| /* |
| * 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.crunch.impl.mr.run; |
| |
| import org.apache.crunch.util.HashUtil; |
| import org.apache.hadoop.mapreduce.Partitioner; |
| |
| /** |
| * Hash partitioner which applies a supplemental hashing function to the hash code of values to ensure better |
| * distribution of keys over partitions. |
| */ |
| public class UniformHashPartitioner<KEY, VALUE> extends Partitioner<KEY, VALUE> { |
| |
| @Override |
| public int getPartition(KEY key, VALUE value, int numPartitions) { |
| return ((HashUtil.smearHash(key.hashCode()) & Integer.MAX_VALUE) % numPartitions); |
| } |
| } |
