Commit 386e80e7 authored by terrymanu's avatar terrymanu
Browse files

refactor MySQLPacketCodec

parent b71d3dae

sharding-jdbc-server/src/main/java/io/shardingjdbc/server/codec/MySQLPacketCodec.java

+5 −8
Original line number Diff line number Diff line
@@ -22,23 +22,20 @@ public final class MySQLPacketCodec extends ByteToMessageCodec<AbstractMySQLSent 
    @Override

    protected void decode(final ChannelHandlerContext context, final ByteBuf in, final List<Object> out) throws Exception {

        int readableBytes = in.readableBytes();

        if (readableBytes < AbstractMySQLPacket.PAYLOAD_LENGTH) {

        if (readableBytes < AbstractMySQLPacket.PAYLOAD_LENGTH + AbstractMySQLPacket.SEQUENCE_LENGTH) {

            return;

        }

        if (log.isDebugEnabled()) {

            log.debug("Read from client: \n {}", ByteBufUtil.prettyHexDump(in));

        }

        int payloadLength = in.markReaderIndex().readMediumLE();

        //mysql协议包头 内容长度3字节 序号1字节 内容n字节

        //readableBytes的长度为3+1+payloadLength

        if (readableBytes - 4 < payloadLength) {

        int realPacketLength = payloadLength + AbstractMySQLPacket.PAYLOAD_LENGTH + AbstractMySQLPacket.SEQUENCE_LENGTH;

        if (readableBytes < realPacketLength) {

            in.resetReaderIndex();

            return;

        }

        if (readableBytes - 4 > payloadLength) {

            //frame长度为1+payloadLength

            ByteBuf frame = in.readRetainedSlice(payloadLength + 1);

            out.add(frame);

        if (readableBytes > realPacketLength) {

            out.add(in.readRetainedSlice(payloadLength + 1));

            return;

        }

        out.add(in);

sharding-jdbc-server/src/main/java/io/shardingjdbc/server/packet/AbstractMySQLPacket.java

+2 −0
Original line number Diff line number Diff line
@@ -14,5 +14,7 @@ public abstract class AbstractMySQLPacket { 
    

    public static final int PAYLOAD_LENGTH = 3;

    

    public static final int SEQUENCE_LENGTH = 1;

    

    private int sequenceId;

}