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    1   /*
    2    $Id: SpreadMap.java,v 1.3 2006/06/06 14:33:47 blackdrag 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
    38   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    39   SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    40   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    41   STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    42   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
    43   OF THE POSSIBILITY OF SUCH DAMAGE.
    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: 1.3 $
    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             mapData.put(values[i++], values[i++]);
    70          }
    71      }
    72
    73      public SpreadMap(Map map) {
    74          this.mapData = map;
    75      }
    76
    77      public Object get(Object obj) {
    78          return mapData.get(obj);
    79      }
    80
    81      public Object put(Object key, Object value) {
    82          throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so ("
    83                                     + key + ": " + value + ") cannot be added.");
    84      }
    85
    86      public Object remove(Object key) {
    87          throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so the key ("
    88                                     + key + ") cannot be deleteded.");
    89      }
    90
    91      public void putAll(Map t) {
    92          throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so the map ("
    93                                     + t + ") cannot be put in this spreadMap.");
    94      }
    95
    96      public int size() {
    97          return mapData.keySet().size();
    98      }
    99
    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 (! InvokerHelper.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 }