#define PERF_LOG

​

using System;

using System.Text;

using System.Threading;

using System.Collections.Generic;

using System.Diagnostics;

​

​

public static class PerfTimer

{

    class LappedWatch

    {

        Stopwatch watch = Stopwatch.StartNew ();

        // Time since the last "lap"

        long lastTime = 0;

​

        internal long Lap ()

        {

            var diff = watch.ElapsedMilliseconds - lastTime;

            lastTime = watch.ElapsedMilliseconds;

            return diff;

        }

​

        internal long Finalize ()

        {

            var total = watch.ElapsedMilliseconds;

            watch.Stop ();

            return total;

        }

    }

    static private List<LappedWatch> stopwatches = new List<LappedWatch> ();

    static StringBuilder log = new StringBuilder ();

    static private int totalStopwatches => stopwatches.Count;

    static private LappedWatch lastWatch => stopwatches[totalStopwatches - 1];

    static string TabLevel => new String ('\t', totalStopwatches);

​

    [Conditional ("PERF_LOG")]

    static public void StartTimer (string name)

    {

        log.Append ($"{TabLevel}{name}:\n");

        stopwatches.Add (new LappedWatch ());

    }

​

    [Conditional ("PERF_LOG")]

    static public void StopTimer ()

    {

        if (totalStopwatches == 0)

#if DEBUG

            throw new ArgumentNullException ("No Timer could be found. Did you call StartTimer first?");

#else

        return;

#endif

​

        var isLast = totalStopwatches == 1;

​

        var indenting = isLast ? "" : TabLevel;

        log.Append ($"{indenting}Total: {lastWatch.Finalize ()}\n");

​

        stopwatches.RemoveAt (totalStopwatches - 1);

​

        if (isLast)

            Console.WriteLine (log);

        else

            lastWatch.Lap ();

    }

​

    [Conditional ("PERF_LOG")]

    static public void Log (string name)

    {

        log.Append ($"{TabLevel}{name}: {lastWatch.Lap ()} \n");

    }

​

    [Conditional ("PERF_LOG")]

    static public void ForceStop ()

    {

        while (totalStopwatches > 0)

            StopTimer ();

    }

}

​

public class Program

{

    public static void Main()

    {

        PerfTimer.StartTimer("Test");

        Thread.Sleep(10);

        PerfTimer.Log("Test1");

        Thread.Sleep(15);

        PerfTimer.Log("Test2");

        PerfTimer.StartTimer("Test3");

        Thread.Sleep(100);

        PerfTimer.Log("SubTest");

        Thread.Sleep(25);

        PerfTimer.Log("SubTest2");

        PerfTimer.ForceStop();

        //PerfTimer.StopTimer();

        //Thread.Sleep(200);

        //PerfTimer.Log("Test4");

        //PerfTimer.StopTimer();

    }

}