org.neo4j.bolt.v1.messaging.BoltRequestMessageReader Maven / Gradle / Ivy

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The core of Neo4j Bolt Protocol, this contains the state machine for Bolt sessions.
There is a newer version: 5.23.0
/*
 * Copyright (c) 2002-2018 "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.bolt.v1.messaging;

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

import org.neo4j.bolt.v1.packstream.PackStream;
import org.neo4j.kernel.api.exceptions.Status;
import org.neo4j.values.virtual.MapValue;

import static java.util.stream.Collectors.toMap;

/**
 * Reader for Bolt request messages made available via a {@link Neo4jPack.Unpacker}.
 */
public class BoltRequestMessageReader
{
    private final Neo4jPack.Unpacker unpacker;

    public BoltRequestMessageReader( Neo4jPack.Unpacker unpacker )
    {
        this.unpacker = unpacker;
    }

    /**
     * Parse and handle a single message by handing it off
     * to a {@link BoltRequestMessageHandler} instance.
     *
     * @param handler handler for request messages
     */
    public void read( BoltRequestMessageHandler handler ) throws IOException
    {
        try
        {
            unpacker.unpackStructHeader();
            int signature = unpacker.unpackStructSignature();
            BoltRequestMessage message = BoltRequestMessage.withSignature( signature );
            if ( message == null )
            {
                throw new BoltIOException( Status.Request.InvalidFormat,
                        String.format( "Message 0x%s is not a valid message signature.", Integer.toHexString( signature ) ) );
            }

            switch ( message )
            {
            case INIT:
                String clientName = unpacker.unpackString();
                Map authToken = readAuthToken( unpacker );
                handler.onInit( clientName, authToken );
                break;
            case ACK_FAILURE:
                handler.onAckFailure();
                break;
            case RESET:
                handler.onReset();
                break;
            case RUN:
                String statement = unpacker.unpackString();
                MapValue params = unpacker.unpackMap();
                handler.onRun( statement, params );
                break;
            case DISCARD_ALL:
                handler.onDiscardAll();
                break;
            case PULL_ALL:
                handler.onPullAll();
                break;
            default:
                throw new BoltIOException( Status.Request.InvalidFormat,
                        String.format( "Message 0x%s is not supported.", Integer.toHexString( signature ) ) );
            }
        }
        catch ( PackStream.PackStreamException e )
        {
            throw new BoltIOException( Status.Request.InvalidFormat,
                    String.format( "Unable to read message type. Error was: %s.", e.getMessage() ), e );
        }
    }

    private static Map readAuthToken( Neo4jPack.Unpacker unpacker ) throws IOException
    {
        MapValue authTokenValue = unpacker.unpackMap();
        AuthTokenValuesWriter writer = new AuthTokenValuesWriter();
        return authTokenValue.entrySet()
                .stream()
                .collect( toMap( Map.Entry::getKey, entry -> writer.valueAsObject( entry.getValue() ) ) );
    }
}