lisp/nnheader.el

   1 ;;; nnheader.el --- header access macros for Gnus and its backends
   2 ;; Copyright (C) 1987,88,89,90,93,94,95,96 Free Software Foundation, Inc.
   3
   4 ;; Author: Masanobu UMEDA <umerin@flab.flab.fujitsu.junet>
   5 ;;      Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
   6 ;; Keywords: news
   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 2, or (at your option)
  13 ;; 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; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; These macros may look very much like the ones in GNUS 4.1.  They
  28 ;; are, in a way, but you should note that the indices they use have
  29 ;; been changed from the internal GNUS format to the NOV format.  The
  30 ;; makes it possible to read headers from XOVER much faster.
  31 ;;
  32 ;; The format of a header is now:
  33 ;; [number subject from date id references chars lines xref]
  34 ;;
  35 ;; (That last entry is defined as "misc" in the NOV format, but Gnus
  36 ;; uses it for xrefs.)
  37
  38 ;;; Code:
  39
  40 (require 'mail-utils)
  41 (eval-when-compile (require 'cl))
  42
  43 (defvar nnheader-max-head-length 4096
  44   "*Max length of the head of articles.")
  45
  46 (defvar nnheader-file-name-translation-alist nil
  47   "*Alist that says how to translate characters in file names.
  48 For instance, if \":\" is illegal as a file character in file names
  49 on your system, you could say something like:
  50
  51 \(setq nnheader-file-name-translation-alist '((?: . ?_)))")
  52
  53 ;;; Header access macros.
  54
  55 (defmacro mail-header-number (header)
  56   "Return article number in HEADER."
  57   `(aref ,header 0))
  58
  59 (defmacro mail-header-set-number (header number)
  60   "Set article number of HEADER to NUMBER."
  61   `(aset ,header 0 ,number))
  62
  63 (defmacro mail-header-subject (header)
  64   "Return subject string in HEADER."
  65   `(aref ,header 1))
  66
  67 (defmacro mail-header-set-subject (header subject)
  68   "Set article subject of HEADER to SUBJECT."
  69   `(aset ,header 1 ,subject))
  70
  71 (defmacro mail-header-from (header)
  72   "Return author string in HEADER."
  73   `(aref ,header 2))
  74
  75 (defmacro mail-header-set-from (header from)
  76   "Set article author of HEADER to FROM."
  77   `(aset ,header 2 ,from))
  78
  79 (defmacro mail-header-date (header)
  80   "Return date in HEADER."
  81   `(aref ,header 3))
  82
  83 (defmacro mail-header-set-date (header date)
  84   "Set article date of HEADER to DATE."
  85   `(aset ,header 3 ,date))
  86
  87 (defalias 'mail-header-message-id 'mail-header-id)
  88 (defmacro mail-header-id (header)
  89   "Return Id in HEADER."
  90   `(aref ,header 4))
  91
  92 (defalias 'mail-header-set-message-id 'mail-header-set-id)
  93 (defmacro mail-header-set-id (header id)
  94   "Set article Id of HEADER to ID."
  95   `(aset ,header 4 ,id))
  96
  97 (defmacro mail-header-references (header)
  98   "Return references in HEADER."
  99   `(aref ,header 5))
 100
 101 (defmacro mail-header-set-references (header ref)
 102   "Set article references of HEADER to REF."
 103   `(aset ,header 5 ,ref))
 104
 105 (defmacro mail-header-chars (header)
 106   "Return number of chars of article in HEADER."
 107   `(aref ,header 6))
 108
 109 (defmacro mail-header-set-chars (header chars)
 110   "Set number of chars in article of HEADER to CHARS."
 111   `(aset ,header 6 ,chars))
 112
 113 (defmacro mail-header-lines (header)
 114   "Return lines in HEADER."
 115   `(aref ,header 7))
 116
 117 (defmacro mail-header-set-lines (header lines)
 118   "Set article lines of HEADER to LINES."
 119   `(aset ,header 7 ,lines))
 120
 121 (defmacro mail-header-xref (header)
 122   "Return xref string in HEADER."
 123   `(aref ,header 8))
 124
 125 (defmacro mail-header-set-xref (header xref)
 126   "Set article xref of HEADER to xref."
 127   `(aset ,header 8 ,xref))
 128
 129 (defun make-mail-header (&optional init)
 130   "Create a new mail header structure initialized with INIT."
 131   (make-vector 9 init))
 132
 133 ;; Parsing headers and NOV lines.
 134
 135 (defsubst nnheader-header-value ()
 136   (buffer-substring (match-end 0) (gnus-point-at-eol)))
 137
 138 (defvar nnheader-newsgroup-none-id 1)
 139
 140 (defun nnheader-parse-head (&optional naked)
 141   (let ((case-fold-search t)
 142         (cur (current-buffer))
 143         (buffer-read-only nil)
 144         end ref in-reply-to lines p)
 145     (goto-char (point-min))
 146     (when naked
 147       (insert "\n"))
 148     ;; Search to the beginning of the next header. Error messages
 149     ;; do not begin with 2 or 3.
 150     (prog1
 151         (when (or naked (re-search-forward "^[23][0-9]+ " nil t))
 152           ;; This implementation of this function, with nine
 153           ;; search-forwards instead of the one re-search-forward and
 154           ;; a case (which basically was the old function) is actually
 155           ;; about twice as fast, even though it looks messier.  You
 156           ;; can't have everything, I guess.  Speed and elegance
 157           ;; doesn't always go hand in hand.
 158           (vector
 159            ;; Number.
 160            (if naked
 161                (progn
 162                  (setq p (point-min))
 163                  0)
 164              (prog1
 165                  (read cur)
 166                (end-of-line)
 167                (setq p (point))
 168                (narrow-to-region (point)
 169                                  (or (and (search-forward "\n.\n" nil t)
 170                                           (- (point) 2))
 171                                      (point)))))
 172            ;; Subject.
 173            (progn
 174              (goto-char p)
 175              (if (search-forward "\nsubject: " nil t)
 176                  (nnheader-header-value) "(none)"))
 177            ;; From.
 178            (progn
 179              (goto-char p)
 180              (if (search-forward "\nfrom: " nil t)
 181                  (nnheader-header-value) "(nobody)"))
 182            ;; Date.
 183            (progn
 184              (goto-char p)
 185              (if (search-forward "\ndate: " nil t)
 186                  (nnheader-header-value) ""))
 187            ;; Message-ID.
 188            (progn
 189              (goto-char p)
 190              (if (search-forward "\nmessage-id: " nil t)
 191                  (nnheader-header-value)
 192                ;; If there was no message-id, we just fake one to make
 193                ;; subsequent routines simpler.
 194                (concat "none+"
 195                        (int-to-string
 196                         (incf nnheader-newsgroup-none-id)))))
 197            ;; References.
 198            (progn
 199              (goto-char p)
 200              (if (search-forward "\nreferences: " nil t)
 201                  (nnheader-header-value)
 202                ;; Get the references from the in-reply-to header if there
 203                ;; were no references and the in-reply-to header looks
 204                ;; promising.
 205                (if (and (search-forward "\nin-reply-to: " nil t)
 206                         (setq in-reply-to (nnheader-header-value))
 207                         (string-match "<[^>]+>" in-reply-to))
 208                    (substring in-reply-to (match-beginning 0)
 209                               (match-end 0))
 210                  "")))
 211            ;; Chars.
 212            0
 213            ;; Lines.
 214            (progn
 215              (goto-char p)
 216              (if (search-forward "\nlines: " nil t)
 217                  (if (numberp (setq lines (read cur)))
 218                      lines 0)
 219                0))
 220            ;; Xref.
 221            (progn
 222              (goto-char p)
 223              (and (search-forward "\nxref: " nil t)
 224                   (nnheader-header-value)))))
 225       (when naked
 226         (goto-char (point-min))
 227         (delete-char 1)))))
 228
 229 (defun nnheader-insert-nov (header)
 230   (princ (mail-header-number header) (current-buffer))
 231   (insert
 232    "\t"
 233    (or (mail-header-subject header) "(none)") "\t"
 234    (or (mail-header-from header) "(nobody)") "\t"
 235    (or (mail-header-date header) "") "\t"
 236    (or (mail-header-id header)
 237        (nnmail-message-id)) "\t"
 238    (or (mail-header-references header) "") "\t")
 239   (princ (or (mail-header-chars header) 0) (current-buffer))
 240   (insert "\t")
 241   (princ (or (mail-header-lines header) 0) (current-buffer))
 242   (insert "\t")
 243   (when (mail-header-xref header)
 244     (insert "Xref: " (mail-header-xref header) "\t"))
 245   (insert "\n"))
 246
 247 (defun nnheader-insert-article-line (article)
 248   (goto-char (point-min))
 249   (insert "220 ")
 250   (princ article (current-buffer))
 251   (insert " Article retrieved.\n")
 252   (search-forward "\n\n" nil 'move)
 253   (delete-region (point) (point-max))
 254   (forward-char -1)
 255   (insert "."))
 256
 257 ;; Various cruft the backends and Gnus need to communicate.
 258
 259 (defvar nntp-server-buffer nil)
 260 (defvar gnus-verbose-backends 7
 261   "*A number that says how talkative the Gnus backends should be.")
 262 (defvar gnus-nov-is-evil nil
 263   "If non-nil, Gnus backends will never output headers in the NOV format.")
 264 (defvar news-reply-yank-from nil)
 265 (defvar news-reply-yank-message-id nil)
 266
 267 (defvar nnheader-callback-function nil)
 268
 269 (defun nnheader-init-server-buffer ()
 270   "Initialize the Gnus-backend communication buffer."
 271   (save-excursion
 272     (setq nntp-server-buffer (get-buffer-create " *nntpd*"))
 273     (set-buffer nntp-server-buffer)
 274     (buffer-disable-undo (current-buffer))
 275     (erase-buffer)
 276     (kill-all-local-variables)
 277     (setq case-fold-search t)           ;Should ignore case.
 278     t))
 279
 280
 281 ;;; Various functions the backends use.
 282
 283 (defun nnheader-file-error (file)
 284   "Return a string that says what is wrong with FILE."
 285   (format
 286    (cond
 287     ((not (file-exists-p file))
 288      "%s does not exist")
 289     ((file-directory-p file)
 290      "%s is a directory")
 291     ((not (file-readable-p file))
 292      "%s is not readable"))
 293    file))
 294
 295 (defun nnheader-insert-head (file)
 296   "Insert the head of the article."
 297   (when (file-exists-p file)
 298     (if (eq nnheader-max-head-length t)
 299         ;; Just read the entire file.
 300         (nnheader-insert-file-contents-literally file)
 301       ;; Read 1K blocks until we find a separator.
 302       (let ((beg 0)
 303             format-alist
 304             (chop 1024))
 305         (while (and (eq chop (nth 1 (insert-file-contents
 306                                      file nil beg (incf beg chop))))
 307                     (prog1 (not (search-forward "\n\n" nil t))
 308                       (goto-char (point-max)))
 309                     (or (null nnheader-max-head-length)
 310                         (< beg nnheader-max-head-length))))))
 311     t))
 312
 313 (defun nnheader-article-p ()
 314   "Say whether the current buffer looks like an article."
 315   (goto-char (point-min))
 316   (if (not (search-forward "\n\n" nil t))
 317       nil
 318     (narrow-to-region (point-min) (1- (point)))
 319     (goto-char (point-min))
 320     (while (looking-at "[A-Z][^ \t]+:.*\n\\([ \t].*\n\\)*\\|From .*\n")
 321       (goto-char (match-end 0)))
 322     (prog1
 323         (eobp)
 324       (widen))))
 325
 326 (defun nnheader-insert-references (references message-id)
 327   "Insert a References header based on REFERENCES and MESSAGE-ID."
 328   (if (and (not references) (not message-id))
 329       ()        ; This is illegal, but not all articles have Message-IDs.
 330     (mail-position-on-field "References")
 331     (let ((begin (save-excursion (beginning-of-line) (point)))
 332           (fill-column 78)
 333           (fill-prefix "\t"))
 334       (if references (insert references))
 335       (if (and references message-id) (insert " "))
 336       (if message-id (insert message-id))
 337       ;; Fold long References lines to conform to RFC1036 (sort of).
 338       ;; The region must end with a newline to fill the region
 339       ;; without inserting extra newline.
 340       (fill-region-as-paragraph begin (1+ (point))))))
 341
 342 (defun nnheader-replace-header (header new-value)
 343   "Remove HEADER and insert the NEW-VALUE."
 344   (save-excursion
 345     (save-restriction
 346       (nnheader-narrow-to-headers)
 347       (prog1
 348           (message-remove-header header)
 349         (goto-char (point-max))
 350         (insert header ": " new-value "\n")))))
 351
 352 (defun nnheader-narrow-to-headers ()
 353   "Narrow to the head of an article."
 354   (widen)
 355   (narrow-to-region
 356    (goto-char (point-min))
 357    (if (search-forward "\n\n" nil t)
 358        (1- (point))
 359      (point-max)))
 360   (goto-char (point-min)))
 361
 362 (defun nnheader-set-temp-buffer (name)
 363   "Set-buffer to an empty (possibly new) buffer called NAME with undo disabled."
 364   (set-buffer (get-buffer-create name))
 365   (buffer-disable-undo (current-buffer))
 366   (erase-buffer)
 367   (current-buffer))
 368
 369 (defmacro nnheader-temp-write (file &rest forms)
 370   "Create a new buffer, evaluate FORM there, and write the buffer to FILE."
 371   `(save-excursion
 372      (let ((nnheader-temp-file ,file)
 373            (nnheader-temp-cur-buffer
 374             (nnheader-set-temp-buffer
 375              (generate-new-buffer-name " *nnheader temp*"))))
 376        (when (and nnheader-temp-file
 377                   (not (file-directory-p (file-name-directory
 378                                           nnheader-temp-file))))
 379          (make-directory (file-name-directory nnheader-temp-file) t))
 380        (unwind-protect
 381            (prog1
 382                (progn
 383                  ,@forms)
 384              (when nnheader-temp-file
 385                (set-buffer nnheader-temp-cur-buffer)
 386                (write-region (point-min) (point-max)
 387                              nnheader-temp-file nil 'nomesg)))
 388          (when (buffer-name nnheader-temp-cur-buffer)
 389            (kill-buffer nnheader-temp-cur-buffer))))))
 390
 391 (put 'nnheader-temp-write 'lisp-indent-function 1)
 392 (put 'nnheader-temp-write 'lisp-indent-hook 1)
 393 (put 'nnheader-temp-write 'edebug-form-spec '(form body))
 394
 395 (defvar jka-compr-compression-info-list)
 396 (defvar nnheader-numerical-files
 397   (if (boundp 'jka-compr-compression-info-list)
 398       (concat "\\([0-9]+\\)\\("
 399               (mapconcat (lambda (i) (aref i 0))
 400                          jka-compr-compression-info-list "\\|")
 401               "\\)?")
 402     "[0-9]+$")
 403   "Regexp that match numerical files.")
 404
 405 (defvar nnheader-numerical-short-files (concat "^" nnheader-numerical-files)
 406   "Regexp that matches numerical file names.")
 407
 408 (defvar nnheader-numerical-full-files (concat "/" nnheader-numerical-files)
 409   "Regexp that matches numerical full file paths.")
 410
 411 (defsubst nnheader-file-to-number (file)
 412   "Take a file name and return the article number."
 413   (if (not (boundp 'jka-compr-compression-info-list))
 414       (string-to-int file)
 415     (string-match nnheader-numerical-short-files file)
 416     (string-to-int (match-string 0 file))))
 417
 418 (defun nnheader-directory-files-safe (&rest args)
 419   ;; It has been reported numerous times that `directory-files'
 420   ;; fails with an alarming frequency on NFS mounted file systems.
 421   ;; This function executes that function twice and returns
 422   ;; the longest result.
 423   (let ((first (apply 'directory-files args))
 424         (second (apply 'directory-files args)))
 425     (if (> (length first) (length second))
 426         first
 427       second)))
 428
 429 (defun nnheader-directory-articles (dir)
 430   "Return a list of all article files in a directory."
 431   (mapcar 'nnheader-file-to-number
 432           (nnheader-directory-files-safe
 433            dir nil nnheader-numerical-short-files t)))
 434
 435 (defun nnheader-article-to-file-alist (dir)
 436   "Return an alist of article/file pairs in DIR."
 437   (mapcar (lambda (file) (cons (nnheader-file-to-number file) file))
 438           (nnheader-directory-files-safe
 439            dir nil nnheader-numerical-short-files t)))
 440
 441 (defun nnheader-fold-continuation-lines ()
 442   "Fold continuation lines in the current buffer."
 443   (goto-char (point-min))
 444   (while (re-search-forward "\\(\r?\n[ \t]+\\)+" nil t)
 445     (replace-match " " t t)))
 446
 447 (defun nnheader-translate-file-chars (file)
 448   (if (null nnheader-file-name-translation-alist)
 449       ;; No translation is necessary.
 450       file
 451     ;; We translate -- but only the file name.  We leave the directory
 452     ;; alone.
 453     (let* ((i 0)
 454            trans leaf path len)
 455       (if (string-match "/[^/]+\\'" file)
 456           ;; This is needed on NT's and stuff.
 457           (setq leaf (substring file (1+ (match-beginning 0)))
 458                 path (substring file 0 (1+ (match-beginning 0))))
 459         ;; Fall back on this.
 460         (setq leaf (file-name-nondirectory file)
 461               path (file-name-directory file)))
 462       (setq len (length leaf))
 463       (while (< i len)
 464         (when (setq trans (cdr (assq (aref leaf i)
 465                                      nnheader-file-name-translation-alist)))
 466           (aset leaf i trans))
 467         (incf i))
 468       (concat path leaf))))
 469
 470 (defun nnheader-report (backend &rest args)
 471   "Report an error from the BACKEND.
 472 The first string in ARGS can be a format string."
 473   (set (intern (format "%s-status-string" backend))
 474        (if (< (length args) 2)
 475            (car args)
 476          (apply 'format args)))
 477   nil)
 478
 479 (defun nnheader-get-report (backend)
 480   (message "%s" (symbol-value (intern (format "%s-status-string" backend)))))
 481
 482 (defun nnheader-insert (format &rest args)
 483   "Clear the communicaton buffer and insert FORMAT and ARGS into the buffer.
 484 If FORMAT isn't a format string, it and all ARGS will be inserted
 485 without formatting."
 486   (save-excursion
 487     (set-buffer nntp-server-buffer)
 488     (erase-buffer)
 489     (if (string-match "%" format)
 490         (insert (apply 'format format args))
 491       (apply 'insert format args))
 492     t))
 493
 494 (defun nnheader-mail-file-mbox-p (file)
 495   "Say whether FILE looks like an Unix mbox file."
 496   (when (and (file-exists-p file)
 497              (file-readable-p file)
 498              (file-regular-p file))
 499     (save-excursion
 500       (nnheader-set-temp-buffer " *mail-file-mbox-p*")
 501       (nnheader-insert-file-contents-literally file)
 502       (goto-char (point-min))
 503       (prog1
 504           (looking-at message-unix-mail-delimiter)
 505         (kill-buffer (current-buffer))))))
 506
 507 (defun nnheader-replace-chars-in-string (string from to)
 508   "Replace characters in STRING from FROM to TO."
 509   (let ((string (substring string 0))   ;Copy string.
 510         (len (length string))
 511         (idx 0))
 512     ;; Replace all occurrences of FROM with TO.
 513     (while (< idx len)
 514       (if (= (aref string idx) from)
 515           (aset string idx to))
 516       (setq idx (1+ idx)))
 517     string))
 518
 519 (defun nnheader-file-to-group (file &optional top)
 520   "Return a group name based on FILE and TOP."
 521   (nnheader-replace-chars-in-string
 522    (if (not top)
 523        file
 524      (condition-case ()
 525          (substring (expand-file-name file)
 526                     (length
 527                      (expand-file-name
 528                       (file-name-as-directory top))))
 529        (error "")))
 530    ?/ ?.))
 531
 532 (defun nnheader-message (level &rest args)
 533   "Message if the Gnus backends are talkative."
 534   (if (or (not (numberp gnus-verbose-backends))
 535           (<= level gnus-verbose-backends))
 536       (apply 'message args)
 537     (apply 'format args)))
 538
 539 (defun nnheader-be-verbose (level)
 540   "Return whether the backends should be verbose on LEVEL."
 541   (or (not (numberp gnus-verbose-backends))
 542       (<= level gnus-verbose-backends)))
 543
 544 (defun nnheader-group-pathname (group dir &optional file)
 545   "Make pathname for GROUP."
 546   (concat
 547    (let ((dir (file-name-as-directory (expand-file-name dir))))
 548      ;; If this directory exists, we use it directly.
 549      (if (file-directory-p (concat dir group))
 550          (concat dir group "/")
 551        ;; If not, we translate dots into slashes.
 552        (concat dir (nnheader-replace-chars-in-string group ?. ?/) "/")))
 553    (cond ((null file) "")
 554          ((numberp file) (int-to-string file))
 555          (t file))))
 556
 557 (defun nnheader-functionp (form)
 558   "Return non-nil if FORM is funcallable."
 559   (or (and (symbolp form) (fboundp form))
 560       (and (listp form) (eq (car form) 'lambda))))
 561
 562 (defun nnheader-concat (dir file)
 563   "Concat DIR as directory to FILE."
 564   (concat (file-name-as-directory dir) file))
 565
 566 (defun nnheader-ms-strip-cr ()
 567   "Strip ^M from the end of all lines."
 568   (save-excursion
 569     (goto-char (point-min))
 570     (while (re-search-forward "\r$" nil t)
 571       (delete-backward-char 1))))
 572
 573 (fset 'nnheader-run-at-time 'run-at-time)
 574 (fset 'nnheader-cancel-timer 'cancel-timer)
 575 (fset 'nnheader-find-file-noselect 'find-file-noselect)
 576 (fset 'nnheader-insert-file-contents-literally
 577       'insert-file-contents-literally)
 578
 579 (when (string-match "XEmacs\\|Lucid" emacs-version)
 580   (require 'nnheaderxm))
 581
 582 (run-hooks 'nnheader-load-hook)
 583
 584 (provide 'nnheader)
 585
 586 ;;; nnheader.el ends here