org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveArrayInspector Maven / Gradle / Ivy

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/*
 * Licensed 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.hive.ql.io.parquet.serde;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.SettableListObjectInspector;
import org.apache.hadoop.io.ArrayWritable;
import org.apache.hadoop.io.Writable;

/**
 * The ParquetHiveArrayInspector will inspect an ArrayWritable, considering it as an Hive array.

 * It can also inspect a List if Hive decides to inspect the result of an inspection.
 *
 */
public class ParquetHiveArrayInspector implements SettableListObjectInspector {

  ObjectInspector arrayElementInspector;

  public ParquetHiveArrayInspector(final ObjectInspector arrayElementInspector) {
    this.arrayElementInspector = arrayElementInspector;
  }

  @Override
  public String getTypeName() {
    return "array<" + arrayElementInspector.getTypeName() + ">";
  }

  @Override
  public Category getCategory() {
    return Category.LIST;
  }

  @Override
  public ObjectInspector getListElementObjectInspector() {
    return arrayElementInspector;
  }

  @Override
  public Object getListElement(final Object data, final int index) {
    if (data == null) {
      return null;
    }

    if (data instanceof ArrayWritable) {
      final Writable[] array = ((ArrayWritable) data).get();
      if (array == null || array.length == 0) {
        return null;
      }

      if (index >= 0 && index < array.length) {
        return array[index];
      } else {
        return null;
      }
    }

    if (data instanceof List) {
      return ((List)data).get(index);
    }

    throw new UnsupportedOperationException("Cannot inspect " + data.getClass().getCanonicalName());
  }

  @Override
  public int getListLength(final Object data) {
    if (data == null) {
      return -1;
    }

    if (data instanceof ArrayWritable) {
      final Writable[] array = ((ArrayWritable) data).get();
      if (array == null) {
        return -1;
      }

      return array.length;
    }

    if (data instanceof List) {
      return ((List)data).size();
    }

    throw new UnsupportedOperationException("Cannot inspect " + data.getClass().getCanonicalName());
  }

  @Override
  public List getList(final Object data) {
    if (data == null) {
      return null;
    }

    if (data instanceof ArrayWritable) {
      final Writable[] array = ((ArrayWritable) data).get();
      if (array == null) {
        return null;
      }
      return new ArrayList(Arrays.asList(array));
    }

    if (data instanceof List) {
      return (List)data;
    }

    throw new UnsupportedOperationException("Cannot inspect " + data.getClass().getCanonicalName());
  }

  @Override
  public Object create(final int size) {
    return new ArrayList