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/
32 (* debugging settings *)
34 let debug_level = `Notice ;;
35 let debug_print s = if debug then prerr_endline s ;;
36 Http_common.debug := false ;;
39 let daemon_name = "UWOBO OCaml" ;;
40 let default_log_file = "uwobo.log" ;; (* relative to execution dir *)
41 let default_port = 58080 ;;
42 let port_env_var = "UWOBO_PORT" ;;
43 let default_media_type = "text/html" ;;
44 let default_encoding = "utf8" ;;
46 Some (try Sys.getenv "UWOBO_LOG_FILE" with Not_found -> default_log_file)
48 let logfile_perm = 0o640 ;;
51 int_of_string (Sys.getenv port_env_var)
53 | Not_found -> default_port
54 | Failure "int_of_string" ->
55 prerr_endline "Warning: invalid port, reverting to default";
59 let respond_html body outchan =
60 Http_daemon.respond ~body ~headers:["Content-Type", "text/html"] outchan
63 (** perform an 'action' that can be applied to a list of keys or, if no keys
64 was given, to all keys *)
65 let act_on_keys keys_param styles logger per_key_action all_keys_action logmsg
69 Pcre.split ~pat:"," keys_param
70 with Http_types.Param_not_found _ -> []
73 | [] -> (* no key provided, act on all stylesheets *)
74 logger#log (sprintf "%s all stylesheets ..." logmsg);
75 (try all_keys_action () with e -> logger#log (Printexc.to_string e));
76 logger#log (sprintf "Done! (all stylesheets)")
79 (fun key -> (* act on a single stylesheet *)
80 logger#log (sprintf "%s stylesheet %s" logmsg key);
81 (try per_key_action key with e -> logger#log (Printexc.to_string e));
82 logger#log (sprintf "Done! (stylesheet %s)" key))
86 (** parse parameters for '/apply' action *)
87 let parse_apply_params =
88 let is_global_param x = Pcre.pmatch ~pat:"^param(\\.[^.]+){1}$" x in
89 let is_local_param x = Pcre.pmatch ~pat:"^param(\\.[^.]+){2}$" x in
90 let is_property x = Pcre.pmatch ~pat:"^prop\\.[^.]+$" x in
92 (fun (old_params, old_properties) (name, value) ->
94 | name when is_global_param name ->
95 let name = Pcre.replace ~pat:"^param\\." name in
96 ((fun x -> (old_params x) @ [name, value]), old_properties)
97 | name when is_local_param name ->
98 let pieces = Pcre.extract ~pat:"^param\\.([^.]+)\\.(.*)" name in
99 let (key, name) = (pieces.(1), pieces.(2)) in
101 | x when x = key -> [name, value] @ (old_params x)
102 | x -> old_params x),
104 | name when is_property name ->
105 let name = Pcre.replace ~pat:"^prop\\." name in
106 (old_params, ((name, value) :: old_properties))
107 | _ -> (old_params, old_properties))
108 ((fun _ -> []), []) (* no parameters, no properties *)
111 (** send ~cmd (without trailing "\n"!) through ~cmd_pipe, then wait for answer
112 on ~res_pipe (with a timeout of 60 seconds) and send over outchan data
113 received from ~res_pipe *)
114 let short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan =
115 (* debug_print (sprintf "Sending command '%s' to grandparent ..." cmd); *)
116 output_string cmd_pipe (cmd ^ "\n"); (* send command to grandfather *)
118 let res_pipe_fd = Unix.descr_of_in_channel res_pipe in
119 let (read_fds, _, _) = (* wait for an answer *)
120 Unix.select [res_pipe_fd] [] [] 60.0
123 | [fd] when fd = res_pipe_fd -> (* send answer to http client *)
124 Http_daemon.send_basic_headers ~code:200 outchan;
125 Http_daemon.send_header "Content-Type" "text/html" outchan;
126 Http_daemon.send_CRLF outchan;
129 output_string outchan ((input_line res_pipe) ^ "\n")
131 with End_of_file -> flush outchan)
132 | _ -> (* no answer received from grandfather *)
133 return_error "Timeout!" outchan)
136 let (add_cmd_RE, remove_cmd_RE, reload_cmd_RE) =
137 (Pcre.regexp "^add ", Pcre.regexp "^remove ", Pcre.regexp "^reload ")
140 exception Restart_HTTP_daemon;;
142 (** log a list of libxslt's messages using a processing logger *)
143 let log_libxslt_msgs logger =
146 | Uwobo_styles.LibXsltErrorMsg msg ->
147 logger#logBold ("LibXSLT ERROR: " ^ msg)
148 | Uwobo_styles.LibXsltDebugMsg msg ->
149 logger#logEmph ("LibXSLT DEBUG " ^ msg))
152 (* request handler action
153 @param syslogger Uwobo_logger.sysLogger instance used for logginf
154 @param styles Uwobo_styles.styles instance which keeps the stylesheets list
155 @param cmd_pipe output _channel_ used to _write_ update messages
156 @param res_pipe input _channel_ used to _read_ grandparent results
157 @param req http request instance
158 @param outchan output channel connected to http client
161 ~syslogger ~styles ~cmd_pipe ~res_pipe () (req: Http_types.request) outchan
164 syslogger#log `Notice (sprintf "Connection from %s" req#clientAddr);
165 syslogger#log `Debug (sprintf "Received request: %s" req#path);
168 (let bindings = req#paramAll "bind" in
169 if bindings = [] then
170 return_error "No [key,stylesheet] binding provided" outchan
172 let cmd = sprintf "add %s" (String.concat ";" bindings) in
173 short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan
176 let cmd = sprintf "remove %s" (req#param "keys") in
177 short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan
179 let cmd = sprintf "reload %s" (req#param "keys") in
180 short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan
182 (let log = new Uwobo_logger.processingLogger () in
183 (match styles#list with
184 | [] -> log#log "No stylesheets loaded (yet)!"
186 log#log "Stylesheets list:";
187 List.iter (fun s -> log#log s) l);
188 respond_html log#asHtml outchan)
190 let logger = new Uwobo_logger.processingLogger () in
191 let xmluri = req#param "xmluri" in
192 let keys = Pcre.split ~pat:"," (req#param "keys") in
193 (* notation: "local" parameters are those defined on a per-stylesheet
194 pasis (i.e. param.key.param=value), "global" parameters are those
195 defined for all stylesheets (i.e. param.param=value) *)
196 let (params, props) = parse_apply_params req#params in
197 syslogger#log `Debug (sprintf "Parsing input document %s ..." xmluri);
198 let domImpl = Gdome.domImplementation () in
199 let input = domImpl#createDocumentFromURI ~uri:xmluri () in
200 syslogger#log `Debug "Applying stylesheet chain ...";
202 let (write_result, media_type, encoding) = (* out_channel -> unit *)
203 let res = Uwobo_engine.apply
204 ~logger:syslogger ~styles ~keys ~input ~params ~props in
207 let content_type = (* value of Content-Type HTTP response header *)
208 sprintf "%s; charset=%s"
209 (match media_type with None -> default_media_type | Some t -> t)
210 (match encoding with None -> default_encoding | Some e -> e)
213 (sprintf "sending output to client (Content-Type: %s)...."
215 Http_daemon.send_basic_headers ~code:200 outchan;
216 Http_daemon.send_header "Content-Type" content_type outchan;
217 Http_daemon.send_CRLF outchan;
219 with Uwobo_failure errmsg ->
221 (sprintf "Stylesheet chain application failed: %s" errmsg)
223 | "/help" -> respond_html usage_string outchan
225 Http_daemon.respond_error ~status:(`Client_error `Bad_request) outchan);
226 syslogger#log `Debug (sprintf "%s done!" req#path);
228 | Http_types.Param_not_found attr_name ->
229 bad_request (sprintf "Parameter '%s' is missing" attr_name) outchan
231 return_error ("Uncaught exception: " ^ (Printexc.to_string exc)) outchan
234 (* UWOBO's startup *)
236 (* (1) system logger *)
240 debug_print "Logging to standard error";
243 debug_print (sprintf "Logging to file %s" f);
244 open_out_gen [Open_wronly; Open_append; Open_creat] logfile_perm f
247 new Uwobo_logger.sysLogger ~level:debug_level ~outchan:logger_outchan ()
250 (* (2) stylesheets list *)
251 let styles = new Uwobo_styles.styles in
252 (* (3) clean up actions *)
253 let last_process = ref true in
254 let http_child = ref None in
255 let die_nice () = (** at_exit callback *)
256 if !last_process then begin
257 (match !http_child with
259 | Some pid -> Unix.kill pid Sys.sigterm);
260 syslogger#log `Notice (sprintf "%s is terminating, bye!" daemon_name);
262 close_out logger_outchan
266 ignore (Sys.signal Sys.sigterm
267 (Sys.Signal_handle (fun _ -> raise Sys.Break)));
268 syslogger#log `Notice
269 (sprintf "%s started and listening on port %d" daemon_name port);
270 syslogger#log `Notice (sprintf "current directory is %s" (Sys.getcwd ()));
271 Unix.putenv "http_proxy" ""; (* reset http_proxy to avoid libxslt problems *)
273 let (cmd_pipe_exit, cmd_pipe_entrance) = Unix.pipe () in
274 let (res_pipe_exit, res_pipe_entrance) = Unix.pipe () in
275 match Unix.fork () with
276 | child when child > 0 -> (* (4) parent: listen on cmd pipe for updates *)
277 http_child := Some child;
278 let stop_http_daemon () = (* kill child *)
279 debug_print (sprintf "UWOBOmaster: killing pid %d" child);
280 Unix.kill child Sys.sigterm; (* kill child ... *)
281 ignore (Unix.waitpid [] child); (* ... and its zombie *)
283 Unix.close cmd_pipe_entrance;
284 Unix.close res_pipe_exit;
285 let cmd_pipe = Unix.in_channel_of_descr cmd_pipe_exit in
286 let res_pipe = Unix.out_channel_of_descr res_pipe_entrance in
289 (* INVARIANT: 'Restart_HTTP_daemon' exception is raised only after
290 child process has been killed *)
291 debug_print "UWOBOmaster: waiting for commands ...";
292 let cmd = input_line cmd_pipe in
293 debug_print (sprintf "UWOBOmaster: received %s command" cmd);
294 (match cmd with (* command from grandchild *)
297 output_string res_pipe "UWOBOmaster: Hello, world!\n";
299 raise Restart_HTTP_daemon
300 | line when Pcre.pmatch ~rex:add_cmd_RE line -> (* /add *)
302 Pcre.split ~pat:";" (Pcre.replace ~rex:add_cmd_RE line)
305 let log = new Uwobo_logger.processingLogger () in
307 (fun binding -> (* add a <key, stylesheet> binding *)
308 let pieces = Pcre.split ~pat:"," binding in
311 log#log (sprintf "adding binding <%s,%s>" key style);
313 log_libxslt_msgs log (styles#add key style)
315 log#log (Printexc.to_string e))
316 | _ -> log#log (sprintf "invalid binding %s" binding))
318 output_string res_pipe log#asHtml;
320 raise Restart_HTTP_daemon
321 | line when Pcre.pmatch ~rex:remove_cmd_RE line -> (* /remove *)
323 let arg = Pcre.replace ~rex:remove_cmd_RE line in
324 let logger = new Uwobo_logger.processingLogger () in
327 (fun key -> log_libxslt_msgs logger (styles#remove key))
328 (fun () -> log_libxslt_msgs logger styles#removeAll)
330 output_string res_pipe (logger#asHtml);
331 raise Restart_HTTP_daemon
332 | line when Pcre.pmatch ~rex:reload_cmd_RE line -> (* /reload *)
334 let arg = Pcre.replace ~rex:reload_cmd_RE line in
335 let logger = new Uwobo_logger.processingLogger () in
338 (fun key -> log_libxslt_msgs logger (styles#reload key))
339 (fun () -> log_libxslt_msgs logger styles#reloadAll)
341 output_string res_pipe (logger#asHtml);
342 raise Restart_HTTP_daemon
343 | cmd -> (* invalid interprocess command received *)
344 syslogger#log `Warning
345 (sprintf "Ignoring invalid interprocess command: '%s'" cmd))
347 with Restart_HTTP_daemon ->
348 close_in cmd_pipe; (* these calls close also fds *)
350 | 0 -> (* (5) child: serve http requests *)
351 Unix.close cmd_pipe_exit;
352 Unix.close res_pipe_entrance;
353 last_process := false;
354 let cmd_pipe = Unix.out_channel_of_descr cmd_pipe_entrance in
355 let res_pipe = Unix.in_channel_of_descr res_pipe_exit in
356 debug_print (sprintf "Starting HTTP daemon on port %d ..." port);
357 (* next invocation doesn't return, process will keep on serving HTTP
358 requests until it will get killed by father *)
359 Http_daemon.start'~port ~mode:`Fork
360 (callback ~syslogger ~styles ~cmd_pipe ~res_pipe ())
361 | _ (* < 0 *) -> (* fork failed :-((( *)
362 failwith "Can't fork :-("
366 (* daemon initialization *)
368 Sys.catch_break true;
370 with Sys.Break -> () (* 'die_nice' registered with at_exit *)