--- /dev/null
+(*
+ * Copyright (C) 2003:
+ * Stefano Zacchiroli <zack@cs.unibo.it>
+ * for the HELM Team http://helm.cs.unibo.it/
+ *
+ * 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://helm.cs.unibo.it/
+ *)
+
+(* $Id$ *)
+
+open Hbugs_misc;;
+open Hbugs_types;;
+open Printf;;
+
+exception Client_already_in of client_id;;
+exception Client_not_found of client_id;;
+exception Musing_already_in of musing_id;;
+exception Musing_not_found of musing_id;;
+exception Tutor_already_in of tutor_id;;
+exception Tutor_not_found of tutor_id;;
+
+class type registry =
+ object
+ method dump: string
+ method purge: unit
+ end
+
+let expire_time = 1800. (* 30 minutes *)
+
+class clients =
+ object (self)
+
+ inherit ThreadSafe.threadSafe
+(*
+ (* <DEBUGGING> *)
+ method private doCritical: 'a. 'a lazy_t -> 'a = fun act -> Lazy.force act
+ method private doWriter: 'a. 'a lazy_t -> 'a = fun act -> Lazy.force act
+ method private doReader: 'a. 'a lazy_t -> 'a = fun act -> Lazy.force act
+ (* </DEBUGGING> *)
+*)
+
+ val timetable: (client_id, float) Hashtbl.t = Hashtbl.create 17
+ val urls: (client_id, string) Hashtbl.t = Hashtbl.create 17
+ val subscriptions: (client_id, tutor_id list) Hashtbl.t = Hashtbl.create 17
+
+ (** INVARIANT: each client registered has an entry in 'urls' hash table
+ _and_ in 'subscriptions hash table even if it hasn't yet invoked
+ 'subscribe' method *)
+
+ method register id url = self#doWriter (lazy (
+ if Hashtbl.mem urls id then
+ raise (Client_already_in id)
+ else begin
+ Hashtbl.add urls id url;
+ Hashtbl.add subscriptions id [];
+ Hashtbl.add timetable id (Unix.time ())
+ end
+ ))
+ method private remove id =
+ Hashtbl.remove urls id;
+ Hashtbl.remove subscriptions id;
+ Hashtbl.remove timetable id
+ method unregister id = self#doWriter (lazy (
+ if Hashtbl.mem urls id then
+ self#remove id
+ else
+ raise (Client_not_found id)
+ ))
+ method isAuthenticated id = self#doReader (lazy (
+ Hashtbl.mem urls id
+ ))
+ method subscribe client_id tutor_ids = self#doWriter (lazy (
+ if Hashtbl.mem urls client_id then
+ Hashtbl.replace subscriptions client_id tutor_ids
+ else
+ raise (Client_not_found client_id)
+ ))
+ method getUrl id = self#doReader (lazy (
+ if Hashtbl.mem urls id then
+ Hashtbl.find urls id
+ else
+ raise (Client_not_found id)
+ ))
+ method getSubscription id = self#doReader (lazy (
+ if Hashtbl.mem urls id then
+ Hashtbl.find subscriptions id
+ else
+ raise (Client_not_found id)
+ ))
+
+ method dump = self#doReader (lazy (
+ "<clients>\n" ^
+ (Hashtbl.fold
+ (fun id url dump ->
+ (dump ^
+ (sprintf "<client id=\"%s\" url=\"%s\">\n" id url) ^
+ "<subscriptions>\n" ^
+ (String.concat "\n" (* id's subscriptions *)
+ (List.map
+ (fun tutor_id -> sprintf "<tutor id=\"%s\" />\n" tutor_id)
+ (Hashtbl.find subscriptions id))) ^
+ "</subscriptions>\n</client>\n"))
+ urls "") ^
+ "</clients>"
+ ))
+ method purge = self#doWriter (lazy (
+ let now = Unix.time () in
+ Hashtbl.iter
+ (fun id birthday ->
+ if now -. birthday > expire_time then
+ self#remove id)
+ timetable
+ ))
+
+ end
+
+class tutors =
+ object (self)
+
+ inherit ThreadSafe.threadSafe
+(*
+ (* <DEBUGGING> *)
+ method private doCritical: 'a. 'a lazy_t -> 'a = fun act -> Lazy.force act
+ method private doWriter: 'a. 'a lazy_t -> 'a = fun act -> Lazy.force act
+ method private doReader: 'a. 'a lazy_t -> 'a = fun act -> Lazy.force act
+ (* </DEBUGGING> *)
+*)
+
+ val timetable: (tutor_id, float) Hashtbl.t = Hashtbl.create 17
+ val tbl: (tutor_id, string * hint_type * string) Hashtbl.t =
+ Hashtbl.create 17
+
+ method register id url hint_type dsc = self#doWriter (lazy (
+ if Hashtbl.mem tbl id then
+ raise (Tutor_already_in id)
+ else begin
+ Hashtbl.add tbl id (url, hint_type, dsc);
+ Hashtbl.add timetable id (Unix.time ())
+ end
+ ))
+ method private remove id =
+ Hashtbl.remove tbl id;
+ Hashtbl.remove timetable id
+ method unregister id = self#doWriter (lazy (
+ if Hashtbl.mem tbl id then
+ self#remove id
+ else
+ raise (Tutor_not_found id)
+ ))
+ method isAuthenticated id = self#doReader (lazy (
+ Hashtbl.mem tbl id
+ ))
+ method exists id = self#doReader (lazy (
+ Hashtbl.mem tbl id
+ ))
+ method getTutor id = self#doReader (lazy (
+ if Hashtbl.mem tbl id then
+ Hashtbl.find tbl id
+ else
+ raise (Tutor_not_found id)
+ ))
+ method getUrl id =
+ let (url, _, _) = self#getTutor id in
+ url
+ method getHintType id =
+ let (_, hint_type, _) = self#getTutor id in
+ hint_type
+ method getDescription id =
+ let (_, _, dsc) = self#getTutor id in
+ dsc
+ method index = self#doReader (lazy (
+ Hashtbl.fold
+ (fun id (url, hint_type, dsc) idx -> (id, dsc) :: idx) tbl []
+ ))
+
+ method dump = self#doReader (lazy (
+ "<tutors>\n" ^
+ (Hashtbl.fold
+ (fun id (url, hint_type, dsc) dump ->
+ dump ^
+ (sprintf
+"<tutor id=\"%s\" url=\"%s\">\n<hint_type>%s</hint_type>\n<description>%s</description>\n</tutor>"
+ id url hint_type dsc))
+ tbl "") ^
+ "</tutors>"
+ ))
+ method purge = self#doWriter (lazy (
+ let now = Unix.time () in
+ Hashtbl.iter
+ (fun id birthday ->
+ if now -. birthday > expire_time then
+ self#remove id)
+ timetable
+ ))
+
+ end
+
+class musings =
+ object (self)
+
+ inherit ThreadSafe.threadSafe
+(*
+ (* <DEBUGGING> *)
+ method private doCritical: 'a. 'a lazy_t -> 'a = fun act -> Lazy.force act
+ method private doWriter: 'a. 'a lazy_t -> 'a = fun act -> Lazy.force act
+ method private doReader: 'a. 'a lazy_t -> 'a = fun act -> Lazy.force act
+ (* </DEBUGGING> *)
+*)
+
+ val timetable: (musing_id, float) Hashtbl.t = Hashtbl.create 17
+ val musings: (musing_id, client_id * tutor_id) Hashtbl.t = Hashtbl.create 17
+ val clients: (client_id, musing_id list) Hashtbl.t = Hashtbl.create 17
+ val tutors: (tutor_id, musing_id list) Hashtbl.t = Hashtbl.create 17
+
+ (** INVARIANT: each registered musing <musing_id, client_id, tutor_id> has
+ an entry in 'musings' table, an entry in 'clients' (i.e. one of the
+ musings for client_id is musing_id) table, an entry in 'tutors' table
+ (i.e. one of the musings for tutor_id is musing_id) and an entry in
+ 'timetable' table *)
+
+
+ method register musing_id client_id tutor_id = self#doWriter (lazy (
+ if Hashtbl.mem musings musing_id then
+ raise (Musing_already_in musing_id)
+ else begin
+ Hashtbl.add musings musing_id (client_id, tutor_id);
+ (* now add this musing as the first one of musings list for client and
+ tutor *)
+ Hashtbl.replace clients client_id
+ (musing_id ::
+ (try Hashtbl.find clients client_id with Not_found -> []));
+ Hashtbl.replace tutors tutor_id
+ (musing_id ::
+ (try Hashtbl.find tutors tutor_id with Not_found -> []));
+ Hashtbl.add timetable musing_id (Unix.time ())
+ end
+ ))
+ method private remove id =
+ (* ASSUMPTION: this method is invoked under a 'writer' lock *)
+ let (client_id, tutor_id) = self#getByMusingId' id in
+ Hashtbl.remove musings id;
+ (* now remove this musing from the list of musings for client and tutor
+ *)
+ Hashtbl.replace clients client_id
+ (List.filter ((<>) id)
+ (try Hashtbl.find clients client_id with Not_found -> []));
+ Hashtbl.replace tutors tutor_id
+ (List.filter ((<>) id)
+ (try Hashtbl.find tutors tutor_id with Not_found -> []));
+ Hashtbl.remove timetable id
+ method unregister id = self#doWriter (lazy (
+ if Hashtbl.mem musings id then
+ self#remove id
+ ))
+ method private getByMusingId' id =
+ (* ASSUMPTION: this method is invoked under a 'reader' lock *)
+ try
+ Hashtbl.find musings id
+ with Not_found -> raise (Musing_not_found id)
+ method getByMusingId id = self#doReader (lazy (
+ self#getByMusingId' id
+ ))
+ method getByClientId id = self#doReader (lazy (
+ try
+ Hashtbl.find clients id
+ with Not_found -> []
+ ))
+ method getByTutorId id = self#doReader (lazy (
+ try
+ Hashtbl.find tutors id
+ with Not_found -> []
+ ))
+ method isActive id = self#doReader (lazy (
+ Hashtbl.mem musings id
+ ))
+
+ method dump = self#doReader (lazy (
+ "<musings>\n" ^
+ (Hashtbl.fold
+ (fun mid (cid, tid) dump ->
+ dump ^
+ (sprintf "<musing id=\"%s\" client=\"%s\" tutor=\"%s\" />\n"
+ mid cid tid))
+ musings "") ^
+ "</musings>"
+ ))
+ method purge = self#doWriter (lazy (
+ let now = Unix.time () in
+ Hashtbl.iter
+ (fun id birthday ->
+ if now -. birthday > expire_time then
+ self#remove id)
+ timetable
+ ))
+
+ end
+
projects / helm.git / blobdiff