//---------------------------------------------------------------------------
// File: TimerTest.cool
//
// A basic class for inheriting Tests that want to get timing information.
//---------------------------------------------------------------------------

using System;
using System.Runtime.InteropServices;

public class TimerTest
{
    public long m_Start;
    public long m_End;
    public long m_Freq;
    long m_Min;
    long m_Max;
    public long m_Count;
    public long m_Sum;

	[DllImport("KERNEL32.DLL", EntryPoint="QueryPerformanceCounter",  SetLastError=true,
		  CharSet=CharSet.Unicode, ExactSpelling=true,
		  CallingConvention=CallingConvention.StdCall)]
    public static extern int QueryPerformanceCounter(ref long time);

	[DllImport("KERNEL32.DLL", EntryPoint="QueryPerformanceFrequency",  SetLastError=true,
		 CharSet=CharSet.Unicode, ExactSpelling=true,
		 CallingConvention=CallingConvention.StdCall)]
	public static extern int QueryPerformanceFrequency(ref long freq);

    public TimerTest()
    { 
        m_Start = m_End = 0; 
        QueryPerformanceFrequency(ref m_Freq);
        m_Min = m_Max = m_Count = m_Sum = 0;
    }

    public void Start()
    {
		long i = 0;
		QueryPerformanceCounter(ref i);
		m_Start = i;
//        m_Start = GetMilliseconds();
        m_End = m_Start;
    }

    public void Stop()
    {
		long i = 0;
		QueryPerformanceCounter(ref i);
		m_End = i;
		m_Sum += (m_End - m_Start);
		m_Count++;
        //m_End = GetMilliseconds();
    }

    public long GetDuration() // in milliseconds.
    {
        return (m_End - m_Start);
    }

    public long GetMilliseconds()
    {
        long i = 0;
        QueryPerformanceCounter(ref i);
        return ((i * (long)1000) / m_Freq);
    }

    // These methods allow you to count up multiple iterations and
    // then get the median, average and percent variation.
    public void Count(long ms)
    {   
        if (m_Min == 0) m_Min = ms;
        if (ms < m_Min) m_Min = ms;
        if (ms > m_Max) m_Max = ms;
        m_Sum += ms;
        m_Count++;
    }

    public long Min()
    {
        return m_Min;
    }

    public long Max()
    {
        return m_Max;
    }

    public double Median()
    {
        return TwoDecimals(m_Min + ((m_Max - m_Min)/2.0));
    }

    public double PercentError()
    {
        double spread = (m_Max - m_Min)/2.0;
        double percent = TwoDecimals((double)(spread*100.0)/(double)(m_Min));
        return percent;
    }

    public double TwoDecimals(double i)
    {
        return Math.Round(i * 100) / 100;
    }

    public long Average()
    {
        return m_Sum / m_Count;
    }

    public void Clear()
    {
        m_Start = m_End = m_Min = m_Max = m_Sum = m_Count = 0;
    }
};