/* EnumMap.java - Map where keys are enum constants Copyright (C) 2004 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. */ package java.util; /** @since 1.5 */ public class EnumMap, V> extends AbstractMap implements Cloneable, Serializable { V[] store; int cardinality; Class enumClass; /** * The cache for {@link #entrySet()}. */ transient Set> entries; static final Object emptySlot = new Object(); public EnumMap(Class keyType) { store = new V[keyType.getEnumConstants().length]; Arrays.fill(store, emptySlot); cardinality = 0; enumClass = keyType; } public EnumMap(EnumMap map) { store = (V[]) map.store.clone(); cardinality = map.cardinality; enumClass = map.enumClass; } public EnumMap(Map map) { if (map instanceof EnumMap) { EnumMap other = (EnumMap) map; store = (V[]) other.store.clone(); cardinality = other.cardinality; enumClass = other.enumClass; } else { for (K key : map.keySet()) { V value = map.get(key); if (store == null) { enumClass = key.getDeclaringClass(); store = new V[enumClass.getEnumConstants().length]; } int o = key.ordinal(); if (store[o] == emptySlot) ++cardinality; store[o] = value; } // There must be a single element. if (store == null) throw new IllegalArgumentException("no elements in map"); } } public int size() { return cardinality; } public boolean containsValue(Object value) { for (V i : store) { if (i != emptySlot && AbstractCollection.equals(i , value)) return true; } return false; } public boolean containsKey(Object key) { if (! (key instanceof Enum)) return false; Enum e = (Enum) key; if (e.enumClass != enumClass) return false; return store[e.ordinal()] != emptySlot; } public V get(Object key) { if (! (key instanceof Enum)) return null; Enum e = (Enum) key; if (e.enumClass != enumClass) return null; return store[e.ordinal()]; } public V put(K key, V value) { int o = key.ordinal(); V result; if (store[o] == emptySlot) { result = null; ++cardinality; } else result = store[o]; store[o] = value; return result; } public V remove(Object key) { if (! (key instanceof Enum)) return null; Enum e = (Enum) key; if (e.enumClass != enumClass) return null; V result = store[e.ordinal()]; if (result == emptySlot) result = null; else --cardinality; store[e.ordinal()] = emptySlot; return result; } public void putAll(Map map) { for (K key : map.keySet()) { V value = map.get(key); int o = key.ordinal(); if (store[o] == emptySlot) ++cardinality; store[o] = value; } } public void clear() { Arrays.fill(store, emptySlot); cardinality = 0; } public Set keySet() { if (keys == null) { keys = new AbstractSet() { public int size() { return cardinality; } public Iterator iterator() { return new Iterator() { int count = 0; int index = -1; public boolean hasNext() { return count < cardinality; } public K next() { ++count; for (++index; store[index] == emptySlot; ++index) ; return enumClass.getEnumConstants()[index]; } public void remove() { --cardinality; store[index] = emptySlot; } }; } public void clear() { EnumMap.this.clear(); } public boolean contains(Object o) { return contains(o); } public boolean remove(Object o) { return EnumMap.this.remove(o); } }; } return keys; } public Collection values() { if (values == null) { values = new AbstractCollection() { public int size() { return cardinality; } public Iterator iterator() { return new Iterator() { int count = 0; int index = -1; public boolean hasNext() { return count < cardinality; } public K next() { ++count; for (++index; store[index] == emptySlot; ++index) ; return store[index]; } public void remove() { --cardinality; store[index] = emptySlot; } }; } public void clear() { EnumMap.this.clear(); } }; } return values; } public Set> entrySet() { if (entries == null) { entries = new AbstractSet>() { public int size() { return cardinality; } public Iterator> iterator() { return new Iterator>() { int count = 0; int index = -1; public boolean hasNext() { return count < cardinality; } public K next() { ++count; for (++index; store[index] == emptySlot; ++index) ; // FIXME: we could just return something that // only knows the index. That would be cleaner. return new AbstractMap.BasicMapEntry(enumClass.getEnumConstants()[index], store[index]) { public V setValue(K newVal) { value = newVal; return put(key, newVal); } }; } public void remove() { --cardinality; store[index] = emptySlot; } }; } public void clear() { EnumMap.this.clear(); } public boolean contains(Object o) { if (! (o instanceof Map.Entry)) return false; Map.Entry other = (Map.Entry) o; return (containsKey(other.getKey()) && AbstractCollection.equals(get(other.getKey()), other.getValue())); } public boolean remove(Object o) { if (! (o instanceof Map.Entry)) return false; Map.Entry other = (Map.Entry) o; return EnumMap.this.remove(other.getKey()); } }; } return entries; } public boolean equals(Object o) { if (! (o instanceof EnumMap)) return false; EnumMap other = (EnumMap) o; if (other.enumClass != enumClass || other.cardinality != cardinality) return false; return Arrays.equals(store, other.store); } public EnumMap clone() { EnumMap r = (EnumMap) super.clone(); r.store = (V[]) store.clone(); return r; } }