| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * |
| * Copyright (c) 1999 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Xalan" and "Apache Software Foundation" must |
| * not be used to endorse or promote products derived from this |
| * software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * nor may "Apache" appear in their name, without prior written |
| * permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation and was |
| * originally based on software copyright (c) 1999, Lotus |
| * Development Corporation., http://www.lotus.com. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| package org.apache.xml.utils; |
| |
| import java.util.EmptyStackException; |
| |
| /** |
| * <meta name="usage" content="internal"/> |
| * Implement a stack of simple integers. |
| * |
| * %OPT% |
| * This is currently based on IntVector, which permits fast acess but pays a |
| * heavy recopying penalty if/when its size is increased. If we expect deep |
| * stacks, we should consider a version based on ChunkedIntVector. |
| */ |
| public class IntStack extends IntVector |
| { |
| |
| /** |
| * Default constructor. Note that the default |
| * block size is very small, for small lists. |
| */ |
| public IntStack() |
| { |
| super(); |
| } |
| |
| /** |
| * Construct a IntVector, using the given block size. |
| * |
| * @param blocksize Size of block to allocate |
| */ |
| public IntStack(int blocksize) |
| { |
| super(blocksize); |
| } |
| |
| /** |
| * Pushes an item onto the top of this stack. |
| * |
| * @param i the int to be pushed onto this stack. |
| * @return the <code>item</code> argument. |
| */ |
| public int push(int i) |
| { |
| |
| if ((m_firstFree + 1) >= m_mapSize) |
| { |
| m_mapSize += m_blocksize; |
| |
| int newMap[] = new int[m_mapSize]; |
| |
| System.arraycopy(m_map, 0, newMap, 0, m_firstFree + 1); |
| |
| m_map = newMap; |
| } |
| |
| m_map[m_firstFree] = i; |
| |
| m_firstFree++; |
| |
| return i; |
| } |
| |
| /** |
| * Removes the object at the top of this stack and returns that |
| * object as the value of this function. |
| * |
| * @return The object at the top of this stack. |
| */ |
| public int pop() |
| { |
| return m_map[--m_firstFree]; |
| } |
| |
| /** |
| * Quickly pops a number of items from the stack. |
| */ |
| |
| public void quickPop(int n) |
| { |
| m_firstFree -= n; |
| } |
| |
| /** |
| * Looks at the object at the top of this stack without removing it |
| * from the stack. |
| * |
| * @return the object at the top of this stack. |
| * @throws EmptyStackException if this stack is empty. |
| */ |
| public int peek() |
| { |
| return m_map[m_firstFree - 1]; |
| } |
| |
| /** |
| * Looks at the object at the position the stack counting down n items. |
| * |
| * @param n The number of items down, indexed from zero. |
| * @return the object at n items down. |
| * @throws EmptyStackException if this stack is empty. |
| */ |
| public int peek(int n) |
| { |
| return m_map[m_firstFree-(1+n)]; |
| } |
| |
| /** |
| * Sets an object at a the top of the statck |
| * |
| * |
| * @param val object to set at the top |
| * @throws EmptyStackException if this stack is empty. |
| */ |
| public void setTop(int val) |
| { |
| m_map[m_firstFree - 1] = val; |
| } |
| |
| /** |
| * Tests if this stack is empty. |
| * |
| * @return <code>true</code> if this stack is empty; |
| * <code>false</code> otherwise. |
| * @since JDK1.0 |
| */ |
| public boolean empty() |
| { |
| return m_firstFree == 0; |
| } |
| |
| /** |
| * Returns where an object is on this stack. |
| * |
| * @param o the desired object. |
| * @return the distance from the top of the stack where the object is] |
| * located; the return value <code>-1</code> indicates that the |
| * object is not on the stack. |
| * @since JDK1.0 |
| */ |
| public int search(int o) |
| { |
| |
| int i = lastIndexOf(o); |
| |
| if (i >= 0) |
| { |
| return size() - i; |
| } |
| |
| return -1; |
| } |
| } |