/*
* 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 io.netty.buffer.ByteBufOutputStream;
import org.apache.giraph.comm.requests.RequestType;
import org.apache.giraph.comm.requests.WritableRequest;
import org.apache.log4j.Logger;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelPromise;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelOutboundHandlerAdapter;
import static org.apache.giraph.utils.ByteUtils.SIZE_OF_INT;
/**
* 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 ChannelOutboundHandlerAdapter {
/** Class logger. */
private static final Logger LOG = Logger.getLogger(ResponseEncoder.class);
@Override
public void write(ChannelHandlerContext ctx, Object msg,
ChannelPromise promise) throws Exception {
if (LOG.isDebugEnabled()) {
LOG.debug("write(" + ctx + "," + 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;
ByteBuf buf = ctx.alloc().buffer(10);
ByteBufOutputStream output = new ByteBufOutputStream(buf);
if (LOG.isDebugEnabled()) {
LOG.debug("encode: Encoding a message of type " + msg.getClass());
}
// Space is reserved now to be filled later by the serialize request size
output.writeInt(0);
// write type of object.
output.writeByte(writableRequest.getType().ordinal());
// write the object itself.
writableRequest.write(output);
output.flush();
output.close();
// Set the correct size at the end.
buf.setInt(0, buf.writerIndex() - SIZE_OF_INT);
if (LOG.isDebugEnabled()) {
LOG.debug("encode: Encoding a message of type " + msg.getClass());
}
ctx.write(buf, promise);
/*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.channel().remoteAddress() + " has " +
"completed authenticating.");
}
ctx.pipeline().remove(this);
}
/*end[HADOOP_NON_SECURE]*/
ctx.write(buf, promise);
}
}