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/*
* Copyright 2014-2015 Open Networking Laboratory
*
* 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 org.onlab.netty;
import static com.google.common.base.Preconditions.checkState;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ReplayingDecoder;
import java.util.List;
import org.onlab.packet.IpAddress;
import org.onlab.packet.IpAddress.Version;
import org.onosproject.store.cluster.messaging.Endpoint;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.base.Charsets;
/**
* Decoder for inbound messages.
*/
public class MessageDecoder extends ReplayingDecoder<DecoderState> {
private final Logger log = LoggerFactory.getLogger(getClass());
private final int correctPreamble;
private long messageId;
private int preamble;
private Version ipVersion;
private IpAddress senderIp;
private int senderPort;
private int messageTypeLength;
private String messageType;
private int contentLength;
public MessageDecoder(int correctPreamble) {
super(DecoderState.READ_MESSAGE_PREAMBLE);
this.correctPreamble = correctPreamble;
}
@Override
protected void decode(
ChannelHandlerContext context,
ByteBuf buffer,
List<Object> out) throws Exception {
switch (state()) {
case READ_MESSAGE_PREAMBLE:
preamble = buffer.readInt();
if (preamble != correctPreamble) {
throw new IllegalStateException("This message had an incorrect preamble.");
}
checkpoint(DecoderState.READ_MESSAGE_ID);
case READ_MESSAGE_ID:
messageId = buffer.readLong();
checkpoint(DecoderState.READ_SENDER_IP_VERSION);
case READ_SENDER_IP_VERSION:
ipVersion = buffer.readByte() == 0x0 ? Version.INET : Version.INET6;
checkpoint(DecoderState.READ_SENDER_IP);
case READ_SENDER_IP:
byte[] octets = new byte[IpAddress.byteLength(ipVersion)];
buffer.readBytes(octets);
senderIp = IpAddress.valueOf(ipVersion, octets);
checkpoint(DecoderState.READ_SENDER_PORT);
case READ_SENDER_PORT:
senderPort = buffer.readInt();
checkpoint(DecoderState.READ_MESSAGE_TYPE_LENGTH);
case READ_MESSAGE_TYPE_LENGTH:
messageTypeLength = buffer.readInt();
checkpoint(DecoderState.READ_MESSAGE_TYPE);
case READ_MESSAGE_TYPE:
byte[] messageTypeBytes = new byte[messageTypeLength];
buffer.readBytes(messageTypeBytes);
messageType = new String(messageTypeBytes, Charsets.UTF_8);
checkpoint(DecoderState.READ_CONTENT_LENGTH);
case READ_CONTENT_LENGTH:
contentLength = buffer.readInt();
checkpoint(DecoderState.READ_CONTENT);
case READ_CONTENT:
//TODO Perform a sanity check on the size before allocating
byte[] payload = new byte[contentLength];
buffer.readBytes(payload);
InternalMessage message = new InternalMessage(messageId,
new Endpoint(senderIp, senderPort),
messageType,
payload);
out.add(message);
checkpoint(DecoderState.READ_MESSAGE_PREAMBLE);
break;
default:
checkState(false, "Must not be here");
}
}
@Override
public void exceptionCaught(ChannelHandlerContext context, Throwable cause) {
log.error("Exception inside channel handling pipeline.", cause);
context.close();
}
}
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