com.github.netty.protocol.nrpc.codec.RpcEncoder Maven / Gradle / Ivy
package com.github.netty.protocol.nrpc.codec;
import com.github.netty.protocol.nrpc.RpcPacket;
import com.github.netty.protocol.nrpc.RpcVersion;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
import java.nio.charset.Charset;
import static com.github.netty.core.util.IOUtil.*;
import static com.github.netty.protocol.nrpc.RpcPacket.*;
/**
* RPC encoder
*
*
* Request Packet (note: 1 = request type)
* -+------8B--------+--1B--+--1B--+------4B------+-----4B-----+-----4B-----+------1B--------+-----length-----+------1B-------+---length----+-----4B------+-------length-------------+
* | header/version | type | ACK | total length | Request ID| timeout/ms | service length | service name | method length | method name | data length | data |
* | NRPC/010 | 1 | 1 | 55 | 1 | 1000 | 8 | "/sys/user" | 7 | getUser | 24 | {"age":10,"name":"wang"} |
* -+----------------+------+------+--------------+-----------+------------+----------------+----------------+---------------+-------------+-------------+--------------------------+
*
*
* Response Packet (note: 2 = response type)
* -+------8B--------+--1B--+--1B--+------4B------+-----4B-----+---2B---+--------1B------+--length--+---1B---+-----4B------+----------length----------+
* | header/version | type | ACK | total length | Request ID | status | message length | message | encode | data length | data |
* | NRPC/010 | 2 | 0 | 35 | 1 | 200 | 2 | ok | 1 | 24 | {"age":10,"name":"wang"} |
* -+----------------+------+------+--------------+------------+--------+----------------+----------+--------+-------------+--------------------------+
*
* @author wangzihao
*/
@ChannelHandler.Sharable
public class RpcEncoder extends MessageToByteEncoder {
/**
* protocol header
* Fixed 8 length
*/
public static final byte[] PROTOCOL_HEADER = RpcVersion.CURRENT_VERSION.getTextBytes();
public static final Charset RPC_CHARSET = Charset.forName("UTF-8");
/**
* Fixed request length (note : Not including the total length.)
* (Request ID)4B + (timeout/ms)4B + (service name length)1B + (service version length)1B + (method length)1B + (data length)4B
*/
private static final int FIXED_REQUEST_LENGTH = INT_LENGTH + INT_LENGTH + BYTE_LENGTH + BYTE_LENGTH + BYTE_LENGTH + INT_LENGTH;
/**
* Fixed response length (note : Not including the total length.)
* (Request ID)4B + (status)2B + (message length)1B + (encode)1B + (data length)4B
*/
private static final int FIXED_RESPONSE_LENGTH = INT_LENGTH + SHORT_LENGTH + BYTE_LENGTH + BYTE_LENGTH + INT_LENGTH;
public RpcEncoder() {
}
@Override
public void encode(ChannelHandlerContext ctx, RpcPacket packet, ByteBuf out) throws Exception {
int packetType = packet.getPacketType();
try {
switch (packetType) {
case TYPE_CLIENT_REQUEST: {
encodePacket((RequestPacket) packet, out);
break;
}
case TYPE_RESPONSE_CHUNK_ACK:
case TYPE_RESPONSE_CHUNK:
case TYPE_RESPONSE_LAST: {
encodePacket((ResponsePacket) packet, out);
break;
}
default: {
//(8 byte) protocol head
out.writeBytes(PROTOCOL_HEADER);
//(1 byte Unsigned) RPC packet type
out.writeByte(packet.getPacketType());
//(1 byte Unsigned) RPC packet ack
out.writeByte(packet.getAck());
//(4 byte Unsigned) data length
byte[] data = packet.getData();
int writeTotalLength = data == null ? 0 : data.length;
//(4 byte Unsigned) total length
out.writeInt(writeTotalLength);
if (writeTotalLength > 0) {
out.writeBytes(data);
}
}
}
} finally {
packet.recycle();
}
}
protected void encodePacket(RequestPacket packet, ByteBuf out) {
int writeCurrentLength;
int writeTotalLength = FIXED_REQUEST_LENGTH;
//(8 byte) protocol head
out.writeBytes(PROTOCOL_HEADER);
//(1 byte Unsigned) RPC packet type
out.writeByte(RpcPacket.TYPE_CLIENT_REQUEST);
//(1 byte Unsigned) RPC packet ack
out.writeByte(packet.getAck());
//(4 byte Unsigned) total length
int writerTotalLengthIndex = out.writerIndex();
out.writerIndex(writerTotalLengthIndex + INT_LENGTH);
//(4 byte) Request ID
out.writeInt(packet.getRequestId());
//(4 byte) Request Timeout
out.writeInt(packet.getTimeout());
//(length byte) service name
out.writerIndex(out.writerIndex() + BYTE_LENGTH);
writeCurrentLength = out.writeCharSequence(packet.getRequestMappingName(), RPC_CHARSET);
//(1 byte Unsigned) service name length
out.setByte(out.writerIndex() - writeCurrentLength - BYTE_LENGTH, writeCurrentLength);
writeTotalLength += writeCurrentLength;
//(length byte) service version
out.writerIndex(out.writerIndex() + BYTE_LENGTH);
writeCurrentLength = out.writeCharSequence(packet.getVersion(), RPC_CHARSET);
//(1 byte Unsigned) service version length
out.setByte(out.writerIndex() - writeCurrentLength - BYTE_LENGTH, writeCurrentLength);
writeTotalLength += writeCurrentLength;
//(length byte Unsigned) method name
out.writerIndex(out.writerIndex() + BYTE_LENGTH);
writeCurrentLength = out.writeCharSequence(packet.getMethodName(), RPC_CHARSET);
//(1 byte Unsigned) method length
out.setByte(out.writerIndex() - writeCurrentLength - BYTE_LENGTH, writeCurrentLength);
writeTotalLength += writeCurrentLength;
//(4 byte Unsigned) data length
byte[] data = packet.getData();
out.writeInt(data.length);
if (data.length > 0) {
//(length byte) data
out.writeBytes(data);
writeTotalLength += data.length;
}
//set total length Unsigned
out.setInt(writerTotalLengthIndex, writeTotalLength);
}
protected void encodePacket(ResponsePacket packet, ByteBuf out) {
int writeCurrentLength;
int writeTotalLength = FIXED_RESPONSE_LENGTH;
//(8 byte) protocol head
out.writeBytes(PROTOCOL_HEADER);
//(1 byte Unsigned) RPC packet type
out.writeByte(packet.getPacketType());
//(1 byte Unsigned) RPC packet ack
out.writeByte(packet.getAck());
//(4 byte Unsigned) total length
int writerTotalLengthIndex = out.writerIndex();
out.writerIndex(writerTotalLengthIndex + INT_LENGTH);
//(4 byte) Request ID
out.writeInt(packet.getRequestId());
//(2 byte Unsigned) Response status
out.writeShort(packet.getStatus());
//(1 byte Unsigned) Whether the data has been encoded
out.writeByte(packet.getEncode().getCode());
//(length byte) Response information
out.writerIndex(out.writerIndex() + BYTE_LENGTH);
writeCurrentLength = out.writeCharSequence(packet.getMessage(), RPC_CHARSET);
//(1 byte Unsigned) Response information length
out.setByte(out.writerIndex() - writeCurrentLength - BYTE_LENGTH, writeCurrentLength);
writeTotalLength += writeCurrentLength;
//(4 byte Unsigned) data length
byte[] data = packet.getData();
writeCurrentLength = data == null ? 0 : data.length;
out.writeInt(writeCurrentLength);
if (writeCurrentLength > 0) {
out.writeBytes(data);
//(length byte) data
writeTotalLength += writeCurrentLength;
}
if (packet instanceof ResponseChunkPacket) {
// (2 byte Unsigned) chunk id
writeTotalLength += SHORT_LENGTH;
out.writeShort(((ResponseChunkPacket) packet).getChunkId());
} else if (packet instanceof ResponseChunkAckPacket) {
// (2 byte Unsigned) ack chunk id
writeTotalLength += SHORT_LENGTH;
out.writeShort(((ResponseChunkAckPacket) packet).getAckChunkId());
}
//set total length
out.setInt(writerTotalLengthIndex, writeTotalLength);
}
}