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.io.UnsupportedEncodingException;
  import java.util.List;
  
  import org.apache.carbondata.common.annotations.InterfaceAudience;
  import org.apache.carbondata.core.datastore.row.CarbonRow;
  import org.apache.carbondata.core.metadata.datatype.DataType;
  import org.apache.carbondata.core.metadata.datatype.DataTypes;
  import org.apache.carbondata.core.metadata.schema.table.column.ColumnSchema;
  import org.apache.carbondata.processing.loading.partition.Partitioner;
  
  /**
   * Hash partitioner implementation, not consistent with spark.
   */
  @InterfaceAudience.Internal
  public class HashPartitionerImpl implements Partitioner<CarbonRow> {
  
    private int numberOfBuckets;
  
    private Hash[] hashes;
  
    public HashPartitionerImpl(List<Integer> indexes, List<ColumnSchema> columnSchemas,
        int numberOfBuckets) {
      this.numberOfBuckets = numberOfBuckets;
      hashes = new Hash[indexes.size()];
      for (int i = 0; i < indexes.size(); i++) {
        DataType dataType = columnSchemas.get(i).getDataType();
        if (dataType == DataTypes.SHORT || dataType == DataTypes.INT || dataType == DataTypes.LONG) {
          hashes[i] = new IntegralHash(indexes.get(i));
        } else if (dataType == DataTypes.DOUBLE || dataType == DataTypes.FLOAT ||
            DataTypes.isDecimal(dataType)) {
          hashes[i] = new DecimalHash(indexes.get(i));
        } else {
          hashes[i] = new StringHash(indexes.get(i));
        }
      }
    }
  
    @Override
    public int getPartition(CarbonRow key) {
      int hashCode = 0;
      for (Hash hash : hashes) {
        hashCode += hash.getHash(key.getData());
      }
      return (hashCode & Integer.MAX_VALUE) % numberOfBuckets;
    }
  
    private interface Hash {
      int getHash(Object[] value);
    }
  
    private static class IntegralHash implements Hash {
  
      private int index;
  
      private IntegralHash(int index) {
        this.index = index;
      }
  
      @Override
      public int getHash(Object[] value) {
        return value[index] != null ? Long.valueOf(value[index].toString()).hashCode() : 0;
      }
    }
  
    private static class DecimalHash implements Hash {
  
      private int index;
  
      private DecimalHash(int index) {
        this.index = index;
      }
  
      @Override
      public int getHash(Object[] value) {
        return value[index] != null ? Double.valueOf(value[index].toString()).hashCode() : 0;
      }
    }
  
    private static class StringHash implements Hash {
  
      private int index;
  
      private StringHash(int index) {
        this.index = index;
      }
  
      @Override
      public int getHash(Object[] value) {
        try {
          String valueStr = new String((byte[]) value[index], "utf-8");
          return value[index] != null ? valueStr.hashCode() : 0;
        } catch (UnsupportedEncodingException e) {
          return 0;
        }
      }
    }
  }
  