public static String Resolve_file(boolean use_file_protocol, Io_url root_dir, String file) {
    String rv = file;

    // resolve relative urls; EX: "./a.js" -> "/xowa/wiki/simple.wikipedia.org/bin/script/a.js"
    if (String_.Has_at_bgn(rv, "./")) {
      // remove "./"
      rv = String_.Mid(rv, 2);

      if (use_file_protocol) rv = root_dir.To_http_file_str() + rv;
      else {
        // if fsys_url && wnt, replace "\" with "/"
        if (Op_sys.Cur().Tid_is_wnt())
          rv = String_.Replace(rv, Op_sys.Lnx.Fsys_dir_spr_str(), Op_sys.Wnt.Fsys_dir_spr_str());
        rv = root_dir.Xto_api() + Op_sys.Cur().Fsys_dir_spr_str() + rv;
      }
    }
    return rv;
  }
 private void Init(Db_engine engine) {
   init = false;
   tbl_mgr.Clear();
   idx_mgr.Clear();
   Dbmeta_parser__tbl tbl_parser = new Dbmeta_parser__tbl();
   Dbmeta_parser__idx idx_parser = new Dbmeta_parser__idx();
   Db_qry__select_in_tbl qry =
       Db_qry__select_in_tbl.new_(
           "sqlite_master",
           String_.Ary_empty,
           String_.Ary("type", "name", "sql"),
           Db_qry__select_in_tbl.Order_by_null);
   Db_rdr rdr = engine.Stmt_by_qry(qry).Exec_select__rls_auto();
   try {
     Gfo_usr_dlg_.Instance.Log_many(
         "", "", "db.schema.load.bgn: conn=~{0}", engine.Conn_info().Db_api());
     while (rdr.Move_next()) {
       String type_str = rdr.Read_str("type");
       String name = rdr.Read_str("name");
       String sql = rdr.Read_str("sql");
       try {
         int type_int = Dbmeta_itm_tid.Xto_int(type_str);
         switch (type_int) {
           case Dbmeta_itm_tid.Tid_table:
             if (String_.Has_at_bgn(name, "sqlite_"))
               continue; // ignore b/c of non-orthodox syntax; EX: "CREATE TABLE
                         // sqlite_sequence(name, seq)"; also "CREATE TABLE
                         // sqlite_stat(tbl,idx,stat)";
             tbl_mgr.Add(tbl_parser.Parse(Bry_.new_u8(sql)));
             break;
           case Dbmeta_itm_tid.Tid_index:
             if (sql == null)
               continue; // ignore "autoindex"; EX: sqlite_autoindex_temp_page_len_avg_1
             idx_mgr.Add(idx_parser.Parse(Bry_.new_u8(sql)));
             break;
           default:
             Gfo_usr_dlg_.Instance.Log_many(
                 "",
                 "",
                 "db.schema.unknown type: conn=~{0} type=~{1} name=~{2} sql=~{3}",
                 engine.Conn_info().Db_api(),
                 type_str,
                 name,
                 sql);
             break;
         }
       } catch (
           Exception
               e) { // tables / indexes may be unparseable; skip them; EX: CREATE TABLE unparseable
                    // (col_1 /*comment*/ int); DATE:2016-06-08
         Gfo_usr_dlg_.Instance.Log_many(
             "",
             "",
             "db.schema.unparseable: conn=~{0} type=~{1} name=~{2} sql=~{3} err=~{4}",
             engine.Conn_info().Db_api(),
             type_str,
             name,
             sql,
             Err_.Message_gplx_log(e));
       }
     }
   } finally {
     rdr.Rls();
   }
 }