snuvi-engine/src/me/hammerle/snuviengine/util/Clock.java

package me.hammerle.snuviengine.util;

public class Clock
{
    private final int dataLength;
    private final long[] data;
    private int index = 0;
    private long sum = 0;
    private long time;
    private boolean stable = false;
    
    private long min = Long.MAX_VALUE;
    private long avg = - 1;
    
    public Clock(int dataLength)
    {
        this.dataLength = dataLength;
        data = new long[dataLength];
    }
    
    public void start()
    {
        time = System.nanoTime();
    }
    
    public void stop()
    {
        time = System.nanoTime() - time;
        sum -= data[index];
        sum += time;
        data[index] = time;
        index = (index + 1) % dataLength;
        if(index == 0)
        {
            stable = true;
        }
    }
    
    public void calculate()
    {
        if(stable)
        {
            avg = sum / dataLength;
            if(avg < min)
            {
                min = avg;
            }
        }
    }
    
    public long getTime()
    {
        if(stable)
        {
            return avg;
        }
        return -1;
    }
    
    public long getMinTime()
    {
        if(stable)
        {
            return min;
        }
        return -1;
    }
}