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package org.apache.velocity.util;
/*
* 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.
*/
/**
* Simple object pool. Based on ThreadPool and few other classes
*
* The pool will ignore overflow and return null if empty.
*
* @author Gal Shachor
* @author Costin
* @author Geir Magnusson Jr.
* @version $Id$
*/
public final class SimplePool
{
/*
* Where the objects are held.
*/
private Object pool[];
/**
* max amount of objects to be managed
* set via CTOR
*/
private int max;
/**
* index of previous to next
* free slot
*/
private int current=-1;
/**
* @param max
*/
public SimplePool(int max)
{
this.max = max;
pool = new Object[max];
}
/**
* Add the object to the pool, silent nothing if the pool is full
* @param o
*/
public void put(Object o)
{
int idx=-1;
synchronized(this)
{
/*
* if we aren't full
*/
if (current < max - 1)
{
/*
* then increment the
* current index.
*/
idx = ++current;
}
if (idx >= 0)
{
pool[idx] = o;
}
}
}
/**
* Get an object from the pool, null if the pool is empty.
* @return The object from the pool.
*/
public Object get()
{
synchronized(this)
{
/*
* if we have any in the pool
*/
if( current >= 0 )
{
/*
* remove the current one
*/
Object o = pool[current];
pool[current] = null;
current--;
return o;
}
}
return null;
}
/**
* Return the size of the pool
* @return The pool size.
*/
public int getMax()
{
return max;
}
/**
* for testing purposes, so we can examine the pool
*
* @return Array of Objects in the pool.
*/
Object[] getPool()
{
return pool;
}
}