core/src/main/java/org/apache/carbondata/core/reader/CarbonIndexFileReader.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.reader;

import java.io.IOException;

import org.apache.carbondata.format.BlockIndex;
import org.apache.carbondata.format.IndexHeader;

import org.apache.hadoop.conf.Configuration;

/**
 * Reader class which will be used to read the index file
 */
public class CarbonIndexFileReader {

  private Configuration configuration;

  public CarbonIndexFileReader() {

  }

  public CarbonIndexFileReader(Configuration configuration) {
    this.configuration = configuration;
  }

  /**
   * reader
   */
  private ThriftReader thriftReader;

  /**
   * Below method will be used to read the index header
   *
   * @return index header
   * @throws IOException if any problem  while reader the header
   */
  public IndexHeader readIndexHeader() throws IOException {
    return (IndexHeader) thriftReader.read(IndexHeader::new);
  }

  /**
   * Below method will be used to close the reader
   */
  public void closeThriftReader() {
    thriftReader.close();
  }

  /**
   * Below method will be used to read the block index from fie
   *
   * @return block index info
   * @throws IOException if problem while reading the block index
   */
  public BlockIndex readBlockIndexInfo() throws IOException {
    return (BlockIndex) thriftReader.read(BlockIndex::new);
  }

  /**
   * Open the thrift reader
   *
   * @param filePath
   * @throws IOException
   */
  public void openThriftReader(String filePath) throws IOException {
    thriftReader = new ThriftReader(filePath, configuration);
    thriftReader.open();
  }

  /**
   * Open the thrift reader
   *
   * @param fileData
   */
  public void openThriftReader(byte[] fileData) {
    thriftReader = new ThriftReader(fileData);
  }

  /**
   * check if any more object is present
   *
   * @return true if any more object can be read
   * @throws IOException
   */
  public boolean hasNext() throws IOException {
    return thriftReader.hasNext();
  }
}