| /* |
| * Copyright 1999-2004 The Apache Software Foundation |
| * |
| * Licensed 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.tomcat.util.collections; |
| |
| /** |
| * 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 Manolache |
| */ |
| public final class SimplePool { |
| |
| |
| private static org.apache.commons.logging.Log log= |
| org.apache.commons.logging.LogFactory.getLog(SimplePool.class ); |
| |
| /* |
| * Where the threads are held. |
| */ |
| private Object pool[]; |
| |
| private int max; |
| private int last; |
| private int current=-1; |
| |
| private Object lock; |
| public static final int DEFAULT_SIZE=32; |
| static final int debug=0; |
| |
| public SimplePool() { |
| this(DEFAULT_SIZE,DEFAULT_SIZE); |
| } |
| |
| public SimplePool(int size) { |
| this(size, size); |
| } |
| |
| public SimplePool(int size, int max) { |
| this.max=max; |
| pool=new Object[size]; |
| this.last=size-1; |
| lock=new Object(); |
| } |
| |
| public void set(Object o) { |
| put(o); |
| } |
| |
| /** |
| * Add the object to the pool, silent nothing if the pool is full |
| */ |
| public void put(Object o) { |
| synchronized( lock ) { |
| if( current < last ) { |
| current++; |
| pool[current] = o; |
| } else if( current < max ) { |
| // realocate |
| int newSize=pool.length*2; |
| if( newSize > max ) newSize=max+1; |
| Object tmp[]=new Object[newSize]; |
| last=newSize-1; |
| System.arraycopy( pool, 0, tmp, 0, pool.length); |
| pool=tmp; |
| current++; |
| pool[current] = o; |
| } |
| if( debug > 0 ) log("put " + o + " " + current + " " + max ); |
| } |
| } |
| |
| /** |
| * Get an object from the pool, null if the pool is empty. |
| */ |
| public Object get() { |
| Object item = null; |
| synchronized( lock ) { |
| if( current >= 0 ) { |
| item = pool[current]; |
| pool[current] = null; |
| current -= 1; |
| } |
| if( debug > 0 ) |
| log("get " + item + " " + current + " " + max); |
| } |
| return item; |
| } |
| |
| /** |
| * Return the size of the pool |
| */ |
| public int getMax() { |
| return max; |
| } |
| |
| /** |
| * Number of object in the pool |
| */ |
| public int getCount() { |
| return current+1; |
| } |
| |
| |
| public void shutdown() { |
| } |
| |
| private void log( String s ) { |
| if (log.isDebugEnabled()) |
| log.debug("SimplePool: " + s ); |
| } |
| } |