snuvi-engine/src/me/hammerle/snuviengine/api/Timer.java

package me.hammerle.snuviengine.api;

public class Timer {
    private static final int SIZE = 32;

    private int index = -1;
    private final long[] times = new long[SIZE];
    private long sum = 0;
    private double callsPerSecond = 0;
    private long lastTime = System.nanoTime();

    public void update() {
        index = (index + 1) % SIZE;
        long time = System.nanoTime();
        sum -= times[index];
        times[index] = time - lastTime;
        sum += times[index];
        lastTime = time;
        callsPerSecond = (1_000_000_000.0 * SIZE) / sum;
    }

    public double getCallPerSecond() {
        return callsPerSecond;
    }
}