@Override
  public void postCompletedSnapshotAction(ObserverContext<MasterCoprocessorEnvironment> c,
    SnapshotDescription snapshot, TableDescriptor tableDescriptor) throws IOException {
    if (needHandleTableHdfsAcl(tableDescriptor, "snapshot " + snapshot.getName())) {
      // Add HDFS acls of users with table read permission to snapshot files
      hdfsAclHelper.snapshotAcl(snapshot);
    }
  }
Provider for mapping principal names to Users
hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/SnapshotScannerHDFSAclController.java