/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.synapse.commons.executors.queues;
import org.apache.synapse.commons.executors.InternalQueue;
import java.util.*;
import java.util.concurrent.locks.Condition;
/**
* An unbounded queue backed by and ArrayList.
* @param <E>
*/
public class UnboundedQueue<E> extends AbstractQueue<E> implements InternalQueue<E> {
private List<E> elements = new ArrayList<E>();
/**
* Priority of this queue
*/
private int priority;
/**
* A waiting queue when this queue is full
*/
private Condition notFullCond;
public UnboundedQueue(int priority) {
this.priority = priority;
}
public Iterator<E> iterator() {
return elements.iterator();
}
public int size() {
return elements.size();
}
public boolean offer(E e) {
return elements.add(e);
}
public E poll() {
if (elements.size() > 0) {
return elements.remove(elements.size() - 1);
}
return null;
}
public E peek() {
if (elements.size() > 0) {
return elements.get(elements.size() - 1);
}
return null;
}
public int getPriority() {
return priority;
}
public void setPriority(int p) {
this.priority = p;
}
public Condition getNotFullCond() {
return notFullCond;
}
public void setNotFullCond(Condition condition) {
this.notFullCond = condition;
}
public int drainTo(Collection<? super E> c) {
int count = elements.size();
c.addAll(elements);
elements.clear();
return count;
}
public int drainTo(Collection<? super E> c, int maxElements) {
if (maxElements >= elements.size()) {
return drainTo(c);
} else {
elements.subList(elements.size() - maxElements - 1, elements.size());
return maxElements;
}
}
public int remainingCapacity() {
return Integer.MAX_VALUE;
}
public int getCapacity() {
return Integer.MAX_VALUE;
}
@Override
public boolean contains(Object o) {
return elements.contains(o);
}
@Override
public boolean remove(Object o) {
return elements.remove(o);
}
}