de.dhke.projects.cutil.collections.WeightedSet.java Source code

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Here is the source code for de.dhke.projects.cutil.collections.WeightedSet.java

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/**
 * (c) 2009-2014 Peter Wullinger
 *
 * $Id$
 *
 * Use, modification and restribution of this file are covered by the
 * terms of the Artistic License 2.0.
 *
 * You should have received a copy of the license terms in a file named
 * "LICENSE" together with this software package.
 *
 * Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT
 * HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
 * A PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE
 * EXTENT PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO
 * COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT
 * OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 **/
package de.dhke.projects.cutil.collections;

import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.apache.commons.collections15.map.HashedMap;

/**
 *
 * @param <K> 
 * @author Peter Wullinger <java@dhke.de>
 */
public class WeightedSet<K> implements Map<K, Double> {
    private final Map<K, Double> _backend = new HashedMap<>();

    public WeightedSet() {
    }

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

    @Override
    public boolean isEmpty() {
        return _backend.isEmpty();
    }

    @Override
    public boolean containsKey(Object key) {
        return _backend.containsKey(key);
    }

    @Override
    public boolean containsValue(Object value) {
        return _backend.containsValue(value);
    }

    @Override
    public Double get(Object key) {
        Double value = _backend.get(key);
        if (value == null)
            return 0.0;
        else
            return value;
    }

    @Override
    public Double put(K key, Double value) {
        if ((value == null) || (value.doubleValue() == 0.0)) {
            value = get(key);
            remove(key);
            return value;
        } else {
            final Double oldValue = _backend.put(key, value);
            if (oldValue == null)
                return 0.0;
            else
                return oldValue;
        }
    }

    @Override
    public Double remove(Object key) {
        return _backend.remove(key);
    }

    @Override
    public void putAll(Map<? extends K, ? extends Double> m) {
        for (Entry<? extends K, ? extends Double> entry : m.entrySet())
            put(entry.getKey(), entry.getValue());
    }

    @Override
    public void clear() {
        _backend.clear();
    }

    @Override
    public Set<K> keySet() {
        return Collections.unmodifiableSet(_backend.keySet());
    }

    @Override
    public Collection<Double> values() {
        return Collections.unmodifiableCollection(_backend.values());
    }

    @Override
    public Set<Entry<K, Double>> entrySet() {
        return Collections.unmodifiableSet(_backend.entrySet());
    }

    public double add(K key, double value) {
        final double oldValue = get(key);
        final Double sum = value + oldValue;
        return put(key, sum);
    }

    public double sub(K key, double value) {
        final double oldValue = get(key);
        final Double diff = oldValue - value;
        return put(key, diff);
    }

    public void addAll(Map<K, Double> m) {
        for (Entry<? extends K, ? extends Double> entry : m.entrySet())
            add(entry.getKey(), entry.getValue());
    }

    public void subAll(Map<K, Double> m) {
        for (Entry<? extends K, ? extends Double> entry : m.entrySet())
            sub(entry.getKey(), entry.getValue());
    }

    @Override
    public String toString() {
        return _backend.toString();
    }
}