Commit 58d6a142 authored by Stefan Monnier's avatar Stefan Monnier
Browse files

(tar-header): New field `header-start'.

(tar-header-block-tokenize): Set it when useful.
Drop "GNUtar " magic value, which even GNU Tar doesn't know about.
(tar-header-data-end): New function.
(tar-summarize-buffer): Use it.
(tar-next-line): Fix goal column for long usernames.
(tar-expunge-internal): Use header-start.
(tar-rename-entry): Handle ustar-style long names.
(tar-alter-one-field): Add optional `descriptor' argument.
(tar-subfile-save-buffer): Use it.
parent 62057df6
2008-05-29 Stefan Monnier <monnier@iro.umontreal.ca>
* tar-mode.el (tar-header): New field `header-start'.
(tar-header-block-tokenize): Set it when useful.
Drop "GNUtar " magic value, which even GNU Tar doesn't know about.
(tar-header-data-end): New function.
(tar-summarize-buffer): Use it.
(tar-next-line): Fix goal column for long usernames.
(tar-expunge-internal): Use header-start.
(tar-rename-entry): Handle ustar-style long names.
(tar-alter-one-field): Add optional `descriptor' argument.
(tar-subfile-save-buffer): Use it.
2008-05-28 Stefan Monnier <monnier@iro.umontreal.ca>
* tar-mode.el (tar-header): New field `header-start'.
(tar-header-block-tokenize): Set header-start for longlink entries.
(tar-expunge-internal): Use header-start to expunge longlink entries.
* files.el (hack-local-variables): Don't signal an error if the local
variable section is not properly terminated.
......
......@@ -93,9 +93,8 @@
;;; Bugs:
;; - Expunge and rename on ././@LongLink files
;; - Rename on ././@LongLink files
;; - Revert confirmation displays the raw data temporarily.
;; - Incorrect goal-column if username is too long.
;;; Code:
......@@ -181,7 +180,10 @@ This information is useful, but it takes screen space away from file names."
make-tar-header (data-start name mode uid gid size date checksum
link-type link-name magic uname gname dmaj dmin)))
data-start name mode uid gid size date checksum link-type link-name
magic uname gname dmaj dmin)
magic uname gname dmaj dmin
;; Start of the header can be nil (meaning it's 512 bytes before data-start)
;; or a marker (in case the header uses LongLink thingies).
header-start)
(defconst tar-name-offset 0)
(defconst tar-mode-offset (+ tar-name-offset 100))
......@@ -223,8 +225,7 @@ write-date, checksum, link-type, and link-name."
(link-p (aref string tar-linkp-offset))
(magic-str (substring string tar-magic-offset
(1- tar-uname-offset)))
(uname-valid-p (member magic-str
'("ustar " "GNUtar " "ustar\0\0")))
(uname-valid-p (car (member magic-str '("ustar " "ustar\0\0"))))
name linkname
(nulsexp "[^\000]*\000"))
(when (string-match nulsexp string tar-name-offset)
......@@ -240,7 +241,7 @@ write-date, checksum, link-type, and link-name."
nil
(- link-p ?0)))
(setq linkname (substring string tar-link-offset link-end))
(when (and uname-valid-p
(when (and (equal uname-valid-p "ustar\0\0")
(string-match nulsexp string tar-prefix-offset)
(> (match-end 0) (1+ tar-prefix-offset)))
(setq name (concat (substring string tar-prefix-offset
......@@ -271,6 +272,8 @@ write-date, checksum, link-type, and link-name."
(setf (tar-header-link-name descriptor) name))
(t
(message "Unrecognized GNU Tar @LongLink format")))
(setf (tar-header-header-start descriptor)
(copy-marker (- pos 512) t))
descriptor)
(make-tar-header
......@@ -291,6 +294,19 @@ write-date, checksum, link-type, and link-name."
(tar-parse-octal-integer string tar-dmin-offset tar-prefix-offset)
))))))
;; Pseudo-field.
(defun tar-header-data-end (descriptor)
(let* ((data-start (tar-header-data-start descriptor))
(link-type (tar-header-link-type descriptor))
(size (tar-header-size descriptor))
(fudge (cond
;; Foo. There's an extra empty block after these.
((memq link-type '(20 55)) 512)
(t 0))))
(+ data-start fudge
(if (and (null link-type) (> size 0))
(tar-roundup-512 size)
0))))
(defun tar-parse-octal-integer (string &optional start end)
(if (null start) (setq start 0))
......@@ -331,7 +347,6 @@ write-date, checksum, link-type, and link-name."
(defun tar-header-block-checksum (string)
"Compute and return a tar-acceptable checksum for this block."
(assert (not (multibyte-string-p string)))
(setq string (string-as-unibyte string))
(let* ((chk-field-start tar-chk-offset)
(chk-field-end (+ chk-field-start 8))
(sum 0)
......@@ -449,27 +464,20 @@ MODE should be an integer which is a file mode value."
(with-current-buffer tar-data-buffer
(while (and (<= (+ pos 512) (point-max))
(setq descriptor (tar-header-block-tokenize pos)))
(setq pos (marker-position (tar-header-data-start descriptor)))
(progress-reporter-update progress-reporter pos)
(if (memq (tar-header-link-type descriptor) '(20 55))
;; Foo. There's an extra empty block after these.
(setq pos (+ pos 512)))
(let ((size (tar-header-size descriptor)))
(if (< size 0)
(error "%s has size %s - corrupted"
(tar-header-name descriptor) size))
;;
;; This is just too slow. Don't really need it anyway....
;;(tar-header-block-check-checksum
;; hblock (tar-header-block-checksum hblock)
;; (tar-header-name descriptor))
(push descriptor result)
(and (null (tar-header-link-type descriptor))
(> size 0)
(setq pos (+ pos (tar-roundup-512 size)))))))
(tar-header-name descriptor) size)))
;;
;; This is just too slow. Don't really need it anyway....
;;(tar-header-block-check-checksum
;; hblock (tar-header-block-checksum hblock)
;; (tar-header-name descriptor))
(push descriptor result)
(setq pos (tar-header-data-end descriptor))
(progress-reporter-update progress-reporter pos)))
(set (make-local-variable 'tar-parse-info) (nreverse result))
;; A tar file should end with a block or two of nulls,
;; but let's not get a fatal error if it doesn't.
......@@ -617,7 +625,7 @@ See also: variables `tar-update-datestamp' and `tar-anal-blocksize'.
(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)
;; Tar data is made of bytes, not chars.
(set-buffer-multibyte nil)
(set-buffer-multibyte nil) ;Hopefully a no-op.
(set (make-local-variable 'tar-data-buffer)
(generate-new-buffer (format " *tar-data %s*"
(file-name-nondirectory
......@@ -674,7 +682,7 @@ appear on disk when you save the tar-file's buffer."
"Move cursor vertically down ARG lines and to the start of the filename."
(interactive "p")
(forward-line arg)
(if (eobp) nil (forward-char (if tar-mode-show-date 54 36))))
(goto-char (or (next-single-property-change (point) 'mouse-face) (point))))
(defun tar-previous-line (arg)
"Move cursor vertically up ARG lines and to the start of the filename."
......@@ -905,14 +913,7 @@ With a prefix argument, un-mark that many files backward."
(defun tar-expunge-internal ()
"Expunge the tar-entry specified by the current line."
(let* ((descriptor (tar-current-descriptor))
;; (line (tar-header-data-start descriptor))
(name (tar-header-name descriptor))
(size (tar-header-size descriptor))
(link-p (tar-header-link-type descriptor))
(start (tar-header-data-start descriptor))
(following-descs (cdr (memq descriptor tar-parse-info))))
(if link-p (setq size 0)) ; size lies for hard-links.
(let ((descriptor (tar-current-descriptor)))
;;
;; delete the current line...
(delete-region (line-beginning-position) (line-beginning-position 2))
......@@ -921,10 +922,10 @@ With a prefix argument, un-mark that many files backward."
(setq tar-parse-info (delq descriptor tar-parse-info))
;;
;; delete the data from inside the file...
(let* ((data-start (- start 512))
(data-end (+ start (tar-roundup-512 size))))
(with-current-buffer tar-data-buffer
(delete-region data-start data-end)))))
(with-current-buffer tar-data-buffer
(delete-region (or (tar-header-header-start descriptor)
(- (tar-header-data-start descriptor) 512))
(tar-header-data-end descriptor)))))
(defun tar-expunge (&optional noconfirm)
......@@ -1019,12 +1020,29 @@ for this to be permanent."
(tar-header-name (tar-current-descriptor)))))
(if (string= "" new-name) (error "zero length name"))
(let ((encoded-new-name (encode-coding-string new-name
tar-file-name-coding-system)))
tar-file-name-coding-system))
(descriptor (tar-current-descriptor))
(prefix nil))
(when (tar-header-header-start descriptor)
;; FIXME: Make it work for ././@LongLink.
(error "Rename with @LongLink format is not implemented"))
(when (and (> (length encoded-new-name) 98)
(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"))
(setq prefix (substring encoded-new-name 0 (match-beginning 0)))
(setq encoded-new-name (substring encoded-new-name (match-end 0))))
(if (> (length encoded-new-name) 98) (error "name too long"))
(setf (tar-header-name (tar-current-descriptor)) new-name)
;; FIXME: Make it work for ././@LongLink.
(setf (tar-header-name descriptor) new-name)
(tar-alter-one-field 0
(substring (concat encoded-new-name (make-string 99 0)) 0 99))))
(substring (concat encoded-new-name (make-string 99 0)) 0 99))
(if prefix
(tar-alter-one-field tar-prefix-offset
(substring (concat prefix (make-string 155 0)) 0 155)))))
(defun tar-chmod-entry (new-mode)
......@@ -1038,41 +1056,43 @@ for this to be permanent."
(concat (substring (format "%6o" new-mode) 0 6) "\000 ")))
(defun tar-alter-one-field (data-position new-data-string)
(let* ((descriptor (tar-current-descriptor)))
;;
;; update the header-line.
(let ((col (current-column)))
(delete-region (line-beginning-position) (line-beginning-position 2))
(insert (tar-header-block-summarize descriptor) "\n")
(forward-line -1) (move-to-column col))
(defun tar-alter-one-field (data-position new-data-string &optional descriptor)
(unless descriptor (setq descriptor (tar-current-descriptor)))
;;
;; update the header-line.
(let ((col (current-column)))
(delete-region (line-beginning-position)
(prog2 (forward-line 1)
(point)
;; Insert the new text after the old, before deleting,
;; to preserve markers such as the window start.
(insert (tar-header-block-summarize descriptor) "\n")))
(forward-line -1) (move-to-column col))
(with-current-buffer tar-data-buffer
(let* ((start (- (tar-header-data-start descriptor) 512)))
(assert (tar-data-swapped-p))
(with-current-buffer tar-data-buffer
(let* ((start (- (tar-header-data-start descriptor) 512)))
;;
;; delete the old field and insert a new one.
(goto-char (+ start data-position))
(delete-region (point) (+ (point) (length new-data-string))) ; <--
(assert (not (or enable-multibyte-characters
(multibyte-string-p new-data-string))))
(insert new-data-string)
;;
;; compute a new checksum and insert it.
(let ((chk (tar-header-block-checksum
(buffer-substring start (+ start 512)))))
(goto-char (+ start tar-chk-offset))
(delete-region (point) (+ (point) 8))
(insert (format "%6o" chk))
(insert 0)
(insert ? )
(setf (tar-header-checksum descriptor) chk)
;;
;; ok, make sure we didn't botch it.
(tar-header-block-check-checksum
(buffer-substring start (+ start 512))
chk (tar-header-name descriptor))
)))))
(buffer-substring start (+ start 512)))))
(goto-char (+ start tar-chk-offset))
(delete-region (point) (+ (point) 8))
(insert (format "%6o\0 " chk))
(setf (tar-header-checksum descriptor) chk)
;;
;; ok, make sure we didn't botch it.
(tar-header-block-check-checksum
(buffer-substring start (+ start 512))
chk (tar-header-name descriptor))
))))
(defun tar-octal-time (timeval)
......@@ -1129,41 +1149,19 @@ to make your changes permanent."
(setf (tar-header-size descriptor) subfile-size)
;;
;; Update the size field in the header block.
(widen)
(let ((header-start (- data-start 512)))
(goto-char (+ header-start tar-size-offset))
(delete-region (point) (+ (point) 12))
(insert (format "%11o " subfile-size))
;;
;; Maybe update the datestamp.
(if (not tar-update-datestamp)
nil
(goto-char (+ header-start tar-time-offset))
(delete-region (point) (+ (point) 12))
(insert (tar-octal-time (current-time)))
(insert ?\s))
;;
;; compute a new checksum and insert it.
(let ((chk (tar-header-block-checksum
(buffer-substring header-start data-start))))
(goto-char (+ header-start tar-chk-offset))
(delete-region (point) (+ (point) 8))
(insert (format "%6o\0 " chk))
(setf (tar-header-checksum descriptor) chk))))))
(widen))))
;;
;; alter the descriptor-line...
;; alter the descriptor-line and header
;;
(let ((position (- (length tar-parse-info) (length head))))
(goto-char (point-min))
(forward-line position)
(let ((p (point))
(after (line-beginning-position 2)))
(goto-char after)
;; Insert the new text after the old, before deleting,
;; to preserve the window start.
(let ((line (tar-header-block-summarize descriptor t)))
(insert-before-markers line "\n"))
(delete-region p after)))
(tar-alter-one-field tar-size-offset (format "%11o " subfile-size))
;;
;; Maybe update the datestamp.
(when tar-update-datestamp
(tar-alter-one-field tar-time-offset
(concat (tar-octal-time (current-time)) " "))))
;; After doing the insertion, add any necessary final padding.
(tar-pad-to-blocksize))
(set-buffer-modified-p t) ; mark the tar file as modified
......
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