| /* |
| * Copyright 2009 Google Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| * use this file except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| package com.google.gwt.dev.util.collect; |
| |
| import java.io.IOException; |
| import java.io.ObjectInputStream; |
| import java.io.ObjectOutputStream; |
| import java.util.Map; |
| |
| /** |
| * A memory-efficient identity hash map. |
| * |
| * @param <K> the key type |
| * @param <V> the value type |
| */ |
| public class IdentityHashMap<K, V> extends HashMap<K, V> { |
| |
| public IdentityHashMap() { |
| } |
| |
| public IdentityHashMap(Map<? extends K, ? extends V> m) { |
| super(m); |
| } |
| |
| @Override |
| protected boolean keyEquals(Object a, Object b) { |
| return a == b; |
| } |
| |
| @Override |
| protected int keyHashCode(Object k) { |
| return System.identityHashCode(k); |
| } |
| |
| @Override |
| protected boolean valueEquals(Object a, Object b) { |
| return a == b; |
| } |
| |
| @Override |
| protected int valueHashCode(Object k) { |
| return System.identityHashCode(k); |
| } |
| |
| private void readObject(ObjectInputStream in) throws IOException, |
| ClassNotFoundException { |
| in.defaultReadObject(); |
| doReadObject(in); |
| } |
| |
| private void writeObject(ObjectOutputStream out) throws IOException { |
| out.defaultWriteObject(); |
| doWriteObject(out); |
| } |
| } |