Benchmark

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Net.WebSockets;
using System.Security.AccessControl;
using System.Text;
using NUnit.Framework;

namespace StructBenchmarking
{
    public class Benchmark : IBenchmark
    {
        public double MeasureDurationInMs(ITask task, int repetitionCount)
        {
            GC.Collect();
            GC.WaitForPendingFinalizers();

            var watch = new Stopwatch();
            task.Run();
            watch.Start();
            for (var i = 0; i < repetitionCount; i++)
            {
                task.Run();
            }
            watch.Stop();
            return (double)watch.ElapsedMilliseconds / repetitionCount;
        }
    }

    public class ForStringBuilder : ITask
    {
        private int repetitionCount;
        private char letter;

        public ForStringBuilder(int repetitionCount, char letter)
        {
            this.repetitionCount = repetitionCount;
            this.letter = letter;
        }

        string WithStringBuilder()
        {
            var strBuilder = new StringBuilder();
            for (var i = 0; i < repetitionCount; i++)
                strBuilder.Append(letter);
            return strBuilder.ToString();
        }

        public void Run()
        {
            WithStringBuilder();
        }
    }

    public class ForConstructor : ITask
    {
        private int repetitionCount;
        private char letter;

        public ForConstructor(int repetitionCount, char letter)
        {
            this.repetitionCount = repetitionCount;
            this.letter = letter;
        }

        string WithConstructor()
        {
            return new string(letter, repetitionCount);
        }

         public void Run()
         {
             WithConstructor();
         }
    }

    [TestFixture]
    public class RealBenchmarkUsageSample
    {
        [Test]
        public void StringConstructorFasterThanStringBuilder()
        {
            var benchmark = new Benchmark();
            var forConstructor = new ForConstructor(4000000, 'a');
            var forBuilder = new ForStringBuilder(4000000, 'a');

            var builderTime = benchmark.MeasureDurationInMs(forBuilder, 20);
            var constructorTime = benchmark.MeasureDurationInMs(forConstructor, 20);
            Assert.Less(constructorTime, builderTime);
        }
    }
}