content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.job.plan.transform.format;
  
  import alluxio.AlluxioURI;
  import alluxio.job.plan.transform.Format;
  import alluxio.job.plan.transform.PartitionInfo;
  import alluxio.job.plan.transform.format.csv.CsvReader;
  import alluxio.job.plan.transform.format.orc.OrcReader;
  import alluxio.job.plan.transform.format.parquet.ParquetReader;
  
  import java.io.Closeable;
  import java.io.IOException;
  
  /**
   * A reader for reading rows in a table.
   */
  public interface TableReader extends Closeable {
    /**
     * @param uri the URI to the input
     * @param pInfo the partition info from catalog service
     * @return the reader for the input
     * @throws IOException when failed to create the reader
     */
    static TableReader create(AlluxioURI uri, PartitionInfo pInfo) throws IOException {
      ReadWriterUtils.checkUri(uri);
      Format format = pInfo.getFormat(uri.getName());
      switch (format) {
        case CSV:
          // fall through
        case GZIP_CSV:
          return CsvReader.create(uri, pInfo);
        case PARQUET:
          return ParquetReader.create(uri);
        case ORC:
          return OrcReader.create(uri);
        default:
          throw new IOException("Unsupported format: " + format);
      }
    }
  
    /**
     * @return the table schema
     * @throws IOException when failed to read the schema
     */
    TableSchema getSchema() throws IOException;
  
    /**
     * @return the next row or null if there are no more rows
     * @throws IOException when read fails
     */
    TableRow read() throws IOException;
  
    /**
     * Closes the reader, which will close the underlying stream.
     *
     * @throws IOException when failing to close the underlying stream
     */
    void close() throws IOException;
  }
  