfer.busy) {
        rate = (fileTransfer.sum - prevSum);
        RateLabel(rate);  //converting prevSum to (int)KB/SEC
        if (rate != 0)
            left = (fileTransfer.fileSize - fileTransfer.sum) / rate;
        TimeSpan t = TimeSpan.FromSeconds(left);
        timeLeftLabel(FormatRemainingText(rate, t)); //show how much left
        prevSum = fileTransfer.sum;
        Thread.Sleep(1000);
    }
}

but the rate and the time left goes up and down like (30MB/sec then 5MB/sec) permanently.

This is the sendfile code:

public static void sendFile(string filePath) {
    // run the progres Form
    Thread thFP = new Thread(fpRUN);
    fileProgress fP = new fileProgress("Sending...");
    thFP.Start(fP);

    FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read);
    string fileName = Path.GetFileName(filePath);
    byte[] fileData;
    try {
        //sending file name and file size to the server
        busy = true;
        fileSize = fs.Length;
        byte[] fileDetial = null;
        string detail =  fileName + "," + fileSize.ToString();
        fileDetial = Encoding.ASCII.GetBytes(detail);
        client.Send(fileDetial);

        //sending file data to the server
        fileData = new byte[packetSize];
        count = 0;
        sum = 0;                          

        fP.SizeLabel(fileSize); // tell the form the file size
        while (sum < fileSize) {
            fs.Seek(sum, SeekOrigin.Begin);
            fs.Read(fileData, 0, fileData.Length);
            count = client.Send(fileData, 0, fileData.Length, SocketFlags.None);
            sum += count;
            fP.ProgressBarFileHandler(sum,fileSize); //progressbar value
            fP.SentLabel(sum);                  //tell the form how much sent
        }
    }
    finally {
        busy = false;
        fs.Close();
        fileData = null;
        MessageBox.Show(string.Format("{0} sent successfully", fileName));
    }
}

How can I fix that? Is there a better way to calculate the speed?

Answer 1

in form constructor

Timer timer1 = new Time();
public Form1()
    {
        InitializeComponent();
        this.timer1.Enabled = true;
        this.timer1.Interval = 1000;
        this.timer1.Tick += new System.EventHandler(this.timer1_Tick);
    }

or add it from toolbox and set the previous values

the sum of sent bytes should be public so our method can get its value every second

    long sentBytes = 0;      //the sent bytes that updated from sending method
    long prevSentBytes = 0;   //which references to the previous sentByte
    double totalSeconds = 0;   //seconds counter to show total time .. it increases everytime the timer1 ticks.
    private void timer1_Tick(object sender, EventArgs e)
    {
        long speed = sentBytes - prevSentBytes ;  //here's the Transfer-Rate or Speed
        prevSentBytes = sentBytes ;
        labelSpeed.Text = CnvrtUnit(speed) + "/S";   //display the speed like (100 kb/s) to a label
        if (speed > 0)                //considering that the speed would be 0 sometimes.. we avoid dividing on 0 exception
        {
            totalSeconds++;     //increasing total-time
            labelTime.Text = TimeToText(TimeSpan.FromSeconds((sizeAll - sumAll) / speed));
            //displaying time-left in label
            labelTotalTime.Text = TimeToText(TimeSpan.FromSeconds(totalSeconds));
            //displaying total-time in label
        }
    }

    private string TimeToText(TimeSpan t)
    {
        return string.Format("{2:D2}:{1:D2}:{0:D2}", t.Seconds, t.Minutes, t.Hours);
    }

    private string CnvrtUnit(long source)
    {
        const int byteConversion = 1024;
        double bytes = Convert.ToDouble(source);

        if (bytes >= Math.Pow(byteConversion, 3)) //GB Range
        {
            return string.Concat(Math.Round(bytes / Math.Pow(byteConversion, 3), 2), " GB");
        }
        else if (bytes >= Math.Pow(byteConversion, 2)) //MB Range
        {
            return string.Concat(Math.Round(bytes / Math.Pow(byteConversion, 2), 2), " MB");
        }
        else if (bytes >= byteConversion) //KB Range
        {
            return string.Concat(Math.Round(bytes / byteConversion, 2), " KB");
        }
        else //Bytes
        {
            return string.Concat(bytes, " Bytes");
        }
    }

Answer 2

You may do some smoothing of the transfer speed to avoid jumping of the value. See http://en.wikipedia.org/wiki/Moving_average for one option. Basically compute some sort of average for the speed over time.

Answer 3

You can't fix that. The only way to 'fix' it is by creating a constant speed network/internet.

the network (and your computer) does not have a constant speed.

The calculation tells you what it is.