ExactTxData.java

/**
 * Copyright (c) 2002-2011 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.index.impl.lucene;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.apache.lucene.search.Query;
import org.apache.lucene.search.Searcher;
import org.neo4j.helpers.Pair;

public class ExactTxData extends TxData
{
    private Map<String, Map<Object, Set<Object>>> data;

    ExactTxData( LuceneIndex index )
    {
        super( index );
    }

    @Override
    TxData add( Object entityId, String key, Object value )
    {
        idCollection( key, value, true ).add( entityId );
        return this;
    }

    private Set<Object> idCollection( String key, Object value, boolean create )
    {
        Map<Object, Set<Object>> keyMap = keyMap( key, create );
        if ( keyMap == null )
        {
            return null;
        }

        Set<Object> ids = keyMap.get( value );
        if ( ids == null && create )
        {
            ids = new HashSet<Object>();
            keyMap.put( value, ids );
        }
        return ids;
    }

    private Map<Object, Set<Object>> keyMap( String key, boolean create )
    {
        if ( data == null )
        {
            if ( create )
            {
                data = new HashMap<String, Map<Object,Set<Object>>>();
            }
            else
            {
                return null;
            }
        }

        Map<Object, Set<Object>> inner = data.get( key );
        if ( inner == null && create )
        {
            inner = new HashMap<Object, Set<Object>>();
            data.put( key, inner );
        }
        return inner;
    }

    private TxData toFullTxData()
    {
        FullTxData data = new FullTxData( index );
        if ( this.data != null )
        {
            for ( Map.Entry<String, Map<Object, Set<Object>>> entry : this.data.entrySet() )
            {
                String key = entry.getKey();
                for ( Map.Entry<Object, Set<Object>> valueEntry : entry.getValue().entrySet() )
                {
                    Object value = valueEntry.getKey();
                    for ( Object id : valueEntry.getValue() )
                    {
                        data.add( id, key, value );
                    }
                }
            }
        }
        return data;
    }

    @Override
    void close()
    {
    }

    @Override
    Pair<Collection<Long>, TxData> query( Query query, QueryContext contextOrNull )
    {
        if ( contextOrNull != null && contextOrNull.tradeCorrectnessForSpeed )
        {
            return Pair.<Collection<Long>, TxData>of( Collections.<Long>emptyList(), this );
        }

        return toFullTxData().query( query, contextOrNull );
    }

    @Override
    TxData remove( Object entityId, String key, Object value )
    {
        if ( data == null )
        {
            return this;
        }
        Collection<Object> ids = idCollection( key, value, false );
        if ( ids != null )
        {
            ids.remove( entityId );
        }
        return this;
    }

    @Override
    Pair<Collection<Long>, TxData> get( String key, Object value )
    {
        value = value instanceof ValueContext ? ((ValueContext) value).getCorrectValue() : value.toString();
        Set<Object> ids = idCollection( key, value, false );
        if ( ids == null || ids.isEmpty() )
        {
            return Pair.<Collection<Long>, TxData>of( Collections.<Long>emptySet(), this );
        }
        return Pair.<Collection<Long>, TxData>of( toLongs( ids ), this );
    }

    private Collection<Long> toLongs( Set<Object> ids )
    {
        if ( ids.iterator().next() instanceof Long )
        {
            return (Collection) ids;
        }
        else
        {
            Collection<Long> longs = new ArrayList<Long>();
            for ( Object id : ids )
            {
                longs.add( ((RelationshipId) id).id );
            }
            return longs;
        }
    }
    
    @Override
    Pair<Searcher, TxData> asSearcher( QueryContext context )
    {
        if ( context != null && context.tradeCorrectnessForSpeed )
        {
            return Pair.<Searcher, TxData>of( null, this );
        }
        return toFullTxData().asSearcher( context );
    }
}