added http_getter OCaml implementation

[helm.git] / helm / http_getter / http_getter_map.ml

diff --git a/helm/http_getter/http_getter_map.ml b/helm/http_getter/http_getter_map.ml
new file mode 100644 (file)
index 0000000..9ee8761
--- /dev/null
+++ b/helm/http_getter/http_getter_map.ml
@@ -0,0 +1,69 @@
+(*
+ *  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/.
+ *)
+
+exception Key_already_in of string;;
+exception Key_not_found of string;;
+
+class map dbname =
+  let perm = 420 in (* permission 644 in decimal notation *)
+  let db = Dbm.opendbm dbname [ Dbm.Dbm_rdwr; Dbm.Dbm_create ] perm in
+  object (self)
+
+    inherit ThreadSafe.threadSafe
+
+    initializer Gc.finalise Dbm.close db  (* close db on GC *)
+
+    method add key value =
+      self#doWriter (lazy (
+        try
+          Dbm.add db key value
+        with Dbm.Dbm_error "Entry already exists" -> raise (Key_already_in key)
+      ))
+
+    method remove key =
+      self#doWriter (lazy (
+        try
+          Dbm.remove db key
+        with Dbm.Dbm_error "dbm_delete" -> raise (Key_not_found key)
+      ))
+
+    method resolve key =
+      self#doReader (lazy (
+        try Dbm.find db key with Not_found -> raise (Key_not_found key)
+      ))
+
+    method iter (f: string -> string -> unit) =
+      self#doReader (lazy (
+        Dbm.iter f db
+      ))
+
+    method clear =
+      self#doWriter (lazy (
+        Dbm.iter (fun k _ -> Dbm.remove db k) db
+      ))
+
+  end
+