lisp/gnus/nnagent.el

   1 ;;; nnagent.el --- offline backend for Gnus
   2
   3 ;; Copyright (C) 1997-2018 Free Software Foundation, Inc.
   4
   5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   6 ;; Keywords: news, mail
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs 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.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;;; Code:
  26
  27 (require 'nnheader)
  28 (require 'nnoo)
  29 (require 'gnus-agent)
  30 (require 'nnml)
  31
  32 (nnoo-declare nnagent
  33   nnml)
  34
  35 \f
  36
  37 (defconst nnagent-version "nnagent 1.0")
  38
  39 (defvoo nnagent-directory nil
  40   "Internal variable."
  41   nnml-directory)
  42
  43 (defvoo nnagent-active-file nil
  44   "Internal variable."
  45   nnml-active-file)
  46
  47 (defvoo nnagent-newsgroups-file nil
  48   "Internal variable."
  49   nnml-newsgroups-file)
  50
  51 (defvoo nnagent-get-new-mail nil
  52   "Internal variable."
  53   nnml-get-new-mail)
  54
  55 ;;; Interface functions.
  56
  57 (nnoo-define-basics nnagent)
  58
  59 (defun nnagent-server (server)
  60   (and server (format "%s+%s" (car gnus-command-method) server)))
  61
  62 (deffoo nnagent-open-server (server &optional defs)
  63   (setq defs
  64         `((nnagent-directory ,(gnus-agent-directory))
  65           (nnagent-active-file ,(gnus-agent-lib-file "active"))
  66           (nnagent-newsgroups-file ,(gnus-agent-lib-file "newsgroups"))
  67           (nnagent-get-new-mail nil)))
  68   (nnoo-change-server 'nnagent
  69                       (nnagent-server server)
  70                       defs)
  71   (let ((dir (gnus-agent-directory))
  72         err)
  73     (cond
  74      ((not (condition-case arg
  75                (file-exists-p dir)
  76              (ftp-error (setq err (format "%s" arg)))))
  77       (nnagent-close-server)
  78       (nnheader-report
  79        'nnagent (or err
  80                     (format "No such file or directory: %s" dir))))
  81      ((not (file-directory-p (file-truename dir)))
  82       (nnagent-close-server)
  83       (nnheader-report 'nnagent "Not a directory: %s" dir))
  84      (t
  85       (nnheader-report 'nnagent "Opened server %s using directory %s"
  86                        server dir)
  87       t))))
  88
  89 (deffoo nnagent-retrieve-groups (groups &optional server)
  90   (save-excursion
  91     (cond
  92      ((file-exists-p (gnus-agent-lib-file "groups"))
  93       (nnmail-find-file (gnus-agent-lib-file "groups"))
  94       'groups)
  95      ((file-exists-p (gnus-agent-lib-file "active"))
  96       (nnmail-find-file (gnus-agent-lib-file "active"))
  97       'active)
  98      (t nil))))
  99
 100 (defun nnagent-request-type (group article)
 101   (unless (stringp article)
 102     (let ((gnus-agent nil))
 103       (if (not (gnus-check-backend-function
 104                 'request-type (car gnus-command-method)))
 105           'unknown
 106         (funcall (gnus-get-function gnus-command-method 'request-type)
 107                  (gnus-group-real-name group) article)))))
 108
 109 (deffoo nnagent-request-newgroups (date server)
 110   nil)
 111
 112 (deffoo nnagent-request-update-info (group info &optional server)
 113   nil)
 114
 115 (deffoo nnagent-request-post (&optional server)
 116   (gnus-agent-insert-meta-information 'news gnus-command-method)
 117   (gnus-request-accept-article "nndraft:queue" nil t t))
 118
 119 (deffoo nnagent-request-set-mark (group action server)
 120   (mm-with-unibyte-buffer
 121     (insert "(gnus-agent-synchronize-group-flags \""
 122             group
 123             "\" '")
 124     (gnus-pp action)
 125     (insert " \""
 126             (gnus-method-to-server gnus-command-method)
 127             "\"")
 128     (insert ")\n")
 129     (let ((coding-system-for-write nnheader-file-coding-system))
 130       (write-region (point-min) (point-max) (gnus-agent-lib-file "flags")
 131                     t 'silent)))
 132   ;; Also set the marks for the original back end that keeps marks in
 133   ;; the local system.
 134   (let ((gnus-agent nil))
 135     (when (and (memq (car gnus-command-method) '(nntp))
 136                (gnus-check-backend-function 'request-set-mark
 137                                             (car gnus-command-method)))
 138       (funcall (gnus-get-function gnus-command-method 'request-set-mark)
 139                group action server)))
 140   nil)
 141
 142 (deffoo nnagent-retrieve-headers (articles &optional group server fetch-old)
 143   (let ((file (gnus-agent-article-name ".overview" group))
 144         arts n first)
 145     (save-excursion
 146       (gnus-agent-load-alist group)
 147       (setq arts (gnus-sorted-difference
 148                   articles (mapcar 'car gnus-agent-article-alist)))
 149       ;; Assume that articles with smaller numbers than the first one
 150       ;; Agent knows are gone.
 151       (setq first (caar gnus-agent-article-alist))
 152       (when first
 153         (while (and arts (< (car arts) first))
 154           (pop arts)))
 155       (set-buffer nntp-server-buffer)
 156       (erase-buffer)
 157       (let ((file-name-coding-system nnmail-pathname-coding-system))
 158         (nnheader-insert-nov-file file (car articles)))
 159       (goto-char (point-min))
 160       (gnus-parse-without-error
 161         (while (and arts (not (eobp)))
 162           (setq n (read (current-buffer)))
 163           (when (> n (car arts))
 164             (beginning-of-line))
 165           (while (and arts (> n (car arts)))
 166             (insert (format
 167                      "%d\t[Undownloaded article %d]\tGnus Agent\t\t\t\n"
 168                      (car arts) (car arts)))
 169             (pop arts))
 170           (when (and arts (= n (car arts)))
 171             (pop arts))
 172           (forward-line 1)))
 173       (while arts
 174         (insert (format
 175                  "%d\t[Undownloaded article %d]\tGnus Agent\t\t\t\n"
 176                  (car arts) (car arts)))
 177         (pop arts))
 178       (if (and fetch-old
 179                (not (numberp fetch-old)))
 180           t                             ; Don't remove anything.
 181         (nnheader-nov-delete-outside-range
 182          (if fetch-old (max 1 (- (car articles) fetch-old))
 183            (car articles))
 184          (car (last articles)))
 185         t)
 186       'nov)))
 187
 188 (deffoo nnagent-request-expire-articles (articles group &optional server force)
 189   articles)
 190
 191 (deffoo nnagent-request-group (group &optional server dont-check info)
 192   (nnoo-parent-function 'nnagent 'nnml-request-group
 193                         (list group (nnagent-server server) dont-check info)))
 194
 195 (deffoo nnagent-close-group (group &optional server)
 196   (nnoo-parent-function 'nnagent 'nnml-close-group
 197                         (list group (nnagent-server server))))
 198
 199 (deffoo nnagent-request-accept-article (group &optional server last)
 200   (nnoo-parent-function 'nnagent 'nnml-request-accept-article
 201                         (list group (nnagent-server server) last)))
 202
 203 (deffoo nnagent-request-article (id &optional group server buffer)
 204   (nnoo-parent-function 'nnagent 'nnml-request-article
 205                         (list id group (nnagent-server server) buffer)))
 206
 207 (deffoo nnagent-request-create-group (group &optional server args)
 208   (nnoo-parent-function 'nnagent 'nnml-request-create-group
 209                         (list group (nnagent-server server) args)))
 210
 211 (deffoo nnagent-request-delete-group (group &optional force server)
 212   (nnoo-parent-function 'nnagent 'nnml-request-delete-group
 213                         (list group force (nnagent-server server))))
 214
 215 (deffoo nnagent-request-list (&optional server)
 216   (nnoo-parent-function 'nnagent 'nnml-request-list
 217                         (list (nnagent-server server))))
 218
 219 (deffoo nnagent-request-list-newsgroups (&optional server)
 220   (nnoo-parent-function 'nnagent 'nnml-request-list-newsgroups
 221                         (list (nnagent-server server))))
 222
 223 (deffoo nnagent-request-move-article
 224     (article group server accept-form &optional last move-is-internal)
 225   (nnoo-parent-function 'nnagent 'nnml-request-move-article
 226                         (list article group (nnagent-server server)
 227                               accept-form last move-is-internal)))
 228
 229 (deffoo nnagent-request-rename-group (group new-name &optional server)
 230   (nnoo-parent-function 'nnagent 'nnml-request-rename-group
 231                         (list group new-name (nnagent-server server))))
 232
 233 (deffoo nnagent-request-scan (&optional group server)
 234   (nnoo-parent-function 'nnagent 'nnml-request-scan
 235                         (list group (nnagent-server server))))
 236
 237 (deffoo nnagent-set-status (article name value &optional group server)
 238   (nnoo-parent-function 'nnagent 'nnml-set-status
 239                         (list article name value group (nnagent-server server))))
 240
 241 (deffoo nnagent-server-opened (&optional server)
 242   (nnoo-parent-function 'nnagent 'nnml-server-opened
 243                         (list (nnagent-server server))))
 244
 245 (deffoo nnagent-status-message (&optional server)
 246   (nnoo-parent-function 'nnagent 'nnml-status-message
 247                         (list (nnagent-server server))))
 248
 249 (deffoo nnagent-request-regenerate (server)
 250   (nnoo-parent-function 'nnagent 'nnml-request-regenerate
 251                         (list (nnagent-server server))))
 252
 253 (deffoo nnagent-retrieve-group-data-early (server infos)
 254   nil)
 255
 256 ;; Use nnml functions for just about everything.
 257 (nnoo-import nnagent
 258   (nnml))
 259
 260 \f
 261 ;;; Internal functions.
 262
 263 (provide 'nnagent)
 264
 265 ;;; nnagent.el ends here