@Override
  public void stop() {
    LOG.debug("Encoded reader is being stopped");
    isStopped.set(true);
    cleanup();
  }
stripeRgs[stripeIx'] => boolean array (could be a bitmask) of rg-s that need to be read.
Contains only stripes that are read, and only columns included. null => read all RGs.
llap-server/src/java/org/apache/hadoop/hive/llap/io/encoded/OrcEncodedDataReader.java