/**
* 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.exec;
import java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
/**
* Resolver for Numeric UDAFs like sum and avg. If the input argument is string
* or date, the resolver returns the evaluator whose iterate function operates
* on doubles.
*/
public class NumericUDAFEvaluatorResolver extends DefaultUDAFEvaluatorResolver {
/**
* Constructor.
*/
public NumericUDAFEvaluatorResolver(Class<? extends UDAF> udafClass) {
super(udafClass);
}
/*
* (non-Javadoc)
*
* @see
* org.apache.hadoop.hive.ql.exec.UDAFMethodResolver#getEvaluatorClass(java
* .util.List)
*/
@Override
public Class<? extends UDAFEvaluator> getEvaluatorClass(
List<TypeInfo> argTypeInfos) throws UDFArgumentException {
// Go through the argClasses and for any string, void or date time, start
// looking for doubles
ArrayList<TypeInfo> args = new ArrayList<TypeInfo>();
for (TypeInfo arg : argTypeInfos) {
if (arg.equals(TypeInfoFactory.voidTypeInfo)
|| arg.equals(TypeInfoFactory.stringTypeInfo)) {
args.add(TypeInfoFactory.doubleTypeInfo);
} else {
args.add(arg);
}
}
return super.getEvaluatorClass(args);
}
}