/*
 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
 */
/*
 * 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
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package com.sun.org.apache.xpath.internal.axes;

import com.sun.org.apache.xml.internal.dtm.DTMIterator;
import com.sun.org.apache.xml.internal.utils.WrappedRuntimeException;
import java.util.ArrayList;
import java.util.List;

Pool of object of a given type to pick from to help memory usage
@xsl.usageinternal
@LastModified: Oct 2017
/** * Pool of object of a given type to pick from to help memory usage * @xsl.usage internal * @LastModified: Oct 2017 */
public final class IteratorPool implements java.io.Serializable { static final long serialVersionUID = -460927331149566998L;
Type of objects in this pool.
/** * Type of objects in this pool. */
private final DTMIterator m_orig;
Stack of given objects this points to.
/** * Stack of given objects this points to. */
private final List<DTMIterator> m_freeStack;
Constructor IteratorPool
Params:
  • original – The original iterator from which all others will be cloned.
/** * Constructor IteratorPool * * @param original The original iterator from which all others will be cloned. */
public IteratorPool(DTMIterator original) { m_orig = original; m_freeStack = new ArrayList<>(); }
Get an instance of the given object in this pool
Returns:An instance of the given object
/** * Get an instance of the given object in this pool * * @return An instance of the given object */
public synchronized DTMIterator getInstanceOrThrow() throws CloneNotSupportedException { // Check if the pool is empty. if (m_freeStack.isEmpty()) { // Create a new object if so. return (DTMIterator)m_orig.clone(); } else { // Remove object from end of free pool. DTMIterator result = m_freeStack.remove(m_freeStack.size() - 1); return result; } }
Get an instance of the given object in this pool
Returns:An instance of the given object
/** * Get an instance of the given object in this pool * * @return An instance of the given object */
public synchronized DTMIterator getInstance() { // Check if the pool is empty. if (m_freeStack.isEmpty()) { // Create a new object if so. try { return (DTMIterator)m_orig.clone(); } catch (Exception ex) { throw new WrappedRuntimeException(ex); } } else { // Remove object from end of free pool. DTMIterator result = m_freeStack.remove(m_freeStack.size() - 1); return result; } }
Add an instance of the given object to the pool
Params:
  • obj – Object to add.
/** * Add an instance of the given object to the pool * * * @param obj Object to add. */
public synchronized void freeInstance(DTMIterator obj) { m_freeStack.add(obj); } }