/*
    * 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.chukwa.extraction.demux;
  
  
  import org.apache.hadoop.chukwa.extraction.engine.ChukwaRecord;
  import org.apache.hadoop.chukwa.extraction.engine.ChukwaRecordKey;
  import org.apache.hadoop.chukwa.extraction.CHUKWA_CONSTANT;
  
  import org.apache.hadoop.mapred.JobConf;
  import org.apache.hadoop.mapred.Partitioner;
  import org.apache.log4j.Logger;
  
  public class ChukwaRecordPartitioner<K, V> implements
      Partitioner<ChukwaRecordKey, ChukwaRecord> {
    static Logger log = Logger.getLogger(ChukwaRecordPartitioner.class);
  
    public void configure(JobConf arg0) {
    }
  
    public int getPartition(
        org.apache.hadoop.chukwa.extraction.engine.ChukwaRecordKey key,
        org.apache.hadoop.chukwa.extraction.engine.ChukwaRecord record,
        int numReduceTasks) {
      if (log.isDebugEnabled()) {
  
        log
            .debug("Partitioner key: ["
                + key.getReduceType()
                + "] - Reducer:"
                + ((key.getReduceType().hashCode() & Integer.MAX_VALUE) % numReduceTasks));
      }
      String hashkey = key.getReduceType();
      if(key.getKey().startsWith(CHUKWA_CONSTANT.INCLUDE_KEY_IN_PARTITIONER)) hashkey = key.getReduceType()+"#"+key.getKey();
      return (hashkey.hashCode() & Integer.MAX_VALUE)
          % numReduceTasks;
    }
  
  }