/*
* Copyright 1999-2011 Alibaba Group.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.alibaba.dubbo.remoting.transport.netty;
import java.io.IOException;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandler;
import org.jboss.netty.channel.ChannelHandler.Sharable;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.jboss.netty.handler.codec.oneone.OneToOneEncoder;
import com.alibaba.dubbo.common.Constants;
import com.alibaba.dubbo.common.URL;
import com.alibaba.dubbo.common.io.Bytes;
import com.alibaba.dubbo.common.io.UnsafeByteArrayInputStream;
import com.alibaba.dubbo.common.io.UnsafeByteArrayOutputStream;
import com.alibaba.dubbo.remoting.Codec;
import com.alibaba.dubbo.remoting.exchange.Request;
import com.alibaba.dubbo.remoting.exchange.Response;
/**
* NettyCodecAdapter.
*
* @author qian.lei
*/
final class NettyCodecAdapter {
private final ChannelHandler encoder = new InternalEncoder();
private final ChannelHandler decoder = new InternalDecoder();
private final Codec upstreamCodec;
private final Codec downstreamCodec;
private final URL url;
private final int bufferSize;
private final com.alibaba.dubbo.remoting.ChannelHandler handler;
public NettyCodecAdapter(Codec codec, URL url, com.alibaba.dubbo.remoting.ChannelHandler handler){
this(codec, codec, url, handler);
}
/**
* server 端如果有消息发送需要分开codec，默认的上行code是dubbo1兼容的
*/
public NettyCodecAdapter(Codec upstreamCodec, Codec downstreamCodec, URL url, com.alibaba.dubbo.remoting.ChannelHandler handler){
this.downstreamCodec = downstreamCodec;
this.upstreamCodec = upstreamCodec;
this.url = url;
this.handler = handler;
int b = url.getPositiveParameter(Constants.BUFFER_KEY, Constants.DEFAULT_BUFFER_SIZE);
this.bufferSize = b >= Constants.MIN_BUFFER_SIZE && b <= Constants.MAX_BUFFER_SIZE ? b : Constants.DEFAULT_BUFFER_SIZE;
}
public ChannelHandler getEncoder() {
return encoder;
}
public ChannelHandler getDecoder() {
return decoder;
}
@Sharable
private class InternalEncoder extends OneToOneEncoder {
@Override
protected Object encode(ChannelHandlerContext ctx, Channel ch, Object msg) throws Exception {
UnsafeByteArrayOutputStream os = new UnsafeByteArrayOutputStream(1024); // 不需要关闭
NettyChannel channel = NettyChannel.getOrAddChannel(ch, url, handler);
try {
if(! (msg instanceof Response)
&& ! (msg instanceof Request
&& ((Request)msg).isHeartbeat())) {
downstreamCodec.encode(channel, os, msg);
}else {
upstreamCodec.encode(channel, os, msg);
}
} finally {
NettyChannel.removeChannelIfDisconnected(ch);
}
return ChannelBuffers.wrappedBuffer(os.toByteBuffer());
}
}
private class InternalDecoder extends SimpleChannelUpstreamHandler {
private int mOffset = 0, mLimit = 0;
private byte[] mBuffer = null;
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent event) throws Exception {
Object o = event.getMessage();
if (! (o instanceof ChannelBuffer)) {
ctx.sendUpstream(event);
return;
}
ChannelBuffer input = (ChannelBuffer) o;
int readable = input.readableBytes();
if (readable <= 0) {
return;
}
int off, limit;
byte[] buf = mBuffer;
if (buf == null) {
buf = new byte[bufferSize];
off = limit = 0;
} else {
off = mOffset;
limit = mLimit;
}
NettyChannel channel = NettyChannel.getOrAddChannel(ctx.getChannel(), url, handler);
boolean remaining = true;
Object msg;
UnsafeByteArrayInputStream bis;
try {
do {
// read data into buffer.
int read = Math.min(readable, buf.length - limit);
input.readBytes(buf, limit, read);
limit += read;
readable -= read;
bis = new UnsafeByteArrayInputStream(buf, off, limit - off); // 不需要关闭
// decode object.
do {
try {
msg = upstreamCodec.decode(channel, bis);
} catch (IOException e) {
remaining = false;
throw e;
}
if (msg == Codec.NEED_MORE_INPUT) {
if (off == 0) {
if (readable > 0) {
buf = Bytes.copyOf(buf, buf.length << 1);
}
} else {
int len = limit - off;
System.arraycopy(buf, off, buf, 0, len); // adjust buffer.
off = 0;
limit = len;
}
break;
} else {
int pos = bis.position();
if (off == pos) {
remaining = false;
throw new IOException("Decode without read data.");
}
if (msg != null) {
Channels.fireMessageReceived(ctx, msg, event.getRemoteAddress());
}
off = pos;
}
} while (bis.available() > 0);
} while (readable > 0);
} finally {
if (remaining) {
int len = limit - off;
if (len < buf.length / 2) {
System.arraycopy(buf, off, buf, 0, len);
off = 0;
limit = len;
}
mBuffer = buf;
mOffset = off;
mLimit = limit;
} else {
mBuffer = null;
mOffset = mLimit = 0;
}
NettyChannel.removeChannelIfDisconnected(ctx.getChannel());
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) throws Exception {
ctx.sendUpstream(e);
}
}
}