/**
 * 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.Collections;
import java.util.HashMap;
import java.util.Map;

import org.neo4j.helpers.Pair;
import org.neo4j.kernel.impl.index.IndexStore;

class IndexTypeCache
{
    private final Map<IndexIdentifier, Pair<Integer, IndexType>> cache = Collections.synchronizedMap(
            new HashMap<IndexIdentifier, Pair<Integer, IndexType>>() );
    private final IndexStore indexStore;
    
    IndexTypeCache( IndexStore indexStore )
    {
        this.indexStore = indexStore;
    }
    
    IndexType getIndexType( IndexIdentifier identifier )
    {
        Pair<Integer, IndexType> type = cache.get( identifier );
        Map<String, String> config = indexStore.get( identifier.entityType.getType(), identifier.indexName );
        if ( type != null && config.hashCode() == type.first() )
        {
            return type.other();
        }
        type = Pair.of( config.hashCode(), IndexType.getIndexType( identifier, config ) );
        cache.put( identifier, type );
        return type.other();
    }
    
    void invalidate( IndexIdentifier identifier )
    {
        cache.remove( identifier );
    }
}