3 * Stefano Zacchiroli <zack@cs.unibo.it>
4 * for the HELM Team http://helm.cs.unibo.it/
6 * This file is part of HELM, an Hypertextual, Electronic
7 * Library of Mathematics, developed at the Computer Science
8 * Department, University of Bologna, Italy.
10 * HELM is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version 2
13 * of the License, or (at your option) any later version.
15 * HELM is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with HELM; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
25 * For details, see the HELM World-Wide-Web page,
26 * http://helm.cs.unibo.it/
33 let debug_print s = if debug then prerr_endline s ;;
34 Http_common.debug := false;;
36 let daemon_name = "H-Bugs Broker" ;;
37 let default_port = 49081 ;;
38 let port_env_var = "HELM_HBUGS_BROKER_PORT" ;;
41 int_of_string (Sys.getenv port_env_var)
43 | Not_found -> default_port
44 | Failure "int_of_string" ->
45 prerr_endline "Warning: invalid port, reverting to default";
48 let usage_string = "HBugs Broker: usage string not yet written :-(";;
50 exception Unexpected_msg of message;;
52 let return_xml_msg body outchan =
53 Http_daemon.respond ~headers:["Content-Type", "text/xml"] ~body outchan
55 let parse_musing_id = function
56 | Musing_started (_, musing_id) -> musing_id
57 | Musing_aborted (_, musing_id) -> musing_id
62 let mutex = Mutex.create () in
65 Mutex.lock mutex; let res = Lazy.force action in Mutex.unlock mutex; res
66 with e -> Mutex.unlock mutex; raise e
70 let clients = new Hbugs_broker_registry.clients in
71 let tutors = new Hbugs_broker_registry.tutors in
72 let musings = new Hbugs_broker_registry.musings in
74 [ (clients :> Hbugs_broker_registry.registry);
75 (tutors :> Hbugs_broker_registry.registry);
76 (musings :> Hbugs_broker_registry.registry) ]
79 let my_own_id = Hbugs_id_generator.new_broker_id () in
81 (* debugging: dump broker internal status, used by '/dump' method *)
82 let dump_registries () =
84 String.concat "\n" (List.map (fun o -> o#dump) registries)
87 let handle_msg outchan = function
89 (* messages from clients *)
92 Hbugs_messages.respond_msg (Usage usage_string) outchan
93 | Register_client (client_id, client_url) -> do_critical (lazy (
95 clients#register client_id client_url;
96 Hbugs_messages.respond_msg (Client_registered my_own_id) outchan
97 with Hbugs_broker_registry.Client_already_in id ->
98 Hbugs_messages.respond_exc "already_registered" id outchan
100 | Unregister_client client_id -> do_critical (lazy (
101 if clients#isAuthenticated client_id then begin
102 clients#unregister client_id;
103 Hbugs_messages.respond_msg (Client_unregistered my_own_id) outchan
105 Hbugs_messages.respond_exc "forbidden" client_id outchan
107 | List_tutors client_id -> do_critical (lazy (
108 if clients#isAuthenticated client_id then begin
109 Hbugs_messages.respond_msg
110 (Tutor_list (my_own_id, tutors#index))
113 Hbugs_messages.respond_exc "forbidden" client_id outchan
115 | Subscribe (client_id, tutor_ids) -> do_critical (lazy (
116 if clients#isAuthenticated client_id then begin
117 if List.length tutor_ids <> 0 then begin (* at least one tutor id *)
118 if List.for_all tutors#exists tutor_ids then begin
119 clients#subscribe client_id tutor_ids;
120 Hbugs_messages.respond_msg
121 (Subscribed (my_own_id, tutor_ids)) outchan
122 end else (* required subscription to at least one unexistent tutor *)
124 List.filter (fun id -> not (tutors#exists id)) tutor_ids
126 Hbugs_messages.respond_exc
127 "tutor_not_found" (String.concat " " missing_tutors) outchan
128 end else (* no tutor id specified *)
129 Hbugs_messages.respond_exc "no_tutor_specified" "" outchan
131 Hbugs_messages.respond_exc "forbidden" client_id outchan
133 | State_change (client_id, new_state) -> do_critical (lazy (
134 if clients#isAuthenticated client_id then begin
135 let active_musings = musings#getByClientId client_id in
137 List.map (* collect Abort_musing message's responses *)
138 (fun id -> (* musing id *)
139 let tutor = snd (musings#getByMusingId id) in
140 Hbugs_messages.submit_req
141 ~url:(tutors#getUrl tutor) (Abort_musing (my_own_id, id)))
144 List.iter musings#unregister active_musings;
145 let started_musing_ids =
146 List.map (* register new musings and collect their ids *)
149 Hbugs_messages.submit_req
150 ~url:(tutors#getUrl tutor_id)
151 (Start_musing (my_own_id, new_state))
153 let musing_id = parse_musing_id res in
154 musings#register musing_id client_id tutor_id;
156 (clients#getSubscription client_id)
158 let stopped_musing_ids = List.map parse_musing_id stop_answers in
159 Hbugs_messages.respond_msg
160 (State_accepted (my_own_id, stopped_musing_ids, started_musing_ids))
163 Hbugs_messages.respond_exc "forbidden" client_id outchan
166 (* messages from tutors *)
168 | Register_tutor (tutor_id, tutor_url, hint_type, dsc) -> do_critical (lazy (
170 tutors#register tutor_id tutor_url hint_type dsc;
171 Hbugs_messages.respond_msg (Tutor_registered my_own_id) outchan
172 with Hbugs_broker_registry.Tutor_already_in id ->
173 Hbugs_messages.respond_exc "already_registered" id outchan
175 | Unregister_tutor tutor_id -> do_critical (lazy (
176 if tutors#isAuthenticated tutor_id then begin
177 tutors#unregister tutor_id;
178 Hbugs_messages.respond_msg (Tutor_unregistered my_own_id) outchan
180 Hbugs_messages.respond_exc "forbidden" tutor_id outchan
182 | Musing_completed (tutor_id, musing_id, result) -> do_critical (lazy (
183 if tutors#isAuthenticated tutor_id then begin
188 let hint = (* TODO decidere la hint *) "hint!!!!" in
190 clients#getUrl (fst (musings#getByMusingId musing_id))
192 Hbugs_messages.submit_req ~url (Hint (my_own_id, hint))
194 ignore res (* TODO mi interessa la risposta? *)
196 Hbugs_messages.respond_msg (Thanks (my_own_id, musing_id)) outchan;
197 musings#unregister musing_id
199 Hbugs_messages.respond_exc "forbidden" tutor_id outchan
202 | msg -> (* unexpected message *)
203 debug_print "Unknown message!";
204 Hbugs_messages.respond_exc
205 "unexpected_msg" (Hbugs_messages.string_of_msg msg) outchan
207 let handle_msg outchan = (* debugging wrapper around 'handle_msg' *)
209 (fun msg -> (* filter handle_msg through a function which dumps input
211 debug_print (Hbugs_messages.string_of_msg msg);
212 handle_msg outchan msg)
218 let callback (req: Http_types.request) outchan =
220 debug_print ("Connection from " ^ req#clientAddr);
221 debug_print ("Received request: " ^ req#path);
223 (* TODO write help message *)
224 | "/help" -> return_xml_msg "<help> not yet written </help>" outchan
225 | "/act" -> handle_msg outchan (Hbugs_messages.msg_of_string req#body)
228 Http_daemon.respond ~body:(dump_registries ()) outchan
230 Http_daemon.respond_error ~code:400 outchan
231 | _ -> Http_daemon.respond_error ~code:400 outchan);
232 debug_print "Done!\n"
234 | Http_types.Param_not_found attr_name ->
235 Hbugs_messages.respond_exc "missing_parameter" attr_name outchan
237 Hbugs_messages.respond_exc
238 "uncaught_exception" (Printexc.to_string exc) outchan
241 (* thread who cleans up ancient client/tutor/musing registrations *)
243 let delay = 3600.0 in (* 1 hour delay *)
246 List.iter (fun o -> o#purge) registries
251 printf "Listening on port %d ...\n" port;
253 ignore (Thread.create ragman ());
254 Http_daemon.start' ~port ~mode:`Thread callback