001/*
002 * Copyright (c) 2014, 2014, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.lir.constopt;
024
025import java.util.*;
026import java.util.function.*;
027
028import com.oracle.graal.lir.*;
029
030/**
031 * Maps variables to a generic type.
032 *
033 * TODO (je) evaluate data structure
034 */
035class VariableMap<T> {
036
037    private final ArrayList<T> content;
038
039    public VariableMap() {
040        content = new ArrayList<>();
041    }
042
043    public T get(Variable key) {
044        if (key == null || key.index >= content.size()) {
045            return null;
046        }
047        return content.get(key.index);
048    }
049
050    public T put(Variable key, T value) {
051        assert key != null : "Key cannot be null";
052        assert value != null : "Value cannot be null";
053        while (key.index >= content.size()) {
054            content.add(null);
055        }
056        return content.set(key.index, value);
057    }
058
059    public T remove(Variable key) {
060        assert key != null : "Key cannot be null";
061        if (key.index >= content.size()) {
062            return null;
063        }
064        return content.set(key.index, null);
065    }
066
067    public void forEach(Consumer<T> action) {
068        for (T e : content) {
069            if (e != null) {
070                action.accept(e);
071            }
072        }
073    }
074
075    /**
076     * Keeps only keys which match the given predicate.
077     */
078    public void filter(Predicate<T> predicate) {
079        for (int i = 0; i < content.size(); i++) {
080            T e = content.get(i);
081            if (e != null && !predicate.test(e)) {
082                content.set(i, null);
083            }
084        }
085    }
086
087}