IndexUpdatePartitioner.java
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上传日期:2018-01-08
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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.contrib.index.mapred;
- import java.util.HashMap;
- import java.util.Map;
- import org.apache.hadoop.mapred.JobConf;
- import org.apache.hadoop.mapred.Partitioner;
- /**
- * This partitioner class puts the values of the same key - in this case the
- * same shard - in the same partition.
- */
- public class IndexUpdatePartitioner implements
- Partitioner<Shard, IntermediateForm> {
- private Shard[] shards;
- private Map<Shard, Integer> map;
- /* (non-Javadoc)
- * @see org.apache.hadoop.mapred.Partitioner#getPartition(java.lang.Object, java.lang.Object, int)
- */
- public int getPartition(Shard key, IntermediateForm value, int numPartitions) {
- int partition = map.get(key).intValue();
- if (partition < numPartitions) {
- return partition;
- } else {
- return numPartitions - 1;
- }
- }
- /* (non-Javadoc)
- * @see org.apache.hadoop.mapred.JobConfigurable#configure(org.apache.hadoop.mapred.JobConf)
- */
- public void configure(JobConf job) {
- shards = Shard.getIndexShards(new IndexUpdateConfiguration(job));
- map = new HashMap<Shard, Integer>();
- for (int i = 0; i < shards.length; i++) {
- map.put(shards[i], i);
- }
- }
- }