1;;; nnoo.el --- OO Gnus Backends 2 3;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 4;; 2004, 2005, 2006, 2007 Free Software Foundation, Inc. 5 6;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org> 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., 51 Franklin Street, Fifth Floor, 24;; Boston, MA 02110-1301, USA. 25 26;;; Commentary: 27 28;;; Code: 29 30(require 'nnheader) 31(eval-when-compile (require 'cl)) 32 33(defvar nnoo-definition-alist nil) 34(defvar nnoo-state-alist nil) 35(defvar nnoo-parent-backend nil) 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 ,(concat doc "\n\nThis is a Gnus server variable. See Info node `(gnus)Select Methods'.")) 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 (if (assq ',backend nnoo-definition-alist) 65 (setcar (cdr (assq ',backend nnoo-definition-alist)) 66 (mapcar 'list ',parents)) 67 (push (list ',backend 68 (mapcar 'list ',parents) 69 nil nil) 70 nnoo-definition-alist)) 71 (unless (assq ',backend nnoo-state-alist) 72 (push (list ',backend "*internal-non-initialized-backend*") 73 nnoo-state-alist)))) 74(put 'nnoo-declare 'lisp-indent-function 1) 75 76(defun nnoo-parents (backend) 77 (nth 1 (assoc backend nnoo-definition-alist))) 78 79(defun nnoo-variables (backend) 80 (nth 2 (assoc backend nnoo-definition-alist))) 81 82(defun nnoo-functions (backend) 83 (nth 3 (assoc backend nnoo-definition-alist))) 84 85(defmacro nnoo-import (backend &rest imports) 86 `(nnoo-import-1 ',backend ',imports)) 87(put 'nnoo-import 'lisp-indent-function 1) 88 89(defun nnoo-import-1 (backend imports) 90 (let ((call-function 91 (if (symbolp (car imports)) (pop imports) 'nnoo-parent-function)) 92 imp functions function) 93 (while (setq imp (pop imports)) 94 (setq functions 95 (or (cdr imp) 96 (nnoo-functions (car imp)))) 97 (while functions 98 (unless (fboundp 99 (setq function 100 (nnoo-symbol backend 101 (nnoo-rest-symbol (car functions))))) 102 (eval `(deffoo ,function (&rest args) 103 (,call-function ',backend ',(car functions) args)))) 104 (pop functions))))) 105 106(defun nnoo-parent-function (backend function args) 107 (let ((pbackend (nnoo-backend function)) 108 (nnoo-parent-backend backend)) 109 (nnoo-change-server pbackend 110 (nnoo-current-server backend) 111 (cdr (assq pbackend (nnoo-parents backend)))) 112 (prog1 113 (apply function args) 114 ;; Copy the changed variables back into the child. 115 (let ((vars (cdr (assq pbackend (nnoo-parents backend))))) 116 (while vars 117 (set (cadar vars) (symbol-value (caar vars))) 118 (setq vars (cdr vars))))))) 119 120(defun nnoo-execute (backend function &rest args) 121 "Execute FUNCTION on behalf of BACKEND." 122 (let ((pbackend (nnoo-backend function)) 123 (nnoo-parent-backend backend)) 124 (nnoo-change-server pbackend 125 (nnoo-current-server backend) 126 (cdr (assq pbackend (nnoo-parents backend)))) 127 (prog1 128 (apply function args) 129 ;; Copy the changed variables back into the child. 130 (let ((vars (cdr (assq pbackend (nnoo-parents backend))))) 131 (while vars 132 (set (cadar vars) (symbol-value (caar vars))) 133 (setq vars (cdr vars))))))) 134 135(defmacro nnoo-map-functions (backend &rest maps) 136 `(nnoo-map-functions-1 ',backend ',maps)) 137(put 'nnoo-map-functions 'lisp-indent-function 1) 138 139(defun nnoo-map-functions-1 (backend maps) 140 (let (m margs i) 141 (while (setq m (pop maps)) 142 (setq i 0 143 margs nil) 144 (while (< i (length (cdr m))) 145 (if (numberp (nth i (cdr m))) 146 (push `(nth ,i args) margs) 147 (push (nth i (cdr m)) margs)) 148 (incf i)) 149 (eval `(deffoo ,(nnoo-symbol backend (nnoo-rest-symbol (car m))) 150 (&rest args) 151 (nnoo-parent-function ',backend ',(car m) 152 ,(cons 'list (nreverse margs)))))))) 153 154(defun nnoo-backend (symbol) 155 (string-match "^[^-]+-" (symbol-name symbol)) 156 (intern (substring (symbol-name symbol) 0 (1- (match-end 0))))) 157 158(defun nnoo-rest-symbol (symbol) 159 (string-match "^[^-]+-" (symbol-name symbol)) 160 (intern (substring (symbol-name symbol) (match-end 0)))) 161 162(defun nnoo-symbol (backend symbol) 163 (intern (format "%s-%s" backend symbol))) 164 165(defun nnoo-define (var map) 166 (let* ((backend (nnoo-backend var)) 167 (def (assq backend nnoo-definition-alist)) 168 (parents (nth 1 def))) 169 (unless def 170 (error "%s belongs to a backend that hasn't been declared" var)) 171 (setcar (nthcdr 2 def) 172 (delq (assq var (nth 2 def)) (nth 2 def))) 173 (setcar (nthcdr 2 def) 174 (cons (cons var (symbol-value var)) 175 (nth 2 def))) 176 (while map 177 (nconc (assq (nnoo-backend (car map)) parents) 178 (list (list (pop map) var)))))) 179 180(defun nnoo-change-server (backend server defs) 181 (let* ((bstate (cdr (assq backend nnoo-state-alist))) 182 (current (car bstate)) 183 (parents (nnoo-parents backend)) 184 (server (if nnoo-parent-backend 185 (format "%s+%s" nnoo-parent-backend server) 186 server)) 187 (bvariables (nnoo-variables backend)) 188 state def) 189 ;; If we don't have a current state, we push an empty state 190 ;; onto the alist. 191 (unless bstate 192 (push (setq bstate (list backend nil)) 193 nnoo-state-alist) 194 (pop bstate)) 195 (if (equal server current) 196 t 197 (nnoo-push-server backend current) 198 (setq state (or (cdr (assoc server (cddr bstate))) 199 (nnoo-variables backend))) 200 (while state 201 (set (caar state) (cdar state)) 202 (pop state)) 203 (setcar bstate server) 204 (unless (cdr (assoc server (cddr bstate))) 205 (while (setq def (pop defs)) 206 (unless (assq (car def) bvariables) 207 (nconc bvariables 208 (list (cons (car def) (and (boundp (car def)) 209 (symbol-value (car def))))))) 210 (if (equal server "*internal-non-initialized-backend*") 211 (set (car def) (symbol-value (cadr def))) 212 (set (car def) (cadr def))))) 213 (while parents 214 (nnoo-change-server 215 (caar parents) (format "%s+%s" backend server) 216 (mapcar (lambda (def) (list (car def) (symbol-value (cadr def)))) 217 (cdar parents))) 218 (pop parents)))) 219 t) 220 221(defun nnoo-push-server (backend current) 222 (let ((bstate (assq backend nnoo-state-alist)) 223 (defs (nnoo-variables backend))) 224 ;; Remove the old definition. 225 (setcdr (cdr bstate) (delq (assoc current (cddr bstate)) (cddr bstate))) 226 ;; If this is the first time we push the server (i. e., this is 227 ;; the nil server), then we update the default values of 228 ;; all the variables to reflect the current values. 229 (when (equal current "*internal-non-initialized-backend*") 230 (let ((defaults (nnoo-variables backend)) 231 def) 232 (while (setq def (pop defaults)) 233 (setcdr def (symbol-value (car def)))))) 234 (let (state) 235 (while defs 236 (push (cons (caar defs) (symbol-value (caar defs))) 237 state) 238 (pop defs)) 239 (nconc bstate (list (cons current state)))))) 240 241(defsubst nnoo-current-server-p (backend server) 242 (equal (nnoo-current-server backend) 243 (if nnoo-parent-backend 244 (format "%s+%s" nnoo-parent-backend server) 245 server))) 246 247(defun nnoo-current-server (backend) 248 (nth 1 (assq backend nnoo-state-alist))) 249 250(defun nnoo-close-server (backend &optional server) 251 (unless server 252 (setq server (nnoo-current-server backend))) 253 (when server 254 (let* ((bstate (cdr (assq backend nnoo-state-alist))) 255 (defs (assoc server (cdr bstate)))) 256 (when bstate 257 (setcar bstate nil) 258 (setcdr bstate (delq defs (cdr bstate))) 259 (pop defs) 260 (while defs 261 (set (car (pop defs)) nil))))) 262 t) 263 264(defun nnoo-close (backend) 265 (setq nnoo-state-alist 266 (delq (assq backend nnoo-state-alist) 267 nnoo-state-alist)) 268 t) 269 270(defun nnoo-status-message (backend server) 271 (nnheader-get-report backend)) 272 273(defun nnoo-server-opened (backend server) 274 (and (nnoo-current-server-p backend server) 275 nntp-server-buffer 276 (buffer-name nntp-server-buffer))) 277 278(defmacro nnoo-define-basics (backend) 279 "Define `close-server', `server-opened' and `status-message'." 280 `(eval-and-compile 281 (nnoo-define-basics-1 ',backend))) 282 283(defun nnoo-define-basics-1 (backend) 284 (let ((functions '(close-server server-opened status-message))) 285 (while functions 286 (eval `(deffoo ,(nnoo-symbol backend (car functions)) 287 (&optional server) 288 (,(nnoo-symbol 'nnoo (pop functions)) ',backend server))))) 289 (eval `(deffoo ,(nnoo-symbol backend 'open-server) 290 (server &optional defs) 291 (nnoo-change-server ',backend server defs)))) 292 293(defmacro nnoo-define-skeleton (backend) 294 "Define all required backend functions for BACKEND. 295All functions will return nil and report an error." 296 `(eval-and-compile 297 (nnoo-define-skeleton-1 ',backend))) 298 299(defun nnoo-define-skeleton-1 (backend) 300 (let ((functions '(retrieve-headers 301 request-close request-article 302 request-group close-group 303 request-list request-post request-list-newsgroups)) 304 function fun) 305 (while (setq function (pop functions)) 306 (when (not (fboundp (setq fun (nnoo-symbol backend function)))) 307 (eval `(deffoo ,fun 308 (&rest args) 309 (nnheader-report ',backend ,(format "%s-%s not implemented" 310 backend function)))))))) 311 312(defun nnoo-set (server &rest args) 313 (let ((parents (nnoo-parents (car server))) 314 (nnoo-parent-backend (car server))) 315 (while parents 316 (nnoo-change-server (caar parents) 317 (cadr server) 318 (cdar parents)) 319 (pop parents))) 320 (nnoo-change-server (car server) 321 (cadr server) (cddr server)) 322 (while args 323 (set (pop args) (pop args)))) 324 325(provide 'nnoo) 326 327;;; arch-tag: 0196b5ed-6f34-4778-a455-73a971f837e7 328;;; nnoo.el ends here 329