/**
* 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.hcatalog.utils;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.Map.Entry;
import org.apache.hcatalog.common.HCatException;
import org.apache.hcatalog.data.transfer.DataTransferFactory;
import org.apache.hcatalog.data.transfer.HCatWriter;
import org.apache.hcatalog.data.transfer.WriteEntity;
import org.apache.hcatalog.data.transfer.WriterContext;
public class DataWriterMaster {
public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {
// This config contains all the configuration that master node wants to provide
// to the HCatalog.
Properties externalConfigs = new Properties();
externalConfigs.load(new FileReader(args[0]));
Map<String, String> config = new HashMap<String, String>();
for (Entry<Object, Object> kv : externalConfigs.entrySet()) {
System.err.println("k: " + kv.getKey() + "\t v: " + kv.getValue());
config.put((String) kv.getKey(), (String) kv.getValue());
}
if (args.length == 3 && "commit".equalsIgnoreCase(args[2])) {
// Then, master commits if everything goes well.
ObjectInputStream ois = new ObjectInputStream(new FileInputStream(new File(args[1])));
WriterContext cntxt = (WriterContext) ois.readObject();
commit(config, true, cntxt);
System.exit(0);
}
// This piece of code runs in master node and gets necessary context.
WriterContext cntxt = runsInMaster(config);
// Master node will serialize writercontext and will make it available at slaves.
File f = new File(args[1]);
f.delete();
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(f));
oos.writeObject(cntxt);
oos.flush();
oos.close();
}
private static WriterContext runsInMaster(Map<String, String> config) throws HCatException {
WriteEntity.Builder builder = new WriteEntity.Builder();
WriteEntity entity = builder.withTable(config.get("table")).build();
HCatWriter writer = DataTransferFactory.getHCatWriter(entity, config);
WriterContext info = writer.prepareWrite();
return info;
}
private static void commit(Map<String, String> config, boolean status, WriterContext cntxt) throws HCatException {
WriteEntity.Builder builder = new WriteEntity.Builder();
WriteEntity entity = builder.withTable(config.get("table")).build();
HCatWriter writer = DataTransferFactory.getHCatWriter(entity, config);
if (status) {
writer.commit(cntxt);
} else {
writer.abort(cntxt);
}
}
}