AbstractFixedSizeQueue.java

/**
 * Copyright (c) 2013, Will Szumski
 *
 * This file is part of formicidae.
 *
 * formicidae is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * formicidae is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with formicidae.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.fluxoid.utils;

import java.util.AbstractQueue;
import java.util.LinkedList;

public abstract class AbstractFixedSizeQueue<V> extends AbstractQueue<V> implements
    FixedSizeQueue<V> {

  protected LinkedList<V> queue;

  protected int maxSize;

  protected LinkedList<V> getQueue() {
    return queue;
  }

  protected int getMaxSize() {
    return maxSize;
  }

  public AbstractFixedSizeQueue(int maxSize) {
    this.queue = new LinkedList<V>();
    this.maxSize = maxSize;
  }

  @Override
  public boolean offer(V e) {
    displace(e);
    return true;
  }

  @Override
  public V displace(V e) {
    V rtn = null;
    if (queue.size() >= maxSize) {
      rtn = queue.poll();
    }
    queue.add(e);
    return rtn;
  }

  @Override
  public int size() {
    return queue.size();
  }

  @Override
  public String toString() {
    return this.getClass().getSimpleName() + " [queue=" + queue + "]";
  }

}