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.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;
  
  import org.apache.spark.unsafe.hash.Murmur3_x86_32;
  import org.apache.spark.unsafe.types.UTF8String;
  
  /**
   * Hash partitioner implementation spark_hash_expression which using Murmur3_x86_32 keep the
   * same hash value as spark for given input.
   */
  @InterfaceAudience.Internal
  public class SparkHashExpressionPartitionerImpl implements Partitioner<CarbonRow> {
  
    private int numberOfBuckets;
  
    private Hash[] hashes;
  
    public SparkHashExpressionPartitionerImpl(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.LONG || dataType == DataTypes.DOUBLE) {
          hashes[i] = new LongHash(indexes.get(i));
        } else if (dataType == DataTypes.SHORT || dataType == DataTypes.INT
            || dataType == DataTypes.FLOAT || dataType == DataTypes.BOOLEAN
            || dataType == DataTypes.DATE) {
          hashes[i] = new IntegralHash(indexes.get(i));
        } else if (DataTypes.isDecimal(dataType)) {
          hashes[i] = new DecimalHash(indexes.get(i));
        } else if (dataType == DataTypes.TIMESTAMP) {
          hashes[i] = new TimestampHash(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());
      }
      int reminder = hashCode % numberOfBuckets;
      if (reminder < 0) {
        return (reminder + numberOfBuckets) % numberOfBuckets;
      } else {
        return reminder;
      }
    }
  
    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) {
        if (value[index] == null) {
          return 42;
        }
        int intValue = 0;
        if (value[index] instanceof Boolean) {
          boolean boolValue = (boolean) value[index];
          intValue = boolValue ? 1 : 0;
        } else if (value[index] instanceof Float) {
          intValue = Float.floatToIntBits((float) value[index]);
        } else {
          intValue = Integer.parseInt(value[index].toString());
        }
        return Murmur3_x86_32.hashInt(intValue, 42);
      }
    }
  
    private static class LongHash implements Hash {
  
      private int index;
  
      private LongHash(int index) {
        this.index = index;
      }
  
      @Override
      public int getHash(Object[] value) {
        if (value[index] == null) {
          return 42;
        }
        long longValue = 0L;
        if (value[index] instanceof java.lang.Double) {
          longValue = Double.doubleToLongBits((double) value[index]);
        } else {
          longValue = Long.parseLong(value[index].toString());
        }
        return Murmur3_x86_32.hashLong(longValue, 42);
      }
    }
  
    private static class TimestampHash implements Hash {
  
      private int index;
  
      private TimestampHash(int index) {
        this.index = index;
      }
  
      @Override
      public int getHash(Object[] value) {
        if (value[index] == null) {
          return 42;
        }
        long timeMilSec = (long) value[index];
        long timeMicSec = timeMilSec * 1000;
        return Murmur3_x86_32.hashLong(timeMicSec, 42);
      }
    }
  
    private static class DecimalHash implements Hash {
  
      private int index;
  
      private DecimalHash(int index) {
        this.index = index;
      }
  
      @Override
      public int getHash(Object[] value) {
        if (value[index] == null) {
          return 42;
        }
        return Double.valueOf(value[index].toString()).hashCode();
      }
    }
  
    private static class StringHash implements Hash {
  
      private int index;
  
      private StringHash(int index) {
        this.index = index;
      }
  
      @Override
      public int getHash(Object[] value) {
        // we should use the same hash method as spark, otherwise the same value will hash into diff
        // bucket in carbon/parquet bucket tables the result of join will not correct.
        if (value[index] == null) {
          return 42;
        }
        UTF8String utf8String = UTF8String.fromBytes((byte[]) value[index]);
        return utf8String.hashCode();
      }
    }
  }
  