org.neo4j.kernel.impl.api.index.UniquePropertyIndexUpdater Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of neo4j-kernel Show documentation

Neo4j kernel is a lightweight, embedded Java database designed to store data structured as graphs rather than tables. For more information, see http://neo4j.org.

There is a newer version: 5.26.0

Show newest version

/*
 * Copyright (c) 2002-2015 "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.api.index;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import org.neo4j.kernel.api.exceptions.index.IndexCapacityExceededException;
import org.neo4j.kernel.api.index.IndexEntryConflictException;
import org.neo4j.kernel.api.index.IndexUpdater;
import org.neo4j.kernel.api.index.NodePropertyUpdate;
import org.neo4j.kernel.impl.util.diffsets.DiffSets;

/**
 * This IndexUpdater ensures that updated properties abide by uniqueness constraints. Updates are grouped up in
 * {@link #process(org.neo4j.kernel.api.index.NodePropertyUpdate)}, and verified in {@link #close()}.
 *
 */
public abstract class UniquePropertyIndexUpdater implements IndexUpdater
{
    private final Map> referenceCount = new HashMap<>();
    private final ArrayList updates = new ArrayList<>();

    @Override
    public void process( NodePropertyUpdate update )
    {
        // build uniqueness verification state
        switch ( update.getUpdateMode() )
        {
            case ADDED:
                propertyValueDiffSet( update.getValueAfter() ).add( update.getNodeId() );
                break;
            case CHANGED:
                propertyValueDiffSet( update.getValueBefore() ).remove( update.getNodeId() );
                propertyValueDiffSet( update.getValueAfter() ).add( update.getNodeId() );
                break;
            case REMOVED:
                propertyValueDiffSet( update.getValueBefore() ).remove( update.getNodeId() );
                break;
            default:
                throw new UnsupportedOperationException();
        }

        // do not flush update before close
        updates.add( update );
    }

    @Override
    public void close() throws IOException, IndexEntryConflictException, IndexCapacityExceededException
    {
        // flush updates
        flushUpdates( updates );
    }

    protected abstract void flushUpdates( Iterable updates )
            throws IOException, IndexEntryConflictException, IndexCapacityExceededException;

    private DiffSets propertyValueDiffSet( Object value )
    {
        DiffSets diffSets = referenceCount.get( value );
        if ( diffSets == null )
        {
            referenceCount.put( value, diffSets = new DiffSets<>() );
        }
        return diffSets;
    }
}