001    /*
002     $Id: SpreadMap.java 4098 2006-10-10 16:09:48Z blackdrag $
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
039     SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
040     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
041     STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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.typehandling.DefaultTypeTransformation;
053    
054    /**
055     * Represents a spreadable map which extends java.util.HashMap.
056     * 
057     * @author Pilho Kim
058     * @version $Revision: 4098 $
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               mapData.put(values[i++], values[i++]);
070            }
071        }
072    
073        public SpreadMap(Map map) {
074            this.mapData = map;
075        }
076    
077        public Object get(Object obj) {
078            return mapData.get(obj);
079        }
080    
081        public Object put(Object key, Object value) {
082            throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so ("
083                                       + key + ": " + value + ") cannot be added.");
084        }
085    
086        public Object remove(Object key) {
087            throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so the key ("
088                                       + key + ") cannot be deleteded.");
089        }
090    
091        public void putAll(Map t) {
092            throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so the map ("
093                                       + t + ") cannot be put in this spreadMap.");
094        }
095    
096        public int size() {
097            return mapData.keySet().size();
098        }
099    
100        public boolean equals(Object that) {
101            if (that instanceof SpreadMap) {
102                return equals((SpreadMap) that);
103            }
104            return false;
105        }
106    
107        public boolean equals(SpreadMap that) {
108            if (that == null) return false;        
109    
110            if (size() == that.size()) {
111                SpreadMap other = (SpreadMap) that;
112                Iterator iter = mapData.keySet().iterator();
113                for (; iter.hasNext(); ) {
114                    Object key = iter.next();
115                    if (! DefaultTypeTransformation.compareEqual(get(key), other.get(key)) ) {
116                        return false;
117                    }
118                }
119                return true;
120            }
121            return false;
122        }
123    
124    
125        public int hashCode() {
126            if (hashCode == 0) {
127                Iterator iter = mapData.keySet().iterator();
128                for (; iter.hasNext(); ) {
129                    Object key = iter.next();
130                    int hash = (key != null) ? key.hashCode() : 0xbabe;
131                    hashCode ^= hash;
132                }
133            }
134            return hashCode;
135        }
136    
137        /**
138         * Returns the string expression of <code>this</code>.
139         *
140         * @return the string expression of <code>this</code>
141         */
142        public String toString() {
143            if (mapData.isEmpty()) {
144                return "*:[:]";
145            }
146            StringBuffer buff = new StringBuffer("*:[");
147            Iterator iter = mapData.keySet().iterator();
148            for (; iter.hasNext(); ) {
149                Object key = iter.next();
150                buff.append(key + ":" + mapData.get(key));
151                if (iter.hasNext())
152                    buff.append(", ");
153            }
154            buff.append("]");
155            return buff.toString();
156        }
157    }