org.neo4j.server.http.cypher.CachingWriter Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of neo4j-server Show documentation
Neo4j web server.
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.server.http.cypher;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.function.BiFunction;
import java.util.stream.Collectors;

import org.neo4j.graphdb.Label;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Relationship;
import org.neo4j.graphdb.spatial.Point;
import org.neo4j.kernel.impl.util.BaseToObjectValueWriter;
import org.neo4j.server.http.cypher.entity.HttpNode;
import org.neo4j.server.http.cypher.entity.HttpPath;
import org.neo4j.server.http.cypher.entity.HttpRelationship;
import org.neo4j.values.ValueMapper;
import org.neo4j.values.storable.CoordinateReferenceSystem;
import org.neo4j.values.storable.StringValue;
import org.neo4j.values.storable.TextArray;
import org.neo4j.values.storable.TextValue;
import org.neo4j.values.virtual.MapValue;
import org.neo4j.values.virtual.NodeValue;
import org.neo4j.values.virtual.RelationshipValue;

public class CachingWriter extends BaseToObjectValueWriter
{
    private Object cachedObject;
    private ValueMapper mapper;

    private BiFunction> getNodeById;

    public CachingWriter( ValueMapper mapper )
    {
        this.mapper = mapper;
        this.getNodeById = ( ignoredA, ignoredB ) -> Optional.empty();
    }

    public Object getCachedObject()
    {
        return cachedObject;
    }

    @Override
    public void writeRelationship( long relId, long startNodeId, long endNodeId, TextValue type, MapValue properties, boolean isDeleted )
    {
        cachedObject = new HttpRelationship( relId, startNodeId, endNodeId, type.stringValue(), processProperties( properties ), isDeleted, getNodeById );
    }

    @Override
    public void writePath( NodeValue[] nodes, RelationshipValue[] relationships )
    {
        var nodeList = convertNodeValues( nodes );
        var relList = convertRelationshipValues( relationships );

        cachedObject = new HttpPath( nodeList, relList );
    }

    @Override
    public void writeNode( long nodeId, TextArray labels, MapValue properties, boolean isDeleted )
    {
        var labelList =
                Arrays.stream( (String[]) labels.asObjectCopy() ).map( Label::label ).collect( Collectors.toList() );

        cachedObject = new HttpNode( nodeId, labelList, processProperties( properties ), isDeleted );
    }

    @Override
    protected Node newNodeEntityById( long id )
    {
        throw new UnsupportedOperationException( "Only can write existing nodes" );
    }

    @Override
    protected Relationship newRelationshipEntityById( long id )
    {
        throw new UnsupportedOperationException( "Only can write existing relationships" );
    }

    @Override
    protected Point newPoint( CoordinateReferenceSystem crs, double[] coordinate )
    {
        throw new UnsupportedOperationException( "Does not write points" );
    }

    public void setGetNodeById( BiFunction> getNodeById )
    {
        this.getNodeById = getNodeById;
    }

    private Map processProperties( MapValue properties )
    {
        var propertyMap = new HashMap();
        properties.foreach( ( k, v ) ->
                            {
                                propertyMap.put( k, v.map( mapper ) );
                            } );
        return propertyMap;
    }

    private List convertNodeValues( NodeValue[] nodeValues )
    {
        var nodeArrayList = new ArrayList();
        for ( NodeValue nodeValue : nodeValues )
        {
            writeNode( nodeValue.id(), nodeValue.labels(), nodeValue.properties(), nodeValue.isDeleted() );
            nodeArrayList.add( (HttpNode) cachedObject );
        }
        return nodeArrayList;
    }

    private List convertRelationshipValues( RelationshipValue[] relationships )
    {
        var relArrayList = new ArrayList();
        for ( RelationshipValue relationship : relationships )
        {
            writeRelationship( relationship.id(), relationship.startNodeId(), relationship.endNodeId(), relationship.type(),
                               relationship.properties(), relationship.isDeleted() );
            relArrayList.add( (HttpRelationship) cachedObject );
        }
        return relArrayList;
    }
}