/**
* 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.hive.ql.udf.generic;
import java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector.PrimitiveCategory;
import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
/**
* PosExplode.
*
*/
@Description(
name = "posexplode",
value = "_FUNC_(a) - behaves like explode for arrays, "
+ "but includes the position of items in the original array")
public class GenericUDTFPosExplode extends GenericUDTF {
private ListObjectInspector listOI = null;
private final Object[] forwardObj = new Object[2];
@Override
public void close() throws HiveException {
}
@Override
public StructObjectInspector initialize(ObjectInspector[] args) throws UDFArgumentException {
if (args.length != 1) {
throw new UDFArgumentException("posexplode() takes only one argument");
}
if (args[0].getCategory() != ObjectInspector.Category.LIST) {
throw new UDFArgumentException("posexplode() takes an array as a parameter");
}
listOI = (ListObjectInspector) args[0];
ArrayList<String> fieldNames = new ArrayList<String>();
ArrayList<ObjectInspector> fieldOIs = new ArrayList<ObjectInspector>();
fieldNames.add("pos");
fieldNames.add("val");
fieldOIs.add(PrimitiveObjectInspectorFactory
.getPrimitiveJavaObjectInspector(PrimitiveCategory.INT));
fieldOIs.add(listOI.getListElementObjectInspector());
return ObjectInspectorFactory.getStandardStructObjectInspector(fieldNames, fieldOIs);
}
@Override
public void process(Object[] o) throws HiveException {
List<?> list = listOI.getList(o[0]);
for (int i = 0; i < list.size(); i++) {
Object r = list.get(i);
forwardObj[0] = new Integer(i);
forwardObj[1] = r;
forward(forwardObj);
}
}
@Override
public String toString() {
return "posexplode";
}
}