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 */
23package org.graalvm.compiler.phases.common.util;
24
25import java.util.EnumSet;
26import java.util.HashSet;
27import java.util.Set;
28
29import org.graalvm.compiler.graph.Graph.NodeEvent;
30import org.graalvm.compiler.graph.Graph.NodeEventListener;
31import org.graalvm.compiler.graph.Node;
32import org.graalvm.compiler.graph.Node.IndirectCanonicalization;
33import org.graalvm.util.Equivalence;
34import org.graalvm.util.EconomicSet;
35
36/**
37 * A simple {@link NodeEventListener} implementation that accumulates event nodes in a
38 * {@link HashSet}.
39 */
40public class HashSetNodeEventListener implements NodeEventListener {
41
42    private final EconomicSet<Node> nodes;
43    private final Set<NodeEvent> filter;
44
45    /**
46     * Creates a {@link NodeEventListener} that collects nodes from all events.
47     */
48    public HashSetNodeEventListener() {
49        this.nodes = EconomicSet.create(Equivalence.IDENTITY);
50        this.filter = EnumSet.allOf(NodeEvent.class);
51    }
52
53    /**
54     * Creates a {@link NodeEventListener} that collects nodes from all events that match a given
55     * filter.
56     */
57    public HashSetNodeEventListener(Set<NodeEvent> filter) {
58        this.nodes = EconomicSet.create(Equivalence.IDENTITY);
59        this.filter = filter;
60    }
61
62    /**
63     * Excludes a given event from those for which nodes are collected.
64     */
65    public HashSetNodeEventListener exclude(NodeEvent e) {
66        filter.remove(e);
67        return this;
68    }
69
70    @Override
71    public void event(NodeEvent e, Node node) {
72        if (filter.contains(e)) {
73            nodes.add(node);
74            if (node instanceof IndirectCanonicalization) {
75                for (Node usage : node.usages()) {
76                    nodes.add(usage);
77                }
78            }
79        }
80    }
81
82    /**
83     * Gets the set being used to accumulate the nodes communicated to this listener.
84     */
85    public EconomicSet<Node> getNodes() {
86        return nodes;
87    }
88}
89