com.mysql.cj.mysqla.io.MultiPacketReader Maven / Gradle / Ivy

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JDBC Type 4 driver for MySQL
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/*
 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, version 2.0, as published by the
 * Free Software Foundation.
 *
 * This program is also distributed with certain software (including but not
 * limited to OpenSSL) that is licensed under separate terms, as designated in a
 * particular file or component or in included license documentation. The
 * authors of MySQL hereby grant you an additional permission to link the
 * program and your derivative works with the separately licensed software that
 * they have included with MySQL.
 *
 * Without limiting anything contained in the foregoing, this file, which is
 * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
 * version 1.0, a copy of which can be found at
 * http://oss.oracle.com/licenses/universal-foss-exception.
 *
 * 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, version 2.0,
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
 */

package com.mysql.cj.mysqla.io;

import java.io.IOException;
import java.util.Optional;

import com.mysql.cj.api.mysqla.io.NativeProtocol.StringLengthDataType;
import com.mysql.cj.api.mysqla.io.PacketHeader;
import com.mysql.cj.api.mysqla.io.PacketPayload;
import com.mysql.cj.api.mysqla.io.PacketReader;
import com.mysql.cj.core.Messages;
import com.mysql.cj.mysqla.MysqlaConstants;

/**
 * A {@link PacketReader} which reads a full packet
 * built from sequence of it's on-wire parts.
 * See http://dev.mysql.com/doc/internals/en/sending-more-than-16mbyte.html
 */
public class MultiPacketReader implements PacketReader {

    private PacketReader packetReader;

    public MultiPacketReader(PacketReader packetReader) {
        this.packetReader = packetReader;
    }

    @Override
    public PacketHeader readHeader() throws IOException {
        return this.packetReader.readHeader();
    }

    @Override
    public PacketPayload readPayload(Optional reuse, int packetLength) throws IOException {

        PacketPayload buf = this.packetReader.readPayload(reuse, packetLength);

        if (packetLength == MysqlaConstants.MAX_PACKET_SIZE) { // it's a multi-packet

            buf.setPosition(MysqlaConstants.MAX_PACKET_SIZE);

            PacketPayload multiPacket = null;
            int multiPacketLength = -1;
            byte multiPacketSeq = getPacketSequence();

            do {
                PacketHeader hdr = readHeader();
                multiPacketLength = hdr.getPacketLength();

                if (multiPacket == null) {
                    multiPacket = new Buffer(multiPacketLength);
                }

                multiPacketSeq++;
                if (multiPacketSeq != hdr.getPacketSequence()) {
                    throw new IOException(Messages.getString("PacketReader.10"));
                }

                this.packetReader.readPayload(Optional.of(multiPacket), multiPacketLength);

                buf.writeBytes(StringLengthDataType.STRING_FIXED, multiPacket.getByteBuffer(), 0, multiPacketLength);

            } while (multiPacketLength == MysqlaConstants.MAX_PACKET_SIZE);

            buf.setPosition(0);
        }

        return buf;
    }

    @Override
    public byte getPacketSequence() {
        return this.packetReader.getPacketSequence();
    }

    @Override
    public void resetPacketSequence() {
        this.packetReader.resetPacketSequence();
    }

    @Override
    public PacketReader undecorateAll() {
        return this.packetReader.undecorateAll();
    }

    @Override
    public PacketReader undecorate() {
        return this.packetReader;
    }

}