/*

  * 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.myfaces.view.facelets.pool.impl;

 import java.util.Queue;

 import java.util.concurrent.ConcurrentLinkedQueue;

 import java.util.concurrent.atomic.AtomicInteger;

 import org.apache.myfaces.view.facelets.pool.ViewEntry;

 /**

  * Fast pool using ConcurrentLinkedQueue, with uses an AtomicInteger as 

  * count limit. The reasons of design this pool in this way are:

  * 

  * <ol>

  * <li>There is no need to put a hard limit about the max number of views stored

  * in the pool. Remember ViewEntry internally has a Soft or Weak reference over

  * the view. The maxCount is just a way to limit the max footprint fo the pool

  * in memory, but if the limit is exceed, the vm can always reclaim the memory space.</li>

  * <li>View creation is quite fast, so according to previous tests done,

  * include any syncronized method in this code will produce worse performance.</li>

  * </ol>

  *

  * @author Leonardo Uribe

  */

 public class ViewPoolEntryHolder

 {

     private Queue<ViewEntry> queue;

     private AtomicInteger count;

     private int maxCount;

     public ViewPoolEntryHolder(int maxCount)

     {

         this.queue = new ConcurrentLinkedQueue<ViewEntry>();

         this.count = new AtomicInteger();

         this.maxCount = maxCount;

     }

     public boolean add(ViewEntry entry)

     {

         if (count.get() < maxCount)

         {

             queue.add(entry);

             count.incrementAndGet();

             return true;

         }

         return false;

     }

     public ViewEntry poll()

     {

         ViewEntry entry = queue.poll();

         count.decrementAndGet();

         return entry;

     }

     public boolean isFull()

     {

         return count.get() >= maxCount;

     }

     public int getCount()

     {

         return count.get();

     }

 }