1 /* 2 * Copyright (c) 2014, 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.graph; 24 25 import java.util.Iterator; 26 import java.util.NoSuchElementException; 27 28 class NodeUsageIterator implements Iterator<Node> { 29 30 final Node node; 31 int index = -1; 32 Node current; 33 34 void advance() { 35 current = null; 36 index++; 37 if (index == 0) { 38 current = node.usage0; 39 } else if (index == 1) { 40 current = node.usage1; 41 } else { 42 int relativeIndex = index - Node.INLINE_USAGE_COUNT; 43 if (relativeIndex < node.extraUsagesCount) { 44 current = node.extraUsages[relativeIndex]; 45 } 46 } 47 } 48 49 NodeUsageIterator(Node node) { 50 this.node = node; 51 advance(); 52 } 53 54 @Override 55 public boolean hasNext() { 56 return current != null; 57 } 58 59 @Override 60 public Node next() { 61 Node result = current; 62 if (result == null) { 63 throw new NoSuchElementException(); 64 } 65 advance(); 66 return result; 67 } 68 69 @Override 70 public void remove() { 71 throw new UnsupportedOperationException(); 72 } 73 }