org.jactr.core.module.declarative.search.map.SortedValueMap.java Source code

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Here is the source code for org.jactr.core.module.declarative.search.map.SortedValueMap.java

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/*
 * Created on Oct 12, 2006 Copyright (C) 2001-6, Anthony Harrison anh23@pitt.edu
 * (jactr.org) This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of the License,
 * or (at your option) any later version. This library is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
 * the GNU Lesser General Public License for more details. You should have
 * received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place, Suite 330, Boston, MA 02111-1307 USA
 */
package org.jactr.core.module.declarative.search.map;

import java.util.Collection;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import javolution.util.FastComparator;
import javolution.util.FastMap;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * extends default value map to provide sortable values
 * @author harrison
 *
 * @param <V>
 * @param <I>
 */
public class SortedValueMap<V extends Comparable<V>, I> extends DefaultValueMap<V, I> {
    /**
     * logger definition
     */
    static public final Log LOGGER = LogFactory.getLog(SortedValueMap.class);

    private SortedSet<V> _sortedValues;

    public SortedValueMap() {
        super();
    }

    /**
     * overridden to create a sortable set to track the sorted keys, but we
     * still use the same core map
     * 
     * @see org.jactr.core.module.declarative.search.map.DefaultValueMap#instantiateCoreMap()
     */
    @Override
    protected Map<V, Collection<I>> instantiateCoreMap() {
        _sortedValues = new TreeSet<V>();
        // return new TreeMap<V, Collection<I>>();
        //return super.instantiateCoreMap();
        FastMap<V, Collection<I>> rtn = new FastMap<V, Collection<I>>();
        //since the values will be sorted, we can assume that the hashes are not
        // evenly distributed
        rtn.setKeyComparator(FastComparator.REHASH);
        return rtn;
    }

    @Override
    protected Collection<I> instantiateCoreCollection(V forValue) {
        _sortedValues.add(forValue);
        return super.instantiateCoreCollection(forValue);
    }

    public void clear() {
        super.clear();
        try {
            getLock().writeLock().lock();
            _sortedValues.clear();
        } finally {
            getLock().writeLock().unlock();
        }
    }

    @Override
    public Collection<I> greaterThan(V value) {
        if (value == null)
            throw new NullPointerException("null values are not permitted as keys");

        Set<I> rtn = instantiateReturnSet();
        ReentrantReadWriteLock lock = getLock();
        try {
            lock.readLock().lock();

            for (V tmpValue : _sortedValues.tailSet(value))
                if (!tmpValue.equals(value))
                    rtn.addAll(get(tmpValue));

            //      TreeMap<V, Collection<I>> coreMap = (TreeMap<V, Collection<I>>) getCoreMap();
            //
            //      Map<V, Collection<I>> tail = coreMap.tailMap(value);
            //      for (V tmpValue : tail.keySet())
            //      {
            //        if (!tmpValue.equals(value)) rtn.addAll(get(tmpValue));
            //      }
            return rtn;
        } finally {
            lock.readLock().unlock();
        }
    }

    @Override
    public Collection<I> lessThan(V value) {
        if (value == null)
            throw new NullPointerException("null values are not permitted as keys");

        Set<I> rtn = instantiateReturnSet();
        ReentrantReadWriteLock lock = getLock();
        try {
            lock.readLock().lock();

            for (V tmpValue : _sortedValues.headSet(value))
                rtn.addAll(get(tmpValue));

            //      TreeMap<V, Collection<I>> coreMap = (TreeMap<V, Collection<I>>) getCoreMap();
            //
            //      Map<V, Collection<I>> head = coreMap.headMap(value);
            //      for (Collection<I> values : head.values())
            //        if (values != null) rtn.addAll(values);
            return rtn;
        } finally {
            lock.readLock().unlock();
        }
    }
}