commons-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From t.@apache.org
Subject svn commit: r1671832 - in /commons/proper/collections/trunk/src: changes/changes.xml main/java/org/apache/commons/collections4/map/LRUMap.java test/java/org/apache/commons/collections4/map/LRUMapTest.java
Date Tue, 07 Apr 2015 12:25:18 GMT
Author: tn
Date: Tue Apr  7 12:25:18 2015
New Revision: 1671832

URL: http://svn.apache.org/r1671832
Log:
[COLLECTIONS-395] Added LRUMap#get(Object, boolean) to query the map without affecting the
lru order. Thanks to David Hawthorne.

Modified:
    commons/proper/collections/trunk/src/changes/changes.xml
    commons/proper/collections/trunk/src/main/java/org/apache/commons/collections4/map/LRUMap.java
    commons/proper/collections/trunk/src/test/java/org/apache/commons/collections4/map/LRUMapTest.java

Modified: commons/proper/collections/trunk/src/changes/changes.xml
URL: http://svn.apache.org/viewvc/commons/proper/collections/trunk/src/changes/changes.xml?rev=1671832&r1=1671831&r2=1671832&view=diff
==============================================================================
--- commons/proper/collections/trunk/src/changes/changes.xml (original)
+++ commons/proper/collections/trunk/src/changes/changes.xml Tue Apr  7 12:25:18 2015
@@ -22,6 +22,10 @@
   <body>
 
   <release version="4.1" date="TBD" description="">
+    <action issue="COLLECTIONS-395" dev="tn" type="add" due-to="David Hawthorne">
+      Added method "LRUMap#get(Object, boolean)" that allows to query the map
+      without affecting the least recently used order.
+    </action>
     <action issue="COLLECTIONS-558" dev="tn" type="fix" due-to="Felix Rabe">
       Changed return type of "ListOrderedSet#remove(int)" from Object to the generic type
parameter.
     </action>

Modified: commons/proper/collections/trunk/src/main/java/org/apache/commons/collections4/map/LRUMap.java
URL: http://svn.apache.org/viewvc/commons/proper/collections/trunk/src/main/java/org/apache/commons/collections4/map/LRUMap.java?rev=1671832&r1=1671831&r2=1671832&view=diff
==============================================================================
--- commons/proper/collections/trunk/src/main/java/org/apache/commons/collections4/map/LRUMap.java
(original)
+++ commons/proper/collections/trunk/src/main/java/org/apache/commons/collections4/map/LRUMap.java
Tue Apr  7 12:25:18 2015
@@ -116,7 +116,7 @@ public class LRUMap<K, V>
      * Constructs a new, empty map with the specified initial capacity and
      * load factor.
      *
-     * @param maxSize  the maximum size of the ma
+     * @param maxSize  the maximum size of the map
      * @param loadFactor  the load factor
      * @param scanUntilRemovable  scan until a removeable entry is found, default false
      * @throws IllegalArgumentException if the maximum size is less than one
@@ -166,18 +166,36 @@ public class LRUMap<K, V>
      * Gets the value mapped to the key specified.
      * <p>
      * This operation changes the position of the key in the map to the
-     * most recently used position (first).
+     * most recently used position (last).
      *
      * @param key  the key
      * @return the mapped value, null if no match
      */
     @Override
     public V get(final Object key) {
+        return get(key, true);
+    }
+
+    /**
+     * Gets the value mapped to the key specified.
+     * <p>
+     * If {@code updateToMRU} is {@code true}, the position of the key in the map
+     * is changed to the most recently used position (last), otherwise the iteration
+     * order is not changed by this operation.
+     *
+     * @param key  the key
+     * @param updateToMRU  whether the key shall be updated to the
+     *   most recently used position
+     * @return the mapped value, null if no match
+     */
+    public V get(final Object key, final boolean updateToMRU) {
         final LinkEntry<K, V> entry = getEntry(key);
         if (entry == null) {
             return null;
         }
-        moveToMRU(entry);
+        if (updateToMRU) {
+            moveToMRU(entry);
+        }
         return entry.getValue();
     }
 
@@ -214,7 +232,7 @@ public class LRUMap<K, V>
     /**
      * Updates an existing key-value mapping.
      * <p>
-     * This implementation moves the updated entry to the top of the list
+     * This implementation moves the updated entry to the end of the list
      * using {@link #moveToMRU(AbstractLinkedMap.LinkEntry)}.
      *
      * @param entry  the entry to update

Modified: commons/proper/collections/trunk/src/test/java/org/apache/commons/collections4/map/LRUMapTest.java
URL: http://svn.apache.org/viewvc/commons/proper/collections/trunk/src/test/java/org/apache/commons/collections4/map/LRUMapTest.java?rev=1671832&r1=1671831&r2=1671832&view=diff
==============================================================================
--- commons/proper/collections/trunk/src/test/java/org/apache/commons/collections4/map/LRUMapTest.java
(original)
+++ commons/proper/collections/trunk/src/test/java/org/apache/commons/collections4/map/LRUMapTest.java
Tue Apr  7 12:25:18 2015
@@ -224,6 +224,55 @@ public class LRUMapTest<K, V> extends Ab
         assertSame(values[3], vit.next());
     }
 
+    public void testAccessOrder2() {
+        if (!isPutAddSupported() || !isPutChangeSupported()) {
+            return;
+        }
+        final K[] keys = getSampleKeys();
+        final V[] values = getSampleValues();
+        Iterator<K> kit = null;
+        Iterator<V> vit = null;
+
+        resetEmpty();
+        LRUMap<K, V> lruMap = (LRUMap<K, V>) map;
+        
+        lruMap.put(keys[0], values[0]);
+        lruMap.put(keys[1], values[1]);
+        kit = lruMap.keySet().iterator();
+        assertSame(keys[0], kit.next());
+        assertSame(keys[1], kit.next());
+        vit = lruMap.values().iterator();
+        assertSame(values[0], vit.next());
+        assertSame(values[1], vit.next());
+
+        // no change to order
+        lruMap.put(keys[1], values[1]);
+        kit = lruMap.keySet().iterator();
+        assertSame(keys[0], kit.next());
+        assertSame(keys[1], kit.next());
+        vit = lruMap.values().iterator();
+        assertSame(values[0], vit.next());
+        assertSame(values[1], vit.next());
+
+        // no change to order
+        lruMap.get(keys[1], false);
+        kit = lruMap.keySet().iterator();
+        assertSame(keys[0], kit.next());
+        assertSame(keys[1], kit.next());
+        vit = lruMap.values().iterator();
+        assertSame(values[0], vit.next());
+        assertSame(values[1], vit.next());
+
+        // change to order
+        lruMap.get(keys[0], true);
+        kit = lruMap.keySet().iterator();
+        assertSame(keys[1], kit.next());
+        assertSame(keys[0], kit.next());
+        vit = lruMap.values().iterator();
+        assertSame(values[1], vit.next());
+        assertSame(values[0], vit.next());
+    }
+
     @SuppressWarnings("unchecked")
     public void testClone() {
         final LRUMap<K, V> map = new LRUMap<K, V>(10);



Mime
View raw message