package org.kne.cloud.network.klalb;

import java.util.Objects;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicReferenceArray;

public class ReceiveSlidingWindow<E> {
	private AtomicReferenceArray<E> array;
	private AtomicInteger windowSize =new AtomicInteger();
	private AtomicLong windowPosition=new AtomicLong();
	
	public int getWindowSize() {
		return windowSize.get();
	}

	public void setWindowSize(int windowSize) {
		this.windowSize.set(windowSize);
	}
	
	public long getWindowPosition() {
		return windowPosition.get();
	}

	public void setWindowPosition(long windowPosition) {
		this.windowPosition.set(windowPosition);
	}

	public ReceiveSlidingWindow(int capacity){
		array=new AtomicReferenceArray<E>(capacity);
	}
	
	public boolean push(E object) {
		Objects.requireNonNull(object);
		if(array.get((int) ((windowPosition.get()-windowSize.get())%array.length()))==null ) {
			array.set((int) (windowPosition.getAndIncrement()%array.length()), object);
			return true;
		}
		return false;
	}

	public E pull(long number) {
		return array.getAndSet((int) (number%array.length()), null);
	}
}