Question

i am very new to C#, and this is my first question, please be gentle on me

I am trying to write a application to capture some tick data from the data provider, below is the main part of the program

void zf_TickEvent(object sender, ZenFire.TickEventArgs e)
{

    output myoutput = new output();

    myoutput.time = e.TimeStamp;
    myoutput.product = e.Product.ToString();
    myoutput.type = Enum.GetName(typeof(ZenFire.TickType), e.Type);
    myoutput.price = e.Price;
    myoutput.volume = e.Volume;

    using (StreamWriter writer = File.AppendText("c:\\log222.txt"))
    {

        writer.Write(myoutput.time.ToString(timeFmt) + ",");
        writer.Write(myoutput.product + "," );
        writer.Write(myoutput.type + "," );
        writer.Write(myoutput.price + ",");
        writer.Write(myoutput.volume + ",");

    }

i have successfully write the data into the text file, however i know that this method will be call like 10000 times a second during peak time, and open a file and append it many times a second is very inefficient, i was pointed to use a buffer or some sort, but i have no idea how to do it, i try reading the document but i still dont understand, thats why i turn in here for help.

Please give me some (working) snippet code so i can pointed to the write direction. thanks

EDIT: i have simplified the code as much as possible

    using (StreamWriter streamWriter = File.AppendText("c:\\output.txt"))
    {
        streamWriter.WriteLine(string.Format("{0},{1},{2},{3},{4}",
                        e.TimeStamp.ToString(timeFmt),
                        e.Product.ToString(),
                        Enum.GetName(typeof(ZenFire.TickType), e.Type),
                        e.Price,
                        e.Volume));
    }

ED has told me to make my stream to a field, how is the syntax looks like? can anyone post some code to help me? thanks a lot

Answer 1

I would use String.Format:

using (StreamWriter writer = new StreamWriter(@"c:\log222.txt", true))
        {
            writer.AutoFlush = true;
            writer.Write(String.Format("{0},{1},{2},{3},{4},", myoutput.time.ToString(timeFmt), 
                myoutput.product, myoutput.type, myoutput.price, myoutput.volume);
        }

If you use @ before string you don’t have to use double \.

This is much faster – you write only once to the file instead of 5 times. Additionally you don’t use + operator with strings which is not the fastest operation 😉

Also – if this is multithreading application – you should consider using some lock. It would prevent application from trying to write to the file from eg. 2 threads at one time.