Extreme Optimization #1.1: Mapping IP addresses to country codes.

// Copyright � 2003 by Jeffrey Sax
// All rights reserved.
// http://www.extremeoptimization.com/
// Filename: timer.cs
// Description: Hi-resolution timer for benchmarking purposes.
// Last modified: April 18, 2003.
using System;

namespace Extreme
{
	public class HiResTimer
	{
		[System.Runtime.InteropServices.DllImport("KERNEL32")]
		private static extern bool QueryPerformanceCounter(ref Int64 lpPerformanceCount);

		[System.Runtime.InteropServices.DllImport("KERNEL32")]
		private static extern bool QueryPerformanceFrequency(ref Int64 lpFrequency);                     

		private Int64 _frequency = 0;
		private Int64 _ticksStart = 0;
		private Int64 _ticksStop = 0;

		public HiResTimer()
		{
			QueryPerformanceFrequency(ref _frequency);
		}

		public void Start()
		{
			_ticksStart = 0;
			QueryPerformanceCounter(ref _ticksStart);
		}
		
		public void Stop()
		{
			_ticksStop = 0;
			QueryPerformanceCounter(ref _ticksStop);
		}

		public void Reset()
		{
			_ticksStart = 0;
			_ticksStop = 0;
		}

		public Single ElapsedSeconds
		{
			get { return (Single)(_ticksStop - _ticksStart) / (Single)_frequency; }
		}
		public Single ElapsedMilliSeconds
		{
			get { return 1000 * ElapsedSeconds; }
		}

		public Int64 Frequency
		{
			get { return _frequency; }
		}
	}
}