001/* Copyright (C) 2013 TU Dortmund
002 * This file is part of AutomataLib, http://www.automatalib.net/.
003 * 
004 * AutomataLib is free software; you can redistribute it and/or
005 * modify it under the terms of the GNU Lesser General Public
006 * License version 3.0 as published by the Free Software Foundation.
007 * 
008 * AutomataLib is distributed in the hope that it will be useful,
009 * but WITHOUT ANY WARRANTY; without even the implied warranty of
010 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
011 * Lesser General Public License for more details.
012 * 
013 * You should have received a copy of the GNU Lesser General Public
014 * License along with AutomataLib; if not, see
015 * http://www.gnu.de/documents/lgpl.en.html.
016 */
017package net.automatalib.commons.util.mappings;
018
019import net.automatalib.commons.util.array.ResizingObjectArray;
020import net.automatalib.commons.util.nid.IDChangeListener;
021import net.automatalib.commons.util.nid.NumericID;
022
023public final class ArrayMapping<K extends NumericID, V> implements MutableMapping<K, V>,
024                IDChangeListener<K> {
025
026        private final ResizingObjectArray storage;
027        
028        public ArrayMapping() {
029                storage = new ResizingObjectArray();
030        }
031        
032        public ArrayMapping(int initialSize) {
033                storage = new ResizingObjectArray(initialSize);
034        }
035        
036        @Override
037        @SuppressWarnings("unchecked")
038        public V get(K elem) {
039                int id = elem.getId();
040                if(id >= storage.array.length)
041                        return null;
042                return (V)storage.array[id];
043        }
044
045        @Override
046        @SuppressWarnings("unchecked")
047        public V put(K key, V value) {
048                int id = key.getId();
049                storage.ensureCapacity(id+1);
050                V old = (V)storage.array[id];
051                storage.array[id] = value;
052                return old;
053        }
054
055        @Override
056        public void idChanged(K obj, int newId, int oldId) {
057                if(newId == -1) {
058                        if(oldId < storage.array.length)
059                                storage.array[oldId] = null;
060                        return;
061                }
062                Object oldVal = null;
063                if(oldId < storage.array.length) {
064                        oldVal = storage.array[oldId];
065                        storage.array[oldId] = oldVal;
066                }
067                storage.ensureCapacity(newId+1);
068                storage.array[newId] = oldVal;
069        }
070        
071}