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eec82323 | 1 | ;;; nnoo.el --- OO Gnus Backends |
16409b0b GM |
2 | |
3 | ;; Copyright (C) 1996, 1997, 1998, 1999, 2000 | |
4 | ;; Free Software Foundation, Inc. | |
eec82323 | 5 | |
6748645f | 6 | ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org> |
eec82323 LMI |
7 | ;; Keywords: news |
8 | ||
9 | ;; This file is part of GNU Emacs. | |
10 | ||
11 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
12 | ;; it under the terms of the GNU General Public License as published by | |
13 | ;; the Free Software Foundation; either version 2, or (at your option) | |
14 | ;; any later version. | |
15 | ||
16 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
17 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | ;; GNU General Public License for more details. | |
20 | ||
21 | ;; You should have received a copy of the GNU General Public License | |
22 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
23 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
24 | ;; Boston, MA 02111-1307, USA. | |
25 | ||
26 | ;;; Commentary: | |
27 | ||
28 | ;;; Code: | |
29 | ||
30 | (require 'nnheader) | |
349f4e97 | 31 | (eval-when-compile (require 'cl)) |
eec82323 LMI |
32 | |
33 | (defvar nnoo-definition-alist nil) | |
34 | (defvar nnoo-state-alist nil) | |
6748645f | 35 | (defvar nnoo-parent-backend nil) |
eec82323 LMI |
36 | |
37 | (defmacro defvoo (var init &optional doc &rest map) | |
38 | "The same as `defvar', only takes list of variables to MAP to." | |
39 | `(prog1 | |
40 | ,(if doc | |
41 | `(defvar ,var ,init ,doc) | |
42 | `(defvar ,var ,init)) | |
43 | (nnoo-define ',var ',map))) | |
44 | (put 'defvoo 'lisp-indent-function 2) | |
45 | (put 'defvoo 'edebug-form-spec '(var init &optional doc &rest map)) | |
46 | ||
47 | (defmacro deffoo (func args &rest forms) | |
48 | "The same as `defun', only register FUNC." | |
49 | `(prog1 | |
50 | (defun ,func ,args ,@forms) | |
51 | (nnoo-register-function ',func))) | |
52 | (put 'deffoo 'lisp-indent-function 2) | |
53 | (put 'deffoo 'edebug-form-spec '(&define name lambda-list def-body)) | |
54 | ||
55 | (defun nnoo-register-function (func) | |
56 | (let ((funcs (nthcdr 3 (assoc (nnoo-backend func) | |
57 | nnoo-definition-alist)))) | |
58 | (unless funcs | |
59 | (error "%s belongs to a backend that hasn't been declared" func)) | |
60 | (setcar funcs (cons func (car funcs))))) | |
61 | ||
62 | (defmacro nnoo-declare (backend &rest parents) | |
63 | `(eval-and-compile | |
64 | (push (list ',backend | |
65 | (mapcar (lambda (p) (list p)) ',parents) | |
66 | nil nil) | |
67 | nnoo-definition-alist) | |
68 | (push (list ',backend "*internal-non-initialized-backend*") | |
69 | nnoo-state-alist))) | |
70 | (put 'nnoo-declare 'lisp-indent-function 1) | |
71 | ||
72 | (defun nnoo-parents (backend) | |
73 | (nth 1 (assoc backend nnoo-definition-alist))) | |
74 | ||
75 | (defun nnoo-variables (backend) | |
76 | (nth 2 (assoc backend nnoo-definition-alist))) | |
77 | ||
78 | (defun nnoo-functions (backend) | |
79 | (nth 3 (assoc backend nnoo-definition-alist))) | |
80 | ||
81 | (defmacro nnoo-import (backend &rest imports) | |
82 | `(nnoo-import-1 ',backend ',imports)) | |
83 | (put 'nnoo-import 'lisp-indent-function 1) | |
84 | ||
85 | (defun nnoo-import-1 (backend imports) | |
86 | (let ((call-function | |
87 | (if (symbolp (car imports)) (pop imports) 'nnoo-parent-function)) | |
88 | imp functions function) | |
89 | (while (setq imp (pop imports)) | |
90 | (setq functions | |
91 | (or (cdr imp) | |
92 | (nnoo-functions (car imp)))) | |
93 | (while functions | |
6748645f LMI |
94 | (unless (fboundp |
95 | (setq function | |
96 | (nnoo-symbol backend | |
97 | (nnoo-rest-symbol (car functions))))) | |
eec82323 LMI |
98 | (eval `(deffoo ,function (&rest args) |
99 | (,call-function ',backend ',(car functions) args)))) | |
100 | (pop functions))))) | |
101 | ||
102 | (defun nnoo-parent-function (backend function args) | |
6748645f LMI |
103 | (let ((pbackend (nnoo-backend function)) |
104 | (nnoo-parent-backend backend)) | |
105 | (nnoo-change-server pbackend | |
106 | (nnoo-current-server backend) | |
eec82323 | 107 | (cdr (assq pbackend (nnoo-parents backend)))) |
6748645f LMI |
108 | (prog1 |
109 | (apply function args) | |
16409b0b GM |
110 | ;; Copy the changed variables back into the child. |
111 | (let ((vars (cdr (assq pbackend (nnoo-parents backend))))) | |
112 | (while vars | |
113 | (set (cadar vars) (symbol-value (caar vars))) | |
114 | (setq vars (cdr vars))))))) | |
eec82323 LMI |
115 | |
116 | (defun nnoo-execute (backend function &rest args) | |
117 | "Execute FUNCTION on behalf of BACKEND." | |
6748645f LMI |
118 | (let ((pbackend (nnoo-backend function)) |
119 | (nnoo-parent-backend backend)) | |
120 | (nnoo-change-server pbackend | |
121 | (nnoo-current-server backend) | |
eec82323 | 122 | (cdr (assq pbackend (nnoo-parents backend)))) |
6748645f LMI |
123 | (prog1 |
124 | (apply function args) | |
125 | ;; Copy the changed variables back into the child. | |
126 | (let ((vars (cdr (assq pbackend (nnoo-parents backend))))) | |
127 | (while vars | |
128 | (set (cadar vars) (symbol-value (caar vars))) | |
129 | (setq vars (cdr vars))))))) | |
eec82323 LMI |
130 | |
131 | (defmacro nnoo-map-functions (backend &rest maps) | |
132 | `(nnoo-map-functions-1 ',backend ',maps)) | |
133 | (put 'nnoo-map-functions 'lisp-indent-function 1) | |
134 | ||
135 | (defun nnoo-map-functions-1 (backend maps) | |
136 | (let (m margs i) | |
137 | (while (setq m (pop maps)) | |
138 | (setq i 0 | |
139 | margs nil) | |
140 | (while (< i (length (cdr m))) | |
141 | (if (numberp (nth i (cdr m))) | |
142 | (push `(nth ,i args) margs) | |
143 | (push (nth i (cdr m)) margs)) | |
144 | (incf i)) | |
145 | (eval `(deffoo ,(nnoo-symbol backend (nnoo-rest-symbol (car m))) | |
146 | (&rest args) | |
147 | (nnoo-parent-function ',backend ',(car m) | |
148 | ,(cons 'list (nreverse margs)))))))) | |
149 | ||
150 | (defun nnoo-backend (symbol) | |
151 | (string-match "^[^-]+-" (symbol-name symbol)) | |
152 | (intern (substring (symbol-name symbol) 0 (1- (match-end 0))))) | |
153 | ||
154 | (defun nnoo-rest-symbol (symbol) | |
155 | (string-match "^[^-]+-" (symbol-name symbol)) | |
156 | (intern (substring (symbol-name symbol) (match-end 0)))) | |
157 | ||
158 | (defun nnoo-symbol (backend symbol) | |
159 | (intern (format "%s-%s" backend symbol))) | |
160 | ||
161 | (defun nnoo-define (var map) | |
162 | (let* ((backend (nnoo-backend var)) | |
163 | (def (assq backend nnoo-definition-alist)) | |
164 | (parents (nth 1 def))) | |
165 | (unless def | |
a8151ef7 | 166 | (error "%s belongs to a backend that hasn't been declared" var)) |
eec82323 LMI |
167 | (setcar (nthcdr 2 def) |
168 | (delq (assq var (nth 2 def)) (nth 2 def))) | |
169 | (setcar (nthcdr 2 def) | |
170 | (cons (cons var (symbol-value var)) | |
171 | (nth 2 def))) | |
172 | (while map | |
173 | (nconc (assq (nnoo-backend (car map)) parents) | |
174 | (list (list (pop map) var)))))) | |
175 | ||
176 | (defun nnoo-change-server (backend server defs) | |
177 | (let* ((bstate (cdr (assq backend nnoo-state-alist))) | |
178 | (current (car bstate)) | |
179 | (parents (nnoo-parents backend)) | |
6748645f LMI |
180 | (server (if nnoo-parent-backend |
181 | (format "%s+%s" nnoo-parent-backend server) | |
182 | server)) | |
eec82323 LMI |
183 | (bvariables (nnoo-variables backend)) |
184 | state def) | |
6748645f LMI |
185 | ;; If we don't have a current state, we push an empty state |
186 | ;; onto the alist. | |
eec82323 LMI |
187 | (unless bstate |
188 | (push (setq bstate (list backend nil)) | |
189 | nnoo-state-alist) | |
190 | (pop bstate)) | |
191 | (if (equal server current) | |
192 | t | |
193 | (nnoo-push-server backend current) | |
194 | (setq state (or (cdr (assoc server (cddr bstate))) | |
195 | (nnoo-variables backend))) | |
196 | (while state | |
197 | (set (caar state) (cdar state)) | |
198 | (pop state)) | |
199 | (setcar bstate server) | |
200 | (unless (cdr (assoc server (cddr bstate))) | |
201 | (while (setq def (pop defs)) | |
202 | (unless (assq (car def) bvariables) | |
203 | (nconc bvariables | |
204 | (list (cons (car def) (and (boundp (car def)) | |
205 | (symbol-value (car def))))))) | |
6748645f LMI |
206 | (if (equal server "*internal-non-initialized-backend*") |
207 | (set (car def) (symbol-value (cadr def))) | |
208 | (set (car def) (cadr def))))) | |
eec82323 LMI |
209 | (while parents |
210 | (nnoo-change-server | |
6748645f | 211 | (caar parents) (format "%s+%s" backend server) |
eec82323 LMI |
212 | (mapcar (lambda (def) (list (car def) (symbol-value (cadr def)))) |
213 | (cdar parents))) | |
214 | (pop parents)))) | |
215 | t) | |
216 | ||
217 | (defun nnoo-push-server (backend current) | |
218 | (let ((bstate (assq backend nnoo-state-alist)) | |
219 | (defs (nnoo-variables backend))) | |
220 | ;; Remove the old definition. | |
221 | (setcdr (cdr bstate) (delq (assoc current (cddr bstate)) (cddr bstate))) | |
222 | ;; If this is the first time we push the server (i. e., this is | |
223 | ;; the nil server), then we update the default values of | |
224 | ;; all the variables to reflect the current values. | |
225 | (when (equal current "*internal-non-initialized-backend*") | |
226 | (let ((defaults (nnoo-variables backend)) | |
227 | def) | |
228 | (while (setq def (pop defaults)) | |
229 | (setcdr def (symbol-value (car def)))))) | |
230 | (let (state) | |
231 | (while defs | |
232 | (push (cons (caar defs) (symbol-value (caar defs))) | |
233 | state) | |
234 | (pop defs)) | |
235 | (nconc bstate (list (cons current state)))))) | |
236 | ||
237 | (defsubst nnoo-current-server-p (backend server) | |
6748645f LMI |
238 | (equal (nnoo-current-server backend) |
239 | (if nnoo-parent-backend | |
240 | (format "%s+%s" nnoo-parent-backend server) | |
241 | server))) | |
eec82323 LMI |
242 | |
243 | (defun nnoo-current-server (backend) | |
244 | (nth 1 (assq backend nnoo-state-alist))) | |
245 | ||
246 | (defun nnoo-close-server (backend &optional server) | |
247 | (unless server | |
248 | (setq server (nnoo-current-server backend))) | |
249 | (when server | |
250 | (let* ((bstate (cdr (assq backend nnoo-state-alist))) | |
251 | (defs (assoc server (cdr bstate)))) | |
252 | (when bstate | |
253 | (setcar bstate nil) | |
254 | (setcdr bstate (delq defs (cdr bstate))) | |
255 | (pop defs) | |
256 | (while defs | |
257 | (set (car (pop defs)) nil))))) | |
258 | t) | |
259 | ||
260 | (defun nnoo-close (backend) | |
261 | (setq nnoo-state-alist | |
262 | (delq (assq backend nnoo-state-alist) | |
263 | nnoo-state-alist)) | |
264 | t) | |
265 | ||
266 | (defun nnoo-status-message (backend server) | |
267 | (nnheader-get-report backend)) | |
268 | ||
269 | (defun nnoo-server-opened (backend server) | |
270 | (and (nnoo-current-server-p backend server) | |
271 | nntp-server-buffer | |
272 | (buffer-name nntp-server-buffer))) | |
273 | ||
274 | (defmacro nnoo-define-basics (backend) | |
275 | "Define `close-server', `server-opened' and `status-message'." | |
276 | `(eval-and-compile | |
277 | (nnoo-define-basics-1 ',backend))) | |
278 | ||
279 | (defun nnoo-define-basics-1 (backend) | |
280 | (let ((functions '(close-server server-opened status-message))) | |
281 | (while functions | |
282 | (eval `(deffoo ,(nnoo-symbol backend (car functions)) | |
283 | (&optional server) | |
284 | (,(nnoo-symbol 'nnoo (pop functions)) ',backend server))))) | |
285 | (eval `(deffoo ,(nnoo-symbol backend 'open-server) | |
286 | (server &optional defs) | |
287 | (nnoo-change-server ',backend server defs)))) | |
288 | ||
289 | (defmacro nnoo-define-skeleton (backend) | |
290 | "Define all required backend functions for BACKEND. | |
291 | All functions will return nil and report an error." | |
292 | `(eval-and-compile | |
293 | (nnoo-define-skeleton-1 ',backend))) | |
294 | ||
295 | (defun nnoo-define-skeleton-1 (backend) | |
296 | (let ((functions '(retrieve-headers | |
297 | request-close request-article | |
298 | request-group close-group | |
299 | request-list request-post request-list-newsgroups)) | |
300 | function fun) | |
301 | (while (setq function (pop functions)) | |
302 | (when (not (fboundp (setq fun (nnoo-symbol backend function)))) | |
303 | (eval `(deffoo ,fun | |
304 | (&rest args) | |
305 | (nnheader-report ',backend ,(format "%s-%s not implemented" | |
306 | backend function)))))))) | |
307 | (provide 'nnoo) | |
308 | ||
715a2ca2 | 309 | ;;; nnoo.el ends here |