org.neo4j.kernel.impl.index.IndexDefineCommand Maven / Gradle / Ivy

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/**
 * Copyright (c) 2002-2013 "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 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */
package org.neo4j.kernel.impl.index;

import static org.neo4j.helpers.collection.MapUtil.reverse;
import static org.neo4j.kernel.impl.util.IoPrimitiveUtils.read2bLengthAndString;
import static org.neo4j.kernel.impl.util.IoPrimitiveUtils.readByte;
import static org.neo4j.kernel.impl.util.IoPrimitiveUtils.write2bLengthAndString;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;

import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.PropertyContainer;
import org.neo4j.graphdb.Relationship;
import org.neo4j.kernel.impl.transaction.xaframework.LogBuffer;
import org.neo4j.kernel.impl.transaction.xaframework.XaCommand;

/**
 * A command which have to be first in the transaction. It will map index names
 * and keys to ids so that all other commands in that transaction only refer
 * to ids instead of names. This reduced the number of bytes needed for commands
 * roughly 50% for transaction with more than a couple of commands in it,
 * depending on the size of the value.
 * 
 * After this command has been created it will act as a factory for other
 * commands so that it can spit out correct index name and key ids.
 */
public class IndexDefineCommand extends XaCommand
{
    private final AtomicInteger nextIndexNameId = new AtomicInteger();
    private final AtomicInteger nextKeyId = new AtomicInteger();
    private final Map indexNameIdRange;
    private final Map keyIdRange;
    private final Map idToIndexName;
    private final Map idToKey;
    
    public IndexDefineCommand()
    {
        indexNameIdRange = new HashMap();
        keyIdRange = new HashMap();
        idToIndexName = new HashMap();
        idToKey = new HashMap();
    }
    
    public IndexDefineCommand( Map indexNames, Map keys )
    {
        this.indexNameIdRange = indexNames;
        this.keyIdRange = keys;
        idToIndexName = reverse( indexNames );
        idToKey = reverse( keys );
    }
    
    private static String getFromMap( Map map, byte id )
    {
        String result = map.get( id );
        if ( result == null )
        {
            throw new IllegalArgumentException( "" + id );
        }
        return result;
    }

    public IndexCommand create( String indexName, Class entityType, Map config )
    {
        return new IndexCommand.CreateCommand( indexNameId( indexName ),
                entityTypeId( entityType ), config );
    }
    
    public IndexCommand add( String indexName, Class entityType, long entityId, String key,
            Object value )
    {
        return new IndexCommand.AddCommand( indexNameId( indexName ), entityTypeId( entityType ),
                entityId, keyId( key ), value );
    }
    
    public IndexCommand addRelationship( String indexName, Class entityType, long entityId, String key,
            Object value, long startNode, long endNode )
    {
        return new IndexCommand.AddRelationshipCommand( indexNameId( indexName ),
                entityTypeId( entityType ), entityId, keyId( key ), value, startNode, endNode );
    }
    
    public IndexCommand remove( String indexName, Class entityType, long entityId,
            String key, Object value )
    {
        return new IndexCommand.RemoveCommand( indexNameId( indexName ), entityTypeId( entityType ),
                entityId, key != null ? keyId( key ) : 0, value );
    }
    
    public IndexCommand delete( String indexName, Class entityType )
    {
        return new IndexCommand.DeleteCommand( indexNameId( indexName ), entityTypeId( entityType ) );
    }
    
    public String getIndexName( byte id )
    {
        return getFromMap( idToIndexName, id );
    }
    
    public String getKey( byte id )
    {
        return getFromMap( idToKey, id );
    }

    public static byte entityTypeId( Class entityType )
    {
        return entityType.equals( Relationship.class ) ? IndexCommand.RELATIONSHIP : IndexCommand.NODE;
    }
    
    public static Class entityType( byte id )
    {
        switch ( id )
        {
        case IndexCommand.NODE: return Node.class;
        case IndexCommand.RELATIONSHIP: return Relationship.class;
        default: throw new IllegalArgumentException( "" + id );
        }
    }
    
    private byte indexNameId( String indexName )
    {
        return id( indexName, indexNameIdRange, nextIndexNameId, idToIndexName );
    }
    
    private byte keyId( String key )
    {
        return id( key, keyIdRange, nextKeyId, idToKey );
    }

    private byte id( String key, Map idRange, AtomicInteger nextId,
            Map reverse )
    {
        Byte id = idRange.get( key );
        if ( id == null )
        {
            id = Byte.valueOf( (byte) nextId.incrementAndGet() );
            idRange.put( key, id );
            reverse.put( id, key );
        }
        return id;
    }

    @Override
    public void execute()
    {
    }

    @Override
    public void writeToFile( LogBuffer buffer ) throws IOException
    {
        buffer.put( (byte)(IndexCommand.DEFINE_COMMAND << 5) );
        buffer.put( (byte)0 );
        buffer.put( (byte)0 );
        writeMap( indexNameIdRange, buffer );
        writeMap( keyIdRange, buffer );
    }
    
    static Map readMap( ReadableByteChannel channel, ByteBuffer buffer )
            throws IOException
    {
        Byte size = readByte( channel, buffer );
        if ( size == null ) return null;
        Map result = new HashMap();
        for ( int i = 0; i < size; i++ )
        {
            String key = read2bLengthAndString( channel, buffer );
            Byte id = readByte( channel, buffer );
            if ( key == null || id == null ) return null;
            result.put( key, id );
        }
        return result;
    }

    private static void writeMap( Map map, LogBuffer buffer ) throws IOException
    {
        buffer.put( (byte)map.size() );
        for ( Map.Entry entry : map.entrySet() )
        {
            write2bLengthAndString( buffer, entry.getKey() );
            buffer.put( entry.getValue() );
        }
    }
    
    @Override
    public boolean equals( Object obj )
    {
        IndexDefineCommand other = (IndexDefineCommand) obj;
        return indexNameIdRange.equals( other.indexNameIdRange ) &&
                keyIdRange.equals( other.keyIdRange );
    }
}