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 static org.graalvm.compiler.graph.Graph.isModificationCountsEnabled;
  26 
  27 import org.graalvm.compiler.graph.iterators.NodeIterable;
  28 
  29 class NodeUsageIterable implements NodeIterable<Node> {
  30 
  31     private final Node node;
  32 
  33     NodeUsageIterable(Node node) {
  34         this.node = node;
  35     }
  36 
  37     @Override
  38     public NodeUsageIterator iterator() {
  39         if (isModificationCountsEnabled()) {
  40             return new NodeUsageWithModCountIterator(node);
  41         } else {
  42             return new NodeUsageIterator(node);
  43         }
  44     }
  45 
  46     @Override
  47     public Node first() {
  48         return node.usage0;
  49     }
  50 
  51     @Override
  52     public boolean isEmpty() {
  53         return node.usage0 == null;
  54     }
  55 
  56     @Override
  57     public boolean isNotEmpty() {
  58         return node.usage0 != null;
  59     }
  60 
  61     @Override
  62     public int count() {
  63         return node.getUsageCount();
  64     }
  65 }