org.apache.hadoop.hive.ql.udf.UDFSign Maven / Gradle / Ivy
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* 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;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.hive.ql.exec.vector.VectorizedExpressions;
import org.apache.hadoop.hive.ql.exec.vector.expressions.gen.FuncSignDecimalToLong;
import org.apache.hadoop.hive.ql.exec.vector.expressions.gen.FuncSignDoubleToDouble;
import org.apache.hadoop.hive.ql.exec.vector.expressions.gen.FuncSignLongToDouble;
import org.apache.hadoop.hive.serde2.io.DoubleWritable;
import org.apache.hadoop.hive.serde2.io.HiveDecimalWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
@Description(name = "sign",
value = "_FUNC_(x) - returns the sign of x )",
extended = "Example:\n "
+ " > SELECT _FUNC_(40) FROM src LIMIT 1;\n"
+ " 1"
)
@VectorizedExpressions({FuncSignLongToDouble.class, FuncSignDoubleToDouble.class, FuncSignDecimalToLong.class})
public class UDFSign extends UDF {
private final DoubleWritable result = new DoubleWritable();
private final IntWritable intWritable = new IntWritable();
/**
* Take sign of a
*/
public DoubleWritable evaluate(DoubleWritable a) {
if (a == null) {
return null;
}
if (a.get() == 0) {
result.set(0);
} else if (a.get() > 0) {
result.set(1);
} else {
result.set(-1);
}
return result;
}
public DoubleWritable evaluate(LongWritable a) {
if (a == null) {
return null;
}
if (a.get() == 0) {
result.set(0);
} else if (a.get() > 0) {
result.set(1);
} else {
result.set(-1);
}
return result;
}
/**
* Get the sign of the decimal input
*
* @param decWritable decimal input
*
* @return -1, 0, or 1 representing the sign of the input decimal
*/
public IntWritable evaluate(HiveDecimalWritable decWritable) {
if (decWritable == null || !decWritable.isSet()) {
return null;
}
intWritable.set(decWritable.signum());
return intWritable;
}
}