/Utilities/Profiling/PerformanceTester.cs

using System;

using System.Diagnostics;



namespace Delta.Utilities.Profiling

{

	/// <summary>

	/// Performance tester helper class for profiling certain code paths

	/// many million times to compare different implementations. Heavily

	/// used for the MartixPerformance class.

	/// </summary>

	public class PerformanceTester

	{

		#region Delegates

		/// <summary>

		/// Just a boring void delegate with no parameters for profiling.

		/// </summary>

		public delegate void ProfileDelegate();

		#endregion



		#region Profile (Static)

		/// <summary>

		/// Profile some test code many million times and return how much time

		/// it took in ms.

		/// </summary>

		/// <param name="iterations">Iterations to execute the delegate</param>

		/// <param name="testDelegate">Test delegate to be executed</param>

		/// <returns>Number of milliseconds elapsed to run testDelegate iterations

		/// number of times</returns>

		public static int Profile(int iterations, ProfileDelegate testDelegate)

		{

			// Just call the test once before the profiling to do some setup to

			// prevent assembly loading and security policy checking which interfere

			// with our performance checking below!

			testDelegate();



			Stopwatch timer = new Stopwatch();

			timer.Start();

			for (int i = 0; i < iterations; i++)

			{

				testDelegate();

			}

			timer.Stop();



			numberOfProfileRuns++;

			totalProfileRunsMs += (int)timer.ElapsedMilliseconds;



			return (int)timer.ElapsedMilliseconds;

		}

		#endregion



		#region Profile10MilionTimes (Static)

		/// <summary>

		/// Helper to profile 10 million times and output the performance result.

		/// Profiles the code with 10 million iterations and output the result.

		/// </summary>

		/// <param name="profileTestName">Name for the test</param>

		/// <param name="testDelegate">Test delegate to execute</param>

		public static void Profile10MilionTimes(string profileTestName,

			ProfileDelegate testDelegate)

		{

			// Test 10 million times (not as quick, but much more accurate,

			// less fluctuations, especially on over clocked systems and i7)

			int ms = Profile(10 * 1000 * 1000, testDelegate);

			Console.WriteLine(ms + "ms for " + profileTestName +

			                  " (10 million calls)");

		}

		#endregion



		#region Profile1MilionTimes (Static)

		/// <summary>

		/// Profiles the code with 1 million iterations and output the result.

		/// </summary>

		/// <param name="profileTestName">Name for the test</param>

		/// <param name="testDelegate">Test delegate to execute</param>

		public static void Profile1MilionTimes(string profileTestName,

			ProfileDelegate testDelegate)

		{

			// Test 1 mio times (much quicker obviously, but not as accurate)

			int ms = Profile(0 * 1000 * 1000, testDelegate);

			Console.WriteLine(ms + "ms for " + profileTestName +

			                  " (1 million calls)");

		}

		#endregion



		#region ShowTotalProfileRuns (Static)

		/// <summary>

		/// Show total profile runs, which just displays the number of tests

		/// that were executed plus the total and average time spend in ms.

		/// After calling this numberOfProfileRuns and totalProfileRunsMs will

		/// both be reset to 0.

		/// </summary>

		public static void ShowTotalProfileRuns()

		{

			Console.WriteLine("In total " + numberOfProfileRuns + " Tests were " +

			                  "executed. Total time=" + totalProfileRunsMs +

			                  "ms, Average time=" +

			                  ((10 * totalProfileRunsMs / numberOfProfileRuns) / 10.0f) +

			                  "ms.");



			// Reset counters

			numberOfProfileRuns = 0;

			totalProfileRunsMs = 0;

		}

		#endregion



		#region Private



		#region numberOfProfileRuns (Private)

		/// <summary>

		/// Helpers for ShowTotalProfileRuns (just displays the number of tests

		/// that were executed plus the total and average time spend in ms).

		/// </summary>

		private static int numberOfProfileRuns;

		#endregion



		#region totalProfileRunsMs (Private)

		/// <summary>

		/// Helpers for ShowTotalProfileRuns (just displays the number of tests

		/// that were executed plus the total and average time spend in ms).

		/// </summary>

		private static int totalProfileRunsMs;

		#endregion



		#endregion

	}

}