;;; tar-mode.el --- simple editing of tar files from GNU emacs
;; Copyright (C) 1990, 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-;; 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+;; 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
;; Author: Jamie Zawinski <jwz@lucid.com>
;; Maintainer: FSF
(defvar tar-data-buffer nil "Buffer that holds the actual raw tar bytes.")
(make-variable-buffer-local 'tar-data-buffer)
+(defvar tar-data-swapped nil
+ "If non-nil, `tar-data-buffer' indeed holds raw tar bytes.")
+(make-variable-buffer-local 'tar-data-swapped)
+
(defun tar-data-swapped-p ()
"Return non-nil if the tar-data is in `tar-data-buffer'."
- ;; We need to be careful to keep track of which buffer holds the tar-data,
- ;; since we swap them back and forth. Since the user may make the summary
- ;; buffer unibyte, we can't rely on the multibyteness of the buffers.
- ;; We could try and recognize the tar-format signature, but instead
- ;; I decided to go for something simpler.
(and (buffer-live-p tar-data-buffer)
- (> (buffer-size tar-data-buffer) (buffer-size))))
-
+ ;; Sanity check to try and make sure tar-data-swapped tracks the swap
+ ;; state correctly: the raw data is expected to be always larger than
+ ;; the summary.
+ (progn
+ (assert (eq tar-data-swapped
+ (> (buffer-size tar-data-buffer) (buffer-size))))
+ tar-data-swapped)))
+
+(defun tar-swap-data ()
+ "Swap buffer contents between current buffer and `tar-data-buffer'.
+Preserve the modified states of the buffers and set `buffer-swapped-with'."
+ (let ((data-buffer-modified-p (buffer-modified-p tar-data-buffer))
+ (current-buffer-modified-p (buffer-modified-p)))
+ (buffer-swap-text tar-data-buffer)
+ (setq tar-data-swapped (not tar-data-swapped))
+ (restore-buffer-modified-p data-buffer-modified-p)
+ (with-current-buffer tar-data-buffer
+ (restore-buffer-modified-p current-buffer-modified-p))))
\f
;;; down to business.
"Round S up to the next multiple of 512."
(ash (ash (+ s 511) -9) 9))
-(defun tar-header-block-tokenize (pos)
+(defun tar-header-block-tokenize (pos coding)
"Return a `tar-header' structure.
This is a list of name, mode, uid, gid, size,
write-date, checksum, link-type, and link-name."
(gname-end (1- tar-dmaj-offset))
(link-p (aref string tar-linkp-offset))
(magic-str (substring string tar-magic-offset
- (1- tar-uname-offset)))
- (uname-valid-p (car (member magic-str '("ustar " "ustar\0\0"))))
+ ;; The magic string is actually 6bytes
+ ;; of magic string plus 2bytes of version
+ ;; which we here ignore.
+ (- tar-uname-offset 2)))
+ ;; The magic string is "ustar\0" for POSIX format, and
+ ;; "ustar " for GNU Tar's format.
+ (uname-valid-p (car (member magic-str '("ustar " "ustar\0"))))
name linkname
(nulsexp "[^\000]*\000"))
(when (string-match nulsexp string tar-name-offset)
nil
(- link-p ?0)))
(setq linkname (substring string tar-link-offset link-end))
- (when (and (equal uname-valid-p "ustar\0\0")
+ (when (and (equal uname-valid-p "ustar\0")
(string-match nulsexp string tar-prefix-offset)
(> (match-end 0) (1+ tar-prefix-offset)))
(setq name (concat (substring string tar-prefix-offset
"/" name)))
(if default-enable-multibyte-characters
(setq name
- (decode-coding-string name tar-file-name-coding-system)
+ (decode-coding-string name coding)
linkname
- (decode-coding-string linkname
- tar-file-name-coding-system)))
+ (decode-coding-string linkname coding)))
(if (and (null link-p) (string-match "/\\'" name))
(setq link-p 5)) ; directory
(if (and (equal name "././@LongLink")
- (equal magic-str "ustar ")) ;OLDGNU_MAGIC.
+ (equal magic-str "ustar ")) ;OLDGNU_MAGIC.
;; This is a GNU Tar long-file-name header.
(let* ((size (tar-parse-octal-integer
string tar-size-offset tar-time-offset))
;; -1 so as to strip the terminating 0 byte.
(name (buffer-substring pos (+ pos size -1)))
(descriptor (tar-header-block-tokenize
- (+ pos (tar-roundup-512 size)))))
+ (+ pos (tar-roundup-512 size))
+ coding)))
(cond
((eq link-p (- ?L ?0)) ;GNUTYPE_LONGNAME.
(setf (tar-header-name descriptor) name))
(let* ((modified (buffer-modified-p))
(result '())
(pos (point-min))
+ (coding tar-file-name-coding-system)
(progress-reporter
(with-current-buffer tar-data-buffer
(make-progress-reporter "Parsing tar file..."
descriptor)
(with-current-buffer tar-data-buffer
(while (and (<= (+ pos 512) (point-max))
- (setq descriptor (tar-header-block-tokenize pos)))
+ (setq descriptor (tar-header-block-tokenize pos coding)))
(let ((size (tar-header-size descriptor)))
(if (< size 0)
(error "%s has size %s - corrupted"
(defun tar-change-major-mode-hook ()
;; Bring the actual Tar data back into the main buffer.
- (when (tar-data-swapped-p) (buffer-swap-text tar-data-buffer))
+ (when (tar-data-swapped-p) (tar-swap-data))
;; Throw away the summary.
(when (buffer-live-p tar-data-buffer) (kill-buffer tar-data-buffer)))
;; buffer for the summary.
(assert (not (tar-data-swapped-p)))
(set (make-local-variable 'revert-buffer-function) 'tar-mode-revert)
+ ;; We started using write-contents-functions, but this hook is not
+ ;; used during auto-save, so we now use
+ ;; write-region-annotate-functions which hooks at a lower-level.
(add-hook 'write-region-annotate-functions 'tar-write-region-annotate nil t)
(add-hook 'kill-buffer-hook 'tar-mode-kill-buffer-hook nil t)
(add-hook 'change-major-mode-hook 'tar-change-major-mode-hook nil t)
(generate-new-buffer (format " *tar-data %s*"
(file-name-nondirectory
(or buffer-file-name (buffer-name))))))
- (buffer-swap-text tar-data-buffer)
+ (tar-swap-data)
(tar-summarize-buffer)
(tar-next-line 0))
(defun tar-mode-revert (&optional no-auto-save no-confirm)
(unwind-protect
(let ((revert-buffer-function nil))
- (if (tar-data-swapped-p) (buffer-swap-text tar-data-buffer))
+ (if (tar-data-swapped-p) (tar-swap-data))
;; FIXME: If we ask for confirmation, the user will be temporarily
;; looking at the raw data.
(revert-buffer no-auto-save no-confirm 'preserve-modes)
- ;; The new raw data may be smaller than the old summary, so let's
- ;; make sure tar-data-swapped-p doesn't get confused.
- (if (buffer-live-p tar-data-buffer) (kill-buffer tar-data-buffer))
;; Recompute the summary.
+ (if (buffer-live-p tar-data-buffer) (kill-buffer tar-data-buffer))
(tar-mode))
- (unless (tar-data-swapped-p) (buffer-swap-text tar-data-buffer))))
+ (unless (tar-data-swapped-p) (tar-swap-data))))
(defun tar-next-line (arg)
(string-match "/" encoded-new-name
(- (length encoded-new-name) 99))
(< (match-beginning 0) 155))
- (unless (equal (tar-header-magic descriptor) "ustar\0\0")
- (tar-alter-one-field tar-magic-offset "ustar\0\0"))
+ (unless (equal (tar-header-magic descriptor) "ustar\0")
+ (tar-alter-one-field tar-magic-offset (concat "ustar\0" "00")))
(setq prefix (substring encoded-new-name 0 (match-beginning 0)))
(setq encoded-new-name (substring encoded-new-name (match-end 0))))
;; When called from M-x write-region, we assume the user wants to save
;; (part of) the summary, not the tar data.
(unless (or start (not (tar-data-swapped-p)))
- (tar-clear-modification-flags)
+ (tar-clear-modification-flags)
(set-buffer tar-data-buffer)
nil))
-\f
+
(provide 'tar-mode)
;; arch-tag: 8a585a4a-340e-42c2-89e7-d3b1013a4b78