/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.giraph.comm.netty.handler;
import org.apache.giraph.comm.requests.RequestType;
import org.apache.giraph.comm.requests.WritableRequest;
import org.apache.log4j.Logger;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBufferOutputStream;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.oneone.OneToOneEncoder;
/**
* How a server should respond to a client. Currently only used for
* responding to client's SASL messages, and removed after client
* authenticates.
*/
public class ResponseEncoder extends OneToOneEncoder {
/** Class logger. */
private static final Logger LOG = Logger.getLogger(ResponseEncoder.class);
/** Holds the place of the message length until known. */
private static final byte[] LENGTH_PLACEHOLDER = new byte[4];
@Override
protected Object encode(ChannelHandlerContext ctx,
Channel channel, Object msg) throws Exception {
if (LOG.isDebugEnabled()) {
LOG.debug("encode(" + ctx + "," + channel + "," + msg);
}
if (!(msg instanceof WritableRequest)) {
throw new IllegalArgumentException(
"encode: cannot encode message of type " + msg.getClass() +
" since it is not an instance of an implementation of " +
" WritableRequest.");
}
@SuppressWarnings("unchecked")
WritableRequest writableRequest =
(WritableRequest) msg;
ChannelBufferOutputStream outputStream =
new ChannelBufferOutputStream(ChannelBuffers.dynamicBuffer(
10, ctx.getChannel().getConfig().getBufferFactory()));
if (LOG.isDebugEnabled()) {
LOG.debug("encode: Encoding a message of type " + msg.getClass());
}
outputStream.write(LENGTH_PLACEHOLDER);
// write type of object.
outputStream.writeByte(writableRequest.getType().ordinal());
// write the object itself.
writableRequest.write(outputStream);
outputStream.flush();
// Set the correct size at the end.
ChannelBuffer encodedBuffer = outputStream.buffer();
encodedBuffer.setInt(0, encodedBuffer.writerIndex() - 4);
if (LOG.isDebugEnabled()) {
LOG.debug("encode: Encoding a message of type " + msg.getClass());
}
/*if[HADOOP_NON_SECURE]
else[HADOOP_NON_SECURE]*/
if (writableRequest.getType() == RequestType.SASL_COMPLETE_REQUEST) {
// We are sending to the client a SASL_COMPLETE response (created by
// the SaslServer handler). The SaslServer handler has removed itself
// from the pipeline after creating this response, and now it's time for
// the ResponseEncoder to remove itself also.
if (LOG.isDebugEnabled()) {
LOG.debug("encode: Removing RequestEncoder handler: no longer needed," +
" since client: " + ctx.getChannel().getRemoteAddress() + " has " +
"completed authenticating.");
}
ctx.getPipeline().remove(this);
}
/*end[HADOOP_NON_SECURE]*/
return encodedBuffer;
}
}