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;;
37 let logfile = Some "uwobo.log";; (* relative to execution dir *)
38 let logfile_perm = 0o640;;
41 let daemon_name = "UWOBO OCaml";;
42 let default_port = 58080;;
43 let port_env_var = "UWOBO_PORT";;
44 let default_media_type = "text/html";;
45 let default_encoding = "utf8";;
48 int_of_string (Sys.getenv port_env_var)
50 | Not_found -> default_port
51 | Failure "int_of_string" ->
52 prerr_endline "Warning: invalid port, reverting to default";
56 let respond_html body outchan =
57 Http_daemon.respond ~body ~headers:["Content-Type", "text/html"] outchan
60 (** perform an 'action' that can be applied to a list of keys or, if no keys
61 was given, to all keys *)
62 let act_on_keys keys_param styles logger per_key_action all_keys_action logmsg
66 Pcre.split ~pat:"," keys_param
67 with Http_types.Param_not_found _ -> []
70 | [] -> (* no key provided, act on all stylesheets *)
71 logger#log (sprintf "%s all stylesheets ..." logmsg);
72 (try all_keys_action () with e -> logger#log (Printexc.to_string e))
75 (fun key -> (* act on a single stylesheet *)
76 logger#log (sprintf "%s stylesheet %s" logmsg key);
77 (try per_key_action key with e -> logger#log (Printexc.to_string e)))
81 (** parse parameters for '/apply' action *)
82 let parse_apply_params =
83 let is_global_param x = Pcre.pmatch ~pat:"^param(\\.[^.]+){1}$" x in
84 let is_local_param x = Pcre.pmatch ~pat:"^param(\\.[^.]+){2}$" x in
85 let is_property x = Pcre.pmatch ~pat:"^prop\\.[^.]+$" x in
87 (fun (old_params, old_properties) (name, value) ->
89 | name when is_global_param name ->
90 let name = Pcre.replace ~pat:"^param\\." name in
91 ((fun x -> (old_params x) @ [name, value]), old_properties)
92 | name when is_local_param name ->
93 let pieces = Pcre.extract ~pat:"^param\\.([^.]+)\\.(.*)" name in
94 let (key, name) = (pieces.(1), pieces.(2)) in
96 | x when x = key -> [name, value] @ (old_params x)
99 | name when is_property name ->
100 let name = Pcre.replace ~pat:"^prop\\." name in
101 (old_params, ((name, value) :: old_properties))
102 | _ -> (old_params, old_properties))
103 ((fun _ -> []), []) (* no parameters, no properties *)
106 (** send ~cmd (without trailing "\n"!) through ~cmd_pipe, then wait for answer
107 on ~res_pipe (with a timeout of 60 seconds) and send over outchan data
108 received from ~res_pipe *)
109 let short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan =
110 (* debug_print (sprintf "Sending command '%s' to grandparent ..." cmd); *)
111 output_string cmd_pipe (cmd ^ "\n"); (* send command to grandfather *)
113 let res_pipe_fd = Unix.descr_of_in_channel res_pipe in
114 let (read_fds, _, _) = (* wait for an answer *)
115 Unix.select [res_pipe_fd] [] [] 60.0
118 | [fd] when fd = res_pipe_fd -> (* send answer to http client *)
119 Http_daemon.send_basic_headers ~code:200 outchan;
120 Http_daemon.send_header "Content-Type" "text/html" outchan;
121 Http_daemon.send_CRLF outchan;
124 output_string outchan ((input_line res_pipe) ^ "\n")
126 with End_of_file -> flush outchan)
127 | _ -> (* no answer received from grandfather *)
128 return_error "Timeout!" outchan)
131 let (add_cmd_RE, remove_cmd_RE, reload_cmd_RE) =
132 (Pcre.regexp "^add ", Pcre.regexp "^remove ", Pcre.regexp "^reload ")
135 exception Restart_HTTP_daemon;;
137 (** log a list of libxslt's messages using a processing logger *)
138 let log_libxslt_msgs logger =
141 | Uwobo_styles.LibXsltErrorMsg msg ->
142 logger#logBold ("LibXSLT ERROR: " ^ msg)
143 | Uwobo_styles.LibXsltDebugMsg msg ->
144 logger#logEmph ("LibXSLT DEBUG " ^ msg))
147 (* request handler action
148 @param syslogger Uwobo_logger.sysLogger instance used for logginf
149 @param styles Uwobo_styles.styles instance which keeps the stylesheets list
150 @param cmd_pipe output _channel_ used to _write_ update messages
151 @param res_pipe input _channel_ used to _read_ grandparent results
152 @param req http request instance
153 @param outchan output channel connected to http client
156 ~syslogger ~styles ~cmd_pipe ~res_pipe () (req: Http_types.request) outchan
159 syslogger#log `Notice (sprintf "Connection from %s" req#clientAddr);
160 syslogger#log `Debug (sprintf "Received request: %s" req#path);
163 (let bindings = req#paramAll "bind" in
164 if bindings = [] then
165 return_error "No [key,stylesheet] binding provided" outchan
167 let cmd = sprintf "add %s" (String.concat ";" bindings) in
168 short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan
171 let cmd = sprintf "remove %s" (req#param "keys") in
172 short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan
174 let cmd = sprintf "reload %s" (req#param "keys") in
175 short_circuit_grandfather_and_client ~cmd ~cmd_pipe ~res_pipe outchan
177 (let log = new Uwobo_logger.processingLogger () in
178 (match styles#list with
179 | [] -> log#log "No stylesheets loaded (yet)!"
181 log#log "Stylesheets list:";
182 List.iter (fun s -> log#log s) l);
183 respond_html log#asHtml outchan)
185 let logger = new Uwobo_logger.processingLogger () in
186 let xmluri = req#param "xmluri" in
187 let keys = Pcre.split ~pat:"," (req#param "keys") in
188 (* notation: "local" parameters are those defined on a per-stylesheet
189 pasis (i.e. param.key.param=value), "global" parameters are those
190 defined for all stylesheets (i.e. param.param=value) *)
191 let (params, props) = parse_apply_params req#params in
192 syslogger#log `Debug (sprintf "Parsing input document %s ..." xmluri);
193 let domImpl = Gdome.domImplementation () in
194 let input = domImpl#createDocumentFromURI ~uri:xmluri () in
195 syslogger#log `Debug "Applying stylesheet chain ...";
197 let (write_result, media_type, encoding) = (* out_channel -> unit *)
198 let res = Uwobo_engine.apply
199 ~logger:syslogger ~styles ~keys ~input ~params ~props in
202 let content_type = (* value of Content-Type HTTP response header *)
203 sprintf "%s; charset=%s"
204 (match media_type with None -> default_media_type | Some t -> t)
205 (match encoding with None -> default_encoding | Some e -> e)
208 (sprintf "sending output to client (Content-Type: %s)...."
210 Http_daemon.send_basic_headers ~code:200 outchan;
211 Http_daemon.send_header "Content-Type" content_type outchan;
212 Http_daemon.send_CRLF outchan;
214 with Uwobo_failure errmsg ->
216 (sprintf "Stylesheet chain application failed: %s" errmsg)
218 | "/help" -> respond_html usage_string outchan
220 Http_daemon.respond_error ~status:(`Client_error `Bad_request) outchan);
221 syslogger#log `Debug (sprintf "%s done!" req#path);
223 | Http_types.Param_not_found attr_name ->
224 bad_request (sprintf "Parameter '%s' is missing" attr_name) outchan
226 return_error ("Uncaught exception: " ^ (Printexc.to_string exc)) outchan
229 (* UWOBO's startup *)
231 (* (1) system logger *)
236 open_out_gen [Open_wronly; Open_append; Open_creat] logfile_perm f
239 new Uwobo_logger.sysLogger ~level:debug_level ~outchan:logger_outchan ()
242 (* (2) stylesheets list *)
243 let styles = new Uwobo_styles.styles in
244 (* (3) clean up actions *)
245 let last_process = ref true in
246 let http_child = ref None in
247 let die_nice () = (** at_exit callback *)
248 if !last_process then begin
249 (match !http_child with
251 | Some pid -> Unix.kill pid Sys.sigterm);
252 syslogger#log `Notice (sprintf "%s is terminating, bye!" daemon_name);
254 close_out logger_outchan
258 ignore (Sys.signal Sys.sigterm
259 (Sys.Signal_handle (fun _ -> raise Sys.Break)));
260 syslogger#log `Notice
261 (sprintf "%s started and listening on port %d" daemon_name port);
262 syslogger#log `Notice (sprintf "current directory is %s" (Sys.getcwd ()));
263 Unix.putenv "http_proxy" ""; (* reset http_proxy to avoid libxslt problems *)
265 let (cmd_pipe_exit, cmd_pipe_entrance) = Unix.pipe () in
266 let (res_pipe_exit, res_pipe_entrance) = Unix.pipe () in
267 match Unix.fork () with
268 | child when child > 0 -> (* (4) parent: listen on cmd pipe for updates *)
269 http_child := Some child;
270 let stop_http_daemon () = (* kill child *)
271 debug_print (sprintf "UWOBOmaster: killing pid %d" child);
272 Unix.kill child Sys.sigterm; (* kill child ... *)
273 ignore (Unix.waitpid [] child); (* ... and its zombie *)
275 Unix.close cmd_pipe_entrance;
276 Unix.close res_pipe_exit;
277 let cmd_pipe = Unix.in_channel_of_descr cmd_pipe_exit in
278 let res_pipe = Unix.out_channel_of_descr res_pipe_entrance in
281 (* INVARIANT: 'Restart_HTTP_daemon' exception is raised only after
282 child process has been killed *)
283 debug_print "UWOBOmaster: waiting for commands ...";
284 let cmd = input_line cmd_pipe in
285 debug_print (sprintf "UWOBOmaster: received %s command" cmd);
286 (match cmd with (* command from grandchild *)
289 output_string res_pipe "UWOBOmaster: Hello, world!\n";
291 raise Restart_HTTP_daemon
292 | line when Pcre.pmatch ~rex:add_cmd_RE line -> (* /add *)
294 Pcre.split ~pat:";" (Pcre.replace ~rex:add_cmd_RE line)
297 let log = new Uwobo_logger.processingLogger () in
299 (fun binding -> (* add a <key, stylesheet> binding *)
300 let pieces = Pcre.split ~pat:"," binding in
303 log#log (sprintf "adding binding <%s,%s>" key style);
305 log_libxslt_msgs log (styles#add key style)
307 log#log (Printexc.to_string e))
308 | _ -> log#log (sprintf "invalid binding %s" binding))
310 output_string res_pipe log#asHtml;
312 raise Restart_HTTP_daemon
313 | line when Pcre.pmatch ~rex:remove_cmd_RE line -> (* /remove *)
315 let arg = Pcre.replace ~rex:remove_cmd_RE line in
316 let logger = new Uwobo_logger.processingLogger () in
319 (fun key -> log_libxslt_msgs logger (styles#remove key))
320 (fun () -> log_libxslt_msgs logger styles#removeAll)
322 output_string res_pipe (logger#asHtml);
323 raise Restart_HTTP_daemon
324 | line when Pcre.pmatch ~rex:reload_cmd_RE line -> (* /reload *)
326 let arg = Pcre.replace ~rex:reload_cmd_RE line in
327 let logger = new Uwobo_logger.processingLogger () in
330 (fun key -> log_libxslt_msgs logger (styles#reload key))
331 (fun () -> log_libxslt_msgs logger styles#reloadAll)
333 output_string res_pipe (logger#asHtml);
334 raise Restart_HTTP_daemon
335 | cmd -> (* invalid interprocess command received *)
336 syslogger#log `Warning
337 (sprintf "Ignoring invalid interprocess command: '%s'" cmd))
339 with Restart_HTTP_daemon ->
340 close_in cmd_pipe; (* these calls close also fds *)
342 | 0 -> (* (5) child: serve http requests *)
343 Unix.close cmd_pipe_exit;
344 Unix.close res_pipe_entrance;
345 last_process := false;
346 let cmd_pipe = Unix.out_channel_of_descr cmd_pipe_entrance in
347 let res_pipe = Unix.in_channel_of_descr res_pipe_exit in
348 debug_print (sprintf "Starting HTTP daemon on port %d ..." port);
349 (* next invocation doesn't return, process will keep on serving HTTP
350 requests until it will get killed by father *)
351 Http_daemon.start'~port ~mode:`Fork
352 (callback ~syslogger ~styles ~cmd_pipe ~res_pipe ())
353 | _ (* < 0 *) -> (* fork failed :-((( *)
354 failwith "Can't fork :-("
358 (* daemon initialization *)
360 Sys.catch_break true;
362 with Sys.Break -> () (* 'die_nice' registered with at_exit *)