content: /*
   * 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
   *
   *     https://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.avro.mapred.tether;
  
  import java.nio.ByteBuffer;
  
  import org.apache.hadoop.io.NullWritable;
  import org.apache.hadoop.mapred.JobConf;
  import org.apache.hadoop.mapred.Partitioner;
  
  import org.apache.avro.Schema;
  import org.apache.avro.io.BinaryData;
  import org.apache.avro.mapred.AvroJob;
  
  class TetherPartitioner implements Partitioner<TetherData, NullWritable> {
  
    private static final ThreadLocal<Integer> CACHE = new ThreadLocal<>();
  
    private Schema schema;
  
    @Override
    public void configure(JobConf job) {
      schema = AvroJob.getMapOutputSchema(job);
    }
  
    static void setNextPartition(int newValue) {
      CACHE.set(newValue);
    }
  
    @Override
    public int getPartition(TetherData key, NullWritable value, int numPartitions) {
      Integer result = CACHE.get();
      if (result != null) // return cached value
        return result;
  
      ByteBuffer b = key.buffer();
      int p = b.position();
      int hashCode = BinaryData.hashCode(b.array(), p, b.limit() - p, schema);
      if (hashCode < 0)
        hashCode = -hashCode;
      return hashCode % numPartitions;
    }
  
  }
  