@Override
  public void close() throws IOException {
    if (sourceBatch.size > 0) {
      addBatchToWriter();
    }
    if (!isAsync) {
      orcWriter.close();
    } else {
      addWriteOp(new CloseOperation());
    }
  }
The class that writes rows from a text reader to an ORC writer using VectorDeserializeRow.
llap-server/src/java/org/apache/hadoop/hive/llap/io/encoded/VectorDeserializeOrcWriter.java