@Override
    public void putFileMetadata(
        ArrayList<Long> fileIds, ArrayList<ByteBuffer> metadata) throws HiveException {
      hive.putFileMetadata(fileIds, metadata);
    }
An implementation of external cache and factory based on metastore.
ql/src/java/org/apache/hadoop/hive/ql/io/orc/MetastoreExternalCachesByConf.java