/**
* 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.FunctionRegistry;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
import org.apache.hadoop.hive.ql.exec.vector.VectorizedExpressions;
import org.apache.hadoop.hive.ql.exec.vector.expressions.FuncPowerDoubleToDouble;
import org.apache.hadoop.hive.ql.exec.vector.expressions.FuncPowerLongToDouble;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.io.DoubleWritable;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector.Category;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters.Converter;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
@Description(name = "power,pow",
value = "_FUNC_(x1, x2) - raise x1 to the power of x2",
extended = "Example:\n"
+ " > SELECT _FUNC_(2, 3) FROM src LIMIT 1;\n" + " 8")
@VectorizedExpressions({FuncPowerLongToDouble.class, FuncPowerDoubleToDouble.class})
public class GenericUDFPower extends GenericUDF {
private final String opName;
private final String opDisplayName;
private transient PrimitiveObjectInspector baseOI;
private transient PrimitiveObjectInspector powerOI;
protected transient PrimitiveObjectInspector resultOI;
private transient Converter baseConverter;
private transient Converter powerConverter;
private final DoubleWritable doubleWritable = new DoubleWritable();
public GenericUDFPower() {
opName = getClass().getSimpleName();
opDisplayName = "power";
resultOI = PrimitiveObjectInspectorFactory.writableDoubleObjectInspector;
}
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
if (arguments.length != 2) {
throw new UDFArgumentException(opName + " requires two arguments.");
}
for (int i = 0; i < 2; i++) {
Category category = arguments[i].getCategory();
if (category != Category.PRIMITIVE) {
throw new UDFArgumentTypeException(i, "The "
+ GenericUDFUtils.getOrdinal(i + 1)
+ " argument of " + opName + " is expected to a "
+ Category.PRIMITIVE.toString().toLowerCase() + " type, but "
+ category.toString().toLowerCase() + " is found");
}
}
baseOI = (PrimitiveObjectInspector) arguments[0];
if (!FunctionRegistry.isNumericType(baseOI.getTypeInfo())) {
throw new UDFArgumentTypeException(0, "The "
+ GenericUDFUtils.getOrdinal(1)
+ " argument of " + opName + " is expected to a "
+ "numeric type, but "
+ baseOI.getTypeName() + " is found");
}
powerOI = (PrimitiveObjectInspector) arguments[1];
if (!FunctionRegistry.isNumericType(powerOI.getTypeInfo())) {
throw new UDFArgumentTypeException(1, "The "
+ GenericUDFUtils.getOrdinal(2)
+ " argument of " + opName + " is expected to a "
+ "numeric type, but "
+ powerOI.getTypeName() + " is found");
}
baseConverter = ObjectInspectorConverters.getConverter(baseOI,
PrimitiveObjectInspectorFactory.writableDoubleObjectInspector);
powerConverter = ObjectInspectorConverters.getConverter(powerOI,
PrimitiveObjectInspectorFactory.writableDoubleObjectInspector);
return resultOI;
}
@Override
public String getDisplayString(String[] children) {
assert (children.length == 2);
return opDisplayName + "(" + children[0] + ", " + children[1] + ")";
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
if (arguments[0] == null || arguments[1] == null) {
return null;
}
Object base = arguments[0].get();
Object power = arguments[1].get();
if (base == null && power == null) {
return null;
}
base = baseConverter.convert(base);
if (base == null) {
return null;
}
power = powerConverter.convert(power);
if (power == null) {
return null;
}
doubleWritable.set(Math.pow(((DoubleWritable)base).get(), ((DoubleWritable)power).get()));
return doubleWritable;
}
}