1 /* 2 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package org.graalvm.compiler.core.common.util; 24 25 import java.util.ArrayList; 26 import java.util.Collection; 27 import java.util.HashSet; 28 import java.util.Set; 29 30 /** 31 * Mimic a set implementation with an ArrayList. Beneficial for small sets (compared to 32 * {@link HashSet}). 33 */ 34 public class ArraySet<E> extends ArrayList<E> implements Set<E> { 35 private static final long serialVersionUID = 4476957522387436654L; 36 37 public ArraySet() { 38 super(); 39 } 40 41 public ArraySet(int i) { 42 super(i); 43 } 44 45 public ArraySet(Collection<? extends E> c) { 46 super(c); 47 } 48 49 @Override 50 public boolean add(E e) { 51 // avoid duplicated entries 52 if (contains(e)) { 53 return false; 54 } 55 return super.add(e); 56 } 57 }