[bpt/emacs.git] / lisp / jka-cmpr-hook.el

;;; jka-cmpr-hook.el --- preloaded code to enable jka-compr.el

;; Copyright (C) 1993, 1994, 1995, 1997, 1999, 2000, 2002, 2003,
;;   2004, 2005, 2006, 2007 Free Software Foundation, Inc.

;; Author: jka@ece.cmu.edu (Jay K. Adams)
;; Maintainer: FSF
;; Keywords: data

;; 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 3, 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., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;; This file contains the code to enable and disable Auto-Compression mode.
;; It is preloaded.  The guts of this mode are in jka-compr.el, which
;; is loaded only when you really try to uncompress something.

;;; Code:

(defgroup compression nil
  "Data compression utilities."
  :group 'data)

(defgroup jka-compr nil
  "jka-compr customization."
  :group 'compression)

;; List of all the elements we actually added to file-coding-system-alist.
(defvar jka-compr-added-to-file-coding-system-alist nil)

(defvar jka-compr-file-name-handler-entry
  nil
  "`file-name-handler-alist' entry used by jka-compr I/O functions.")

;; Compiler defvars.  These three variables will be defined later with
;; `defcustom' when everything used in the :set functions is defined.
(defvar jka-compr-compression-info-list)
(defvar jka-compr-mode-alist-additions)
(defvar jka-compr-load-suffixes)

(defvar jka-compr-compression-info-list--internal nil
  "Stored value of `jka-compr-compression-info-list'.
If Auto Compression mode is enabled, this is the value of
`jka-compr-compression-info-list' when `jka-compr-install' was last called.
Otherwise, it is nil.")

(defvar jka-compr-mode-alist-additions--internal nil
  "Stored value of `jka-compr-mode-alist-additions'.
If Auto Compression mode is enabled, this is the value of
`jka-compr-mode-alist-additions' when `jka-compr-install' was last called.
Otherwise, it is nil.")

(defvar jka-compr-load-suffixes--internal nil
  "Stored value of `jka-compr-load-suffixes'.
If Auto Compression mode is enabled, this is the value of
`jka-compr-load-suffixes' when `jka-compr-install' was last called.
Otherwise, it is nil.")

\f
(defun jka-compr-build-file-regexp ()
  (mapconcat
   'jka-compr-info-regexp
   jka-compr-compression-info-list
   "\\|"))

;; Functions for accessing the return value of jka-compr-get-compression-info
(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-info-file-magic-bytes     (info)  (aref info 9))


(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)))

(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))

  (push jka-compr-file-name-handler-entry file-name-handler-alist)

  (setq jka-compr-compression-info-list--internal
	jka-compr-compression-info-list
	jka-compr-mode-alist-additions--internal
	jka-compr-mode-alist-additions
	jka-compr-load-suffixes--internal
	jka-compr-load-suffixes)

  (dolist (x jka-compr-compression-info-list)
    ;; Don't do multibyte encoding on the compressed files.
    (let ((elt (cons (jka-compr-info-regexp x)
                     '(no-conversion . no-conversion))))
      (push elt file-coding-system-alist)
      (push elt jka-compr-added-to-file-coding-system-alist))

    (and (jka-compr-info-strip-extension x)
         ;; Make entries in auto-mode-alist so that modes
         ;; are chosen right according to the file names
         ;; sans `.gz'.
         (push (list (jka-compr-info-regexp x) nil 'jka-compr) auto-mode-alist)
         ;; Also add these regexps to
         ;; inhibit-first-line-modes-suffixes, so that a
         ;; -*- line in the first file of a compressed tar
         ;; file doesn't override tar-mode.
         (push (jka-compr-info-regexp x)
               inhibit-first-line-modes-suffixes)))
  (setq auto-mode-alist
	(append auto-mode-alist jka-compr-mode-alist-additions))

  ;; Make sure that (load "foo") will find /bla/foo.el.gz.
  (setq load-file-rep-suffixes
	(append load-file-rep-suffixes jka-compr-load-suffixes nil)))

(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))

(defun jka-compr-update ()
  "Update Auto Compression mode for changes in option values.
If you change the options `jka-compr-compression-info-list',
`jka-compr-mode-alist-additions' or `jka-compr-load-suffixes'
outside Custom, while Auto Compression mode is already enabled
\(as it is by default), then you have to call this function
afterward to properly update other variables.  Setting these
options through Custom does this automatically."
  (when (jka-compr-installed-p)
    (jka-compr-uninstall)
    (jka-compr-install)))

(defun jka-compr-set (variable value)
  "Internal Custom :set function."
  (set-default variable value)
  (jka-compr-update))

;; I have this defined so that .Z files are assumed to be in unix
;; compress format; and .gz files, in gzip format, and .bz2 files in bzip fmt.
(defcustom jka-compr-compression-info-list
  ;;[regexp
  ;; compr-message  compr-prog  compr-args
  ;; uncomp-message uncomp-prog uncomp-args
  ;; can-append strip-extension-flag file-magic-bytes]
  '(["\\.Z\\(~\\|\\.~[0-9]+~\\)?\\'"
     "compressing"    "compress"     ("-c")
     ;; gzip is more common than uncompress. It can only read, not write.
     "uncompressing"  "gzip"   ("-c" "-q" "-d")
     nil t "\037\235"]
     ;; Formerly, these had an additional arg "-c", but that fails with
     ;; "Version 0.1pl2, 29-Aug-97." (RedHat 5.1 GNU/Linux) and
     ;; "Version 0.9.0b, 9-Sept-98".
    ["\\.bz2\\(~\\|\\.~[0-9]+~\\)?\\'"
     "bzip2ing"        "bzip2"         nil
     "bunzip2ing"      "bzip2"         ("-d")
     nil t "BZh"]
    ["\\.tbz\\'"
     "bzip2ing"        "bzip2"         nil
     "bunzip2ing"      "bzip2"         ("-d")
     nil nil "BZh"]
    ["\\.\\(?:tgz\\|svgz\\)\\'"
     "compressing"        "gzip"         ("-c" "-q")
     "uncompressing"      "gzip"         ("-c" "-q" "-d")
     t nil "\037\213"]
    ["\\.g?z\\(~\\|\\.~[0-9]+~\\)?\\'"
     "compressing"        "gzip"         ("-c" "-q")
     "uncompressing"      "gzip"         ("-c" "-q" "-d")
     t t "\037\213"]
    ;; dzip is gzip with random access.  Its compression program can't
    ;; read/write stdin/out, so .dz files can only be viewed without
    ;; saving, having their contents decompressed with gzip.
    ["\\.dz\\'"
     nil              nil            nil
     "uncompressing"      "gzip"         ("-c" "-q" "-d")
     nil t "\037\213"])

  "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 STRIP-EXTENSION-FLAG FILE-MAGIC-CHARS], 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
                         (nil means visit file in read-only mode)

   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

   strip-extension-flag  non-nil means strip the regexp from file names
                         before attempting to set the mode.

   file-magic-chars      is a string of characters that you would find
			 at the beginning of a file compressed in this way.

If you set this outside Custom while Auto Compression mode is
already enabled \(as it is by default), you have to call
`jka-compr-update' after setting it to properly update other
variables.  Setting this through Custom does that automatically."
  :type '(repeat (vector regexp
			 (choice :tag "Compress Message"
				 (string :format "%v")
				 (const :tag "No Message" nil))
			 (choice :tag "Compress Program"
				 (string)
				 (const :tag "None" nil))
			 (repeat :tag "Compress Arguments" string)
			 (choice :tag "Uncompress Message"
				 (string :format "%v")
				 (const :tag "No Message" nil))
			 (choice :tag "Uncompress Program"
				 (string)
				 (const :tag "None" nil))
			 (repeat :tag "Uncompress Arguments" string)
			 (boolean :tag "Append")
			 (boolean :tag "Strip Extension")
			 (string :tag "Magic Bytes")))
  :set 'jka-compr-set
  :group 'jka-compr)

(defcustom jka-compr-mode-alist-additions
  (list (cons "\\.tgz\\'" 'tar-mode) (cons "\\.tbz\\'" 'tar-mode))
  "List of pairs added to `auto-mode-alist' when installing jka-compr.
Uninstalling jka-compr removes all pairs from `auto-mode-alist' that
installing added.

If you set this outside Custom while Auto Compression mode is
already enabled \(as it is by default), you have to call
`jka-compr-update' after setting it to properly update other
variables.  Setting this through Custom does that automatically."
  :type '(repeat (cons string symbol))
  :set 'jka-compr-set
  :group 'jka-compr)

(defcustom jka-compr-load-suffixes '(".gz")
  "List of compression related suffixes to try when loading files.
Enabling Auto Compression mode appends this list to `load-file-rep-suffixes',
which see.  Disabling Auto Compression mode removes all suffixes
from `load-file-rep-suffixes' that enabling added.

If you set this outside Custom while Auto Compression mode is
already enabled \(as it is by default), you have to call
`jka-compr-update' after setting it to properly update other
variables.  Setting this through Custom does that automatically."
  :type '(repeat string)
  :set 'jka-compr-set
  :group 'jka-compr)

(define-minor-mode auto-compression-mode
  "Toggle automatic file compression and uncompression.
With prefix argument ARG, turn auto compression on if positive, else off.
Return the new status of auto compression (non-nil means on)."
  :global t :init-value t :group 'jka-compr :version "22.1"
  (let* ((installed (jka-compr-installed-p))
	 (flag auto-compression-mode))
    (cond
     ((and flag installed) t)		; already installed
     ((and (not flag) (not installed)) nil) ; already not installed
     (flag (jka-compr-install))
     (t (jka-compr-uninstall)))))

(defmacro with-auto-compression-mode (&rest body)
  "Evalute BODY with automatic file compression and uncompression enabled."
  (let ((already-installed (make-symbol "already-installed")))
    `(let ((,already-installed (jka-compr-installed-p)))
       (unwind-protect
	   (progn
	     (unless ,already-installed
	       (jka-compr-install))
	     ,@body)
	 (unless ,already-installed
	   (jka-compr-uninstall))))))
(put 'with-auto-compression-mode 'lisp-indent-function 0)


;; This is what we need to know about jka-compr-handler
;; in order to decide when to call it.

(put 'jka-compr-handler 'safe-magic t)
(put 'jka-compr-handler 'operations '(byte-compiler-base-file-name
				      write-region insert-file-contents
				      file-local-copy load))

;; Turn on the mode.
(when auto-compression-mode (auto-compression-mode 1))

(provide 'jka-cmpr-hook)

;; arch-tag: 4bd73429-f400-45fe-a065-270a113e31a8
;;; jka-cmpr-hook.el ends here
Commit	Line	Data
550bd514	1	;;; jka-cmpr-hook.el --- preloaded code to enable jka-compr.el
216b5993	2
fde4e97e	3	;; Copyright (C) 1993, 1994, 1995, 1997, 1999, 2000, 2002, 2003,
d7a0267c	4	;; 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
216b5993 RS	5
	6	;; Author: jka@ece.cmu.edu (Jay K. Adams)
	7	;; Maintainer: FSF
	8	;; Keywords: data
	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
b4aa6026	14	;; the Free Software Foundation; either version 3, or (at your option)
216b5993 RS	15	;; 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; see the file COPYING. If not, write to the
086add15 LK	24	;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
086add15 LK	25	;; Boston, MA 02110-1301, USA.
216b5993 RS	26
	27	;;; Commentary:
	28
ea8e0537	29	;; This file contains the code to enable and disable Auto-Compression mode.
216b5993 RS	30	;; It is preloaded. The guts of this mode are in jka-compr.el, which
	31	;; is loaded only when you really try to uncompress something.
	32
	33	;;; Code:
	34
	35	(defgroup compression nil
7ae4587b	36	"Data compression utilities."
216b5993 RS	37	:group 'data)
	38
	39	(defgroup jka-compr nil
7ae4587b	40	"jka-compr customization."
216b5993 RS	41	:group 'compression)
216b5993 RS	42
216b5993 RS	43	;; List of all the elements we actually added to file-coding-system-alist.
	44	(defvar jka-compr-added-to-file-coding-system-alist nil)
	45
	46	(defvar jka-compr-file-name-handler-entry
	47	nil
ea8e0537 LT	48	"`file-name-handler-alist' entry used by jka-compr I/O functions.")
	49
	50	;; Compiler defvars. These three variables will be defined later with
	51	;; `defcustom' when everything used in the :set functions is defined.
	52	(defvar jka-compr-compression-info-list)
	53	(defvar jka-compr-mode-alist-additions)
	54	(defvar jka-compr-load-suffixes)
	55
	56	(defvar jka-compr-compression-info-list--internal nil
	57	"Stored value of `jka-compr-compression-info-list'.
	58	If Auto Compression mode is enabled, this is the value of
	59	`jka-compr-compression-info-list' when `jka-compr-install' was last called.
	60	Otherwise, it is nil.")
	61
	62	(defvar jka-compr-mode-alist-additions--internal nil
	63	"Stored value of `jka-compr-mode-alist-additions'.
	64	If Auto Compression mode is enabled, this is the value of
	65	`jka-compr-mode-alist-additions' when `jka-compr-install' was last called.
	66	Otherwise, it is nil.")
	67
	68	(defvar jka-compr-load-suffixes--internal nil
	69	"Stored value of `jka-compr-load-suffixes'.
	70	If Auto Compression mode is enabled, this is the value of
	71	`jka-compr-load-suffixes' when `jka-compr-install' was last called.
	72	Otherwise, it is nil.")
	73
216b5993 RS	74	\f
	75	(defun jka-compr-build-file-regexp ()
	76	(mapconcat
	77	'jka-compr-info-regexp
	78	jka-compr-compression-info-list
	79	"\\\|"))
	80
be93a2c4	81	;; Functions for accessing the return value of jka-compr-get-compression-info
216b5993 RS	82	(defun jka-compr-info-regexp (info) (aref info 0))
	83	(defun jka-compr-info-compress-message (info) (aref info 1))
	84	(defun jka-compr-info-compress-program (info) (aref info 2))
	85	(defun jka-compr-info-compress-args (info) (aref info 3))
	86	(defun jka-compr-info-uncompress-message (info) (aref info 4))
	87	(defun jka-compr-info-uncompress-program (info) (aref info 5))
	88	(defun jka-compr-info-uncompress-args (info) (aref info 6))
	89	(defun jka-compr-info-can-append (info) (aref info 7))
	90	(defun jka-compr-info-strip-extension (info) (aref info 8))
	91	(defun jka-compr-info-file-magic-bytes (info) (aref info 9))
	92
	93
	94	(defun jka-compr-get-compression-info (filename)
	95	"Return information about the compression scheme of FILENAME.
	96	The determination as to which compression scheme, if any, to use is
	97	based on the filename itself and `jka-compr-compression-info-list'."
	98	(catch 'compression-info
	99	(let ((case-fold-search nil))
	100	(mapcar
	101	(function (lambda (x)
	102	(and (string-match (jka-compr-info-regexp x) filename)
	103	(throw 'compression-info x))))
	104	jka-compr-compression-info-list)
	105	nil)))
	106
	107	(defun jka-compr-install ()
	108	"Install jka-compr.
	109	This adds entries to `file-name-handler-alist' and `auto-mode-alist'
	110	and `inhibit-first-line-modes-suffixes'."
	111
	112	(setq jka-compr-file-name-handler-entry
	113	(cons (jka-compr-build-file-regexp) 'jka-compr-handler))
	114
be93a2c4 SM	115	(push jka-compr-file-name-handler-entry file-name-handler-alist)
be93a2c4 SM	116
ea8e0537 LT	117	(setq jka-compr-compression-info-list--internal
	118	jka-compr-compression-info-list
	119	jka-compr-mode-alist-additions--internal
	120	jka-compr-mode-alist-additions
	121	jka-compr-load-suffixes--internal
	122	jka-compr-load-suffixes)
	123
be93a2c4 SM	124	(dolist (x jka-compr-compression-info-list)
	125	;; Don't do multibyte encoding on the compressed files.
	126	(let ((elt (cons (jka-compr-info-regexp x)
	127	'(no-conversion . no-conversion))))
	128	(push elt file-coding-system-alist)
	129	(push elt jka-compr-added-to-file-coding-system-alist))
	130
	131	(and (jka-compr-info-strip-extension x)
	132	;; Make entries in auto-mode-alist so that modes
	133	;; are chosen right according to the file names
	134	;; sans `.gz'.
	135	(push (list (jka-compr-info-regexp x) nil 'jka-compr) auto-mode-alist)
	136	;; Also add these regexps to
	137	;; inhibit-first-line-modes-suffixes, so that a
	138	;; -*- line in the first file of a compressed tar
	139	;; file doesn't override tar-mode.
	140	(push (jka-compr-info-regexp x)
	141	inhibit-first-line-modes-suffixes)))
216b5993 RS	142	(setq auto-mode-alist
	143	(append auto-mode-alist jka-compr-mode-alist-additions))
	144
	145	;; Make sure that (load "foo") will find /bla/foo.el.gz.
ea8e0537 LT	146	(setq load-file-rep-suffixes
ea8e0537 LT	147	(append load-file-rep-suffixes jka-compr-load-suffixes nil)))
216b5993 RS	148
	149	(defun jka-compr-installed-p ()
	150	"Return non-nil if jka-compr is installed.
	151	The return value is the entry in `file-name-handler-alist' for jka-compr."
	152
	153	(let ((fnha file-name-handler-alist)
	154	(installed nil))
	155
	156	(while (and fnha (not installed))
	157	(and (eq (cdr (car fnha)) 'jka-compr-handler)
	158	(setq installed (car fnha)))
	159	(setq fnha (cdr fnha)))
	160
	161	installed))
	162
ea8e0537 LT	163	(defun jka-compr-update ()
	164	"Update Auto Compression mode for changes in option values.
	165	If you change the options `jka-compr-compression-info-list',
	166	`jka-compr-mode-alist-additions' or `jka-compr-load-suffixes'
	167	outside Custom, while Auto Compression mode is already enabled
	168	\(as it is by default), then you have to call this function
	169	afterward to properly update other variables. Setting these
	170	options through Custom does this automatically."
	171	(when (jka-compr-installed-p)
	172	(jka-compr-uninstall)
	173	(jka-compr-install)))
	174
	175	(defun jka-compr-set (variable value)
	176	"Internal Custom :set function."
	177	(set-default variable value)
	178	(jka-compr-update))
	179
df66263e LT	180	;; I have this defined so that .Z files are assumed to be in unix
	181	;; compress format; and .gz files, in gzip format, and .bz2 files in bzip fmt.
	182	(defcustom jka-compr-compression-info-list
	183	;;[regexp
	184	;; compr-message compr-prog compr-args
	185	;; uncomp-message uncomp-prog uncomp-args
5b668628	186	;; can-append strip-extension-flag file-magic-bytes]
df66263e LT	187	'(["\\.Z\\(~\\\|\\.~[0-9]+~\\)?\\'"
df66263e LT	188	"compressing" "compress" ("-c")
13c8188a	189	;; gzip is more common than uncompress. It can only read, not write.
aad96659	190	"uncompressing" "gzip" ("-c" "-q" "-d")
df66263e LT	191	nil t "\037\235"]
	192	;; Formerly, these had an additional arg "-c", but that fails with
	193	;; "Version 0.1pl2, 29-Aug-97." (RedHat 5.1 GNU/Linux) and
	194	;; "Version 0.9.0b, 9-Sept-98".
73c03f76	195	["\\.bz2\\(~\\\|\\.~[0-9]+~\\)?\\'"
df66263e LT	196	"bzip2ing" "bzip2" nil
	197	"bunzip2ing" "bzip2" ("-d")
	198	nil t "BZh"]
	199	["\\.tbz\\'"
	200	"bzip2ing" "bzip2" nil
	201	"bunzip2ing" "bzip2" ("-d")
	202	nil nil "BZh"]
5b668628	203	["\\.\\(?:tgz\\\|svgz\\)\\'"
df66263e LT	204	"compressing" "gzip" ("-c" "-q")
	205	"uncompressing" "gzip" ("-c" "-q" "-d")
	206	t nil "\037\213"]
	207	["\\.g?z\\(~\\\|\\.~[0-9]+~\\)?\\'"
	208	"compressing" "gzip" ("-c" "-q")
	209	"uncompressing" "gzip" ("-c" "-q" "-d")
	210	t t "\037\213"]
	211	;; dzip is gzip with random access. Its compression program can't
	212	;; read/write stdin/out, so .dz files can only be viewed without
	213	;; saving, having their contents decompressed with gzip.
	214	["\\.dz\\'"
	215	nil nil nil
	216	"uncompressing" "gzip" ("-c" "-q" "-d")
	217	nil t "\037\213"])
	218
	219	"List of vectors that describe available compression techniques.
	220	Each element, which describes a compression technique, is a vector of
	221	the form [REGEXP COMPRESS-MSG COMPRESS-PROGRAM COMPRESS-ARGS
	222	UNCOMPRESS-MSG UNCOMPRESS-PROGRAM UNCOMPRESS-ARGS
	223	APPEND-FLAG STRIP-EXTENSION-FLAG FILE-MAGIC-CHARS], where:
	224
	225	regexp is a regexp that matches filenames that are
	226	compressed with this format
	227
	228	compress-msg is the message to issue to the user when doing this
	229	type of compression (nil means no message)
	230
	231	compress-program is a program that performs this compression
	232	(nil means visit file in read-only mode)
	233
	234	compress-args is a list of args to pass to the compress program
	235
	236	uncompress-msg is the message to issue to the user when doing this
	237	type of uncompression (nil means no message)
	238
	239	uncompress-program is a program that performs this compression
	240
	241	uncompress-args is a list of args to pass to the uncompress program
	242
	243	append-flag is non-nil if this compression technique can be
	244	appended
	245
	246	strip-extension-flag non-nil means strip the regexp from file names
	247	before attempting to set the mode.
	248
	249	file-magic-chars is a string of characters that you would find
	250	at the beginning of a file compressed in this way.
	251
df66263e LT	252	If you set this outside Custom while Auto Compression mode is
	253	already enabled \(as it is by default), you have to call
	254	`jka-compr-update' after setting it to properly update other
	255	variables. Setting this through Custom does that automatically."
	256	:type '(repeat (vector regexp
	257	(choice :tag "Compress Message"
	258	(string :format "%v")
	259	(const :tag "No Message" nil))
	260	(choice :tag "Compress Program"
	261	(string)
	262	(const :tag "None" nil))
	263	(repeat :tag "Compress Arguments" string)
	264	(choice :tag "Uncompress Message"
	265	(string :format "%v")
	266	(const :tag "No Message" nil))
	267	(choice :tag "Uncompress Program"
	268	(string)
	269	(const :tag "None" nil))
	270	(repeat :tag "Uncompress Arguments" string)
	271	(boolean :tag "Append")
	272	(boolean :tag "Strip Extension")
	273	(string :tag "Magic Bytes")))
	274	:set 'jka-compr-set
	275	:group 'jka-compr)
	276
	277	(defcustom jka-compr-mode-alist-additions
	278	(list (cons "\\.tgz\\'" 'tar-mode) (cons "\\.tbz\\'" 'tar-mode))
	279	"List of pairs added to `auto-mode-alist' when installing jka-compr.
	280	Uninstalling jka-compr removes all pairs from `auto-mode-alist' that
	281	installing added.
	282
	283	If you set this outside Custom while Auto Compression mode is
	284	already enabled \(as it is by default), you have to call
	285	`jka-compr-update' after setting it to properly update other
	286	variables. Setting this through Custom does that automatically."
	287	:type '(repeat (cons string symbol))
	288	:set 'jka-compr-set
	289	:group 'jka-compr)
	290
	291	(defcustom jka-compr-load-suffixes '(".gz")
	292	"List of compression related suffixes to try when loading files.
	293	Enabling Auto Compression mode appends this list to `load-file-rep-suffixes',
	294	which see. Disabling Auto Compression mode removes all suffixes
	295	from `load-file-rep-suffixes' that enabling added.
	296
	297	If you set this outside Custom while Auto Compression mode is
	298	already enabled \(as it is by default), you have to call
	299	`jka-compr-update' after setting it to properly update other
	300	variables. Setting this through Custom does that automatically."
	301	:type '(repeat string)
	302	:set 'jka-compr-set
	303	:group 'jka-compr)
	304
216b5993 RS	305	(define-minor-mode auto-compression-mode
	306	"Toggle automatic file compression and uncompression.
	307	With prefix argument ARG, turn auto compression on if positive, else off.
ea8e0537	308	Return the new status of auto compression (non-nil means on)."
e64a3dcf	309	:global t :init-value t :group 'jka-compr :version "22.1"
216b5993 RS	310	(let* ((installed (jka-compr-installed-p))
	311	(flag auto-compression-mode))
	312	(cond
	313	((and flag installed) t) ; already installed
	314	((and (not flag) (not installed)) nil) ; already not installed
	315	(flag (jka-compr-install))
	316	(t (jka-compr-uninstall)))))
	317
	318	(defmacro with-auto-compression-mode (&rest body)
	319	"Evalute BODY with automatic file compression and uncompression enabled."
	320	(let ((already-installed (make-symbol "already-installed")))
	321	`(let ((,already-installed (jka-compr-installed-p)))
	322	(unwind-protect
	323	(progn
	324	(unless ,already-installed
	325	(jka-compr-install))
	326	,@body)
	327	(unless ,already-installed
	328	(jka-compr-uninstall))))))
	329	(put 'with-auto-compression-mode 'lisp-indent-function 0)
	330
	331
be93a2c4 SM	332	;; This is what we need to know about jka-compr-handler
be93a2c4 SM	333	;; in order to decide when to call it.
216b5993 RS	334
216b5993 RS	335	(put 'jka-compr-handler 'safe-magic t)
9c40111a	336	(put 'jka-compr-handler 'operations '(byte-compiler-base-file-name
216b5993 RS	337	write-region insert-file-contents
	338	file-local-copy load))
	339
be93a2c4	340	;; Turn on the mode.
12d94429	341	(when auto-compression-mode (auto-compression-mode 1))
216b5993	342
550bd514	343	(provide 'jka-cmpr-hook)
216b5993	344
b21eabf6	345	;; arch-tag: 4bd73429-f400-45fe-a065-270a113e31a8
550bd514	346	;;; jka-cmpr-hook.el ends here