1
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mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-24 10:38:38 +00:00
emacs/lisp/nnheader.el
Karl Heuer 50ef36f521 (nnheader-insert-head): Handle the case that the
length of header is changed because of code conversion.
1997-02-20 05:38:08 +00:00

621 lines
19 KiB
EmacsLisp

;;; nnheader.el --- header access macros for Gnus and its backends
;; Copyright (C) 1987,88,89,90,93,94,95,96 Free Software Foundation, Inc.
;; Author: Masanobu UMEDA <umerin@flab.flab.fujitsu.junet>
;; Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
;; Keywords: news
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;; Commentary:
;; These macros may look very much like the ones in GNUS 4.1. They
;; are, in a way, but you should note that the indices they use have
;; been changed from the internal GNUS format to the NOV format. The
;; makes it possible to read headers from XOVER much faster.
;;
;; The format of a header is now:
;; [number subject from date id references chars lines xref]
;;
;; (That last entry is defined as "misc" in the NOV format, but Gnus
;; uses it for xrefs.)
;;; Code:
(require 'mail-utils)
(eval-when-compile (require 'cl))
(defvar nnheader-max-head-length 4096
"*Max length of the head of articles.")
(defvar nnheader-file-name-translation-alist nil
"*Alist that says how to translate characters in file names.
For instance, if \":\" is illegal as a file character in file names
on your system, you could say something like:
\(setq nnheader-file-name-translation-alist '((?: . ?_)))")
;;; Header access macros.
(defmacro mail-header-number (header)
"Return article number in HEADER."
`(aref ,header 0))
(defmacro mail-header-set-number (header number)
"Set article number of HEADER to NUMBER."
`(aset ,header 0 ,number))
(defmacro mail-header-subject (header)
"Return subject string in HEADER."
`(aref ,header 1))
(defmacro mail-header-set-subject (header subject)
"Set article subject of HEADER to SUBJECT."
`(aset ,header 1 ,subject))
(defmacro mail-header-from (header)
"Return author string in HEADER."
`(aref ,header 2))
(defmacro mail-header-set-from (header from)
"Set article author of HEADER to FROM."
`(aset ,header 2 ,from))
(defmacro mail-header-date (header)
"Return date in HEADER."
`(aref ,header 3))
(defmacro mail-header-set-date (header date)
"Set article date of HEADER to DATE."
`(aset ,header 3 ,date))
(defalias 'mail-header-message-id 'mail-header-id)
(defmacro mail-header-id (header)
"Return Id in HEADER."
`(aref ,header 4))
(defalias 'mail-header-set-message-id 'mail-header-set-id)
(defmacro mail-header-set-id (header id)
"Set article Id of HEADER to ID."
`(aset ,header 4 ,id))
(defmacro mail-header-references (header)
"Return references in HEADER."
`(aref ,header 5))
(defmacro mail-header-set-references (header ref)
"Set article references of HEADER to REF."
`(aset ,header 5 ,ref))
(defmacro mail-header-chars (header)
"Return number of chars of article in HEADER."
`(aref ,header 6))
(defmacro mail-header-set-chars (header chars)
"Set number of chars in article of HEADER to CHARS."
`(aset ,header 6 ,chars))
(defmacro mail-header-lines (header)
"Return lines in HEADER."
`(aref ,header 7))
(defmacro mail-header-set-lines (header lines)
"Set article lines of HEADER to LINES."
`(aset ,header 7 ,lines))
(defmacro mail-header-xref (header)
"Return xref string in HEADER."
`(aref ,header 8))
(defmacro mail-header-set-xref (header xref)
"Set article xref of HEADER to xref."
`(aset ,header 8 ,xref))
(defun make-mail-header (&optional init)
"Create a new mail header structure initialized with INIT."
(make-vector 9 init))
;; Parsing headers and NOV lines.
(defsubst nnheader-header-value ()
(buffer-substring (match-end 0) (gnus-point-at-eol)))
(defvar nnheader-newsgroup-none-id 1)
(defun nnheader-parse-head (&optional naked)
(let ((case-fold-search t)
(cur (current-buffer))
(buffer-read-only nil)
end ref in-reply-to lines p)
(goto-char (point-min))
(when naked
(insert "\n"))
;; Search to the beginning of the next header. Error messages
;; do not begin with 2 or 3.
(prog1
(when (or naked (re-search-forward "^[23][0-9]+ " nil t))
;; This implementation of this function, with nine
;; search-forwards instead of the one re-search-forward and
;; a case (which basically was the old function) is actually
;; about twice as fast, even though it looks messier. You
;; can't have everything, I guess. Speed and elegance
;; doesn't always go hand in hand.
(vector
;; Number.
(if naked
(progn
(setq p (point-min))
0)
(prog1
(read cur)
(end-of-line)
(setq p (point))
(narrow-to-region (point)
(or (and (search-forward "\n.\n" nil t)
(- (point) 2))
(point)))))
;; Subject.
(progn
(goto-char p)
(if (search-forward "\nsubject: " nil t)
(nnheader-header-value) "(none)"))
;; From.
(progn
(goto-char p)
(if (search-forward "\nfrom: " nil t)
(nnheader-header-value) "(nobody)"))
;; Date.
(progn
(goto-char p)
(if (search-forward "\ndate: " nil t)
(nnheader-header-value) ""))
;; Message-ID.
(progn
(goto-char p)
(if (search-forward "\nmessage-id: " nil t)
(nnheader-header-value)
;; If there was no message-id, we just fake one to make
;; subsequent routines simpler.
(concat "none+"
(int-to-string
(incf nnheader-newsgroup-none-id)))))
;; References.
(progn
(goto-char p)
(if (search-forward "\nreferences: " nil t)
(nnheader-header-value)
;; Get the references from the in-reply-to header if there
;; were no references and the in-reply-to header looks
;; promising.
(if (and (search-forward "\nin-reply-to: " nil t)
(setq in-reply-to (nnheader-header-value))
(string-match "<[^>]+>" in-reply-to))
(substring in-reply-to (match-beginning 0)
(match-end 0))
"")))
;; Chars.
0
;; Lines.
(progn
(goto-char p)
(if (search-forward "\nlines: " nil t)
(if (numberp (setq lines (read cur)))
lines 0)
0))
;; Xref.
(progn
(goto-char p)
(and (search-forward "\nxref: " nil t)
(nnheader-header-value)))))
(when naked
(goto-char (point-min))
(delete-char 1)))))
(defun nnheader-insert-nov (header)
(princ (mail-header-number header) (current-buffer))
(insert
"\t"
(or (mail-header-subject header) "(none)") "\t"
(or (mail-header-from header) "(nobody)") "\t"
(or (mail-header-date header) "") "\t"
(or (mail-header-id header)
(nnmail-message-id)) "\t"
(or (mail-header-references header) "") "\t")
(princ (or (mail-header-chars header) 0) (current-buffer))
(insert "\t")
(princ (or (mail-header-lines header) 0) (current-buffer))
(insert "\t")
(when (mail-header-xref header)
(insert "Xref: " (mail-header-xref header) "\t"))
(insert "\n"))
(defun nnheader-insert-article-line (article)
(goto-char (point-min))
(insert "220 ")
(princ article (current-buffer))
(insert " Article retrieved.\n")
(search-forward "\n\n" nil 'move)
(delete-region (point) (point-max))
(forward-char -1)
(insert "."))
;; Various cruft the backends and Gnus need to communicate.
(defvar nntp-server-buffer nil)
(defvar gnus-verbose-backends 7
"*A number that says how talkative the Gnus backends should be.")
(defvar gnus-nov-is-evil nil
"If non-nil, Gnus backends will never output headers in the NOV format.")
(defvar news-reply-yank-from nil)
(defvar news-reply-yank-message-id nil)
(defvar nnheader-callback-function nil)
(defun nnheader-init-server-buffer ()
"Initialize the Gnus-backend communication buffer."
(save-excursion
(setq nntp-server-buffer (get-buffer-create " *nntpd*"))
(set-buffer nntp-server-buffer)
(buffer-disable-undo (current-buffer))
(erase-buffer)
(kill-all-local-variables)
(setq case-fold-search t) ;Should ignore case.
t))
;;; Various functions the backends use.
(defun nnheader-file-error (file)
"Return a string that says what is wrong with FILE."
(format
(cond
((not (file-exists-p file))
"%s does not exist")
((file-directory-p file)
"%s is a directory")
((not (file-readable-p file))
"%s is not readable"))
file))
(defun nnheader-insert-head (file)
"Insert the head of the article."
(when (file-exists-p file)
(if (eq nnheader-max-head-length t)
;; Just read the entire file.
(nnheader-insert-file-contents-literally file)
;; Read 1K blocks until we find a separator.
(let ((beg 0)
format-alist
(chop 1024))
(while (and (not (zerop (nth 1 (insert-file-contents
file nil beg (incf beg chop)))))
(prog1 (not (search-forward "\n\n" nil t))
(goto-char (point-max)))
(or (null nnheader-max-head-length)
(< beg nnheader-max-head-length))))))
t))
(defun nnheader-article-p ()
"Say whether the current buffer looks like an article."
(goto-char (point-min))
(if (not (search-forward "\n\n" nil t))
nil
(narrow-to-region (point-min) (1- (point)))
(goto-char (point-min))
(while (looking-at "[A-Z][^ \t]+:.*\n\\([ \t].*\n\\)*\\|From .*\n")
(goto-char (match-end 0)))
(prog1
(eobp)
(widen))))
(defun nnheader-insert-references (references message-id)
"Insert a References header based on REFERENCES and MESSAGE-ID."
(if (and (not references) (not message-id))
() ; This is illegal, but not all articles have Message-IDs.
(mail-position-on-field "References")
(let ((begin (save-excursion (beginning-of-line) (point)))
(fill-column 78)
(fill-prefix "\t"))
(if references (insert references))
(if (and references message-id) (insert " "))
(if message-id (insert message-id))
;; Fold long References lines to conform to RFC1036 (sort of).
;; The region must end with a newline to fill the region
;; without inserting extra newline.
(fill-region-as-paragraph begin (1+ (point))))))
(defun nnheader-replace-header (header new-value)
"Remove HEADER and insert the NEW-VALUE."
(save-excursion
(save-restriction
(nnheader-narrow-to-headers)
(prog1
(message-remove-header header)
(goto-char (point-max))
(insert header ": " new-value "\n")))))
(defun nnheader-narrow-to-headers ()
"Narrow to the head of an article."
(widen)
(narrow-to-region
(goto-char (point-min))
(if (search-forward "\n\n" nil t)
(1- (point))
(point-max)))
(goto-char (point-min)))
(defun nnheader-set-temp-buffer (name)
"Set-buffer to an empty (possibly new) buffer called NAME with undo disabled."
(set-buffer (get-buffer-create name))
(buffer-disable-undo (current-buffer))
(erase-buffer)
(current-buffer))
(defmacro nnheader-temp-write (file &rest forms)
"Create a new buffer, evaluate FORM there, and write the buffer to FILE."
`(save-excursion
(let ((nnheader-temp-file ,file)
(nnheader-temp-cur-buffer
(nnheader-set-temp-buffer
(generate-new-buffer-name " *nnheader temp*"))))
(when (and nnheader-temp-file
(not (file-directory-p (file-name-directory
nnheader-temp-file))))
(make-directory (file-name-directory nnheader-temp-file) t))
(unwind-protect
(prog1
(progn
,@forms)
(when nnheader-temp-file
(set-buffer nnheader-temp-cur-buffer)
(write-region (point-min) (point-max)
nnheader-temp-file nil 'nomesg)))
(when (buffer-name nnheader-temp-cur-buffer)
(kill-buffer nnheader-temp-cur-buffer))))))
(put 'nnheader-temp-write 'lisp-indent-function 1)
(put 'nnheader-temp-write 'lisp-indent-hook 1)
(put 'nnheader-temp-write 'edebug-form-spec '(form body))
(defvar jka-compr-compression-info-list)
(defvar nnheader-numerical-files
(if (boundp 'jka-compr-compression-info-list)
(concat "\\([0-9]+\\)\\("
(mapconcat (lambda (i) (aref i 0))
jka-compr-compression-info-list "\\|")
"\\)?")
"[0-9]+$")
"Regexp that match numerical files.")
(defvar nnheader-numerical-short-files (concat "^" nnheader-numerical-files)
"Regexp that matches numerical file names.")
(defvar nnheader-numerical-full-files (concat "/" nnheader-numerical-files)
"Regexp that matches numerical full file paths.")
(defsubst nnheader-file-to-number (file)
"Take a file name and return the article number."
(if (not (boundp 'jka-compr-compression-info-list))
(string-to-int file)
(string-match nnheader-numerical-short-files file)
(string-to-int (match-string 0 file))))
(defun nnheader-directory-files-safe (&rest args)
;; It has been reported numerous times that `directory-files'
;; fails with an alarming frequency on NFS mounted file systems.
;; This function executes that function twice and returns
;; the longest result.
(let ((first (apply 'directory-files args))
(second (apply 'directory-files args)))
(if (> (length first) (length second))
first
second)))
(defun nnheader-directory-articles (dir)
"Return a list of all article files in a directory."
(mapcar 'nnheader-file-to-number
(nnheader-directory-files-safe
dir nil nnheader-numerical-short-files t)))
(defun nnheader-article-to-file-alist (dir)
"Return an alist of article/file pairs in DIR."
(mapcar (lambda (file) (cons (nnheader-file-to-number file) file))
(nnheader-directory-files-safe
dir nil nnheader-numerical-short-files t)))
(defun nnheader-fold-continuation-lines ()
"Fold continuation lines in the current buffer."
(goto-char (point-min))
(while (re-search-forward "\\(\r?\n[ \t]+\\)+" nil t)
(replace-match " " t t)))
(defun nnheader-translate-file-chars (file)
(if (null nnheader-file-name-translation-alist)
;; No translation is necessary.
file
;; We translate -- but only the file name. We leave the directory
;; alone.
(let* ((i 0)
trans leaf path len)
(if (string-match "/[^/]+\\'" file)
;; This is needed on NT's and stuff.
(setq leaf (substring file (1+ (match-beginning 0)))
path (substring file 0 (1+ (match-beginning 0))))
;; Fall back on this.
(setq leaf (file-name-nondirectory file)
path (file-name-directory file)))
(setq len (length leaf))
(while (< i len)
(when (setq trans (cdr (assq (aref leaf i)
nnheader-file-name-translation-alist)))
(aset leaf i trans))
(incf i))
(concat path leaf))))
(defun nnheader-report (backend &rest args)
"Report an error from the BACKEND.
The first string in ARGS can be a format string."
(set (intern (format "%s-status-string" backend))
(if (< (length args) 2)
(car args)
(apply 'format args)))
nil)
(defun nnheader-get-report (backend)
(message "%s" (symbol-value (intern (format "%s-status-string" backend)))))
(defun nnheader-insert (format &rest args)
"Clear the communicaton buffer and insert FORMAT and ARGS into the buffer.
If FORMAT isn't a format string, it and all ARGS will be inserted
without formatting."
(save-excursion
(set-buffer nntp-server-buffer)
(erase-buffer)
(if (string-match "%" format)
(insert (apply 'format format args))
(apply 'insert format args))
t))
(defun nnheader-mail-file-mbox-p (file)
"Say whether FILE looks like an Unix mbox file."
(when (and (file-exists-p file)
(file-readable-p file)
(file-regular-p file))
(save-excursion
(nnheader-set-temp-buffer " *mail-file-mbox-p*")
(nnheader-insert-file-contents-literally file)
(goto-char (point-min))
(prog1
(looking-at message-unix-mail-delimiter)
(kill-buffer (current-buffer))))))
(defun nnheader-replace-chars-in-string (string from to)
"Replace characters in STRING from FROM to TO."
(let ((string (substring string 0)) ;Copy string.
(len (length string))
(idx 0))
;; Replace all occurrences of FROM with TO.
(while (< idx len)
(if (= (aref string idx) from)
(aset string idx to))
(setq idx (1+ idx)))
string))
(defun nnheader-file-to-group (file &optional top)
"Return a group name based on FILE and TOP."
(nnheader-replace-chars-in-string
(if (not top)
file
(condition-case ()
(substring (expand-file-name file)
(length
(expand-file-name
(file-name-as-directory top))))
(error "")))
?/ ?.))
(defun nnheader-message (level &rest args)
"Message if the Gnus backends are talkative."
(if (or (not (numberp gnus-verbose-backends))
(<= level gnus-verbose-backends))
(apply 'message args)
(apply 'format args)))
(defun nnheader-be-verbose (level)
"Return whether the backends should be verbose on LEVEL."
(or (not (numberp gnus-verbose-backends))
(<= level gnus-verbose-backends)))
(defun nnheader-group-pathname (group dir &optional file)
"Make pathname for GROUP."
(concat
(let ((dir (file-name-as-directory (expand-file-name dir))))
;; If this directory exists, we use it directly.
(if (file-directory-p (concat dir group))
(concat dir group "/")
;; If not, we translate dots into slashes.
(concat dir (nnheader-replace-chars-in-string group ?. ?/) "/")))
(cond ((null file) "")
((numberp file) (int-to-string file))
(t file))))
(defun nnheader-functionp (form)
"Return non-nil if FORM is funcallable."
(or (and (symbolp form) (fboundp form))
(and (listp form) (eq (car form) 'lambda))))
(defun nnheader-concat (dir file)
"Concat DIR as directory to FILE."
(concat (file-name-as-directory dir) file))
(defun nnheader-ms-strip-cr ()
"Strip ^M from the end of all lines."
(save-excursion
(goto-char (point-min))
(while (re-search-forward "\r$" nil t)
(delete-backward-char 1))))
(defun nnheader-file-size (file)
"Return the file size of FILE or 0."
(or (nth 7 (file-attributes file)) 0))
(defun nnheader-find-etc-directory (package)
"Go through the path and find the \".../etc/PACKAGE\" directory."
(let ((path load-path)
dir result)
;; We try to find the dir by looking at the load path,
;; stripping away the last component and adding "etc/".
(while path
(if (and (car path)
(file-exists-p
(setq dir (concat
(file-name-directory
(directory-file-name (car path)))
"etc/" package "/")))
(file-directory-p dir))
(setq result dir
path nil)
(setq path (cdr path))))
result))
(defvar ange-ftp-path-format)
(defvar efs-path-regexp)
(defun nnheader-re-read-dir (path)
"Re-read directory PATH if PATH is on a remote system."
(if (boundp 'ange-ftp-path-format)
(when (string-match (car ange-ftp-path-format) path)
(ange-ftp-re-read-dir path))
(if (boundp 'efs-path-regexp)
(when (string-match efs-path-regexp path)
(efs-re-read-dir path)))))
(fset 'nnheader-run-at-time 'run-at-time)
(fset 'nnheader-cancel-timer 'cancel-timer)
(fset 'nnheader-find-file-noselect 'find-file-noselect)
(fset 'nnheader-insert-file-contents-literally
'insert-file-contents-literally)
(when (string-match "XEmacs\\|Lucid" emacs-version)
(require 'nnheaderxm))
(run-hooks 'nnheader-load-hook)
(provide 'nnheader)
;;; nnheader.el ends here