core/src/main/java/org/apache/carbondata/core/util/DataFileFooterConverter.java

/*
 * 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.core.util;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.carbondata.core.datastore.FileReader;
import org.apache.carbondata.core.datastore.block.TableBlockInfo;
import org.apache.carbondata.core.datastore.impl.FileFactory;
import org.apache.carbondata.core.metadata.ColumnarFormatVersion;
import org.apache.carbondata.core.metadata.blocklet.BlockletInfo;
import org.apache.carbondata.core.metadata.blocklet.DataFileFooter;
import org.apache.carbondata.core.metadata.blocklet.index.BlockletIndex;
import org.apache.carbondata.core.metadata.schema.table.column.ColumnSchema;
import org.apache.carbondata.core.reader.CarbonFooterReader;
import org.apache.carbondata.format.FileFooter;

import org.apache.hadoop.conf.Configuration;

/**
 * Below class will be used to convert the thrift object of data file
 * meta data to wrapper object
 */
public class DataFileFooterConverter extends AbstractDataFileFooterConverter {

  public DataFileFooterConverter(Configuration configuration) {
    super(configuration);
  }

  public DataFileFooterConverter() {
    super(FileFactory.getConfiguration());
  }

  /**
   * Below method will be used to convert thrift file meta to wrapper file meta
   */
  @Override
  public DataFileFooter readDataFileFooter(TableBlockInfo tableBlockInfo)
      throws IOException {
    DataFileFooter dataFileFooter = new DataFileFooter();
    FileReader fileReader = null;
    try {
      long completeBlockLength = tableBlockInfo.getBlockLength();
      long footerPointer = completeBlockLength - 8;
      fileReader = FileFactory.getFileHolder(FileFactory.getFileType(tableBlockInfo.getFilePath()));
      long actualFooterOffset = fileReader.readLong(tableBlockInfo.getFilePath(), footerPointer);
      CarbonFooterReader reader =
          new CarbonFooterReader(tableBlockInfo.getFilePath(), actualFooterOffset);
      FileFooter footer = reader.readFooter();
      dataFileFooter.setVersionId(ColumnarFormatVersion.valueOf((short) footer.getVersion()));
      dataFileFooter.setNumberOfRows(footer.getNum_rows());
      dataFileFooter.setColumnInTable(convertColumnSchemaList(footer.getTable_columns()));

      List<org.apache.carbondata.format.BlockletIndex> leaf_node_indices_Thrift =
          footer.getBlocklet_index_list();
      List<BlockletIndex> blockletIndexList = new ArrayList<BlockletIndex>();
      for (int i = 0; i < leaf_node_indices_Thrift.size(); i++) {
        BlockletIndex blockletIndex = getBlockletIndex(leaf_node_indices_Thrift.get(i));
        blockletIndexList.add(blockletIndex);
      }

      List<org.apache.carbondata.format.BlockletInfo> leaf_node_infos_Thrift =
          footer.getBlocklet_info_list();
      List<BlockletInfo> blockletInfoList = new ArrayList<BlockletInfo>();
      for (int i = 0; i < leaf_node_infos_Thrift.size(); i++) {
        BlockletInfo blockletInfo = getBlockletInfo(leaf_node_infos_Thrift.get(i));
        blockletInfo.setBlockletIndex(blockletIndexList.get(i));
        blockletInfoList.add(blockletInfo);
      }
      dataFileFooter.setBlockletList(blockletInfoList);
      dataFileFooter.setBlockletIndex(getBlockletIndexForDataFileFooter(blockletIndexList));
    } finally {
      if (null != fileReader) {
        fileReader.finish();
      }
    }
    return dataFileFooter;
  }

  /**
   * Below method is to convert the blocklet info of the thrift to wrapper
   * blocklet info
   *
   * @param blockletInfoThrift blocklet info of the thrift
   * @return blocklet info wrapper
   */
  private BlockletInfo getBlockletInfo(
      org.apache.carbondata.format.BlockletInfo blockletInfoThrift) {
    BlockletInfo blockletInfo = new BlockletInfo();
    blockletInfo.setNumberOfRows(blockletInfoThrift.getNum_rows());
    return blockletInfo;
  }

  @Override
  public List<ColumnSchema> getSchema(TableBlockInfo tableBlockInfo) throws IOException {
    FileReader fileReader = null;
    try {
      long completeBlockLength = tableBlockInfo.getBlockLength();
      long footerPointer = completeBlockLength - 8;
      fileReader = FileFactory.getFileHolder(FileFactory.getFileType(tableBlockInfo.getFilePath()));
      long actualFooterOffset = fileReader.readLong(tableBlockInfo.getFilePath(), footerPointer);
      CarbonFooterReader reader =
          new CarbonFooterReader(tableBlockInfo.getFilePath(), actualFooterOffset);
      return convertColumnSchemaList(reader.readFooter().getTable_columns());
    } finally {
      if (null != fileReader) {
        fileReader.finish();
      }
    }
  }
}