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 *)
66 keys_param styles logger per_key_action all_keys_action all_keys logmsg
70 Pcre.split ~pat:"," keys_param
71 with Http_types.Param_not_found _ -> []
74 | [] -> (* no key provided, act on all stylesheets *)
75 logger#log (sprintf "%s all stylesheets (keys = %s) ..."
76 logmsg (String.concat ", " all_keys));
77 (try all_keys_action () with e -> logger#log (Printexc.to_string e));
78 logger#log (sprintf "Done! (all stylesheets)")
81 (fun key -> (* act on a single stylesheet *)
82 logger#log (sprintf "%s stylesheet %s" logmsg key);
83 (try per_key_action key with e -> logger#log (Printexc.to_string e));
84 logger#log (sprintf "Done! (stylesheet %s)" key))
88 (** parse parameters for '/apply' action *)
89 let parse_apply_params =
90 let is_global_param x = Pcre.pmatch ~pat:"^param(\\.[^.]+){1}$" x in
91 let is_local_param x = Pcre.pmatch ~pat:"^param(\\.[^.]+){2}$" x in
92 let is_property x = Pcre.pmatch ~pat:"^prop\\.[^.]+$" x in
94 (fun (old_params, old_properties) (name, value) ->
96 | name when is_global_param name ->
97 let name = Pcre.replace ~pat:"^param\\." name in
98 ((fun x -> (old_params x) @ [name, value]), old_properties)
99 | name when is_local_param name ->
100 let pieces = Pcre.extract ~pat:"^param\\.([^.]+)\\.(.*)" name in
101 let (key, name) = (pieces.(1), pieces.(2)) in
103 | x when x = key -> [name, value] @ (old_params x)
104 | x -> old_params x),
106 | name when is_property name ->
107 let name = Pcre.replace ~pat:"^prop\\." name in
108 (old_params, ((name, value) :: old_properties))
109 | _ -> (old_params, old_properties))
110 ((fun _ -> []), []) (* no parameters, no properties *)
113 (** Parse libxslt's message modes for error and debugging messages. Default is
114 to ignore mesages of both kind *)
115 let parse_libxslt_msgs_mode (req: Http_types.request) =
117 (match req#param "errormode" with
118 | s when String.lowercase s = "ignore" -> LibXsltMsgIgnore
119 | s when String.lowercase s = "comment" -> LibXsltMsgComment
120 | s when String.lowercase s = "embed" -> LibXsltMsgEmbed
124 "Unknown value '%s' for parameter '%s', use one of '%s' or '%s'"
125 err "errormode" "ignore" "comment")))
126 with Http_types.Param_not_found _ -> LibXsltMsgIgnore),
128 (match req#param "debugmode" with
129 | s when String.lowercase s = "ignore" -> LibXsltMsgIgnore
130 | s when String.lowercase s = "comment" -> LibXsltMsgComment
131 | s when String.lowercase s = "embed" -> LibXsltMsgEmbed
135 "Unknown value '%s' for parameter '%s', use one of '%s' or '%s'"
136 err "debugmode" "ignore" "comment")))
137 with Http_types.Param_not_found _ -> LibXsltMsgIgnore))
140 (** send ~cmd (without trailing "\n"!) through ~cmd_pipe, then wait for answer
141 on ~res_pipe (with a timeout of 60 seconds) and send over outchan data
142 received from ~res_pipe *)
143 let short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan =
144 (* debug_print (sprintf "Sending command '%s' to grandparent ..." cmd); *)
145 output_string cmd_pipe (cmd ^ "\n"); (* send command to grandfather *)
147 let res_pipe_fd = Unix.descr_of_in_channel res_pipe in
148 let (read_fds, _, _) = (* wait for an answer *)
149 Unix.select [res_pipe_fd] [] [] 60.0
152 | [fd] when fd = res_pipe_fd -> (* send answer to http client *)
153 Http_daemon.send_basic_headers ~code:200 outchan;
154 Http_daemon.send_header "Content-Type" "text/html" outchan;
155 Http_daemon.send_CRLF outchan;
158 output_string outchan ((input_line res_pipe) ^ "\n")
160 with End_of_file -> flush outchan)
161 | _ -> (* no answer received from grandfather *)
162 return_error "Timeout!" outchan)
165 let (add_cmd_RE, remove_cmd_RE, reload_cmd_RE) =
166 (Pcre.regexp "^add ", Pcre.regexp "^remove ", Pcre.regexp "^reload ")
169 (** raised by child processes when HTTP daemon process have to be restarted *)
170 exception Restart_HTTP_daemon ;;
172 (** log a list of libxslt's messages using a processing logger *)
173 let log_libxslt_msgs logger libxslt_logger =
176 | (LibXsltErrorMsg _) as msg -> logger#logBold (string_of_xslt_msg msg)
177 | (LibXsltDebugMsg _) as msg -> logger#logEmph (string_of_xslt_msg msg))
182 let veillogger = new Uwobo_common.libXsltLogger ;;
184 (* request handler action
185 @param syslogger Uwobo_logger.sysLogger instance used for logginf
186 @param styles Uwobo_styles.styles instance which keeps the stylesheets list
187 @param cmd_pipe output _channel_ used to _write_ update messages
188 @param res_pipe input _channel_ used to _read_ grandparent results
189 @param req http request instance
190 @param outchan output channel connected to http client
193 ~syslogger ~styles ~cmd_pipe ~res_pipe () (req: Http_types.request) outchan
196 syslogger#log `Notice (sprintf "Connection from %s" req#clientAddr);
197 syslogger#log `Debug (sprintf "Received request: %s" req#path);
200 (let bindings = req#paramAll "bind" in
201 if bindings = [] then
202 return_error "No [key,stylesheet] binding provided" outchan
204 let cmd = sprintf "add %s" (String.concat ";" bindings) in
205 short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan
208 let cmd = sprintf "remove %s" (req#param "keys") in
209 short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan
211 let cmd = sprintf "reload %s" (req#param "keys") in
212 short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan
214 (let logger = new Uwobo_logger.processingLogger () in
215 (match styles#list with
216 | [] -> logger#log "No stylesheets loaded (yet)!"
218 logger#log "Stylesheets list:";
219 List.iter (fun s -> logger#log s) l);
220 respond_html logger#asHtml outchan)
222 let logger = new Uwobo_logger.processingLogger () in
223 veillogger#clearMsgs;
224 let xmluri = req#param "xmluri" in
225 let keys = Pcre.split ~pat:"," (req#param "keys") in
226 (* notation: "local" parameters are those defined on a per-stylesheet
227 pasis (i.e. param.key.param=value), "global" parameters are those
228 defined for all stylesheets (i.e. param.param=value) *)
229 let (params, props) = parse_apply_params req#params in
230 let (libxslt_errormode, libxslt_debugmode) =
231 parse_libxslt_msgs_mode req
233 syslogger#log `Debug (sprintf "Parsing input document %s ..." xmluri);
234 let domImpl = Gdome.domImplementation () in
235 let input = domImpl#createDocumentFromURI ~uri:xmluri () in
236 syslogger#log `Debug "Applying stylesheet chain ...";
238 let (write_result, media_type, encoding) = (* out_channel -> unit *)
240 ~logger:syslogger ~styles ~keys ~params ~props ~veillogger
241 ~errormode:libxslt_errormode ~debugmode:libxslt_debugmode
244 let content_type = (* value of Content-Type HTTP response header *)
245 sprintf "%s; charset=%s"
246 (match media_type with None -> default_media_type | Some t -> t)
247 (match encoding with None -> default_encoding | Some e -> e)
250 (sprintf "sending output to client (Content-Type: %s)...."
252 Http_daemon.send_basic_headers ~code:200 outchan;
253 Http_daemon.send_header "Content-Type" content_type outchan;
254 Http_daemon.send_CRLF outchan;
256 with Uwobo_failure errmsg ->
258 ("Stylesheet chain application failed: " ^ errmsg)
259 ~body: ("<h2>LibXSLT's messages:</h2>" ^
260 String.concat "<br />\n"
261 (List.map string_of_xslt_msg veillogger#msgs))
263 | "/help" -> respond_html usage_string outchan
265 Http_daemon.respond_error ~status:(`Client_error `Bad_request) outchan);
266 syslogger#log `Debug (sprintf "%s done!" req#path);
268 | Http_types.Param_not_found attr_name ->
269 bad_request (sprintf "Parameter '%s' is missing" attr_name) outchan
271 return_error ("Uncaught exception: " ^ (Printexc.to_string exc)) outchan
274 (* UWOBO's startup *)
276 (* (1) system logger *)
280 debug_print "Logging to standard error";
283 debug_print (sprintf "Logging to file %s" f);
284 open_out_gen [Open_wronly; Open_append; Open_creat] logfile_perm f
287 new Uwobo_logger.sysLogger ~level:debug_level ~outchan:logger_outchan ()
290 (* (2) stylesheets list *)
291 let styles = new Uwobo_styles.styles in
292 (* (3) clean up actions *)
293 let last_process = ref true in
294 let http_child = ref None in
295 let die_nice () = (** at_exit callback *)
296 if !last_process then begin
297 (match !http_child with
299 | Some pid -> Unix.kill pid Sys.sigterm);
300 syslogger#log `Notice (sprintf "%s is terminating, bye!" daemon_name);
302 close_out logger_outchan
306 ignore (Sys.signal Sys.sigterm
307 (Sys.Signal_handle (fun _ -> raise Sys.Break)));
308 syslogger#log `Notice
309 (sprintf "%s started and listening on port %d" daemon_name port);
310 syslogger#log `Notice (sprintf "current directory is %s" (Sys.getcwd ()));
311 Unix.putenv "http_proxy" ""; (* reset http_proxy to avoid libxslt problems *)
313 let (cmd_pipe_exit, cmd_pipe_entrance) = Unix.pipe () in
314 let (res_pipe_exit, res_pipe_entrance) = Unix.pipe () in
315 match Unix.fork () with
316 | child when child > 0 -> (* (4) parent: listen on cmd pipe for updates *)
317 http_child := Some child;
318 let stop_http_daemon () = (* kill child *)
319 debug_print (sprintf "UWOBOmaster: killing pid %d" child);
320 Unix.kill child Sys.sigterm; (* kill child ... *)
321 ignore (Unix.waitpid [] child); (* ... and its zombie *)
323 Unix.close cmd_pipe_entrance;
324 Unix.close res_pipe_exit;
325 let cmd_pipe = Unix.in_channel_of_descr cmd_pipe_exit in
326 let res_pipe = Unix.out_channel_of_descr res_pipe_entrance in
329 (* INVARIANT: 'Restart_HTTP_daemon' exception is raised only after
330 child process has been killed *)
331 debug_print "UWOBOmaster: waiting for commands ...";
332 let cmd = input_line cmd_pipe in
333 debug_print (sprintf "UWOBOmaster: received %s command" cmd);
334 (match cmd with (* command from grandchild *)
337 output_string res_pipe "UWOBOmaster: Hello, world!\n";
339 raise Restart_HTTP_daemon
340 | line when Pcre.pmatch ~rex:add_cmd_RE line -> (* /add *)
342 Pcre.split ~pat:";" (Pcre.replace ~rex:add_cmd_RE line)
345 let logger = new Uwobo_logger.processingLogger () in
347 (fun binding -> (* add a <key, stylesheet> binding *)
348 let pieces = Pcre.split ~pat:"," binding in
351 logger#log (sprintf "adding binding <%s,%s>" key style);
352 veillogger#clearMsgs;
354 veillogger#clearMsgs;
355 styles#add key style;
356 log_libxslt_msgs logger veillogger;
358 logger#log (Printexc.to_string e))
359 | _ -> logger#log (sprintf "invalid binding %s" binding))
361 output_string res_pipe logger#asHtml;
363 raise Restart_HTTP_daemon
364 | line when Pcre.pmatch ~rex:remove_cmd_RE line -> (* /remove *)
366 let arg = Pcre.replace ~rex:remove_cmd_RE line in
367 let logger = new Uwobo_logger.processingLogger () in
368 veillogger#clearMsgs;
371 styles#remove (fun () -> styles#removeAll) styles#keys
373 log_libxslt_msgs logger veillogger;
374 output_string res_pipe (logger#asHtml);
375 raise Restart_HTTP_daemon
376 | line when Pcre.pmatch ~rex:reload_cmd_RE line -> (* /reload *)
378 let arg = Pcre.replace ~rex:reload_cmd_RE line in
379 let logger = new Uwobo_logger.processingLogger () in
380 veillogger#clearMsgs;
383 styles#reload (fun () -> styles#reloadAll) styles#keys
385 output_string res_pipe (logger#asHtml);
386 raise Restart_HTTP_daemon
387 | cmd -> (* invalid interprocess command received *)
388 syslogger#log `Warning
389 (sprintf "Ignoring invalid interprocess command: '%s'" cmd))
391 with Restart_HTTP_daemon ->
392 close_in cmd_pipe; (* these calls close also fds *)
394 | 0 -> (* (5) child: serve http requests *)
395 Unix.close cmd_pipe_exit;
396 Unix.close res_pipe_entrance;
397 last_process := false;
398 let cmd_pipe = Unix.out_channel_of_descr cmd_pipe_entrance in
399 let res_pipe = Unix.in_channel_of_descr res_pipe_exit in
400 debug_print (sprintf "Starting HTTP daemon on port %d ..." port);
401 (* next invocation doesn't return, process will keep on serving HTTP
402 requests until it will get killed by father *)
403 Http_daemon.start'~port ~mode:`Fork
404 (callback ~syslogger ~styles ~cmd_pipe ~res_pipe ())
405 | _ (* < 0 *) -> (* fork failed :-((( *)
406 failwith "Can't fork :-("
410 (* daemon initialization *)
412 Sys.catch_break true;
414 with Sys.Break -> () (* 'die_nice' registered with at_exit *)