/tags/release-0.0.0-rc0/hive/external/ql/src/java/org/apache/hadoop/hive/ql/udf/UDFOPPlus.java

/**
 * 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.serde2.io.ByteWritable;
import org.apache.hadoop.hive.serde2.io.DoubleWritable;
import org.apache.hadoop.hive.serde2.io.ShortWritable;
import org.apache.hadoop.io.FloatWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;

/**
 * The reason that we list evaluate methods with all numeric types is for both
 * better performance and type checking (so we know int + int is still an int
 * instead of a double); otherwise a single method that takes (Number a, Number
 * b) and use a.doubleValue() == b.doubleValue() is enough.
 * 
 * The case of int + double will be handled by implicit type casting using
 * UDFRegistry.implicitConvertable method.
 */
@Description(name = "+", value = "a _FUNC_ b - Returns a+b")
public class UDFOPPlus extends UDFBaseNumericOp {

  public UDFOPPlus() {
  }

  @Override
  public ByteWritable evaluate(ByteWritable a, ByteWritable b) {
    // LOG.info("Get input " + a.getClass() + ":" + a + " " + b.getClass() + ":"
    // + b);
    if ((a == null) || (b == null)) {
      return null;
    }

    byteWritable.set((byte) (a.get() + b.get()));
    return byteWritable;
  }

  @Override
  public ShortWritable evaluate(ShortWritable a, ShortWritable b) {
    // LOG.info("Get input " + a.getClass() + ":" + a + " " + b.getClass() + ":"
    // + b);
    if ((a == null) || (b == null)) {
      return null;
    }

    shortWritable.set((short) (a.get() + b.get()));
    return shortWritable;
  }

  @Override
  public IntWritable evaluate(IntWritable a, IntWritable b) {
    // LOG.info("Get input " + a.getClass() + ":" + a + " " + b.getClass() + ":"
    // + b);
    if ((a == null) || (b == null)) {
      return null;
    }

    intWritable.set((a.get() + b.get()));
    return intWritable;
  }

  @Override
  public LongWritable evaluate(LongWritable a, LongWritable b) {
    // LOG.info("Get input " + a.getClass() + ":" + a + " " + b.getClass() + ":"
    // + b);
    if ((a == null) || (b == null)) {
      return null;
    }

    longWritable.set(a.get() + b.get());
    return longWritable;
  }

  @Override
  public FloatWritable evaluate(FloatWritable a, FloatWritable b) {
    // LOG.info("Get input " + a.getClass() + ":" + a + " " + b.getClass() + ":"
    // + b);
    if ((a == null) || (b == null)) {
      return null;
    }

    floatWritable.set(a.get() + b.get());
    return floatWritable;
  }

  @Override
  public DoubleWritable evaluate(DoubleWritable a, DoubleWritable b) {
    // LOG.info("Get input " + a.getClass() + ":" + a + " " + b.getClass() + ":"
    // + b);
    if ((a == null) || (b == null)) {
      return null;
    }

    doubleWritable.set(a.get() + b.get());
    return doubleWritable;
  }

}