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Neo4j property value system.

There is a newer version: 5.25.1

/*
 * 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.values.virtual;

import java.util.HashMap;
import java.util.Map;

import org.neo4j.values.AnyValue;

import static org.neo4j.memory.HeapEstimator.sizeOf;
import static org.neo4j.util.Preconditions.requirePositive;

public class MapValueBuilder
{
    private final Map map;
    private long payloadSize;

    public MapValueBuilder()
    {
        this.map = new HashMap<>();
    }

    public MapValueBuilder( int expectedSize )
    {
        this.map = new HashMap<>( capacity( expectedSize ) );
    }

    public AnyValue add( String key, AnyValue value )
    {
        AnyValue put = map.put( key, value );
        if ( put == null )
        {
            payloadSize += sizeOf( key ) + value.estimatedHeapUsage();
        }
        else
        {
            payloadSize += value.estimatedHeapUsage() - put.estimatedHeapUsage();
        }
        return put;
    }

    public void clear()
    {
        map.clear();
        payloadSize = 0;
    }

    public MapValue build()
    {
        return new MapValue.MapWrappingMapValue( map, payloadSize );
    }

    private static int capacity( int expectedSize )
    {
        if ( expectedSize < 3 )
        {
            requirePositive( expectedSize );
            return expectedSize + 1;
        }
        return (int) ((float) expectedSize / 0.75f + 1.0f );
    }
}