001/* 002 * This file is part of the Jikes RVM project (http://jikesrvm.org). 003 * 004 * This file is licensed to You under the Eclipse Public License (EPL); 005 * You may not use this file except in compliance with the License. You 006 * may obtain a copy of the License at 007 * 008 * http://www.opensource.org/licenses/eclipse-1.0.php 009 * 010 * See the COPYRIGHT.txt file distributed with this work for information 011 * regarding copyright ownership. 012 */ 013package org.jikesrvm.util; 014 015import org.jikesrvm.runtime.Magic; 016import org.jikesrvm.util.HashMapRVM.Bucket; 017 018/** 019 * The same as {@link HashMapRVM} except object identities determine equality 020 * not the equals method. 021 */ 022public final class IdentityHashMapRVM<K, V> extends AbstractHashMapRVM<K, V> { 023 @Override 024 boolean same(K k1, K k2) { 025 return k1 == k2; 026 } 027 028 @Override 029 protected int hashTheKey(K key) { 030 if (!org.jikesrvm.VM.runningVM) { 031 return Magic.bootImageIdentityHashCode(key); 032 } else { 033 return System.identityHashCode(key); 034 } 035 } 036 037 @Override 038 AbstractBucket<K,V> createNewBucket(K key, V value, AbstractBucket<K, V> next) { 039 return new Bucket<K,V>(key, value, next); 040 } 041 042 public IdentityHashMapRVM() { 043 super(DEFAULT_SIZE); 044 } 045 046 public IdentityHashMapRVM(int size) { 047 super(size); 048 } 049}