added contract to LRUMap - subclasses can override removeLRU()

and remove(Object) to manipulate objects on their way out of the cache


git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/collections/trunk@130522 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/collections/LRUMap.java

@@ -1,7 +1,7 @@
 /*
- * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/java/org/apache/commons/collections/LRUMap.java,v 1.6 2002/02/14 20:21:49 morgand Exp $
- * $Revision: 1.6 $
- * $Date: 2002/02/14 20:21:49 $
+ * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/java/org/apache/commons/collections/LRUMap.java,v 1.7 2002/02/14 20:58:48 morgand Exp $
+ * $Revision: 1.7 $
+ * $Date: 2002/02/14 20:58:48 $
  *
  * ====================================================================
  *
@@ -154,14 +154,10 @@ public class LRUMap extends HashMap implements Externalizable {
         maximumSize = i;
         bubbleList = new ArrayList( i );
     }
-
-    /** Removes the least recently used object from the Map.
-      * @return the key of the removed item
-      */
+

     /**
      * <p>
      *   Removes the least recently used object from the Map.
      * </p>
      * 
      * <p>
      * This method will determine the object to
      * remove and call remove(Object).  If you want a subclass
      * to perform some operation before removing an Object,
      * you can override remove(Object) for all remove
      * operations, or removeLRU() if you only want to affect
      * automatic removes.
      * </p>
      * 
      * @return the key of the removed item
      */
     public Object removeLRU() {
         int lastItem = size() - 1;
-        Object key = bubbleList.remove( lastItem );
-        ValuePositionPair pair = removePair( key );
+        Object key = bubbleList.get( lastItem );

         remove( key );
         return key;
     }
     
@@ -188,14 +184,12 @@ public class LRUMap extends HashMap implements Externalizable {
         }
         return pair.value;
     }
-
+

     /**
      * <p>Removes the key and its Object from the Map.</p>
      * 
      * <p>(Note: this may result in the "Least Recently Used"
      * object being removed from the Map.  In that case,
      * the removeLRU() method is called.  See javadoc for
      * removeLRU() for more details.)</p>
      * 
      * @param key    Key of the Object to add.
      * @param value  Object to add
      * @return Former value of the key
      * @see removeLRU()
      */
     public Object put( Object key, Object value ) {

         ValuePositionPair pair = new ValuePositionPair( value );
         int mapSize = size();

         // check to see if the object already exists in
         // our LRUMap, if it does then the position in the
         // bubble sort is OK
         int keyIndex = bubbleList.indexOf(key);
         if (keyIndex != -1) {

             pair.position = keyIndex;

         } else if ( mapSize >= maximumSize ) {
             // lets retire the least recently used item in the cache
             int lastIndex = maximumSize - 1;
-            pair.position = lastIndex;
-            Object oldKey = bubbleList.set( lastIndex, key );
-            super.remove( oldKey );
+            pair.position = lastIndex;

             removeLRU();

             bubbleList.add(lastIndex, key);
         } else {
             pair.position = mapSize;
             bubbleList.add( mapSize, key );