org.apache.hadoop.hive.serde2.columnar.ColumnarSerDeBase Maven / Gradle / Ivy

/**
 * 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.hadoop.hive.serde2.columnar;

import org.apache.hadoop.hive.serde2.AbstractSerDe;
import org.apache.hadoop.hive.serde2.ByteStream;
import org.apache.hadoop.hive.serde2.SerDeException;
import org.apache.hadoop.hive.serde2.SerDeStats;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.io.Writable;

public abstract class ColumnarSerDeBase extends AbstractSerDe {

  // The object for storing row data
  ColumnarStructBase cachedLazyStruct;
  // We need some initial values in case user don't call initialize()
  protected ObjectInspector cachedObjectInspector;

  protected long serializedSize;
  protected SerDeStats stats;
  protected boolean lastOperationSerialize;
  protected boolean lastOperationDeserialize;

  BytesRefArrayWritable serializeCache = new BytesRefArrayWritable();
  BytesRefWritable field[];
  ByteStream.Output serializeStream = new ByteStream.Output();

  @Override
  public Object deserialize(Writable blob) throws SerDeException {
    if (!(blob instanceof BytesRefArrayWritable)) {
      throw new SerDeException(getClass().toString()
            + ": expects BytesRefArrayWritable!");
    }

    BytesRefArrayWritable cols = (BytesRefArrayWritable) blob;
    cachedLazyStruct.init(cols);
    lastOperationSerialize = false;
    lastOperationDeserialize = true;
    return cachedLazyStruct;
  }

  @Override
  public SerDeStats getSerDeStats() {
    // must be different
    assert (lastOperationSerialize != lastOperationDeserialize);

    if (lastOperationSerialize) {
      stats.setRawDataSize(serializedSize);
    } else {
      stats.setRawDataSize(cachedLazyStruct.getRawDataSerializedSize());
    }
    return stats;
  }

  @Override
  public Class getSerializedClass() {
    return BytesRefArrayWritable.class;
  }

  protected void initialize(int size) throws SerDeException {
    field = new BytesRefWritable[size];
    for (int i = 0; i < size; i++) {
      field[i] = new BytesRefWritable();
      serializeCache.set(i, field[i]);
    }

    serializedSize = 0;
    stats = new SerDeStats();
    lastOperationSerialize = false;
    lastOperationDeserialize = false;
  }

  @Override
  public ObjectInspector getObjectInspector() throws SerDeException {
    return cachedObjectInspector;
  }

}