Mercurial > hg > truffle
view graal/com.oracle.max.base/src/com/sun/max/collect/LinkedIdentityHashMap.java @ 4213:e4cfa571d8c4
Do not emit stack-to-stack moves.
author | Christian Wimmer <Christian.Wimmer@Oracle.com> |
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date | Tue, 03 Jan 2012 18:47:27 -0800 |
parents | bc8527f3071c |
children |
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/* * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.max.collect; import java.util.*; import com.sun.max.*; /** */ public class LinkedIdentityHashMap<K, V> extends IdentityHashMap<K, V> implements Iterable<K> { /** * */ private static final long serialVersionUID = -8084814503481369783L; private final LinkedList<K> order = new LinkedList<>(); public LinkedIdentityHashMap() { } public LinkedIdentityHashMap(int expectedMaxSize) { super(expectedMaxSize); } @Override public V put(K key, V value) { final V oldValue = super.put(key, value); if (oldValue == null) { if (value != null) { order.add(key); } } else { if (value == null) { order.remove(key); } } return oldValue; } public Iterator<K> iterator() { return order.iterator(); } public K first() { return order.getFirst(); } public K last() { return order.getLast(); } @Override public boolean equals(Object other) { if (other instanceof LinkedIdentityHashMap) { final LinkedIdentityHashMap map = (LinkedIdentityHashMap) other; if (order.size() != map.order.size()) { return false; } final Iterator iterator = map.order.iterator(); for (K key : order) { if (key != iterator.next() || !get(key).equals(map.get(key))) { return false; } } return true; } return false; } @Override public int hashCode() { return order.hashCode(); } @Override public LinkedIdentityHashMap<K, V> clone() { return Utils.cast(super.clone()); } public Collection<K> toCollection() { return keySet(); } }