Batcher3.java

package org.andork.util;

import java.util.LinkedList;
import java.util.Timer;
import java.util.TimerTask;
import java.util.function.BooleanSupplier;
import java.util.function.Consumer;

public class Batcher3<T> implements Consumer<T> {
	private class HandleTask extends TimerTask {
		@Override
		public void run() {
			if (!isBusy.getAsBoolean()) {
				timer.cancel();

				LinkedList<T> queueToHandle = null;

				synchronized (lock) {
					if (!queue.isEmpty()) {
						queueToHandle = queue;
						queue = new LinkedList<>();
					}
				}

				if (queueToHandle != null) {
					handler.accept(queueToHandle);
				}
			}
		}
	}

	private final Object lock = new Object();
	private LinkedList<T> queue = new LinkedList<T>();

	private int maxSize = Integer.MAX_VALUE;
	private BooleanSupplier isBusy;
	private Consumer<LinkedList<T>> handler;
	private Consumer<T> interruptor;
	private Timer timer;

	private long delay;

	public Batcher3(Consumer<LinkedList<T>> handler, BooleanSupplier isBusy) {
		super();
		this.handler = handler;
		this.isBusy = isBusy;
	}

	@Override
	public void accept(T t) {
		synchronized (lock) {
			if (queue.size() < maxSize) {
				queue.add(t);
			}
			if (queue.size() == 1) {
				timer.scheduleAtFixedRate(new HandleTask(), delay, delay);
			}
		}

		if (interruptor != null) {
			interruptor.accept(t);
		}
	}

	public Consumer<T> getInterruptor() {
		return interruptor;
	}

	public int getMaxSize() {
		return maxSize;
	}

	public void setInterruptor(Consumer<T> interruptor) {
		this.interruptor = interruptor;
	}

	public void setMaxSize(int maxSize) {
		this.maxSize = maxSize;
	}
}