private void ensureCodecFromFileMetadata() {
    if (codec != null) return;
    codec = WriterImpl.createCodec(fileMetadata.getCompressionKind());
  }
Ensure codec is created for the split, to decode values from cache. Can only be called
after initializing fileMetadata.
llap-server/src/java/org/apache/hadoop/hive/llap/io/encoded/OrcEncodedDataReader.java