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1 /*
2  * The Apache Software License, Version 1.1
3  *
4  *
5  * Copyright (c) 2000,2001 The Apache Software Foundation.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  * notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  * notice, this list of conditions and the following disclaimer in
17  * the documentation and/or other materials provided with the
18  * distribution.
19  *
20  * 3. The end-user documentation included with the redistribution,
21  * if any, must include the following acknowledgment:
22  * "This product includes software developed by the
23  * Apache Software Foundation (http://www.apache.org/)."
24  * Alternately, this acknowledgment may appear in the software itself,
25  * if and wherever such third-party acknowledgments normally appear.
26  *
27  * 4. The names "Xerces" and "Apache Software Foundation" must
28  * not be used to endorse or promote products derived from this
29  * software without prior written permission. For written
30  * permission, please contact apache@apache.org.
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32  * 5. Products derived from this software may not be called "Apache",
33  * nor may "Apache" appear in their name, without prior written
34  * permission of the Apache Software Foundation.
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36  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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38  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
42  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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44  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
45  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
46  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47  * SUCH DAMAGE.
48  * ====================================================================
49  *
50  * This software consists of voluntary contributions made by many
51  * individuals on behalf of the Apache Software Foundation and was
52  * originally based on software copyright (c) 1999, International
53  * Business Machines, Inc., http://www.apache.org. For more
54  * information on the Apache Software Foundation, please see
55  * <http://www.apache.org/>.
56  */
57
58 package org.enhydra.apache.xerces.utils;
59
60 /**
61  * A simple integer based stack.
62  *
63  * @author Andy Clark, IBM
64  *
65  * @version $Id: IntStack.java,v 1.1.1.1 2003/03/10 16:34:39 taweili Exp $
66  */
67 public final class IntStack {
68
69     //
70 // Data
71 //
72
73     /** Stack depth. */
74     private int fDepth;
75
76     /** Stack data. */
77     private int[] fData;
78
79     //
80 // Public methods
81 //
82
83     /** Returns the size of the stack. */
84     public int size() {
85         return fDepth;
86     }
87
88     /** Pushes a value onto the stack. */
89     public void push(int value) {
90         ensureCapacity(fDepth + 1);
91         fData[fDepth++] = value;
92     }
93
94     /** Peeks at the top of the stack. */
95     public int peek() {
96         return fData[fDepth - 1];
97     }
98
99     /** Pops a value off of the stack. */
100     public int pop() {
101         return fData[--fDepth];
102     }
103
104     /** Clears the stack. */
105     public void clear() {
106         fDepth = 0;
107     }
108
109     // debugging
110
111     /** Prints the stack. */
112     public void print() {
113         System.out.print('(');
114         System.out.print(fDepth);
115         System.out.print(") {");
116         for (int i = 0; i < fDepth; i++) {
117             if (i == 3) {
118                 System.out.print(" ...");
119                 break;
120             }
121             System.out.print(' ');
122             System.out.print(fData[i]);
123             if (i < fDepth - 1) {
124                 System.out.print(',');
125             }
126         }
127         System.out.print(" }");
128         System.out.println();
129     }
130
131     //
132 // Private methods
133 //
134
135     /** Ensures capacity. */
136     private boolean ensureCapacity(int size) {
137         try {
138             return fData[size] != 0;
139         }
140         catch (NullPointerException JavaDoc e) {
141             fData = new int[32];
142         }
143         catch (ArrayIndexOutOfBoundsException JavaDoc e) {
144             int[] newdata = new int[fData.length * 2];
145             System.arraycopy(fData, 0, newdata, 0, fData.length);
146             fData = newdata;
147         }
148         return true;
149     }
150
151 } // class IntStack
152
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