/**
* 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 org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
import org.apache.hadoop.hive.ql.exec.vector.VectorizedExpressions;
import org.apache.hadoop.hive.ql.exec.vector.expressions.gen.FuncAbsDecimalToDecimal;
import org.apache.hadoop.hive.ql.exec.vector.expressions.gen.FuncAbsDoubleToDouble;
import org.apache.hadoop.hive.ql.exec.vector.expressions.gen.FuncAbsLongToLong;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters.Converter;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.io.LongWritable;
/**
* GenericUDFAbs.
*
*/
@Description(name = "sq_count_check",
value = "_FUNC_(x) - Internal check on scalar subquery expression to make sure atmost one row is returned",
extended = "For internal use only")
@VectorizedExpressions({FuncAbsLongToLong.class, FuncAbsDoubleToDouble.class, FuncAbsDecimalToDecimal.class})
public class GenericUDFSQCountCheck extends GenericUDF {
private final LongWritable resultLong = new LongWritable();
private transient Converter[] converters = new Converter[1];
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
if (arguments.length > 2) {
throw new UDFArgumentLengthException(
"Invalid scalar subquery expression. Subquery count check expected two argument but received: " + arguments.length);
}
converters[0] = ObjectInspectorConverters.getConverter(arguments[0],
PrimitiveObjectInspectorFactory.writableLongObjectInspector);
ObjectInspector outputOI = null;
outputOI = PrimitiveObjectInspectorFactory.writableLongObjectInspector;
return outputOI;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
Long val = getLongValue(arguments, 0, converters);
switch (arguments.length){
case 1: //Scalar queries, should expect value/count less than 1
if (val > 1) {
throw new UDFArgumentException(
" Scalar subquery expression returns more than one row.");
}
break;
case 2:
Object valObject = arguments[0].get();
if( valObject != null
&& getLongValue(arguments, 0, converters) == 0){
throw new UDFArgumentException(
" IN/NOT IN subquery with aggregate returning zero result. Currently this is not supported.");
}
else if(valObject == null) {
throw new UDFArgumentException(
" IN/NOT IN subquery with aggregate returning zero result. Currently this is not supported.");
}
break;
}
resultLong.set(val);
return resultLong;
}
@Override
protected String getFuncName() {
return "sq_count_check";
}
@Override
public String getDisplayString(String[] children) {
return getStandardDisplayString(getFuncName(), children);
}
}