lisp/nnheader.el

   1 ;;; nnheader.el --- header access macros for Gnus and its backends
   2
   3 ;; Copyright (C) 1987,88,89,90,93,94,95 Free Software Foundation, Inc.
   4
   5 ;; Author: Masanobu UMEDA <umerin@flab.flab.fujitsu.junet>
   6 ;;      Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
   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 ;; These macros may look very much like the ones in GNUS 4.1. They
  29 ;; are, in a way, but you should note that the indices they use have
  30 ;; been changed from the internal GNUS format to the NOV format. Makes
  31 ;; it possible to read headers from XOVER much faster.
  32 ;;
  33 ;; The format of a header is now:
  34 ;; [number subject from date id references chars lines xref]
  35 ;;
  36 ;; (That last entry is defined as "misc" in the NOV format, but Gnus
  37 ;; uses it for xrefs.)
  38
  39 ;;; Code:
  40
  41 (defalias 'nntp-header-number 'mail-header-number)
  42 (defmacro mail-header-number (header)
  43   "Return article number in HEADER."
  44   (` (aref (, header) 0)))
  45
  46 (defalias 'nntp-set-header-number 'mail-header-set-number)
  47 (defmacro mail-header-set-number (header number)
  48   "Set article number of HEADER to NUMBER."
  49   (` (aset (, header) 0 (, number))))
  50
  51 (defalias 'nntp-header-subject 'mail-header-subject)
  52 (defmacro mail-header-subject (header)
  53   "Return subject string in HEADER."
  54   (` (aref (, header) 1)))
  55
  56 (defalias 'nntp-set-header-subject 'mail-header-set-subject)
  57 (defmacro mail-header-set-subject (header subject)
  58   "Set article subject of HEADER to SUBJECT."
  59   (` (aset (, header) 1 (, subject))))
  60
  61 (defalias 'nntp-header-from 'mail-header-from)
  62 (defmacro mail-header-from (header)
  63   "Return author string in HEADER."
  64   (` (aref (, header) 2)))
  65
  66 (defalias 'nntp-set-header-from 'mail-header-set-from)
  67 (defmacro mail-header-set-from (header from)
  68   "Set article author of HEADER to FROM."
  69   (` (aset (, header) 2 (, from))))
  70
  71 (defalias 'nntp-header-date 'mail-header-date)
  72 (defmacro mail-header-date (header)
  73   "Return date in HEADER."
  74   (` (aref (, header) 3)))
  75
  76 (defalias 'nntp-set-header-date 'mail-header-set-date)
  77 (defmacro mail-header-set-date (header date)
  78   "Set article date of HEADER to DATE."
  79   (` (aset (, header) 3 (, date))))
  80
  81 (defalias 'nntp-header-id 'mail-header-id)
  82 (defmacro mail-header-id (header)
  83   "Return Id in HEADER."
  84   (` (aref (, header) 4)))
  85
  86 (defalias 'nntp-set-header-id 'mail-header-set-id)
  87 (defmacro mail-header-set-id (header id)
  88   "Set article Id of HEADER to ID."
  89   (` (aset (, header) 4 (, id))))
  90
  91 (defalias 'nntp-header-references 'mail-header-references)
  92 (defmacro mail-header-references (header)
  93   "Return references in HEADER."
  94   (` (aref (, header) 5)))
  95
  96 (defalias 'nntp-set-header-references 'mail-header-set-references)
  97 (defmacro mail-header-set-references (header ref)
  98   "Set article references of HEADER to REF."
  99   (` (aset (, header) 5 (, ref))))
 100
 101 (defalias 'nntp-header-chars 'mail-header-chars)
 102 (defmacro mail-header-chars (header)
 103   "Return number of chars of article in HEADER."
 104   (` (aref (, header) 6)))
 105
 106 (defalias 'nntp-set-header-chars 'mail-header-set-chars)
 107 (defmacro mail-header-set-chars (header chars)
 108   "Set number of chars in article of HEADER to CHARS."
 109   (` (aset (, header) 6 (, chars))))
 110
 111 (defalias 'nntp-header-lines 'mail-header-lines)
 112 (defmacro mail-header-lines (header)
 113   "Return lines in HEADER."
 114   (` (aref (, header) 7)))
 115
 116 (defalias 'nntp-set-header-lines 'mail-header-set-lines)
 117 (defmacro mail-header-set-lines (header lines)
 118   "Set article lines of HEADER to LINES."
 119   (` (aset (, header) 7 (, lines))))
 120
 121 (defalias 'nntp-header-xref 'mail-header-xref)
 122 (defmacro mail-header-xref (header)
 123   "Return xref string in HEADER."
 124   (` (aref (, header) 8)))
 125
 126 (defalias 'nntp-set-header-xref 'mail-header-set-xref)
 127 (defmacro mail-header-set-xref (header xref)
 128   "Set article xref of HEADER to xref."
 129   (` (aset (, header) 8 (, xref))))
 130
 131
 132 ;; Various cruft the backends and Gnus need to communicate.
 133
 134 (defvar nntp-server-buffer nil)
 135 (defvar gnus-verbose-backends t
 136   "*If non-nil, Gnus backends will generate lots of comments.")
 137 (defvar gnus-nov-is-evil nil
 138   "If non-nil, Gnus backends will never output headers in the NOV format.")
 139 (defvar news-reply-yank-from nil)
 140 (defvar news-reply-yank-message-id nil)
 141
 142 ;; All backends use this function, so I moved it to this file.
 143
 144 (defun nnheader-init-server-buffer ()
 145   (save-excursion
 146     (setq nntp-server-buffer (get-buffer-create " *nntpd*"))
 147     (set-buffer nntp-server-buffer)
 148     (buffer-disable-undo (current-buffer))
 149     (erase-buffer)
 150     (kill-all-local-variables)
 151     (setq case-fold-search t)           ;Should ignore case.
 152     t))
 153
 154 (defun nnheader-set-init-variables (server defs)
 155   (let ((s server)
 156         val)
 157     ;; First we set the server variables in the sequence required.  We
 158     ;; use the definitions from the `defs' list where that is
 159     ;; possible.
 160     (while s
 161       (set (car (car s))
 162            (if (setq val (assq (car (car s)) defs))
 163                (nth 1 val)
 164              (nth 1 (car s))))
 165       (setq s (cdr s)))
 166     ;; The we go through the defs list and set any variables that were
 167     ;; not set in the first sweep.
 168     (while defs
 169       (if (not (assq (car (car defs)) server))
 170           (set (car (car defs))
 171                (if (and (symbolp (nth 1 (car defs)))
 172                         (not (boundp (nth 1 (car defs)))))
 173                    (nth 1 (car defs))
 174                  (eval (nth 1 (car defs))))))
 175       (setq defs (cdr defs)))))
 176
 177 (defun nnheader-save-variables (server)
 178   (let (out)
 179     (while server
 180       (setq out (cons (list (car (car server))
 181                             (symbol-value (car (car server))))
 182                       out))
 183       (setq server (cdr server)))
 184     (nreverse out)))
 185
 186 (defun nnheader-restore-variables (state)
 187   (while state
 188     (set (car (car state)) (nth 1 (car state)))
 189     (setq state (cdr state))))
 190
 191 ;; Read the head of an article.
 192 (defun nnheader-insert-head (file)
 193   (let ((beg 0)
 194         (chop 1024))
 195     (while (and (eq chop (nth 1 (nnheader-insert-file-contents-literally
 196                                  file nil beg (setq beg (+ chop beg)))))
 197                 (prog1 (not (search-backward "\n\n" nil t))
 198                   (goto-char (point-max)))))))
 199
 200 (defun nnheader-article-p ()
 201   (goto-char (point-min))
 202   (if (not (search-forward "\n\n" nil t))
 203       nil
 204     (narrow-to-region (point-min) (1- (point)))
 205     (goto-char (point-min))
 206     (while (looking-at "[A-Z][^ \t]+:.*\n\\([ \t].*\n\\)*\\|From .*\n")
 207       (goto-char (match-end 0)))
 208     (prog1
 209         (eobp)
 210       (widen))))
 211
 212 ;; Written by Erik Naggum <erik@naggum.no>.
 213 (defun nnheader-insert-file-contents-literally (filename &optional visit beg end replace)
 214   "Like `insert-file-contents', q.v., but only reads in the file.
 215 A buffer may be modified in several ways after reading into the buffer due
 216 to advanced Emacs features, such as file-name-handlers, format decoding,
 217 find-file-hooks, etc.
 218   This function ensures that none of these modifications will take place."
 219   (let (                                ; (file-name-handler-alist nil)
 220         (format-alist nil)
 221         (after-insert-file-functions nil)
 222         (find-buffer-file-type-function
 223          (if (fboundp 'find-buffer-file-type)
 224              (symbol-function 'find-buffer-file-type)
 225            nil)))
 226     (unwind-protect
 227         (progn
 228           (fset 'find-buffer-file-type (lambda (filename) t))
 229           (insert-file-contents filename visit beg end replace))
 230       (if find-buffer-file-type-function
 231           (fset 'find-buffer-file-type find-buffer-file-type-function)
 232         (fmakunbound 'find-buffer-file-type)))))
 233
 234 (defun nnheader-find-file-noselect (filename &optional nowarn rawfile)
 235   "Read file FILENAME into a buffer and return the buffer.
 236 If a buffer exists visiting FILENAME, return that one, but
 237 verify that the file has not changed since visited or saved.
 238 The buffer is not selected, just returned to the caller."
 239   (setq filename
 240         (abbreviate-file-name
 241          (expand-file-name filename)))
 242   (if (file-directory-p filename)
 243       (if find-file-run-dired
 244           (dired-noselect filename)
 245         (error "%s is a directory." filename))
 246     (let* ((buf (get-file-buffer filename))
 247            (truename (abbreviate-file-name (file-truename filename)))
 248            (number (nthcdr 10 (file-attributes truename)))
 249            ;; Find any buffer for a file which has same truename.
 250            (other (and (not buf)
 251                        (if (fboundp 'find-buffer-visiting)
 252                            (find-buffer-visiting filename)
 253                          (get-file-buffer filename))))
 254            error)
 255       ;; Let user know if there is a buffer with the same truename.
 256       (if other
 257           (progn
 258             (or nowarn
 259                 (string-equal filename (buffer-file-name other))
 260                 (message "%s and %s are the same file"
 261                          filename (buffer-file-name other)))
 262             ;; Optionally also find that buffer.
 263             (if (or (and (boundp 'find-file-existing-other-name)
 264                          find-file-existing-other-name)
 265                     find-file-visit-truename)
 266                 (setq buf other))))
 267       (if buf
 268           (or nowarn
 269               (verify-visited-file-modtime buf)
 270               (cond ((not (file-exists-p filename))
 271                      (error "File %s no longer exists!" filename))
 272                     ((yes-or-no-p
 273                       (if (string= (file-name-nondirectory filename)
 274                                    (buffer-name buf))
 275                           (format
 276                            (if (buffer-modified-p buf)
 277                                "File %s changed on disk.  Discard your edits? "
 278                              "File %s changed on disk.  Reread from disk? ")
 279                            (file-name-nondirectory filename))
 280                         (format
 281                          (if (buffer-modified-p buf)
 282                              "File %s changed on disk.  Discard your edits in %s? "
 283                            "File %s changed on disk.  Reread from disk into %s? ")
 284                          (file-name-nondirectory filename)
 285                          (buffer-name buf))))
 286                      (save-excursion
 287                        (set-buffer buf)
 288                        (revert-buffer t t)))))
 289         (save-excursion
 290 ;;; The truename stuff makes this obsolete.
 291 ;;;       (let* ((link-name (car (file-attributes filename)))
 292 ;;;              (linked-buf (and (stringp link-name)
 293 ;;;                               (get-file-buffer link-name))))
 294 ;;;         (if (bufferp linked-buf)
 295 ;;;             (message "Symbolic link to file in buffer %s"
 296 ;;;                      (buffer-name linked-buf))))
 297           (setq buf (create-file-buffer filename))
 298           ;;      (set-buffer-major-mode buf)
 299           (set-buffer buf)
 300           (erase-buffer)
 301           (if rawfile
 302               (condition-case ()
 303                   (nnheader-insert-file-contents-literally filename t)
 304                 (file-error
 305                  ;; Unconditionally set error
 306                  (setq error t)))
 307             (condition-case ()
 308                 (insert-file-contents filename t)
 309               (file-error
 310                ;; Run find-file-not-found-hooks until one returns non-nil.
 311                (or t                    ; (run-hook-with-args-until-success 'find-file-not-found-hooks)
 312                    ;; If they fail too, set error.
 313                    (setq error t)))))
 314           ;; Find the file's truename, and maybe use that as visited name.
 315           (setq buffer-file-truename truename)
 316           (setq buffer-file-number number)
 317           ;; On VMS, we may want to remember which directory in a search list
 318           ;; the file was found in.
 319           (and (eq system-type 'vax-vms)
 320                (let (logical)
 321                  (if (string-match ":" (file-name-directory filename))
 322                      (setq logical (substring (file-name-directory filename)
 323                                               0 (match-beginning 0))))
 324                  (not (member logical find-file-not-true-dirname-list)))
 325                (setq buffer-file-name buffer-file-truename))
 326           (if find-file-visit-truename
 327               (setq buffer-file-name
 328                     (setq filename
 329                           (expand-file-name buffer-file-truename))))
 330           ;; Set buffer's default directory to that of the file.
 331           (setq default-directory (file-name-directory filename))
 332           ;; Turn off backup files for certain file names.  Since
 333           ;; this is a permanent local, the major mode won't eliminate it.
 334           (and (not (funcall backup-enable-predicate buffer-file-name))
 335                (progn
 336                  (make-local-variable 'backup-inhibited)
 337                  (setq backup-inhibited t)))
 338           (if rawfile
 339               nil
 340             (after-find-file error (not nowarn)))))
 341       buf)))
 342
 343 (defun nnheader-insert-references (references message-id)
 344   (if (and (not references) (not message-id))
 345       () ; This is illegal, but not all articles have Message-IDs.
 346     (mail-position-on-field "References")
 347     ;; Fold long references line to follow RFC1036.
 348     (let ((begin (gnus-point-at-bol))
 349           (fill-column 78)
 350           (fill-prefix "\t"))
 351       (if references (insert references))
 352       (if (and references message-id) (insert " "))
 353       (if message-id (insert message-id))
 354       ;; The region must end with a newline to fill the region
 355       ;; without inserting extra newline.
 356       (fill-region-as-paragraph begin (1+ (point))))))
 357
 358 (provide 'nnheader)
 359
 360 ;;; nnheader.el ends here