protected static int getIndex(TableName tbl, List<TableName> sTableList) {
    if (sTableList == null) {
      return 0;
    }

    for (int i = 0; i < sTableList.size(); i++) {
      if (tbl.equals(sTableList.get(i))) {
        return i;
      }
    }
    return -1;
  }
Check if a given path is belongs to active WAL directory
@param p path
@return true, if yes
hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/impl/IncrementalTableBackupClient.java