1 (* Copyright (C) 2004, HELM Team.
3 * This file is part of HELM, an Hypertextual, Electronic
4 * Library of Mathematics, developed at the Computer Science
5 * Department, University of Bologna, Italy.
7 * HELM is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
12 * HELM is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with HELM; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
22 * For details, see the HELM World-Wide-Web page,
23 * http://helm.cs.unibo.it/
30 if debug then prerr_endline ("Helm_registry debugging: " ^ s)
32 exception Malformed_key of string
33 exception Key_not_found of string
34 exception Cyclic_definition of string
35 exception Type_error of string * string * string (* expected type, value, msg *)
36 exception Parse_error of string * int * int * string (* file, line, col, msg *)
37 exception Invalid_value of (string * string) * string (* key, value, descr *)
39 type validator_id = int
41 (* root XML tag: used by save_to, ignored by load_from *)
42 let root_tag = "helm_registry"
44 let get_next_validator_id =
45 let next_id = ref 0 in
51 let validators = Hashtbl.create magic_size
52 let registry = Hashtbl.create magic_size
54 let backup_registry () = Hashtbl.copy registry
55 let restore_registry backup =
56 Hashtbl.clear registry;
57 Hashtbl.iter (fun key value -> Hashtbl.replace registry key value) backup
60 * - no sequences of '_' longer than 1 are permitted
61 * - no uppercase letter are permitted
63 let valid_step_rex_raw = "[a-z0-9]+\\(_[a-z0-9]+\\)*"
64 let valid_key_rex_raw =
65 sprintf "%s\(\\.%s\)*" valid_step_rex_raw valid_step_rex_raw
66 let valid_key_rex = Str.regexp ("^" ^ valid_key_rex_raw ^ "$")
67 let interpolated_key_rex = Str.regexp ("\\$(" ^ valid_key_rex_raw ^ ")")
68 let dot_rex = Str.regexp "\\."
69 let spaces_rex = Str.regexp "[ \t\n\r]+"
70 let heading_spaces_rex = Str.regexp "^[ \t\n\r]+"
73 (* trailing blanks are removed per default by split *)
74 Str.split spaces_rex (Str.global_replace heading_spaces_rex "" s)
75 let merge l = String.concat " " l
77 (* escapes for xml configuration file *)
78 let (escape, unescape) =
79 let (in_enc, out_enc) = (`Enc_utf8, `Enc_utf8) in
80 (Netencoding.Html.encode ~in_enc ~out_enc (),
81 Netencoding.Html.decode ~in_enc ~out_enc ~entity_base:`Xml ())
83 let key_is_valid key =
84 (* if not (Pcre.pmatch ~rex:valid_key_rex key) then *)
85 if not (Str.string_match valid_key_rex key 0) then
86 raise (Malformed_key key)
88 let value_is_valid ~key ~value =
90 (fun (validator, descr) ->
91 if not (validator value) then
92 raise (Invalid_value ((key, value), descr)))
93 (Hashtbl.find_all validators key)
95 let set' registry ~key ~value =
96 debug_print (sprintf "Setting %s = %s" key value);
98 value_is_valid ~key ~value;
99 Hashtbl.replace registry key value
101 let unset = Hashtbl.remove registry
103 let env_var_of_key key =
104 (* Pcre.replace ~rex:dot_rex ~templ:"__" (String.uppercase key) *)
105 Str.global_replace dot_rex "__" (String.uppercase key)
108 let rec aux stack key =
110 if List.mem key stack then begin
111 let msg = (String.concat " -> " (List.rev stack)) ^ " -> " ^ key in
112 raise (Cyclic_definition msg)
114 let registry_value = (* internal value *)
116 Some (Hashtbl.find registry key)
117 with Not_found -> None
119 let env_value = (* environment value *)
121 Some (Sys.getenv (env_var_of_key key))
122 with Not_found -> None
124 let value = (* resulting value *)
125 match (registry_value, env_value) with
126 | Some reg, Some env -> env
127 | Some reg, None -> reg
128 | None, Some env -> env
129 | None, None -> raise (Key_not_found key)
131 interpolate (key :: stack) value
132 and interpolate stack value =
133 Str.global_substitute interpolated_key_rex
135 let matched = Str.matched_string s in
136 (* "$(var)" -> "var" *)
137 let key = String.sub matched 2 (String.length matched - 3) in
143 let set = set' registry
145 let mk_get_set type_name (from_string: string -> 'a) (to_string: 'a -> string) =
147 let value = get key in
151 raise (Type_error (type_name, value, Printexc.to_string exn))
153 let setter ~key ~value = set ~key ~value:(to_string value) in
156 let (get_string, set_string) = (get, set)
157 let (get_int, set_int) = mk_get_set "int" int_of_string string_of_int
158 let (get_float, set_float) = mk_get_set "float" float_of_string string_of_float
159 let (get_bool, set_bool) = mk_get_set "bool" bool_of_string string_of_bool
160 let (get_string_list, set_string_list) = mk_get_set "string list" split merge
162 let get_opt getter key =
165 with Key_not_found _ -> None
166 let set_opt setter ~key ~value =
169 | Some value -> setter ~key ~value
173 let dtd = new dtd default_config.warner `Enc_utf8 in
174 let rec create_key node sections key value =
176 | [] -> create_element_node ~valcheck:false default_spec dtd
180 debug_print ("Saving configuration to " ^ fname);
181 let oc = open_out fname in
182 output_string oc "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
183 output_string oc "<helm_registry>\n";
187 fprintf oc " <value key=\"%s\">%s</value>\n" key (escape value))
189 output_string oc "</helm_registry>";
195 let add_validator ~key ~validator ~descr =
196 let id = get_next_validator_id () in
197 Hashtbl.add validators key (validator, descr);
204 let load_from_absolute =
205 let config = default_config in
206 let entry = `Entry_document [ `Extend_dtd_fully; `Parse_xml_decl ] in
207 let fold_key key_stack key =
210 | _ -> String.concat "." key_stack ^ "." ^ key
213 debug_print ("Loading configuration from " ^ fname);
215 parse_wfdocument_entity config (from_file fname) default_spec
217 let rec aux key_stack node =
218 node#iter_nodes (fun n ->
220 (match n#node_type with
221 | T_element "section" ->
222 let section = n#required_string_attribute "name" in
223 aux (key_stack @ [section]) n
225 let key = n#required_string_attribute "name" in
226 let value = n#data in
227 set ~key:(fold_key key_stack key) ~value
230 let (fname, line, pos) = n#position in
231 raise (Parse_error (fname, line, pos,
232 "Uncaught exception: " ^ Printexc.to_string exn)))
234 let backup = backup_registry () in
235 Hashtbl.clear registry;
239 restore_registry backup;
242 let load_from ?path fname =
243 if Filename.is_relative fname then begin
244 let no_file_found = ref true in
247 | Some path -> path (* path given as argument *)
248 | None -> [ Sys.getcwd () ] (* no path given, try with cwd *)
252 let conffile = dir ^ "/" ^ fname in
253 if Sys.file_exists conffile then begin
254 no_file_found := false;
255 load_from_absolute conffile
258 if !no_file_found then
260 "Helm_registry.init: no configuration file named %s in [ %s ]"
261 fname (String.concat "; " path))
263 load_from_absolute fname
267 let dump () = Hashtbl.iter (fun k v -> printf "%s = %s\n" k v) registry