ArrayMap.java Source code

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Here is the source code for ArrayMap.java

Source

//package ru.susu.algebra.util;

import java.util.AbstractMap;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

/**
 * @author akargapolov
 * @since: 05.05.2010
 */
public class ArrayMap<K, V> extends AbstractMap<K, V> {
    private ArrayList<K> _keys = new ArrayList<K>();
    private ArrayList<V> _values = new ArrayList<V>();

    private Map<K, Integer> _index = null;

    public ArrayList<K> getKeys() {
        return _keys;
    }

    public ArrayList<V> getValues() {
        return _values;
    }

    @Override
    public int size() {
        return _keys.size();
    }

    public void trimToSize() {
        _keys.trimToSize();
        _values.trimToSize();
    }

    @Override
    public V put(K key, V value) {
        ensureIndexInitilized();
        Integer index = _index.get(key);
        if (index == null) {
            _keys.add(key);
            _values.add(value);
            index = _values.size() - 1;
            _index.put(key, index);
        } else {
            _keys.set(index, key);
            _values.set(index, value);
        }
        return _values.get(index);
    }

    @Override
    public boolean containsKey(Object key) {
        return null != get(key);
    }

    @Override
    public V get(Object key) {
        ensureIndexInitilized();
        Integer index = _index.get(key);
        return index == null ? null : _values.get(index);
    }

    protected void ensureIndexInitilized() {
        if (_index == null) {
            _index = new HashMap<K, Integer>();
            for (int index = 0; index < _keys.size(); index++) {
                _index.put(_keys.get(index), index);
            }
        }
    }

    public void dropIndex() {
        _index = null;
    }

    @Override
    public void clear() {
        _keys = new ArrayList<K>();
        _values = new ArrayList<V>();
        _index = null;
    }

}