1 /*
   2  * Copyright (c) 2014, 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.lir.constopt;
  24 
  25 import java.util.ArrayList;
  26 import java.util.function.Consumer;
  27 import java.util.function.Predicate;
  28 
  29 import org.graalvm.compiler.lir.Variable;
  30 
  31 /**
  32  * Maps variables to a generic type.
  33  *
  34  * TODO (je) evaluate data structure
  35  */
  36 class VariableMap<T> {
  37 
  38     private final ArrayList<T> content;
  39 
  40     VariableMap() {
  41         content = new ArrayList<>();
  42     }
  43 
  44     public T get(Variable key) {
  45         if (key == null || key.index >= content.size()) {
  46             return null;
  47         }
  48         return content.get(key.index);
  49     }
  50 
  51     public T put(Variable key, T value) {
  52         assert key != null : "Key cannot be null";
  53         assert value != null : "Value cannot be null";
  54         while (key.index >= content.size()) {
  55             content.add(null);
  56         }
  57         return content.set(key.index, value);
  58     }
  59 
  60     public T remove(Variable key) {
  61         assert key != null : "Key cannot be null";
  62         if (key.index >= content.size()) {
  63             return null;
  64         }
  65         return content.set(key.index, null);
  66     }
  67 
  68     public void forEach(Consumer<T> action) {
  69         for (T e : content) {
  70             if (e != null) {
  71                 action.accept(e);
  72             }
  73         }
  74     }
  75 
  76     /**
  77      * Keeps only keys which match the given predicate.
  78      */
  79     public void filter(Predicate<T> predicate) {
  80         for (int i = 0; i < content.size(); i++) {
  81             T e = content.get(i);
  82             if (e != null && !predicate.test(e)) {
  83                 content.set(i, null);
  84             }
  85         }
  86     }
  87 
  88 }