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1   /*
2    $Id: SpreadMap.java,v 1.1 2005/05/11 01:17:38 phk Exp $
3   
4    Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
5   
6    Redistribution and use of this software and associated documentation
7    ("Software"), with or without modification, are permitted provided
8    that the following conditions are met:
9   
10   1. Redistributions of source code must retain copyright
11      statements and notices.  Redistributions must also contain a
12      copy of this document.
13  
14   2. Redistributions in binary form must reproduce the
15      above copyright notice, this list of conditions and the
16      following disclaimer in the documentation and/or other
17      materials provided with the distribution.
18  
19   3. The name "groovy" must not be used to endorse or promote
20      products derived from this Software without prior written
21      permission of The Codehaus.  For written permission,
22      please contact info@codehaus.org.
23  
24   4. Products derived from this Software may not be called "groovy"
25      nor may "groovy" appear in their names without prior written
26      permission of The Codehaus. "groovy" is a registered
27      trademark of The Codehaus.
28  
29   5. Due credit should be given to The Codehaus -
30      http://groovy.codehaus.org/
31  
32   THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
33   ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
34   NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
35   FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
36   THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
37   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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44  
45   */
46  package groovy.lang;
47  
48  import java.util.HashMap;
49  import java.util.Map;
50  import java.util.Iterator;
51  
52  import org.codehaus.groovy.runtime.InvokerHelper;
53  
54  /***
55   * Represents a spreadable map which extends java.util.HashMap.
56   * 
57   * @author Pilho Kim
58   * @version $Revision: 1.1 $
59   */
60  public class SpreadMap extends HashMap {
61  
62      private Map mapData;
63      private int hashCode;
64  
65      public SpreadMap(Object[] values) {
66          mapData = new HashMap(values.length / 2);
67          int i = 0;
68          while (i < values.length) {
69             /// System.out.println(" ...  i = " + i);
70             mapData.put(values[i++], values[i++]);
71          }
72             /// System.out.println("    >>>  i = " + i);
73      }
74  
75      public SpreadMap(Map map) {
76          this.mapData = map;
77      }
78  
79      public Object get(Object obj) {
80          return mapData.get(obj);
81      }
82  
83      public Object put(Object key, Object value) {
84          throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so ("
85                                     + key + ": " + value + ") cannot be added.");
86      }
87  
88      public Object remove(Object key) {
89          throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so the key ("
90                                     + key + ") cannot be deleteded.");
91      }
92  
93      public void putAll(Map t) {
94          throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so the map ("
95                                     + t + ") cannot be put in this spreadMap.");
96      }
97  
98      public int size() {
99          return mapData.keySet().size();
100     }
101 
102     public boolean equals(Object that) {
103         if (that instanceof SpreadMap) {
104             return equals((SpreadMap) that);
105         }
106         return false;
107     }
108 
109     public boolean equals(SpreadMap that) {
110         if (this == null && that == null)
111             return true;
112         else if (this != null && that == null)
113             return false;
114         else if (this == null && that != null)
115             return false;
116 
117         if (size() == that.size()) {
118             SpreadMap other = (SpreadMap) that;
119             Iterator iter = mapData.keySet().iterator();
120             for (; iter.hasNext(); ) {
121                 Object key = iter.next();
122                 if (! InvokerHelper.compareEqual(get(key), other.get(key)) ) {
123                     return false;
124                 }
125             }
126             return true;
127         }
128         return false;
129     }
130 
131 
132     public int hashCode() {
133         if (hashCode == 0) {
134             Iterator iter = mapData.keySet().iterator();
135             for (; iter.hasNext(); ) {
136                 Object key = iter.next();
137                 int hash = (key != null) ? key.hashCode() : 0xbabe;
138                 hashCode ^= hash;
139             }
140         }
141         return hashCode;
142     }
143 }