test branch

[helm.git] / helm / ocaml / mathql_interpreter / mQIConn.ml

diff --git a/helm/ocaml/mathql_interpreter/mQIConn.ml b/helm/ocaml/mathql_interpreter/mQIConn.ml
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+(* Copyright (C) 2000, HELM Team.
+ * 
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ * 
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA  02111-1307, USA.
+ * 
+ * For details, see the HELM World-Wide-Web page,
+ * http://cs.unibo.it/helm/.
+ *)
+
+(*  AUTOR: Ferruccio Guidi <fguidi@cs.unibo.it>
+ *)
+
+(* $Id$ *)
+
+type connection = MySQL_C    of HMysql.dbd
+                | Postgres_C of Postgres.connection
+               | No_C
+                  
+type flag = Galax | Postgres | Queries | Result | Source | Times | Warn
+
+type handle = {
+   log : string -> unit; (* logging function        *)
+   set : flag list;      (* options                 *)
+   pgc : connection;     (* PG connection           *)
+   pgm : MQIMap.pg_map;  (* PG conversion function  *)
+   pga : MQIMap.pg_alias (* PG table aliases        *)
+}
+
+let tables handle p = MQIMap.get_tables handle.pgm p
+
+let field handle p t = MQIMap.get_field handle.pgm p t
+
+let resolve handle a = MQIMap.resolve handle.pga a
+
+let log handle = handle.log
+
+let set handle flag = List.mem flag handle.set
+
+let pgc handle = handle.pgc 
+
+let flags handle = handle.set 
+
+let string_of_flag = function
+      | Galax    -> "G"
+      | Postgres -> "P"
+      | Queries  -> "Q"
+      | Result   -> "R"
+      | Source   -> "S"      
+      | Times    -> "T"
+      | Warn     -> "W"
+
+let flag_of_char = function
+      | 'G' -> [Galax]
+      | 'P' -> [Postgres]
+      | 'Q' -> [Queries] 
+      | 'R' -> [Result]
+      | 'S' -> [Source]
+      | 'T' -> [Times]
+      | 'W' -> [Warn] 
+      | _   -> []
+
+let string_fold_left f a s =
+   let l = String.length s in
+   let rec aux b i = if i = l then b else aux (f b s.[i]) (succ i) in 
+   aux a 0
+
+let string_of_flags flags =
+   List.fold_left (fun s flag -> s ^ string_of_flag flag) "" flags
+
+let flags_of_string s =
+   string_fold_left (fun l c -> l @ flag_of_char c) [] s
+
+let init ?(flags = []) ?(log = ignore) () =
+   let flags = 
+      if flags = [] then
+         flags_of_string (Helm_registry.get "mathql_interpreter.flags")
+      else 
+         flags
+   in
+   let m, a =
+      let g = 
+         if List.mem Galax flags 
+           then MQIMap.empty_map else MQIMap.read_map
+      in g ()
+   in
+   {log = log; set = flags; 
+    pgc = begin
+      try
+         if List.mem Galax flags then No_C else
+         if List.mem Postgres flags then Postgres_C (MQIPostgres.init ()) else
+        MySQL_C (MQIMySql.init ())
+      with Failure "mqi_connection" -> No_C
+    end;
+    pgm = m; pga = a
+   }      
+
+let close handle =
+   match pgc handle with
+      | MySQL_C c    -> MQIMySql.close c
+      | Postgres_C c -> MQIPostgres.close c
+      | No_C         -> ()
+
+let exec handle out table cols ct cfl =
+   match pgc handle with
+      | MySQL_C c    -> MQIMySql.exec (c, out) table cols ct cfl
+      | Postgres_C c -> MQIPostgres.exec (c, out) table cols ct cfl
+      | No_C         -> []
+
+let connected handle =
+   pgc handle <> No_C  
+
+let init_if_connected ?(flags = []) ?(log = ignore) () =
+   let handle = init ~flags:flags ~log:log () in
+   if connected handle then handle else raise (Failure "mqi connection failed")