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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.

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/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.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.schema;

import org.neo4j.index.internal.gbptree.Layout;
import org.neo4j.io.pagecache.PageCursor;
import org.neo4j.kernel.impl.index.schema.config.IndexSpecificSpaceFillingCurveSettings;

import static org.neo4j.kernel.impl.index.schema.NativeIndexKey.NO_ENTITY_ID;

class PointLayout extends IndexLayout
{
    private final IndexSpecificSpaceFillingCurveSettings spatialSettings;

    PointLayout( IndexSpecificSpaceFillingCurveSettings spatialSettings )
    {
        super( false, Layout.namedIdentifier( "PL", 1 ), 0, 1 );
        this.spatialSettings = spatialSettings;
    }

    @Override
    public PointKey newKey()
    {
        return new PointKey( spatialSettings );
    }

    @Override
    public PointKey copyKey( PointKey key, PointKey into )
    {
        into.copyFrom( key );
        return into;
    }

    @Override
    public int keySize( PointKey key )
    {
        return key.size();
    }

    @Override
    public void writeKey( PageCursor cursor, PointKey key )
    {
        key.writeToCursor( cursor );
    }

    @Override
    public void readKey( PageCursor cursor, PointKey into, int keySize )
    {
        into.readFromCursor( cursor, keySize );
    }

    @Override
    public void initializeAsLowest( PointKey key )
    {
        // none of the parameters matter as this layout does not support composite keys
        // and it supports just one type
        key.initValueAsLowest( -1, null );
    }

    @Override
    public void initializeAsHighest( PointKey key )
    {
        // none of the parameters matter as this layout does not support composite keys
        // and it supports just one type
        key.initValueAsHighest( -1, null );
    }

    @Override
    public void minimalSplitter( PointKey left, PointKey right, PointKey into )
    {
        into.copyFrom( right );
        if ( left.compareValueTo( right ) != 0 )
        {
            // Since the point value is enough to serve as minimal splitter, we remove the entity id
            // which will serve as divider if the point values are equal.
            into.setEntityId( NO_ENTITY_ID );
        }
    }

    IndexSpecificSpaceFillingCurveSettings getSpaceFillingCurveSettings()
    {
        return spatialSettings;
    }
}