/**
* 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.data;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hive.cli.CliSessionState;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.metastore.api.MetaException;
import org.apache.hadoop.hive.ql.CommandNeedRetryException;
import org.apache.hadoop.hive.ql.Driver;
import org.apache.hadoop.hive.ql.session.SessionState;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hcatalog.common.HCatException;
import org.apache.hcatalog.data.transfer.DataTransferFactory;
import org.apache.hcatalog.data.transfer.HCatReader;
import org.apache.hcatalog.data.transfer.HCatWriter;
import org.apache.hcatalog.data.transfer.ReadEntity;
import org.apache.hcatalog.data.transfer.ReaderContext;
import org.apache.hcatalog.data.transfer.WriteEntity;
import org.apache.hcatalog.data.transfer.WriterContext;
import org.junit.Assert;
import org.junit.Test;
public class TestReaderWriter {
@Test
public void test() throws MetaException, CommandNeedRetryException, IOException, ClassNotFoundException {
HiveConf conf = new HiveConf(getClass());
Driver driver = new Driver(conf);
SessionState.start(new CliSessionState(conf));
driver.run("drop table mytbl");
driver.run("create table mytbl (a string, b int)");
Iterator<Entry<String,String>> itr = conf.iterator();
Map<String,String> map = new HashMap<String, String>();
while(itr.hasNext()){
Entry<String,String> kv = itr.next();
map.put(kv.getKey(), kv.getValue());
}
WriterContext cntxt = runsInMaster(map);
File writeCntxtFile = File.createTempFile("hcat-write", "temp");
writeCntxtFile.deleteOnExit();
// Serialize context.
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(writeCntxtFile));
oos.writeObject(cntxt);
oos.flush();
oos.close();
// Now, deserialize it.
ObjectInputStream ois = new ObjectInputStream(new FileInputStream(writeCntxtFile));
cntxt = (WriterContext) ois.readObject();
ois.close();
runsInSlave(cntxt);
commit(map, true, cntxt);
ReaderContext readCntxt = runsInMaster(map, false);
File readCntxtFile = File.createTempFile("hcat-read", "temp");
readCntxtFile.deleteOnExit();
oos = new ObjectOutputStream(new FileOutputStream(readCntxtFile));
oos.writeObject(readCntxt);
oos.flush();
oos.close();
ois = new ObjectInputStream(new FileInputStream(readCntxtFile));
readCntxt = (ReaderContext) ois.readObject();
ois.close();
for(InputSplit split : readCntxt.getSplits()){
runsInSlave(split, readCntxt.getConf());
}
}
private WriterContext runsInMaster(Map<String, String> config) throws HCatException {
WriteEntity.Builder builder = new WriteEntity.Builder();
WriteEntity entity = builder.withTable("mytbl").build();
HCatWriter writer = DataTransferFactory.getHCatWriter(entity, config);
WriterContext info = writer.prepareWrite();
return info;
}
private ReaderContext runsInMaster(Map<String,String> config, boolean bogus) throws HCatException {
ReadEntity.Builder builder = new ReadEntity.Builder();
ReadEntity entity = builder.withTable("mytbl").build();
HCatReader reader = DataTransferFactory.getHCatReader(entity, config);
ReaderContext cntxt = reader.prepareRead();
return cntxt;
}
private void runsInSlave(InputSplit split, Configuration config) throws HCatException {
HCatReader reader = DataTransferFactory.getHCatReader(split, config);
Iterator<HCatRecord> itr = reader.read();
int i = 1;
while(itr.hasNext()){
HCatRecord read = itr.next();
HCatRecord written = getRecord(i++);
// Argh, HCatRecord doesnt implement equals()
Assert.assertTrue("Read: " + read.get(0) + "Written: " + written.get(0), written.get(0).equals(read.get(0)));
Assert.assertTrue("Read: " + read.get(1) + "Written: " + written.get(1), written.get(1).equals(read.get(1)));
Assert.assertEquals(2, read.size());
}
Assert.assertFalse(itr.hasNext());
}
private void runsInSlave(WriterContext context) throws HCatException {
HCatWriter writer = DataTransferFactory.getHCatWriter(context);
writer.write(new HCatRecordItr());
}
private void commit(Map<String, String> config, boolean status, WriterContext context) throws IOException {
WriteEntity.Builder builder = new WriteEntity.Builder();
WriteEntity entity = builder.withTable("mytbl").build();
HCatWriter writer = DataTransferFactory.getHCatWriter(entity, config);
if(status){
writer.commit(context);
} else {
writer.abort(context);
}
}
private static HCatRecord getRecord(int i) {
List<Object> list = new ArrayList<Object>(2);
list.add("Row #: " + i);
list.add(i);
return new DefaultHCatRecord(list);
}
private static class HCatRecordItr implements Iterator<HCatRecord> {
int i = 0;
@Override
public boolean hasNext() {
return i++ < 100 ? true : false;
}
@Override
public HCatRecord next() {
return getRecord(i);
}
@Override
public void remove() {
throw new RuntimeException();
}
}
}