001    /*
002     $Id: SpreadMap.java,v 1.1 2005/05/11 01:17:38 phk Exp $
003    
004     Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005    
006     Redistribution and use of this software and associated documentation
007     ("Software"), with or without modification, are permitted provided
008     that the following conditions are met:
009    
010     1. Redistributions of source code must retain copyright
011        statements and notices.  Redistributions must also contain a
012        copy of this document.
013    
014     2. Redistributions in binary form must reproduce the
015        above copyright notice, this list of conditions and the
016        following disclaimer in the documentation and/or other
017        materials provided with the distribution.
018    
019     3. The name "groovy" must not be used to endorse or promote
020        products derived from this Software without prior written
021        permission of The Codehaus.  For written permission,
022        please contact info@codehaus.org.
023    
024     4. Products derived from this Software may not be called "groovy"
025        nor may "groovy" appear in their names without prior written
026        permission of The Codehaus. "groovy" is a registered
027        trademark of The Codehaus.
028    
029     5. Due credit should be given to The Codehaus -
030        http://groovy.codehaus.org/
031    
032     THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
033     ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
034     NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
035     FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
036     THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
037     INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
038     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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042     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
043     OF THE POSSIBILITY OF SUCH DAMAGE.
044    
045     */
046    package groovy.lang;
047    
048    import java.util.HashMap;
049    import java.util.Map;
050    import java.util.Iterator;
051    
052    import org.codehaus.groovy.runtime.InvokerHelper;
053    
054    /**
055     * Represents a spreadable map which extends java.util.HashMap.
056     * 
057     * @author Pilho Kim
058     * @version $Revision: 1.1 $
059     */
060    public class SpreadMap extends HashMap {
061    
062        private Map mapData;
063        private int hashCode;
064    
065        public SpreadMap(Object[] values) {
066            mapData = new HashMap(values.length / 2);
067            int i = 0;
068            while (i < values.length) {
069               /// System.out.println(" ...  i = " + i);
070               mapData.put(values[i++], values[i++]);
071            }
072               /// System.out.println("    >>>  i = " + i);
073        }
074    
075        public SpreadMap(Map map) {
076            this.mapData = map;
077        }
078    
079        public Object get(Object obj) {
080            return mapData.get(obj);
081        }
082    
083        public Object put(Object key, Object value) {
084            throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so ("
085                                       + key + ": " + value + ") cannot be added.");
086        }
087    
088        public Object remove(Object key) {
089            throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so the key ("
090                                       + key + ") cannot be deleteded.");
091        }
092    
093        public void putAll(Map t) {
094            throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so the map ("
095                                       + t + ") cannot be put in this spreadMap.");
096        }
097    
098        public int size() {
099            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    }