(defgroup compression nil
"Data compression utilities"
:group 'data)
(defgroup jka-compr nil
"jka-compr customization"
:group 'compression)
(defcustom jka-compr-shell "sh"
"*Shell to be used for calling compression programs.
The value of this variable only matters if you want to discard the
stderr of a compression/decompression program (see the documentation
for `jka-compr-compression-info-list')."
:type 'string
:group 'jka-compr)
(defvar jka-compr-use-shell
(not (memq system-type '(ms-dos windows-nt))))
(defcustom jka-compr-compression-info-list
'(["\\.Z\\(~\\|\\.~[0-9]+~\\)?\\'"
"compressing" "compress" ("-c")
"uncompressing" "uncompress" ("-c")
nil t]
["\\.bz2\\'"
"bzip2ing" "bzip2" nil
"bunzip2ing" "bzip2" ("-d")
nil t]
["\\.tgz\\'"
"zipping" "gzip" ("-c" "-q")
"unzipping" "gzip" ("-c" "-q" "-d")
t nil]
["\\.gz\\(~\\|\\.~[0-9]+~\\)?\\'"
"zipping" "gzip" ("-c" "-q")
"unzipping" "gzip" ("-c" "-q" "-d")
t t])
"List of vectors that describe available compression techniques.
Each element, which describes a compression technique, is a vector of
the form [REGEXP COMPRESS-MSG COMPRESS-PROGRAM COMPRESS-ARGS
UNCOMPRESS-MSG UNCOMPRESS-PROGRAM UNCOMPRESS-ARGS
APPEND-FLAG EXTENSION], where:
regexp is a regexp that matches filenames that are
compressed with this format
compress-msg is the message to issue to the user when doing this
type of compression (nil means no message)
compress-program is a program that performs this compression
compress-args is a list of args to pass to the compress program
uncompress-msg is the message to issue to the user when doing this
type of uncompression (nil means no message)
uncompress-program is a program that performs this compression
uncompress-args is a list of args to pass to the uncompress program
append-flag is non-nil if this compression technique can be
appended
auto-mode flag non-nil means strip the regexp from file names
before attempting to set the mode.
Because of the way `call-process' is defined, discarding the stderr output of
a program adds the overhead of starting a shell each time the program is
invoked."
:type '(repeat (vector regexp
(choice :tag "Compress Message"
(string :format "%v")
(const :tag "No Message" nil))
(string :tag "Compress Program")
(repeat :tag "Compress Arguments" string)
(choice :tag "Uncompress Message"
(string :format "%v")
(const :tag "No Message" nil))
(string :tag "Uncompress Program")
(repeat :tag "Uncompress Arguments" string)
(boolean :tag "Append")
(boolean :tag "Auto Mode")))
:group 'jka-compr)
(defvar jka-compr-mode-alist-additions
(list (cons "\\.tgz\\'" 'tar-mode))
"A list of pairs to add to `auto-mode-alist' when jka-compr is installed.")
(defvar jka-compr-added-to-file-coding-system-alist nil)
(defvar jka-compr-file-name-handler-entry
nil
"The entry in `file-name-handler-alist' used by the jka-compr I/O functions.")
(defun jka-compr-info-regexp (info) (aref info 0))
(defun jka-compr-info-compress-message (info) (aref info 1))
(defun jka-compr-info-compress-program (info) (aref info 2))
(defun jka-compr-info-compress-args (info) (aref info 3))
(defun jka-compr-info-uncompress-message (info) (aref info 4))
(defun jka-compr-info-uncompress-program (info) (aref info 5))
(defun jka-compr-info-uncompress-args (info) (aref info 6))
(defun jka-compr-info-can-append (info) (aref info 7))
(defun jka-compr-info-strip-extension (info) (aref info 8))
(defun jka-compr-get-compression-info (filename)
"Return information about the compression scheme of FILENAME.
The determination as to which compression scheme, if any, to use is
based on the filename itself and `jka-compr-compression-info-list'."
(catch 'compression-info
(let ((case-fold-search nil))
(mapcar
(function (lambda (x)
(and (string-match (jka-compr-info-regexp x) filename)
(throw 'compression-info x))))
jka-compr-compression-info-list)
nil)))
(put 'compression-error 'error-conditions '(compression-error file-error error))
(defvar jka-compr-acceptable-retval-list '(0 2 141))
(defun jka-compr-error (prog args infile message &optional errfile)
(let ((errbuf (get-buffer-create " *jka-compr-error*"))
(curbuf (current-buffer)))
(with-current-buffer errbuf
(widen) (erase-buffer)
(insert (format "Error while executing \"%s %s < %s\"\n\n"
prog
(mapconcat 'identity args " ")
infile))
(and errfile
(insert-file-contents errfile)))
(display-buffer errbuf))
(signal 'compression-error
(list "Opening input file" (format "error %s" message) infile)))
(defvar jka-compr-dd-program
"/bin/dd")
(defvar jka-compr-dd-blocksize 256)
(defun jka-compr-partial-uncompress (prog message args infile beg len)
"Call program PROG with ARGS args taking input from INFILE.
Fourth and fifth args, BEG and LEN, specify which part of the output
to keep: LEN chars starting BEG chars from the beginning."
(let* ((skip (/ beg jka-compr-dd-blocksize))
(prefix (- beg (* skip jka-compr-dd-blocksize)))
(count (and len (1+ (/ (+ len prefix) jka-compr-dd-blocksize))))
(start (point))
(err-file (jka-compr-make-temp-name))
(run-string (format "%s %s 2> %s | %s bs=%d skip=%d %s 2> /dev/null"
prog
(mapconcat 'identity args " ")
err-file
jka-compr-dd-program
jka-compr-dd-blocksize
skip
(if count (concat "count=" (1+ count)) ""))))
(unwind-protect
(or (memq (call-process jka-compr-shell
infile t nil "-c"
run-string)
jka-compr-acceptable-retval-list)
(jka-compr-error prog args infile message err-file))
(jka-compr-delete-temp-file err-file))
(and
len
(< (+ start prefix len) (point))
(delete-region (+ start prefix len) (point)))
(delete-region start (+ start prefix))))
(defun jka-compr-call-process (prog message infile output temp args)
(if jka-compr-use-shell
(let ((err-file (jka-compr-make-temp-name))
(coding-system-for-read (or coding-system-for-read 'undecided))
(coding-system-for-write 'no-conversion))
(unwind-protect
(or (memq
(call-process jka-compr-shell infile
(if (stringp output) nil output)
nil
"-c"
(format "%s %s 2> %s %s"
prog
(mapconcat 'identity args " ")
err-file
(if (stringp output)
(concat "> " output)
"")))
jka-compr-acceptable-retval-list)
(jka-compr-error prog args infile message err-file))
(jka-compr-delete-temp-file err-file)))
(or (zerop
(apply 'call-process
prog
infile
(if (stringp output) temp output)
nil
args))
(jka-compr-error prog args infile message))
(and (stringp output)
(with-current-buffer temp
(write-region (point-min) (point-max) output)
(erase-buffer)))))
(defcustom jka-compr-temp-name-template
(expand-file-name "jka-com" temporary-file-directory)
"Prefix added to all temp files created by jka-compr.
There should be no more than seven characters after the final `/'."
:type 'string
:group 'jka-compr)
(defvar jka-compr-temp-name-table (make-vector 31 nil))
(defun jka-compr-make-temp-name (&optional local-copy)
"This routine will return the name of a new file."
(let* ((lastchar ?a)
(prevchar ?a)
(template (concat jka-compr-temp-name-template "aa"))
(lastpos (1- (length template)))
(not-done t)
file
entry)
(while not-done
(aset template lastpos lastchar)
(setq file (concat (make-temp-name template) "#"))
(setq entry (intern file jka-compr-temp-name-table))
(if (or (get entry 'active)
(file-exists-p file))
(progn
(setq lastchar (1+ lastchar))
(if (> lastchar ?z)
(progn
(setq prevchar (1+ prevchar))
(setq lastchar ?a)
(if (> prevchar ?z)
(error "Can't allocate temp file.")
(aset template (1- lastpos) prevchar)))))
(put entry 'active (not local-copy))
(setq not-done nil)))
file))
(defun jka-compr-delete-temp-file (temp)
(put (intern temp jka-compr-temp-name-table)
'active nil)
(condition-case ()
(delete-file temp)
(error nil)))
(defun jka-compr-write-region (start end file &optional append visit)
(let* ((filename (expand-file-name file))
(visit-file (if (stringp visit) (expand-file-name visit) filename))
(info (jka-compr-get-compression-info visit-file)))
(if info
(let ((can-append (jka-compr-info-can-append info))
(compress-program (jka-compr-info-compress-program info))
(compress-message (jka-compr-info-compress-message info))
(uncompress-program (jka-compr-info-uncompress-program info))
(uncompress-message (jka-compr-info-uncompress-message info))
(compress-args (jka-compr-info-compress-args info))
(uncompress-args (jka-compr-info-uncompress-args info))
(base-name (file-name-nondirectory visit-file))
temp-file temp-buffer
(coding-system-used last-coding-system-used))
(setq temp-buffer (get-buffer-create " *jka-compr-wr-temp*"))
(with-current-buffer temp-buffer
(widen) (erase-buffer))
(if (and append
(not can-append)
(file-exists-p filename))
(let* ((local-copy (file-local-copy filename))
(local-file (or local-copy filename)))
(setq temp-file local-file))
(setq temp-file (jka-compr-make-temp-name)))
(and
compress-message
(message "%s %s..." compress-message base-name))
(jka-compr-run-real-handler 'write-region
(list start end temp-file t 'dont))
(setq coding-system-used last-coding-system-used)
(let ((coding-system-for-read 'no-conversion))
(jka-compr-call-process compress-program
(concat compress-message
" " base-name)
temp-file
temp-buffer
nil
compress-args))
(with-current-buffer temp-buffer
(let ((coding-system-for-write 'no-conversion))
(if (memq system-type '(ms-dos windows-nt))
(setq buffer-file-type t) )
(jka-compr-run-real-handler 'write-region
(list (point-min) (point-max)
filename
(and append can-append) 'dont))
(erase-buffer)) )
(jka-compr-delete-temp-file temp-file)
(and
compress-message
(message "%s %s...done" compress-message base-name))
(cond
((eq visit t)
(setq buffer-file-name filename)
(set-visited-file-modtime))
((stringp visit)
(setq buffer-file-name visit)
(let ((buffer-file-name filename))
(set-visited-file-modtime))))
(and (or (eq visit t)
(eq visit nil)
(stringp visit))
(message "Wrote %s" visit-file))
(setq last-coding-system-used coding-system-used)
nil)
(jka-compr-run-real-handler 'write-region
(list start end filename append visit)))))
(defun jka-compr-insert-file-contents (file &optional visit beg end replace)
(barf-if-buffer-read-only)
(and (or beg end)
visit
(error "Attempt to visit less than an entire file"))
(let* ((filename (expand-file-name file))
(info (jka-compr-get-compression-info filename)))
(if info
(let ((uncompress-message (jka-compr-info-uncompress-message info))
(uncompress-program (jka-compr-info-uncompress-program info))
(uncompress-args (jka-compr-info-uncompress-args info))
(base-name (file-name-nondirectory filename))
(notfound nil)
(local-copy
(jka-compr-run-real-handler 'file-local-copy (list filename)))
local-file
size start
(coding-system-for-read
(or coding-system-for-read
(and (null enable-multibyte-characters)
(or (auto-coding-alist-lookup
(jka-compr-byte-compiler-base-file-name file))
'raw-text))
(let ((coding (find-operation-coding-system
'insert-file-contents
(jka-compr-byte-compiler-base-file-name file))))
(and (consp coding) (car coding)))
'undecided)) )
(setq local-file (or local-copy filename))
(and
visit
(setq buffer-file-name filename))
(unwind-protect
(progn
(and
uncompress-message
(message "%s %s..." uncompress-message base-name))
(condition-case error-code
(progn
(if replace
(goto-char (point-min)))
(setq start (point))
(if (or beg end)
(jka-compr-partial-uncompress uncompress-program
(concat uncompress-message
" " base-name)
uncompress-args
local-file
(or beg 0)
(if (and beg end)
(- end beg)
end))
(let ((buffer-file-name
(if visit nil buffer-file-name)))
(jka-compr-call-process uncompress-program
(concat uncompress-message
" " base-name)
local-file
t
nil
uncompress-args)))
(setq size (- (point) start))
(if replace
(let* ((del-beg (point))
(del-end (+ del-beg size)))
(delete-region del-beg
(min del-end (point-max)))))
(goto-char start))
(error
(if (and (eq (car error-code) 'file-error)
(eq (nth 3 error-code) local-file))
(if visit
(setq notfound error-code)
(signal 'file-error
(cons "Opening input file"
(nthcdr 2 error-code))))
(signal (car error-code) (cdr error-code))))))
(and
local-copy
(file-exists-p local-copy)
(delete-file local-copy)))
(and
visit
(progn
(unlock-buffer)
(setq buffer-file-name filename)
(set-visited-file-modtime)))
(and
uncompress-message
(message "%s %s...done" uncompress-message base-name))
(and
visit
notfound
(signal 'file-error
(cons "Opening input file" (nth 2 notfound))))
(list filename size))
(jka-compr-run-real-handler 'insert-file-contents
(list file visit beg end replace)))))
(defun jka-compr-file-local-copy (file)
(let* ((filename (expand-file-name file))
(info (jka-compr-get-compression-info filename)))
(if info
(let ((uncompress-message (jka-compr-info-uncompress-message info))
(uncompress-program (jka-compr-info-uncompress-program info))
(uncompress-args (jka-compr-info-uncompress-args info))
(base-name (file-name-nondirectory filename))
(local-copy
(jka-compr-run-real-handler 'file-local-copy (list filename)))
(temp-file (jka-compr-make-temp-name t))
(temp-buffer (get-buffer-create " *jka-compr-flc-temp*"))
(notfound nil)
local-file)
(setq local-file (or local-copy filename))
(unwind-protect
(with-current-buffer temp-buffer
(and
uncompress-message
(message "%s %s..." uncompress-message base-name))
(let ((coding-system-for-read 'no-conversion)
(coding-system-for-write 'no-conversion))
(jka-compr-call-process uncompress-program
(concat uncompress-message
" " base-name)
local-file
t
nil
uncompress-args)
(and
uncompress-message
(message "%s %s...done" uncompress-message base-name))
(write-region
(point-min) (point-max) temp-file nil 'dont)))
(and
local-copy
(file-exists-p local-copy)
(delete-file local-copy))
(kill-buffer temp-buffer))
temp-file)
(jka-compr-run-real-handler 'file-local-copy (list filename)))))
(defun jka-compr-load (file &optional noerror nomessage nosuffix)
"Documented as original."
(let* ((local-copy (jka-compr-file-local-copy file))
(load-file (or local-copy file)))
(unwind-protect
(let (inhibit-file-name-operation
inhibit-file-name-handlers)
(or nomessage
(message "Loading %s..." file))
(let ((load-force-doc-strings t))
(load load-file noerror t t))
(or nomessage
(message "Loading %s...done." file)))
(jka-compr-delete-temp-file local-copy))
t))
(defun jka-compr-byte-compiler-base-file-name (file)
(let ((info (jka-compr-get-compression-info file)))
(if (and info (jka-compr-info-strip-extension info))
(save-match-data
(substring file 0 (string-match (jka-compr-info-regexp info) file)))
file)))
(put 'write-region 'jka-compr 'jka-compr-write-region)
(put 'insert-file-contents 'jka-compr 'jka-compr-insert-file-contents)
(put 'file-local-copy 'jka-compr 'jka-compr-file-local-copy)
(put 'load 'jka-compr 'jka-compr-load)
(put 'byte-compiler-base-file-name 'jka-compr
'jka-compr-byte-compiler-base-file-name)
(defvar jka-compr-inhibit nil
"Non-nil means inhibit automatic uncompression temporarily.
Lisp programs can bind this to t to do that.
It is not recommended to set this variable permanently to anything but nil.")
(defun jka-compr-handler (operation &rest args)
(save-match-data
(let ((jka-op (get operation 'jka-compr)))
(if (and jka-op (not jka-compr-inhibit))
(apply jka-op args)
(jka-compr-run-real-handler operation args)))))
(defun jka-compr-run-real-handler (operation args)
(let ((inhibit-file-name-handlers
(cons 'jka-compr-handler
(and (eq inhibit-file-name-operation operation)
inhibit-file-name-handlers)))
(inhibit-file-name-operation operation))
(apply operation args)))
(defun toggle-auto-compression (&optional arg message)
"Toggle automatic file compression and uncompression.
With prefix argument ARG, turn auto compression on if positive, else off.
Returns the new status of auto compression (non-nil means on).
If the argument MESSAGE is non-nil, it means to print a message
saying whether the mode is now on or off."
(interactive "P\np")
(let* ((installed (jka-compr-installed-p))
(flag (if (null arg)
(not installed)
(or (eq arg t) (listp arg) (and (integerp arg) (> arg 0))))))
(cond
((and flag installed) t)
((and (not flag) (not installed)) nil)
(flag
(jka-compr-install))
(t
(jka-compr-uninstall)))
(and message
(if flag
(message "Automatic file (de)compression is now ON.")
(message "Automatic file (de)compression is now OFF.")))
flag))
(defun jka-compr-build-file-regexp ()
(concat
"\\("
(mapconcat
'jka-compr-info-regexp
jka-compr-compression-info-list
"\\)\\|\\(")
"\\)"))
(defun jka-compr-install ()
"Install jka-compr.
This adds entries to `file-name-handler-alist' and `auto-mode-alist'
and `inhibit-first-line-modes-suffixes'."
(setq jka-compr-file-name-handler-entry
(cons (jka-compr-build-file-regexp) 'jka-compr-handler))
(setq file-name-handler-alist (cons jka-compr-file-name-handler-entry
file-name-handler-alist))
(setq jka-compr-added-to-file-coding-system-alist nil)
(mapcar
(function (lambda (x)
(let ((elt (cons (jka-compr-info-regexp x)
'(no-conversion . no-conversion))))
(setq file-coding-system-alist
(cons elt file-coding-system-alist))
(setq jka-compr-added-to-file-coding-system-alist
(cons elt jka-compr-added-to-file-coding-system-alist)))
(and (jka-compr-info-strip-extension x)
(setq auto-mode-alist
(cons (list (jka-compr-info-regexp x)
nil 'jka-compr)
auto-mode-alist))
(setq inhibit-first-line-modes-suffixes
(cons (jka-compr-info-regexp x)
inhibit-first-line-modes-suffixes)))))
jka-compr-compression-info-list)
(setq auto-mode-alist
(append auto-mode-alist jka-compr-mode-alist-additions)))
(defun jka-compr-uninstall ()
"Uninstall jka-compr.
This removes the entries in `file-name-handler-alist' and `auto-mode-alist'
and `inhibit-first-line-modes-suffixes' that were added
by `jka-compr-installed'."
(mapcar
(function (lambda (x)
(and (jka-compr-info-strip-extension x)
(setq inhibit-first-line-modes-suffixes
(delete (jka-compr-info-regexp x)
inhibit-first-line-modes-suffixes)))))
jka-compr-compression-info-list)
(let* ((fnha (cons nil file-name-handler-alist))
(last fnha))
(while (cdr last)
(if (eq (cdr (car (cdr last))) 'jka-compr-handler)
(setcdr last (cdr (cdr last)))
(setq last (cdr last))))
(setq file-name-handler-alist (cdr fnha)))
(let* ((ama (cons nil auto-mode-alist))
(last ama)
entry)
(while (cdr last)
(setq entry (car (cdr last)))
(if (or (member entry jka-compr-mode-alist-additions)
(and (consp (cdr entry))
(eq (nth 2 entry) 'jka-compr)))
(setcdr last (cdr (cdr last)))
(setq last (cdr last))))
(setq auto-mode-alist (cdr ama)))
(let* ((ama (cons nil file-coding-system-alist))
(last ama)
entry)
(while (cdr last)
(setq entry (car (cdr last)))
(if (member entry jka-compr-added-to-file-coding-system-alist)
(setcdr last (cdr (cdr last)))
(setq last (cdr last))))
(setq file-coding-system-alist (cdr ama))))
(defun jka-compr-installed-p ()
"Return non-nil if jka-compr is installed.
The return value is the entry in `file-name-handler-alist' for jka-compr."
(let ((fnha file-name-handler-alist)
(installed nil))
(while (and fnha (not installed))
(and (eq (cdr (car fnha)) 'jka-compr-handler)
(setq installed (car fnha)))
(setq fnha (cdr fnha)))
installed))
(and (jka-compr-installed-p)
(jka-compr-uninstall))
(jka-compr-install)
(provide 'jka-compr)