Author: jason.greene(a)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); } }