PerfTestBase.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;

namespace ServiceStack.Common.Tests
{
	public class PerfTestBase
	{
		protected int DefaultIterations { get; set; }
		protected List<int> MultipleIterations { get; set; }

		public PerfTestBase()
		{
			this.DefaultIterations = 10000;
			this.MultipleIterations = new List<int> { 1000, 10000, 100000, 1000000 };
		}

		protected StringBuilder SbLog = new StringBuilder();

		public void Log(string message, params object[] args)
		{
			Console.WriteLine(message, args);

			SbLog.AppendFormat(message, args);
			SbLog.AppendLine();
		}

		protected void CompareMultipleRuns(string run1Name, Action run1Action, string run2Name, Action run2Action)
		{
			WarmUp(run1Action, run2Action);
			foreach (var iteration in this.MultipleIterations)
			{
				Log("\n{0} times:", iteration);
				CompareRuns(iteration, run1Name, run1Action, run2Name, run2Action);
			}
		}

		protected void CompareRuns(string run1Name, Action run1Action, string run2Name, Action run2Action)
		{
			CompareRuns(DefaultIterations, run1Name, run1Action, run2Name, run2Action);
		}

		protected void CompareRuns(int iterations, string run1Name, Action run1Action, string run2Name, Action run2Action)
		{
			var run1 = RunAction(run1Action, iterations, run1Name);
			var run2 = RunAction(run2Action, iterations, run2Name);

			var runDiff = run1.Ticks - run2.Ticks;
			var run1IsSlower = runDiff > 0;
			var slowerRun = run1IsSlower ? run1Name : run2Name;
			var fasterRun = run1IsSlower ? run2Name : run1Name;
			var runDiffTime = run1IsSlower ? runDiff : runDiff * -1;
			var runDiffAvg = run1IsSlower ? run1.Ticks / (double)run2.Ticks : run2.Ticks / (double)run1.Ticks;

			Log("{0} was {1}ms or {2} times slower than {3}",
			    slowerRun, runDiffTime, Math.Round(runDiffAvg, 2), fasterRun);
		}

		protected void WarmUp(params Action[] actions)
		{
			foreach (var action in actions)
			{
				action();
				GC.Collect();
			}
		}

		protected void RunMultipleTimes(Action action, string actionName)
		{
			WarmUp(action);
			foreach (var iteration in this.MultipleIterations)
			{
				Log("\n{0} times:", iteration);
				RunAction(action, iteration, actionName ?? "Action");
			}
		}

		protected TimeSpan RunAction(Action action, int iterations)
		{
			return RunAction(action, iterations, null);
		}

		protected TimeSpan RunAction(Action action, int iterations, string actionName)
		{
			actionName = actionName ?? action.GetType().Name;
			var ticksTaken = Measure(action, iterations);
			var timeSpan = TimeSpan.FromSeconds(ticksTaken * 1d / Stopwatch.Frequency);

			Log("{0} took {1}ms ({2} ticks), avg: {3} ticks", actionName, timeSpan.TotalMilliseconds, timeSpan.Ticks, (timeSpan.Ticks / iterations));

			return timeSpan; 
		}

		protected long Measure(Action action, decimal iterations)
		{
			GC.Collect();
			var begin = Stopwatch.GetTimestamp();

			for (var i = 0; i < iterations; i++)
			{
				action();
			}

			var end = Stopwatch.GetTimestamp();

			return (end - begin);
		}
	}
}