SQL Editor for Database Developers

// -------------------------------------------------------
// SqlBuilder by Elm�Soft
// www.netcult.ch/elmue
// www.codeproject.com/KB/database/SqlBuilder.aspx
// -------------------------------------------------------

using System;
using System.Runtime.InteropServices;

namespace SqlBuilder
{
	/// <summary>
	/// The performance counter is better than 1 ms while the Tickcount only increments approx every 15 ms
	/// If the hardware supportes it, this class uses the more exact performance counter.
	/// .NET does not support a performance counter. DateTime.Tick is not precise!
	/// </summary>
	public class Measure
	{
		[DllImport("kernel32.dll", EntryPoint="QueryPerformanceCounter")]
		private static extern int QueryPerformanceCounter(out long s64_Counter);

		[DllImport("kernel32.dll", EntryPoint="QueryPerformanceFrequency")]
		private static extern int QueryPerformanceFrequency(out long s64_Frequency);

		private static long s64_Frequency = 0;
		private long        s64_Start;

		public Measure()
		{
			if (s64_Frequency == 0)
			{
				QueryPerformanceFrequency(out s64_Frequency);
				s64_Frequency /= 1000;
			}
			Start();
		}

		/// <summary>
		/// Start a new measurement
		/// </summary>
		public void Start()
		{
			if (s64_Frequency == 0)
				s64_Start = Environment.TickCount;
			else
				QueryPerformanceCounter(out s64_Start);
		}

		/// <summary>
		/// returns the time in ms which has elapsed since creating this class or calling Start()
		/// </summary>
		public int ElapsedTimeInt
		{
			get
			{
				if (s64_Frequency == 0) // hardware does not support Performance counters
				{
					return Environment.TickCount - (int)s64_Start;
				}
				else
				{
					long s64_Now;
					QueryPerformanceCounter(out s64_Now);
					return (int) ((s64_Now - s64_Start) / s64_Frequency);
				}
			}
		}

		public string ElapsedTimeStr
		{
			get
			{
				int s32_Elapsed = ElapsedTimeInt;
				return string.Format("{0}.{1}", s32_Elapsed/1000, (s32_Elapsed%1000).ToString("000"));
			}
		}
	}
}