/*
* 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.hadoop.mapred;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.net.InetSocketAddress;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableUtils;
/**
* Descriptor of the corona session
*/
public class CoronaSessionInfo implements Writable {
/** Number of tcp ports */
private final static int TCP_PORT_NUM = 1<<16;
/** The string handle of the session */
private String sessionHandle;
/** The address of the job tracker RPC server */
private InetSocketAddress jobTrackerAddr;
/** The adress of secondary tracker to fallback,
* It is the local job tracker address
* */
private InetSocketAddress secondaryTrackerAddr = null;
/**
* The default constructor for the session info
*/
public CoronaSessionInfo() {
}
/**
* CoronaSessionInfo constructor given the handle and the address of teh
* jobTracker rpc server
* @param sessionHandle the handle of the session
* @param jobTrackerAddr the address of the rpc server
*/
public CoronaSessionInfo(String sessionHandle,
InetSocketAddress jobTrackerAddr) {
this.sessionHandle = sessionHandle;
this.jobTrackerAddr = jobTrackerAddr;
}
/**
* CoronaSessionInfo constructor given the handle and the addresses of the
* jobTracker and secondary tracker RPC server
* @param sessionHandle the handle of the session
* @param jobTrackerAddr the address of the rpc server
* @param secondaryTrackerAddr address for obtaining new job tracker address
*/
public CoronaSessionInfo(String sessionHandle,
InetSocketAddress jobTrackerAddr,
InetSocketAddress secondaryTrackerAddr) {
this.sessionHandle = sessionHandle;
this.jobTrackerAddr = jobTrackerAddr;
this.secondaryTrackerAddr = secondaryTrackerAddr;
}
public String getSessionHandle() {
return sessionHandle;
}
public InetSocketAddress getJobTrackerAddr() {
return jobTrackerAddr;
}
public InetSocketAddress getSecondaryTracker() {
return secondaryTrackerAddr;
}
@Override
public void write(DataOutput out) throws IOException {
WritableUtils.writeString(out, sessionHandle);
WritableUtils.writeString(out, jobTrackerAddr.getHostName());
int port = jobTrackerAddr.getPort() % TCP_PORT_NUM;
//Because the port number is a 2 bytes unsigned integer.
//When there is a secondaryTrackerAddr followed,
//we just make the current port to be port + TCP_PORT_NUM
//otherwise we do nothing.
if (secondaryTrackerAddr != null) {
port += TCP_PORT_NUM;
WritableUtils.writeVInt(out, port);
InetSocketAddressWritable.writeAddress(out, secondaryTrackerAddr);
} else {
WritableUtils.writeVInt(out, port);
}
}
@Override
public void readFields(DataInput in) throws IOException {
this.sessionHandle = WritableUtils.readString(in);
String hostName = WritableUtils.readString(in);
int port = WritableUtils.readVInt(in);
this.jobTrackerAddr = new InetSocketAddress(hostName, port % TCP_PORT_NUM);
//When decoding, we just need to check if port / TCP_PORT_NUM > 0,
//if so, it means there is a secondaryTrackerAddr followed to be decoded.
if (port / TCP_PORT_NUM > 0) {
this.secondaryTrackerAddr = InetSocketAddressWritable.readAddress(in);
}
}
/**
* Encapsulates InetSocketAddress as Writable type
*/
public static class InetSocketAddressWritable implements Writable {
/** Encapsulated address */
private InetSocketAddress address;
/**
* Default c'tor
*/
public InetSocketAddressWritable() {
}
/**
* Encapsulating c'tor
* @param address an address to encapsulate
*/
public InetSocketAddressWritable(InetSocketAddress address) {
this.address = address;
}
public InetSocketAddress getAddress() {
return address;
}
@Override
public void write(DataOutput out) throws IOException {
writeAddress(out, address);
}
@Override
public void readFields(DataInput in) throws IOException {
this.address = readAddress(in);
}
/**
* Writes InetSocketAddress to data out
* @param out data output
* @param addr InetSocketAddress
* @throws IOException
*/
public static void writeAddress(DataOutput out, InetSocketAddress addr)
throws IOException {
WritableUtils.writeString(out, addr.getHostName());
WritableUtils.writeVInt(out, addr.getPort());
}
/**
* Reads InetSocketAddress from data input
* @param in data input
* @return InetSocketAddress
* @throws IOException
*/
public static InetSocketAddress readAddress(DataInput in)
throws IOException {
String hostName = WritableUtils.readString(in);
int port = WritableUtils.readVInt(in);
return new InetSocketAddress(hostName, port);
}
}
}