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Diffstat (limited to 'velocity-engine-core/src/main/java/org/apache/velocity/util/SimplePool.java')
-rw-r--r-- | velocity-engine-core/src/main/java/org/apache/velocity/util/SimplePool.java | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/velocity-engine-core/src/main/java/org/apache/velocity/util/SimplePool.java b/velocity-engine-core/src/main/java/org/apache/velocity/util/SimplePool.java new file mode 100644 index 00000000..2fb9d34b --- /dev/null +++ b/velocity-engine-core/src/main/java/org/apache/velocity/util/SimplePool.java @@ -0,0 +1,137 @@ +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 <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a> + * @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; + } +} |