[jbosscache-commits] JBoss Cache SVN: r6450 - core/trunk/src/main/java/org/jboss/cache/util.

[jbosscache-commits at lists.jboss.org]

Author: jason.greene at jboss.com
Date: 2008-07-30 19:46:45 -0400 (Wed, 30 Jul 2008)
New Revision: 6450

Modified:
   core/trunk/src/main/java/org/jboss/cache/util/FastCopyHashMap.java
Log:
Fix null handling for iterators/views
Add optimized copy constructor

Modified: core/trunk/src/main/java/org/jboss/cache/util/FastCopyHashMap.java
===================================================================
--- core/trunk/src/main/java/org/jboss/cache/util/FastCopyHashMap.java	2008-07-30 22:58:03 UTC (rev 6449)
+++ core/trunk/src/main/java/org/jboss/cache/util/FastCopyHashMap.java	2008-07-30 23:46:45 UTC (rev 6450)
@@ -40,8 +40,14 @@
  */
 public class FastCopyHashMap<K, V> extends AbstractMap<K, V> implements Map<K, V>, Cloneable, Serializable
 {
+   /**
+    * Marks null keys.
+    */
+   private static final Object NULL = new Object();
 
-   private static final Object NULL = new Object();
+   /**
+    * Serialization ID
+    */
    private static final long serialVersionUID = 10929568968762L;
 
    /**
@@ -80,7 +86,7 @@
    private final float loadFactor;
 
    /**
-    * Counter used to detech changes made outside of an iterator
+    * Counter used to detect changes made outside of an iterator
     */
    private transient int modCount;
 
@@ -104,13 +110,22 @@
       init(initialCapacity, loadFactor);
    }
 
-   public FastCopyHashMap(Map<K, V> data)
+   public FastCopyHashMap(Map<? extends K, ? extends V> map)
    {
-      this();
-      putAll(data);
+      this(map.size());
+      putAll(map);
    }
 
    @SuppressWarnings("unchecked")
+   public FastCopyHashMap(FastCopyHashMap<? extends K, ? extends V> map)
+   {
+      this.table = (Entry<K, V>[])map.table.clone();
+      this.loadFactor = map.loadFactor;
+      this.size = map.size;
+      this.threshold = map.threshold;
+   }
+
+   @SuppressWarnings("unchecked")
    private void init(int initialCapacity, float loadFactor)
    {
       int c = 1;
@@ -139,6 +154,17 @@
       return h ^ (h >>> 7) ^ (h >>> 4);
    }
 
+   @SuppressWarnings("unchecked")
+   private static final <K> K maskNull(K key)
+   {
+      return key == null ? (K) NULL : key;
+   }
+
+   private static final <K> K unmaskNull(K key)
+   {
+      return key == NULL ? null : key;
+   }
+
    private int nextIndex(int index, int length)
    {
       index = (index >= length - 1) ? 0 : index + 1;
@@ -167,7 +193,7 @@
 
    public V get(Object key)
    {
-      if (key == null) key = NULL;
+      key = maskNull(key);
 
       int hash = hash(key);
       int length = table.length;
@@ -188,7 +214,7 @@
 
    public boolean containsKey(Object key)
    {
-      if (key == null) key = NULL;
+      key = maskNull(key);
 
       int hash = hash(key);
       int length = table.length;
@@ -216,12 +242,10 @@
       return false;
    }
 
-   @SuppressWarnings("unchecked")
    public V put(K key, V value)
    {
-      if (key == null) key = (K) NULL;
+      key = maskNull(key);
 
-
       Entry<K, V>[] table = this.table;
       int hash = hash(key);
       int length = table.length;
@@ -306,7 +330,7 @@
 
    public V remove(Object key)
    {
-      if (key == null) key = NULL;
+      key = maskNull(key);
 
       Entry<K, V>[] table = this.table;
       int length = table.length;
@@ -424,7 +448,6 @@
       System.out.println(" Optimal:         " + optimal + " (" + (float) optimal * 100 / total + "%)");
       System.out.println(" Average Distnce: " + ((float) totalSkew / (total - optimal)));
       System.out.println(" Max Distance:    " + maxSkew);
-
    }
 
    public Set<Map.Entry<K, V>> entrySet()
@@ -471,7 +494,7 @@
    @SuppressWarnings("unchecked")
    private void putForCreate(K key, V value)
    {
-      if (key == null) key = (K) NULL;
+      key = maskNull(key);
 
       Entry<K, V>[] table = this.table;
       int hash = hash(key);
@@ -493,11 +516,11 @@
       s.defaultWriteObject();
       s.writeInt(size);
 
-      for (Entry e : table)
+      for (Entry<K,V> e : table)
       {
          if (e != null)
          {
-            s.writeObject(e.key);
+            s.writeObject(unmaskNull(e.key));
             s.writeObject(e.value);
          }
       }
@@ -631,7 +654,7 @@
    {
       public K next()
       {
-         return nextEntry().key;
+         return unmaskNull(nextEntry().key);
       }
    }
 
@@ -664,7 +687,7 @@
       public Map.Entry<K, V> next()
       {
          Entry<K, V> e = nextEntry();
-         return new WriteThroughEntry(e.key, e.value);
+         return new WriteThroughEntry(unmaskNull(e.key), e.value);
       }
 
    }