lisp/gnus/nnheader.el

   1 ;;; nnheader.el --- header access macros for Gnus and its backends
   2
   3 ;; Copyright (C) 1987-1990, 1993-1998, 2000-2014 Free Software
   4 ;; Foundation, Inc.
   5
   6 ;; Author: Masanobu UMEDA <umerin@flab.flab.fujitsu.junet>
   7 ;;      Lars Magne Ingebrigtsen <larsi@gnus.org>
   8 ;; Keywords: news
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;;; Code:
  28
  29 (eval-when-compile (require 'cl))
  30
  31 (defvar nnmail-extra-headers)
  32 (defvar gnus-newsgroup-name)
  33 (defvar nnheader-file-coding-system)
  34 (defvar jka-compr-compression-info-list)
  35
  36 ;; Requiring `gnus-util' at compile time creates a circular
  37 ;; dependency between nnheader.el and gnus-util.el.
  38 ;;(eval-when-compile (require 'gnus-util))
  39
  40 (require 'mail-utils)
  41 (require 'mm-util)
  42 (require 'gnus-util)
  43 (autoload 'gnus-range-add "gnus-range")
  44 (autoload 'gnus-remove-from-range "gnus-range")
  45 ;; FIXME none of these are used explicitly in this file.
  46 (autoload 'gnus-sorted-intersection "gnus-range")
  47 (autoload 'gnus-intersection "gnus-range")
  48 (autoload 'gnus-sorted-complement "gnus-range")
  49 (autoload 'gnus-sorted-difference "gnus-range")
  50
  51 (defcustom gnus-verbose-backends 7
  52   "Integer that says how verbose the Gnus backends should be.
  53 The higher the number, the more messages the Gnus backends will flash
  54 to say what it's doing.  At zero, the Gnus backends will be totally
  55 mute; at five, they will display most important messages; and at ten,
  56 they will keep on jabbering all the time."
  57   :group 'gnus-start
  58   :type 'integer)
  59
  60 (defcustom gnus-nov-is-evil nil
  61   "If non-nil, Gnus backends will never output headers in the NOV format."
  62   :group 'gnus-server
  63   :type 'boolean)
  64
  65 (defvar nnheader-max-head-length 8192
  66   "*Max length of the head of articles.
  67
  68 Value is an integer, nil, or t.  nil means read in chunks of a file
  69 indefinitely until a complete head is found\; t means always read the
  70 entire file immediately, disregarding `nnheader-head-chop-length'.
  71
  72 Integer values will in effect be rounded up to the nearest multiple of
  73 `nnheader-head-chop-length'.")
  74
  75 (defvar nnheader-head-chop-length 2048
  76   "*Length of each read operation when trying to fetch HEAD headers.")
  77
  78 (defvar nnheader-read-timeout
  79   (if (string-match "windows-nt\\|os/2\\|cygwin"
  80                     (symbol-name system-type))
  81       ;; http://thread.gmane.org/v9655t3pjo.fsf@marauder.physik.uni-ulm.de
  82       ;;
  83       ;; IIRC, values lower than 1.0 didn't/don't work on Windows/DOS.
  84       ;;
  85       ;; There should probably be a runtime test to determine the timing
  86       ;; resolution, or a primitive to report it.  I don't know off-hand
  87       ;; what's possible.  Perhaps better, maybe the Windows/DOS primitive
  88       ;; could round up non-zero timeouts to a minimum of 1.0?
  89       1.0
  90     ;; 2008-05-19 change by Larsi:
  91     ;; Change the default timeout from 0.1 seconds to 0.01 seconds.  This will
  92     ;; make nntp and pop3 article retrieval faster in some cases, but might
  93     ;; make CPU usage larger.  If this has any bad side effects, we might
  94     ;; revert this change.
  95     0.01)
  96   ;; When changing this variable, consider changing `pop3-read-timeout' as
  97   ;; well.
  98   "How long nntp should wait between checking for the end of output.
  99 Shorter values mean quicker response, but are more CPU intensive.")
 100
 101 (defvar nnheader-file-name-translation-alist
 102   (let ((case-fold-search t))
 103     (cond
 104      ((string-match "windows-nt\\|os/2\\|cygwin"
 105                     (symbol-name system-type))
 106       (append (mapcar (lambda (c) (cons c ?_))
 107                       '(?: ?* ?\" ?< ?> ??))
 108               (if (string-match "windows-nt\\|cygwin"
 109                                 (symbol-name system-type))
 110                   nil
 111                 '((?+ . ?-)))))
 112      (t nil)))
 113   "*Alist that says how to translate characters in file names.
 114 For instance, if \":\" is invalid as a file character in file names
 115 on your system, you could say something like:
 116
 117 \(setq nnheader-file-name-translation-alist '((?: . ?_)))")
 118
 119 (defvar nnheader-directory-separator-character
 120   (string-to-char (substring (file-name-as-directory ".") -1))
 121   "*A character used to a directory separator.")
 122
 123 (autoload 'nnmail-message-id "nnmail")
 124 (autoload 'mail-position-on-field "sendmail")
 125 (autoload 'gnus-buffer-live-p "gnus-util")
 126
 127 ;;; Header access macros.
 128
 129 ;; These macros may look very much like the ones in GNUS 4.1.  They
 130 ;; are, in a way, but you should note that the indices they use have
 131 ;; been changed from the internal GNUS format to the NOV format.  The
 132 ;; makes it possible to read headers from XOVER much faster.
 133 ;;
 134 ;; The format of a header is now:
 135 ;; [number subject from date id references chars lines xref extra]
 136 ;;
 137 ;; (That next-to-last entry is defined as "misc" in the NOV format,
 138 ;; but Gnus uses it for xrefs.)
 139
 140 (defmacro mail-header-number (header)
 141   "Return article number in HEADER."
 142   `(aref ,header 0))
 143
 144 (defmacro mail-header-set-number (header number)
 145   "Set article number of HEADER to NUMBER."
 146   `(aset ,header 0 ,number))
 147
 148 (defmacro mail-header-subject (header)
 149   "Return subject string in HEADER."
 150   `(aref ,header 1))
 151
 152 (defmacro mail-header-set-subject (header subject)
 153   "Set article subject of HEADER to SUBJECT."
 154   `(aset ,header 1 ,subject))
 155
 156 (defmacro mail-header-from (header)
 157   "Return author string in HEADER."
 158   `(aref ,header 2))
 159
 160 (defmacro mail-header-set-from (header from)
 161   "Set article author of HEADER to FROM."
 162   `(aset ,header 2 ,from))
 163
 164 (defmacro mail-header-date (header)
 165   "Return date in HEADER."
 166   `(aref ,header 3))
 167
 168 (defmacro mail-header-set-date (header date)
 169   "Set article date of HEADER to DATE."
 170   `(aset ,header 3 ,date))
 171
 172 (defalias 'mail-header-message-id 'mail-header-id)
 173 (defmacro mail-header-id (header)
 174   "Return Id in HEADER."
 175   `(aref ,header 4))
 176
 177 (defalias 'mail-header-set-message-id 'mail-header-set-id)
 178 (defmacro mail-header-set-id (header id)
 179   "Set article Id of HEADER to ID."
 180   `(aset ,header 4 ,id))
 181
 182 (defmacro mail-header-references (header)
 183   "Return references in HEADER."
 184   `(aref ,header 5))
 185
 186 (defmacro mail-header-set-references (header ref)
 187   "Set article references of HEADER to REF."
 188   `(aset ,header 5 ,ref))
 189
 190 (defmacro mail-header-chars (header)
 191   "Return number of chars of article in HEADER."
 192   `(aref ,header 6))
 193
 194 (defmacro mail-header-set-chars (header chars)
 195   "Set number of chars in article of HEADER to CHARS."
 196   `(aset ,header 6 ,chars))
 197
 198 (defmacro mail-header-lines (header)
 199   "Return lines in HEADER."
 200   `(aref ,header 7))
 201
 202 (defmacro mail-header-set-lines (header lines)
 203   "Set article lines of HEADER to LINES."
 204   `(aset ,header 7 ,lines))
 205
 206 (defmacro mail-header-xref (header)
 207   "Return xref string in HEADER."
 208   `(aref ,header 8))
 209
 210 (defmacro mail-header-set-xref (header xref)
 211   "Set article XREF of HEADER to xref."
 212   `(aset ,header 8 ,xref))
 213
 214 (defmacro mail-header-extra (header)
 215   "Return the extra headers in HEADER."
 216   `(aref ,header 9))
 217
 218 (defun mail-header-set-extra (header extra)
 219   "Set the extra headers in HEADER to EXTRA."
 220   (aset header 9 extra))
 221
 222 (defsubst make-mail-header (&optional init)
 223   "Create a new mail header structure initialized with INIT."
 224   (make-vector 10 init))
 225
 226 (defsubst make-full-mail-header (&optional number subject from date id
 227                                            references chars lines xref
 228                                            extra)
 229   "Create a new mail header structure initialized with the parameters given."
 230   (vector number subject from date id references chars lines xref extra))
 231
 232 ;; fake message-ids: generation and detection
 233
 234 (defvar nnheader-fake-message-id 1)
 235
 236 (defsubst nnheader-generate-fake-message-id (&optional number)
 237   (if (numberp number)
 238       (format "fake+none+%s+%d" gnus-newsgroup-name number)
 239     (format "fake+none+%s+%s"
 240             gnus-newsgroup-name
 241             (int-to-string (incf nnheader-fake-message-id)))))
 242
 243 (defsubst nnheader-fake-message-id-p (id)
 244   (save-match-data                     ; regular message-id's are <.*>
 245     (string-match "\\`fake\\+none\\+.*\\+[0-9]+\\'" id)))
 246
 247 ;; Parsing headers and NOV lines.
 248
 249 (defsubst nnheader-remove-cr-followed-by-lf ()
 250   (goto-char (point-max))
 251   (while (search-backward "\r\n" nil t)
 252     (delete-char 1)))
 253
 254 (defsubst nnheader-header-value ()
 255   (skip-chars-forward " \t")
 256   (buffer-substring (point) (point-at-eol)))
 257
 258 (autoload 'ietf-drums-unfold-fws "ietf-drums")
 259
 260 (defun nnheader-parse-naked-head (&optional number)
 261   ;; This function unfolds continuation lines in this buffer
 262   ;; destructively.  When this side effect is unwanted, use
 263   ;; `nnheader-parse-head' instead of this function.
 264   (let ((case-fold-search t)
 265         (buffer-read-only nil)
 266         (cur (current-buffer))
 267         (p (point-min))
 268         in-reply-to lines ref)
 269     (nnheader-remove-cr-followed-by-lf)
 270     (ietf-drums-unfold-fws)
 271     (subst-char-in-region (point-min) (point-max) ?\t ? )
 272     (goto-char p)
 273     (insert "\n")
 274     (prog1
 275         ;; This implementation of this function, with nine
 276         ;; search-forwards instead of the one re-search-forward and a
 277         ;; case (which basically was the old function) is actually
 278         ;; about twice as fast, even though it looks messier.  You
 279         ;; can't have everything, I guess.  Speed and elegance don't
 280         ;; always go hand in hand.
 281         (vector
 282          ;; Number.
 283          (or number 0)
 284          ;; Subject.
 285          (progn
 286            (goto-char p)
 287            (if (search-forward "\nsubject:" nil t)
 288                (nnheader-header-value) "(none)"))
 289          ;; From.
 290          (progn
 291            (goto-char p)
 292            (if (search-forward "\nfrom:" nil t)
 293                (nnheader-header-value) "(nobody)"))
 294          ;; Date.
 295          (progn
 296            (goto-char p)
 297            (if (search-forward "\ndate:" nil t)
 298                (nnheader-header-value) ""))
 299          ;; Message-ID.
 300          (progn
 301            (goto-char p)
 302            (if (search-forward "\nmessage-id:" nil t)
 303                (buffer-substring
 304                 (1- (or (search-forward "<" (point-at-eol) t)
 305                         (point)))
 306                 (or (search-forward ">" (point-at-eol) t) (point)))
 307              ;; If there was no message-id, we just fake one to make
 308              ;; subsequent routines simpler.
 309              (nnheader-generate-fake-message-id number)))
 310          ;; References.
 311          (progn
 312            (goto-char p)
 313            (if (search-forward "\nreferences:" nil t)
 314                (nnheader-header-value)
 315              ;; Get the references from the in-reply-to header if
 316              ;; there were no references and the in-reply-to header
 317              ;; looks promising.
 318              (if (and (search-forward "\nin-reply-to:" nil t)
 319                       (setq in-reply-to (nnheader-header-value))
 320                       (string-match "<[^\n>]+>" in-reply-to))
 321                  (let (ref2)
 322                    (setq ref (substring in-reply-to (match-beginning 0)
 323                                         (match-end 0)))
 324                    (while (string-match "<[^\n>]+>"
 325                                         in-reply-to (match-end 0))
 326                      (setq ref2 (substring in-reply-to (match-beginning 0)
 327                                            (match-end 0)))
 328                      (when (> (length ref2) (length ref))
 329                        (setq ref ref2)))
 330                    ref)
 331                nil)))
 332          ;; Chars.
 333          0
 334          ;; Lines.
 335          (progn
 336            (goto-char p)
 337            (if (search-forward "\nlines: " nil t)
 338                (if (numberp (setq lines (read cur)))
 339                    lines 0)
 340              0))
 341          ;; Xref.
 342          (progn
 343            (goto-char p)
 344            (and (search-forward "\nxref:" nil t)
 345                 (nnheader-header-value)))
 346          ;; Extra.
 347          (when nnmail-extra-headers
 348            (let ((extra nnmail-extra-headers)
 349                  out)
 350              (while extra
 351                (goto-char p)
 352                (when (search-forward
 353                       (concat "\n" (symbol-name (car extra)) ":") nil t)
 354                  (push (cons (car extra) (nnheader-header-value))
 355                        out))
 356                (pop extra))
 357              out)))
 358       (goto-char p)
 359       (delete-char 1))))
 360
 361 (defun nnheader-parse-head (&optional naked)
 362   (let ((cur (current-buffer)) num beg end)
 363     (when (if naked
 364               (setq num 0
 365                     beg (point-min)
 366                     end (point-max))
 367             ;; Search to the beginning of the next header.  Error
 368             ;; messages do not begin with 2 or 3.
 369             (when (re-search-forward "^[23][0-9]+ " nil t)
 370               (setq num (read cur)
 371                     beg (point)
 372                     end (if (search-forward "\n.\n" nil t)
 373                             (goto-char  (- (point) 2))
 374                           (point)))))
 375       (with-temp-buffer
 376         (insert-buffer-substring cur beg end)
 377         (nnheader-parse-naked-head num)))))
 378
 379 (defmacro nnheader-nov-skip-field ()
 380   '(search-forward "\t" eol 'move))
 381
 382 (defmacro nnheader-nov-field ()
 383   '(buffer-substring (point) (if (nnheader-nov-skip-field) (1- (point)) eol)))
 384
 385 (defmacro nnheader-nov-read-integer ()
 386   '(prog1
 387        (if (eq (char-after) ?\t)
 388            0
 389          (let ((num (condition-case nil
 390                         (read (current-buffer))
 391                       (error nil))))
 392            (if (numberp num) num 0)))
 393      (or (eobp) (forward-char 1))))
 394
 395 (defmacro nnheader-nov-parse-extra ()
 396   '(let (out string)
 397      (while (not (memq (char-after) '(?\n nil)))
 398        (setq string (nnheader-nov-field))
 399        (when (string-match "^\\([^ :]+\\): " string)
 400          (push (cons (intern (match-string 1 string))
 401                      (substring string (match-end 0)))
 402                out)))
 403      out))
 404
 405 (eval-and-compile
 406   (defvar nnheader-uniquify-message-id nil))
 407
 408 (defmacro nnheader-nov-read-message-id (&optional number)
 409   `(let ((id (nnheader-nov-field)))
 410      (if (string-match "^<[^>]+>$" id)
 411          ,(if nnheader-uniquify-message-id
 412               `(if (string-match "__[^@]+@" id)
 413                    (concat (substring id 0 (match-beginning 0))
 414                            (substring id (1- (match-end 0))))
 415                  id)
 416             'id)
 417        (nnheader-generate-fake-message-id ,number))))
 418
 419 (defun nnheader-parse-nov ()
 420   (let ((eol (point-at-eol))
 421         (number (nnheader-nov-read-integer)))
 422     (vector
 423      number                             ; number
 424      (nnheader-nov-field)               ; subject
 425      (nnheader-nov-field)               ; from
 426      (nnheader-nov-field)               ; date
 427      (nnheader-nov-read-message-id number) ; id
 428      (nnheader-nov-field)               ; refs
 429      (nnheader-nov-read-integer)        ; chars
 430      (nnheader-nov-read-integer)        ; lines
 431      (if (eq (char-after) ?\n)
 432          nil
 433        (if (looking-at "Xref: ")
 434            (goto-char (match-end 0)))
 435        (nnheader-nov-field))            ; Xref
 436      (nnheader-nov-parse-extra))))      ; extra
 437
 438 (defun nnheader-insert-nov (header)
 439   (princ (mail-header-number header) (current-buffer))
 440   (let ((p (point)))
 441     (insert
 442      "\t"
 443      (or (mail-header-subject header) "(none)") "\t"
 444      (or (mail-header-from header) "(nobody)") "\t"
 445      (or (mail-header-date header) "") "\t"
 446      (or (mail-header-id header)
 447          (nnmail-message-id))
 448      "\t"
 449      (or (mail-header-references header) "") "\t")
 450     (princ (or (mail-header-chars header) 0) (current-buffer))
 451     (insert "\t")
 452     (princ (or (mail-header-lines header) 0) (current-buffer))
 453     (insert "\t")
 454     (when (mail-header-xref header)
 455       (insert "Xref: " (mail-header-xref header)))
 456     (when (or (mail-header-xref header)
 457               (mail-header-extra header))
 458       (insert "\t"))
 459     (when (mail-header-extra header)
 460       (let ((extra (mail-header-extra header)))
 461         (while extra
 462           (insert (symbol-name (caar extra))
 463                   ": " (if (stringp (cdar extra)) (cdar extra) "") "\t")
 464           (pop extra))))
 465     (insert "\n")
 466     (backward-char 1)
 467     (while (search-backward "\n" p t)
 468       (delete-char 1))
 469     (forward-line 1)))
 470
 471 (defun nnheader-parse-overview-file (file)
 472   "Parse FILE and return a list of headers."
 473   (mm-with-unibyte-buffer
 474     (nnheader-insert-file-contents file)
 475     (goto-char (point-min))
 476     (let (headers)
 477       (while (not (eobp))
 478         (push (nnheader-parse-nov) headers)
 479         (forward-line 1))
 480       (nreverse headers))))
 481
 482 (defun nnheader-write-overview-file (file headers)
 483   "Write HEADERS to FILE."
 484   (with-temp-file file
 485     (mapcar 'nnheader-insert-nov headers)))
 486
 487 (defun nnheader-insert-header (header)
 488   (insert
 489    "Subject: " (or (mail-header-subject header) "(none)") "\n"
 490    "From: " (or (mail-header-from header) "(nobody)") "\n"
 491    "Date: " (or (mail-header-date header) "") "\n"
 492    "Message-ID: " (or (mail-header-id header) (nnmail-message-id)) "\n"
 493    "References: " (or (mail-header-references header) "") "\n"
 494    "Lines: ")
 495   (princ (or (mail-header-lines header) 0) (current-buffer))
 496   (insert "\n\n"))
 497
 498 (defun nnheader-insert-article-line (article)
 499   (goto-char (point-min))
 500   (insert "220 ")
 501   (princ article (current-buffer))
 502   (insert " Article retrieved.\n")
 503   (search-forward "\n\n" nil 'move)
 504   (delete-region (point) (point-max))
 505   (forward-char -1)
 506   (insert "."))
 507
 508 (defun nnheader-nov-delete-outside-range (beg end)
 509   "Delete all NOV lines that lie outside the BEG to END range."
 510   ;; First we find the first wanted line.
 511   (nnheader-find-nov-line beg)
 512   (delete-region (point-min) (point))
 513   ;; Then we find the last wanted line.
 514   (when (nnheader-find-nov-line end)
 515     (forward-line 1))
 516   (delete-region (point) (point-max)))
 517
 518 (defun nnheader-find-nov-line (article)
 519   "Put point at the NOV line that start with ARTICLE.
 520 If ARTICLE doesn't exist, put point where that line
 521 would have been.  The function will return non-nil if
 522 the line could be found."
 523   ;; This function basically does a binary search.
 524   (let ((max (point-max))
 525         (min (goto-char (point-min)))
 526         (cur (current-buffer))
 527         (prev (point-min))
 528         num found)
 529     (while (not found)
 530       (goto-char (+ min (/ (- max min) 2)))
 531       (beginning-of-line)
 532       (if (or (= (point) prev)
 533               (eobp))
 534           (setq found t)
 535         (setq prev (point))
 536         (while (and (not (numberp (setq num (read cur))))
 537                     (not (eobp)))
 538           (gnus-delete-line))
 539         (cond ((> num article)
 540                (setq max (point)))
 541               ((< num article)
 542                (setq min (point)))
 543               (t
 544                (setq found 'yes)))))
 545     ;; We may be at the first line.
 546     (when (and (not num)
 547                (not (eobp)))
 548       (setq num (read cur)))
 549     ;; Now we may have found the article we're looking for, or we
 550     ;; may be somewhere near it.
 551     (when (and (not (eq found 'yes))
 552                (not (eq num article)))
 553       (setq found (point))
 554       (while (and (< (point) max)
 555                   (or (not (numberp num))
 556                       (< num article)))
 557         (forward-line 1)
 558         (setq found (point))
 559         (or (eobp)
 560             (= (setq num (read cur)) article)))
 561       (unless (eq num article)
 562         (goto-char found)))
 563     (beginning-of-line)
 564     (eq num article)))
 565
 566 ;; Various cruft the backends and Gnus need to communicate.
 567
 568 (defvar nntp-server-buffer nil)
 569 (defvar nntp-process-response nil)
 570
 571 (defvar nnheader-callback-function nil)
 572
 573 (defun nnheader-init-server-buffer ()
 574   "Initialize the Gnus-backend communication buffer."
 575   (unless (gnus-buffer-live-p nntp-server-buffer)
 576     (setq nntp-server-buffer (get-buffer-create " *nntpd*")))
 577   (with-current-buffer nntp-server-buffer
 578     (erase-buffer)
 579     (mm-enable-multibyte)
 580     (kill-all-local-variables)
 581     (setq case-fold-search t)           ;Should ignore case.
 582     (set (make-local-variable 'nntp-process-response) nil)
 583     t))
 584
 585 ;;; Various functions the backends use.
 586
 587 (defun nnheader-file-error (file)
 588   "Return a string that says what is wrong with FILE."
 589   (format
 590    (cond
 591     ((not (file-exists-p file))
 592      "%s does not exist")
 593     ((file-directory-p file)
 594      "%s is a directory")
 595     ((not (file-readable-p file))
 596      "%s is not readable"))
 597    file))
 598
 599 (defun nnheader-insert-head (file)
 600   "Insert the head of the article."
 601   (when (file-exists-p file)
 602     (if (eq nnheader-max-head-length t)
 603         ;; Just read the entire file.
 604         (nnheader-insert-file-contents file)
 605       ;; Read blocks of the size specified by `nnheader-head-chop-length'
 606       ;; until we find a separator.
 607       (let ((beg 0)
 608             (start (point))
 609             ;; Use `binary' to prevent the contents from being decoded,
 610             ;; or it will change the number of characters that
 611             ;; `insert-file-contents' returns.
 612             (coding-system-for-read 'binary))
 613         (while (and (eq nnheader-head-chop-length
 614                         (nth 1 (mm-insert-file-contents
 615                                 file nil beg
 616                                 (incf beg nnheader-head-chop-length))))
 617                     ;; CRLF or CR might be used for the line-break code.
 618                     (prog1 (not (re-search-forward "\n\r?\n\\|\r\r" nil t))
 619                       (goto-char (point-max)))
 620                     (or (null nnheader-max-head-length)
 621                         (< beg nnheader-max-head-length))))
 622         ;; Finally decode the contents.
 623         (when (mm-coding-system-p nnheader-file-coding-system)
 624           (mm-decode-coding-region start (point-max)
 625                                    nnheader-file-coding-system))))
 626     t))
 627
 628 (defun nnheader-article-p ()
 629   "Say whether the current buffer looks like an article."
 630   (goto-char (point-min))
 631   (if (not (search-forward "\n\n" nil t))
 632       nil
 633     (narrow-to-region (point-min) (1- (point)))
 634     (goto-char (point-min))
 635     (while (looking-at "[a-zA-Z][^ \t]+:.*\n\\([ \t].*\n\\)*\\|From .*\n")
 636       (goto-char (match-end 0)))
 637     (prog1
 638         (eobp)
 639       (widen))))
 640
 641 (defun nnheader-insert-references (references message-id)
 642   "Insert a References header based on REFERENCES and MESSAGE-ID."
 643   (if (and (not references) (not message-id))
 644       ;; This is invalid, but not all articles have Message-IDs.
 645       ()
 646     (mail-position-on-field "References")
 647     (let ((begin (point-at-bol))
 648           (fill-column 78)
 649           (fill-prefix "\t"))
 650       (when references
 651         (insert references))
 652       (when (and references message-id)
 653         (insert " "))
 654       (when message-id
 655         (insert message-id))
 656       ;; Fold long References lines to conform to RFC1036 (sort of).
 657       ;; The region must end with a newline to fill the region
 658       ;; without inserting extra newline.
 659       (fill-region-as-paragraph begin (1+ (point))))))
 660
 661 (declare-function message-remove-header "message"
 662                   (header &optional is-regexp first reverse))
 663
 664 (defun nnheader-replace-header (header new-value)
 665   "Remove HEADER and insert the NEW-VALUE."
 666   (require 'message)
 667   (save-excursion
 668     (save-restriction
 669       (nnheader-narrow-to-headers)
 670       (prog1
 671           (message-remove-header header)
 672         (goto-char (point-max))
 673         (insert header ": " new-value "\n")))))
 674
 675 (defun nnheader-narrow-to-headers ()
 676   "Narrow to the head of an article."
 677   (widen)
 678   (narrow-to-region
 679    (goto-char (point-min))
 680    (if (search-forward "\n\n" nil t)
 681        (1- (point))
 682      (point-max)))
 683   (goto-char (point-min)))
 684
 685 (defun nnheader-get-lines-and-char ()
 686   "Return the number of lines and chars in the article body."
 687   (goto-char (point-min))
 688   (if (not (re-search-forward "\n\r?\n" nil t))
 689       (list 0 0)
 690     (list (count-lines (point) (point-max))
 691           (- (point-max) (point)))))
 692
 693 (defun nnheader-remove-body ()
 694   "Remove the body from an article in this current buffer."
 695   (goto-char (point-min))
 696   (when (re-search-forward "\n\r?\n" nil t)
 697     (delete-region (point) (point-max))))
 698
 699 (defun nnheader-set-temp-buffer (name &optional noerase)
 700   "Set-buffer to an empty (possibly new) buffer called NAME with undo disabled."
 701   (set-buffer (get-buffer-create name))
 702   (buffer-disable-undo)
 703   (unless noerase
 704     (erase-buffer))
 705   (current-buffer))
 706
 707 (defvar nnheader-numerical-files
 708   (if (boundp 'jka-compr-compression-info-list)
 709       (concat "\\([0-9]+\\)\\("
 710               (mapconcat (lambda (i) (aref i 0))
 711                          jka-compr-compression-info-list "\\|")
 712               "\\)?")
 713     "[0-9]+$")
 714   "Regexp that match numerical files.")
 715
 716 (defvar nnheader-numerical-short-files (concat "^" nnheader-numerical-files)
 717   "Regexp that matches numerical file names.")
 718
 719 (defvar nnheader-numerical-full-files (concat "/" nnheader-numerical-files)
 720   "Regexp that matches numerical full file names.")
 721
 722 (defsubst nnheader-file-to-number (file)
 723   "Take a FILE name and return the article number."
 724   (if (string= nnheader-numerical-short-files "^[0-9]+$")
 725       (string-to-number file)
 726     (string-match nnheader-numerical-short-files file)
 727     (string-to-number (match-string 0 file))))
 728
 729 (defvar nnheader-directory-files-is-safe
 730   (or (eq system-type 'windows-nt)
 731       (not (featurep 'xemacs)))
 732   "If non-nil, Gnus believes `directory-files' is safe.
 733 It has been reported numerous times that `directory-files' fails with
 734 an alarming frequency on NFS mounted file systems. If it is nil,
 735 `nnheader-directory-files-safe' is used.")
 736
 737 (defun nnheader-directory-files-safe (&rest args)
 738   "Execute `directory-files' twice and returns the longer result."
 739   (let ((first (apply 'directory-files args))
 740         (second (apply 'directory-files args)))
 741     (if (> (length first) (length second))
 742         first
 743       second)))
 744
 745 (defun nnheader-directory-articles (dir)
 746   "Return a list of all article files in directory DIR."
 747   (mapcar 'nnheader-file-to-number
 748           (if nnheader-directory-files-is-safe
 749               (directory-files
 750                dir nil nnheader-numerical-short-files t)
 751             (nnheader-directory-files-safe
 752              dir nil nnheader-numerical-short-files t))))
 753
 754 (defun nnheader-article-to-file-alist (dir)
 755   "Return an alist of article/file pairs in DIR."
 756   (mapcar (lambda (file) (cons (nnheader-file-to-number file) file))
 757           (if nnheader-directory-files-is-safe
 758               (directory-files
 759                dir nil nnheader-numerical-short-files t)
 760             (nnheader-directory-files-safe
 761              dir nil nnheader-numerical-short-files t))))
 762
 763 (defun nnheader-fold-continuation-lines ()
 764   "Fold continuation lines in the current buffer."
 765   (nnheader-replace-regexp "\\(\r?\n[ \t]+\\)+" " "))
 766
 767 (defun nnheader-translate-file-chars (file &optional full)
 768   "Translate FILE into something that can be a file name.
 769 If FULL, translate everything."
 770   (if (null nnheader-file-name-translation-alist)
 771       ;; No translation is necessary.
 772       file
 773     (let* ((i 0)
 774            trans leaf path len)
 775       (if full
 776           ;; Do complete translation.
 777           (setq leaf (copy-sequence file)
 778                 path ""
 779                 i (if (and (< 1 (length leaf)) (eq ?: (aref leaf 1)))
 780                       2 0))
 781         ;; We translate -- but only the file name.  We leave the directory
 782         ;; alone.
 783         (if (and (featurep 'xemacs)
 784                  (memq system-type '(windows-nt cygwin)))
 785             ;; This is needed on NT and stuff, because
 786             ;; file-name-nondirectory is not enough to split
 787             ;; file names, containing ':', e.g.
 788             ;; "d:\\Work\\News\\nntp+news.fido7.ru:fido7.ru.gnu.SCORE"
 789             ;;
 790             ;; we are trying to correctly split such names:
 791             ;; "d:file.name" -> "a:" "file.name"
 792             ;; "aaa:bbb.ccc" -> "" "aaa:bbb.ccc"
 793             ;; "d:aaa\\bbb:ccc"   -> "d:aaa\\" "bbb:ccc"
 794             ;; etc.
 795             ;; to translate then only the file name part.
 796             (progn
 797               (setq leaf file
 798                     path "")
 799               (if (string-match "\\(^\\w:\\|[/\\]\\)\\([^/\\]+\\)$" file)
 800                   (setq leaf (substring file (match-beginning 2))
 801                         path (substring file 0 (match-beginning 2)))))
 802           ;; Emacs DTRT, says andrewi.
 803           (setq leaf (file-name-nondirectory file)
 804                 path (file-name-directory file))))
 805       (setq len (length leaf))
 806       (while (< i len)
 807         (when (setq trans (cdr (assq (aref leaf i)
 808                                      nnheader-file-name-translation-alist)))
 809           (aset leaf i trans))
 810         (incf i))
 811       (concat path leaf))))
 812
 813 (defun nnheader-report (backend &rest args)
 814   "Report an error from the BACKEND.
 815 The first string in ARGS can be a format string."
 816   (set (intern (format "%s-status-string" backend))
 817        (if (< (length args) 2)
 818            (car args)
 819          (apply 'format args)))
 820   nil)
 821
 822 (defun nnheader-get-report-string (backend)
 823   "Get the most recent report from BACKEND."
 824   (condition-case ()
 825       (format "%s" (symbol-value (intern (format "%s-status-string"
 826                                                  backend))))
 827     (error "")))
 828
 829 (defun nnheader-get-report (backend)
 830   "Get the most recent report from BACKEND."
 831   (nnheader-message 5 (nnheader-get-report-string backend)))
 832
 833 (defun nnheader-insert (format &rest args)
 834   "Clear the communication buffer and insert FORMAT and ARGS into the buffer.
 835 If FORMAT isn't a format string, it and all ARGS will be inserted
 836 without formatting."
 837   (with-current-buffer nntp-server-buffer
 838     (erase-buffer)
 839     (if (string-match "%" format)
 840         (insert (apply 'format format args))
 841       (apply 'insert format args))
 842     t))
 843
 844 (defsubst nnheader-replace-chars-in-string (string from to)
 845   (mm-subst-char-in-string from to string))
 846
 847 (defun nnheader-replace-duplicate-chars-in-string (string from to)
 848   "Replace characters in STRING from FROM to TO."
 849   (let ((string (substring string 0))   ;Copy string.
 850         (len (length string))
 851         (idx 0) prev i)
 852     ;; Replace all occurrences of FROM with TO.
 853     (while (< idx len)
 854       (setq i (aref string idx))
 855       (when (and (eq prev from) (= i from))
 856         (aset string (1- idx) to)
 857         (aset string idx to))
 858       (setq prev i)
 859       (setq idx (1+ idx)))
 860     string))
 861
 862 (defun nnheader-file-to-group (file &optional top)
 863   "Return a group name based on FILE and TOP."
 864   (nnheader-replace-chars-in-string
 865    (if (not top)
 866        file
 867      (condition-case ()
 868          (substring (expand-file-name file)
 869                     (length
 870                      (expand-file-name
 871                       (file-name-as-directory top))))
 872        (error "")))
 873    nnheader-directory-separator-character ?.))
 874
 875 (defun nnheader-message (level &rest args)
 876   "Message if the Gnus backends are talkative."
 877   (if (or (not (numberp gnus-verbose-backends))
 878           (<= level gnus-verbose-backends))
 879       (if gnus-add-timestamp-to-message
 880           (apply 'gnus-message-with-timestamp args)
 881         (apply 'message args))
 882     (apply 'format args)))
 883
 884 (defun nnheader-be-verbose (level)
 885   "Return whether the backends should be verbose on LEVEL."
 886   (or (not (numberp gnus-verbose-backends))
 887       (<= level gnus-verbose-backends)))
 888
 889 (defvar nnheader-pathname-coding-system 'iso-8859-1
 890   "*Coding system for file name.")
 891
 892 (defun nnheader-group-pathname (group dir &optional file)
 893   "Make file name for GROUP."
 894   (concat
 895    (let ((dir (file-name-as-directory (expand-file-name dir))))
 896      ;; If this directory exists, we use it directly.
 897      (file-name-as-directory
 898       (if (file-directory-p (concat dir group))
 899           (expand-file-name group dir)
 900         ;; If not, we translate dots into slashes.
 901         (expand-file-name (mm-encode-coding-string
 902                            (nnheader-replace-chars-in-string group ?. ?/)
 903                            nnheader-pathname-coding-system)
 904                           dir))))
 905    (cond ((null file) "")
 906          ((numberp file) (int-to-string file))
 907          (t file))))
 908
 909 (defun nnheader-concat (dir &rest files)
 910   "Concat DIR as directory to FILES."
 911   (apply 'concat (file-name-as-directory dir) files))
 912
 913 (defun nnheader-ms-strip-cr ()
 914   "Strip ^M from the end of all lines."
 915   (save-excursion
 916     (nnheader-remove-cr-followed-by-lf)))
 917
 918 (defun nnheader-file-size (file)
 919   "Return the file size of FILE or 0."
 920   (or (nth 7 (file-attributes file)) 0))
 921
 922 (defun nnheader-find-etc-directory (package &optional file first)
 923   "Go through `load-path' and find the \"../etc/PACKAGE\" directory.
 924 This function will look in the parent directory of each `load-path'
 925 entry, and look for the \"etc\" directory there.
 926 If FILE, find the \".../etc/PACKAGE\" file instead.
 927 If FIRST is non-nil, return the directory or the file found at the
 928 first.  Otherwise, find the newest one, though it may take a time."
 929   (let ((path load-path)
 930         dir results)
 931     ;; We try to find the dir by looking at the load path,
 932     ;; stripping away the last component and adding "etc/".
 933     (while path
 934       (if (and (car path)
 935                (file-exists-p
 936                 (setq dir (concat
 937                            (file-name-directory
 938                             (directory-file-name (car path)))
 939                            "etc/" package
 940                            (if file "" "/"))))
 941                (or file (file-directory-p dir)))
 942           (progn
 943             (or (member dir results)
 944                 (push dir results))
 945             (setq path (if first nil (cdr path))))
 946         (setq path (cdr path))))
 947     (if (or first (not (cdr results)))
 948         (car results)
 949       (car (sort results 'file-newer-than-file-p)))))
 950
 951 (defvar ange-ftp-path-format)
 952 (defvar efs-path-regexp)
 953 (defun nnheader-re-read-dir (path)
 954   "Re-read directory PATH if PATH is on a remote system."
 955   (if (and (fboundp 'efs-re-read-dir) (boundp 'efs-path-regexp))
 956       (when (string-match efs-path-regexp path)
 957         (efs-re-read-dir path))
 958     (when (and (fboundp 'ange-ftp-re-read-dir) (boundp 'ange-ftp-path-format))
 959       (when (string-match (car ange-ftp-path-format) path)
 960         (ange-ftp-re-read-dir path)))))
 961
 962 (defvar nnheader-file-coding-system 'raw-text
 963   "Coding system used in file backends of Gnus.")
 964
 965 (defun nnheader-insert-file-contents (filename &optional visit beg end replace)
 966   "Like `insert-file-contents', q.v., but only reads in the file.
 967 A buffer may be modified in several ways after reading into the buffer due
 968 to advanced Emacs features, such as file-name-handlers, format decoding,
 969 find-file-hooks, etc.
 970   This function ensures that none of these modifications will take place."
 971   (let ((coding-system-for-read nnheader-file-coding-system))
 972     (mm-insert-file-contents filename visit beg end replace)))
 973
 974 (defun nnheader-insert-nov-file (file first)
 975   (let ((size (nth 7 (file-attributes file)))
 976         (cutoff (* 32 1024)))
 977     (when size
 978       (if (< size cutoff)
 979           ;; If the file is small, we just load it.
 980           (nnheader-insert-file-contents file)
 981         ;; We start on the assumption that FIRST is pretty recent.  If
 982         ;; not, we just insert the rest of the file as well.
 983         (let (current)
 984           (nnheader-insert-file-contents file nil (- size cutoff) size)
 985           (goto-char (point-min))
 986           (delete-region (point) (or (search-forward "\n" nil 'move) (point)))
 987           (setq current (ignore-errors (read (current-buffer))))
 988           (if (and (numberp current)
 989                    (< current first))
 990               t
 991             (delete-region (point-min) (point-max))
 992             (nnheader-insert-file-contents file)))))))
 993
 994 (defun nnheader-find-file-noselect (&rest args)
 995   "Open a file with some variables bound.
 996 See `find-file-noselect' for the arguments."
 997   (letf* ((format-alist nil)
 998           (auto-mode-alist (mm-auto-mode-alist))
 999           ((default-value 'major-mode) 'fundamental-mode)
1000           (enable-local-variables nil)
1001           (after-insert-file-functions nil)
1002           (enable-local-eval nil)
1003           (coding-system-for-read nnheader-file-coding-system)
1004           (version-control 'never)
1005           (ffh (if (boundp 'find-file-hook)
1006                    'find-file-hook
1007                  'find-file-hooks))
1008           (val (symbol-value ffh)))
1009     (set ffh nil)
1010     (unwind-protect
1011         (apply 'find-file-noselect args)
1012       (set ffh val))))
1013
1014 (defun nnheader-directory-regular-files (dir)
1015   "Return a list of all regular files in DIR."
1016   (let ((files (directory-files dir t))
1017         out)
1018     (while files
1019       (when (file-regular-p (car files))
1020         (push (car files) out))
1021       (pop files))
1022     (nreverse out)))
1023
1024 (defun nnheader-directory-files (&rest args)
1025   "Same as `directory-files', but prune \".\" and \"..\"."
1026   (let ((files (apply 'directory-files args))
1027         out)
1028     (while files
1029       (unless (member (file-name-nondirectory (car files)) '("." ".."))
1030         (push (car files) out))
1031       (pop files))
1032     (nreverse out)))
1033
1034 (defmacro nnheader-skeleton-replace (from &optional to regexp)
1035   `(let ((new (generate-new-buffer " *nnheader replace*"))
1036          (cur (current-buffer))
1037          (start (point-min)))
1038      (set-buffer cur)
1039      (goto-char (point-min))
1040      (while (,(if regexp 're-search-forward 'search-forward)
1041              ,from nil t)
1042        (insert-buffer-substring
1043         cur start (prog1 (match-beginning 0) (set-buffer new)))
1044        (goto-char (point-max))
1045        ,(when to `(insert ,to))
1046        (set-buffer cur)
1047        (setq start (point)))
1048      (insert-buffer-substring
1049       cur start (prog1 (point-max) (set-buffer new)))
1050      (copy-to-buffer cur (point-min) (point-max))
1051      (kill-buffer (current-buffer))
1052      (set-buffer cur)))
1053
1054 (defun nnheader-replace-string (from to)
1055   "Do a fast replacement of FROM to TO from point to `point-max'."
1056   (nnheader-skeleton-replace from to))
1057
1058 (defun nnheader-replace-regexp (from to)
1059   "Do a fast regexp replacement of FROM to TO from point to `point-max'."
1060   (nnheader-skeleton-replace from to t))
1061
1062 (defun nnheader-strip-cr ()
1063   "Strip all \r's from the current buffer."
1064   (nnheader-skeleton-replace "\r"))
1065
1066 (defalias 'nnheader-cancel-timer 'cancel-timer)
1067 (defalias 'nnheader-cancel-function-timers 'cancel-function-timers)
1068
1069 ;; When changing this function, consider changing `pop3-accept-process-output'
1070 ;; as well.
1071 (defun nnheader-accept-process-output (process)
1072   (accept-process-output
1073    process
1074    (truncate nnheader-read-timeout)
1075    (truncate (* (- nnheader-read-timeout
1076                    (truncate nnheader-read-timeout))
1077                 1000))))
1078
1079 (defun nnheader-update-marks-actions (backend-marks actions)
1080   (dolist (action actions)
1081     (let ((range (nth 0 action))
1082           (what  (nth 1 action))
1083           (marks (nth 2 action)))
1084       (dolist (mark marks)
1085         (setq backend-marks
1086               (gnus-update-alist-soft
1087                mark
1088                (cond
1089                 ((eq what 'add)
1090                  (gnus-range-add (cdr (assoc mark backend-marks)) range))
1091                 ((eq what 'del)
1092                  (gnus-remove-from-range
1093                   (cdr (assoc mark backend-marks)) range))
1094                 ((eq what 'set)
1095                  range))
1096                backend-marks)))))
1097   backend-marks)
1098
1099 (defmacro nnheader-insert-buffer-substring (buffer &optional start end)
1100   "Copy string from unibyte buffer to multibyte current buffer."
1101   (if (featurep 'xemacs)
1102       `(insert-buffer-substring ,buffer ,start ,end)
1103     `(if enable-multibyte-characters
1104          (insert (with-current-buffer ,buffer
1105                    (mm-string-to-multibyte
1106                     ,(if (or start end)
1107                          `(buffer-substring (or ,start (point-min))
1108                                             (or ,end (point-max)))
1109                        '(buffer-string)))))
1110        (insert-buffer-substring ,buffer ,start ,end))))
1111
1112 (defvar nnheader-last-message-time '(0 0))
1113 (defun nnheader-message-maybe (&rest args)
1114   (let ((now (current-time)))
1115     (when (> (float-time (time-subtract now nnheader-last-message-time)) 1)
1116       (setq nnheader-last-message-time now)
1117       (apply 'nnheader-message args))))
1118
1119 (when (featurep 'xemacs)
1120   (require 'nnheaderxm))
1121
1122 (run-hooks 'nnheader-load-hook)
1123
1124 (provide 'nnheader)
1125
1126 ;;; nnheader.el ends here