/**
 * @author chmilevfa
 * @since 24.04.17
 */
public class RpsChecker {

    private final int RATE = 1000;

    private int rpr; //requests per rate
    private long lastTime;
    private double threshold;

    public RpsChecker(int rpr) {
        this.rpr = rpr;
        this.lastTime = System.currentTimeMillis();
        this.threshold = 0;
    }

    public boolean isRequestAllowed() {
        long currentTime = System.currentTimeMillis();
        long diffTime = currentTime - lastTime;
        lastTime = currentTime;

        if (threshold > rpr) {
            threshold = rpr;
        }
        threshold += diffTime * (rpr/RATE);
        if (threshold < 1.0) {
            return false;
        } else {
            threshold -= 1;
            return true;
        }
    }
}