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
   *
   *    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.carbondata.processing.loading.partition.impl;
  
  import java.util.Arrays;
  import java.util.Comparator;
  
  import org.apache.carbondata.common.annotations.InterfaceAudience;
  import org.apache.carbondata.common.logging.LogServiceFactory;
  import org.apache.carbondata.core.datastore.row.CarbonRow;
  import org.apache.carbondata.processing.loading.partition.Partitioner;
  
  import org.apache.log4j.Logger;
  
  @InterfaceAudience.Internal
  public class RangePartitionerImpl implements Partitioner<CarbonRow> {
    private static final Logger LOGGER =
        LogServiceFactory.getLogService(RangePartitionerImpl.class.getName());
    private CarbonRow[] rangeBounds;
    private Comparator<CarbonRow> comparator;
  
    public RangePartitionerImpl(CarbonRow[] rangeBounds, Comparator<CarbonRow> comparator) {
      this.rangeBounds = rangeBounds;
      LOGGER.info("Use range partitioner to distribute data to "
          + (rangeBounds.length + 1) + " ranges.");
      this.comparator = comparator;
    }
  
    /**
     * learned from spark org.apache.spark.RangePartitioner
     *
     * @param key key
     * @return partitionId
     */
    @Override
    public int getPartition(CarbonRow key) {
      int partition = 0;
      if (rangeBounds.length <= 128) {
        // If we have less than 128 partitions naive search
        while (partition < rangeBounds.length
            && comparator.compare(key, rangeBounds[partition]) > 0) {
          partition += 1;
        }
      } else {
        // binary search. binarySearch either returns the match location or -[insertion point]-1
        partition = Arrays.binarySearch(rangeBounds, 0, rangeBounds.length, key, comparator);
        if (partition < 0) {
          partition = -partition - 1;
        }
        if (partition > rangeBounds.length) {
          partition = rangeBounds.length;
        }
      }
  
      return partition;
    }
  }
  