framework/src/main/java/org/opendaylight/protocol/framework/ProtocolMessageDecoder.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.protocol.framework;
   9
  10 import io.netty.buffer.ByteBuf;
  11 import io.netty.buffer.ByteBufUtil;
  12 import io.netty.channel.ChannelHandlerContext;
  13 import io.netty.handler.codec.ByteToMessageDecoder;
  14
  15 import java.util.List;
  16
  17 import com.google.common.base.Preconditions;
  18
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21
  22 public final class ProtocolMessageDecoder<T> extends ByteToMessageDecoder {
  23
  24         private final static Logger LOG = LoggerFactory.getLogger(ProtocolMessageDecoder.class);
  25
  26         private final ProtocolMessageFactory<T> factory;
  27
  28         public ProtocolMessageDecoder(final ProtocolMessageFactory<T> factory) {
  29                 this.factory = Preconditions.checkNotNull(factory);
  30         }
  31
  32         @Override
  33         protected void decode(final ChannelHandlerContext ctx, final ByteBuf in, final List<Object> out) throws Exception {
  34                 if (in.readableBytes() == 0) {
  35                         LOG.debug("No more content in incoming buffer.");
  36                         return;
  37                 }
  38                 in.markReaderIndex();
  39                 try {
  40                         LOG.trace("Received to decode: {}", ByteBufUtil.hexDump(in));
  41                         final byte[] bytes = new byte[in.readableBytes()];
  42                         in.readBytes(bytes);
  43                         out.add(this.factory.parse(bytes));
  44                 } catch (DeserializerException | DocumentedException e) {
  45                         LOG.debug("Failed to decode protocol message", e);
  46                         this.exceptionCaught(ctx, e);
  47                 }
  48                 in.discardReadBytes();
  49         }
  50 }