void addBatchToWriter() throws IOException {
    propagateSourceBatchFieldsToDest();
    if (!isAsync) {
      orcWriter.addRowBatch(destinationBatch);
    } else {
      //Lock ColumnVectors so we don't accidentally reset them before they're written out
      for (ColumnVector cv : destinationBatch.cols) {
        if (cv != null) {
          cv.incRef();
        }
      }
      currentBatches.add(destinationBatch);
      addWriteOp(new VrbOperation(destinationBatch));
    }
  }
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