/*
* 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.pig.test.udf.evalfunc;
import java.io.IOException;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.EvalFunc;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.DataType;
import org.apache.pig.data.DefaultBagFactory;
import org.apache.pig.data.Tuple;
import org.apache.pig.data.DefaultTupleFactory;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.apache.pig.PigException;
import org.apache.pig.backend.executionengine.ExecException;
import java.util.*;
public class TOBAG extends EvalFunc<DataBag> {
//String List<String> bagColumnNames = new ArrayList<String>();
//byte List<byte> fieldTypes = new ArrayList<byte>();
String bagColName;
String tupleColName;
byte fieldType;
public TOBAG() {}
public TOBAG(String bagColName, String tupleColName, String fieldType) {
if ( bagColName== null || tupleColName == null || fieldType == null) {
throw new RuntimeException("The bagColName and fieldType cannot be null");
}
this.bagColName = bagColName;
this.tupleColName = tupleColName;
if ( fieldType.equalsIgnoreCase( "CHARARRAY" )){
this.fieldType = DataType.CHARARRAY;
} else if ( fieldType.equalsIgnoreCase( "DOUBLE" )){
this.fieldType = DataType.DOUBLE;
} else if ( fieldType.equalsIgnoreCase( "FLOAT" )){
this.fieldType = DataType.FLOAT;
} else if ( fieldType.equalsIgnoreCase( "BOOLEAN" )){
this.fieldType = DataType.BOOLEAN;
} else if ( fieldType.equalsIgnoreCase( "INTEGER" )){
this.fieldType = DataType.INTEGER;
} else if ( fieldType.equalsIgnoreCase( "LONG" )){
this.fieldType = DataType.LONG;
} else if ( fieldType.equalsIgnoreCase( "MAP" )){
this.fieldType = DataType.MAP;
} else {
throw new RuntimeException("This type"+ fieldType +"is not supported in TOBAG");
}
}
@Override
public DataBag exec(Tuple input) throws IOException {
try {
DataBag bag = DefaultBagFactory.getInstance().newDefaultBag();
if ( input == null || input.size()== 0) {
return bag; //an empty bag
}
if ( this.fieldType == DataType.MAP ) {
Tuple t = DefaultTupleFactory.getInstance().newTuple(1);
t.set(0, createMap(input));
bag.add( t );
} else {
bag.add(input);
}
return bag;
} catch (Exception e) {
throw new RuntimeException( "Error while computing size in " + this.getClass().getSimpleName());
}
}
private HashMap<String, Object> createMap(Tuple input ) throws IOException {
try {
HashMap<String, Object> map = new HashMap<String, Object>();
if ( input == null || input.size()== 0) {
return map; //an empty map
}
for (int i = 0; i < input.size(); i=i+2) {
String key= input.get(i).toString();
if ( null!=key && ( i+1 < input.size() )) {
map.put( key , input.get(i+1));
}
}
return map;
} catch (Exception e) {
int errCode = 2106;
String msg = "Error while creating map with" + this.getClass().getSimpleName();
throw new ExecException(msg, errCode, PigException.BUG, e);
}
}
@Override
public Schema outputSchema(Schema input) {
try {
// subschema describing the fields in the tuples of the bag
List<Schema.FieldSchema> tokenFs = new ArrayList<Schema.FieldSchema>();
//tokenFs.add(new Schema.FieldSchema(null, this.fieldType ));
tokenFs.add(new Schema.FieldSchema( this.tupleColName.toUpperCase(), this.fieldType ));
Schema tupleSchema = new Schema( tokenFs );
Schema.FieldSchema tupleFs = new Schema.FieldSchema( this.bagColName.toUpperCase(), tupleSchema, DataType.TUPLE);
Schema bagSchema = new Schema(tupleFs);
bagSchema.setTwoLevelAccessRequired(true);
Schema.FieldSchema bagFs = new Schema.FieldSchema( null, bagSchema, DataType.BAG);
return new Schema(bagFs);
} catch (FrontendException e) {
throw new RuntimeException("Unable to create schema for BAG.");
}
}
}