private void discardData() {
    try {
      cacheWriter.discardData();
    } catch (Exception ex) {
      LlapIoImpl.LOG.error("Failed to close an async cache writer", ex);
    }
  }
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