/**
* 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.pig.backend.hadoop.executionengine.tez.runtime;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.Partitioner;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.Tuple;
import org.apache.pig.impl.io.NullableTuple;
public class HashValuePartitioner extends Partitioner<Writable, Writable> {
@SuppressWarnings("rawtypes")
@Override
public int getPartition(Writable key, Writable value, int numPartitions) {
int hash = 17;
Tuple tuple;
if (value instanceof Tuple) {
// union optimizer turned off
tuple = (Tuple) value;
} else {
// union followed by order by or skewed join
tuple = (Tuple)((NullableTuple) value).getValueAsPigType();
}
if (tuple != null) {
for (Object o : tuple.getAll()) {
if (o != null) {
// Skip computing hashcode for bags.
// Order of elements in the map/bag may be different on each run
// Can't even include size as some DataBag implementations
// iterate through all elements in the bag to get the size.
if (o instanceof DataBag) {
hash = 31 * hash;
} else {
hash = 31 * hash + o.hashCode();
}
}
}
}
return (hash & Integer.MAX_VALUE) % numPartitions;
}
}