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annotate lisp/userlock.el @ 5839:d139eb1fead8
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| author | Marcus Crestani <marcus@crestani.de> |
|---|---|
| date | Sat, 13 Dec 2014 14:09:33 +0100 |
| parents | 308d34e9f07d |
| children |
| rev | line source |
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| 428 | 1 ;;; userlock.el --- handle file access contention between multiple users |
| 2 | |
| 3 ;; Copyright (C) 1985, 1986, 1993 Free Software Foundation, inc. | |
| 4 | |
| 5 ;; Maintainer: FSF | |
| 6 ;; Keywords: internal | |
| 7 | |
| 8 ;; This file is part of XEmacs. | |
| 9 | |
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10 ;; XEmacs is free software: you can redistribute it and/or modify it |
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11 ;; under the terms of the GNU General Public License as published by the |
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12 ;; Free Software Foundation, either version 3 of the License, or (at your |
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13 ;; option) any later version. |
| 428 | 14 |
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15 ;; XEmacs is distributed in the hope that it will be useful, but WITHOUT |
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16 ;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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17 ;; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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18 ;; for more details. |
| 428 | 19 |
| 20 ;; You should have received a copy of the GNU General Public License | |
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21 ;; along with XEmacs. If not, see <http://www.gnu.org/licenses/>. |
| 428 | 22 |
| 23 ;;; Synched up with: FSF 19.34. | |
| 24 | |
| 25 ;;; Commentary: | |
| 26 | |
| 27 ;; This file is autoloaded to handle certain conditions | |
| 28 ;; detected by the file-locking code within XEmacs. | |
| 29 ;; The two entry points are `ask-user-about-lock' and | |
| 30 ;; `ask-user-about-supersession-threat'. | |
| 31 | |
| 32 ;;; Code: | |
| 33 | |
| 34 (define-error 'file-locked "File is locked" 'file-error) ; XEmacs | |
| 35 | |
| 444 | 36 (defun ask-user-about-lock-minibuf (filename other-user) |
| 428 | 37 (save-window-excursion |
| 38 (let (answer) | |
| 39 (while (null answer) | |
| 444 | 40 (message "%s is locking %s: action (s, q, p, ?)? " other-user filename) |
| 428 | 41 (let ((tem (let ((inhibit-quit t) |
| 42 (cursor-in-echo-area t)) | |
| 43 (prog1 (downcase (read-char)) | |
| 44 (setq quit-flag nil))))) | |
| 45 (if (= tem help-char) | |
| 46 (ask-user-about-lock-help) | |
| 47 (setq answer (assoc tem '((?s . t) | |
| 48 (?q . yield) | |
| 49 (?\C-g . yield) | |
| 50 (?p . nil) | |
| 51 (?? . help)))) | |
| 52 (cond ((null answer) | |
| 53 (beep) | |
| 54 (message "Please type q, s, or p; or ? for help") | |
| 55 (sit-for 3)) | |
| 56 ((eq (cdr answer) 'help) | |
| 57 (ask-user-about-lock-help) | |
| 58 (setq answer nil)) | |
| 59 ((eq (cdr answer) 'yield) | |
| 444 | 60 (signal 'file-locked (list "File is locked" filename other-user))))))) |
| 428 | 61 (cdr answer)))) |
| 62 | |
| 63 (defun ask-user-about-lock-help () | |
| 64 (with-output-to-temp-buffer "*Help*" | |
| 65 (princ "It has been detected that you want to modify a file that someone else has | |
| 66 already started modifying in EMACS. | |
| 67 | |
| 68 You can <s>teal the file; The other user becomes the | |
| 69 intruder if (s)he ever unmodifies the file and then changes it again. | |
| 70 You can <p>roceed; you edit at your own (and the other user's) risk. | |
| 71 You can <q>uit; don't modify this file.") | |
| 72 (save-excursion | |
| 73 (set-buffer standard-output) | |
| 74 (help-mode)))) | |
| 75 | |
| 76 (define-error 'file-supersession "File changed on disk" 'file-error) ; XEmacs | |
| 77 | |
| 444 | 78 (defun ask-user-about-supersession-threat-minibuf (filename) |
| 428 | 79 (save-window-excursion |
| 80 (let (answer) | |
| 81 (while (null answer) | |
| 82 (message "%s changed on disk; really edit the buffer? (y, n, r or C-h) " | |
| 444 | 83 (file-name-nondirectory filename)) |
| 428 | 84 (let ((tem (downcase (let ((cursor-in-echo-area t)) |
| 85 (read-char))))) | |
| 86 (setq answer | |
| 87 (if (= tem help-char) | |
| 88 'help | |
| 89 (cdr (assoc tem '((?n . yield) | |
| 90 (?\C-g . yield) | |
| 91 (?y . proceed) | |
| 92 (?r . revert) | |
| 93 (?? . help)))))) | |
| 94 (cond ((null answer) | |
| 95 (beep) | |
| 96 (message "Please type y, n or r; or ? for help") | |
| 97 (sit-for 3)) | |
| 98 ((eq answer 'help) | |
| 99 (ask-user-about-supersession-help) | |
| 100 (setq answer nil)) | |
| 101 ((eq answer 'revert) | |
| 102 (revert-buffer nil (not (buffer-modified-p))) | |
| 103 ; ask confirmation iff buffer modified | |
| 104 (signal 'file-supersession | |
| 444 | 105 (list "File reverted" filename))) |
| 428 | 106 ((eq answer 'yield) |
| 107 (signal 'file-supersession | |
| 444 | 108 (list "File changed on disk" filename)))))) |
| 428 | 109 (message |
| 110 "File on disk now will become a backup file if you save these changes.") | |
| 111 (setq buffer-backed-up nil)))) | |
| 112 | |
| 113 (defun ask-user-about-supersession-help () | |
| 114 (with-output-to-temp-buffer "*Help*" | |
| 115 (princ "You want to modify a buffer whose disk file has changed | |
| 116 since you last read it in or saved it with this buffer. | |
| 117 | |
| 118 If you say `y' to go ahead and modify this buffer, | |
| 119 you risk ruining the work of whoever rewrote the file. | |
| 120 If you say `r' to revert, the contents of the buffer are refreshed | |
| 121 from the file on disk. | |
| 122 If you say `n', the change you started to make will be aborted. | |
| 123 | |
| 124 Usually, you should type `n' and then `M-x revert-buffer', | |
| 125 to get the latest version of the file, then make the change again.") | |
| 126 (save-excursion | |
| 127 (set-buffer standard-output) | |
| 128 (help-mode)))) | |
| 129 | |
| 130 ;;; dialog-box versions [XEmacs] | |
| 131 | |
| 444 | 132 (defun ask-user-about-lock-dbox (filename other-user) |
| 442 | 133 (let ((echo-keystrokes 0)) |
| 134 (make-dialog-box | |
| 135 'question | |
| 136 :question (format "%s is locking %s\n | |
| 428 | 137 It has been detected that you want to modify a file that |
| 138 someone else has already started modifying in XEmacs." | |
| 444 | 139 other-user filename) |
| 442 | 140 :buttons |
| 141 '(["Steal Lock\n\nThe other user will\nbecome the intruder" steal t] | |
| 142 ["Proceed\n\nEdit file at your own\n\(and the other user's) risk" | |
| 143 proceed t] | |
| 144 nil | |
| 145 ["Abort\n\nDon't modify the buffer\n" yield t])) | |
| 428 | 146 (catch 'aual-done |
| 147 (while t | |
| 148 (let ((event (next-command-event))) | |
| 442 | 149 (cond ((and (misc-user-event-p event) |
| 150 (eq (event-object event) 'proceed)) | |
| 428 | 151 (throw 'aual-done nil)) |
| 442 | 152 ((and (misc-user-event-p event) |
| 153 (eq (event-object event) 'steal)) | |
| 428 | 154 (throw 'aual-done t)) |
| 442 | 155 ((and (misc-user-event-p event) |
| 156 (eq (event-object event) 'yield)) | |
| 444 | 157 (signal 'file-locked (list "File is locked" filename other-user))) |
| 428 | 158 ((and (misc-user-event-p event) |
| 159 (eq (event-object event) 'menu-no-selection-hook)) | |
| 160 (signal 'quit nil)) | |
| 442 | 161 ;; safety check, so we're not endlessly stuck when no |
| 162 ;; dialog box up | |
| 163 ((not (popup-up-p)) | |
| 164 (signal 'quit nil)) | |
| 428 | 165 ((button-release-event-p event) ;; don't beep twice |
| 166 nil) | |
| 167 (t | |
| 168 (beep) | |
| 169 (message "please answer the dialog box")))))))) | |
| 170 | |
| 444 | 171 (defun ask-user-about-supersession-threat-dbox (filename) |
| 442 | 172 (let ((echo-keystrokes 0)) |
| 173 (make-dialog-box | |
| 174 'question | |
| 175 :question | |
| 176 (format "File %s has changed on disk | |
| 428 | 177 since its buffer was last read in or saved. |
| 178 | |
| 444 | 179 Do you really want to edit the buffer? " filename) |
| 442 | 180 :buttons |
| 181 '(["Yes\n\nEdit the buffer anyway,\nignoring the disk file" | |
| 182 proceed t] | |
| 183 ["No\n\nDon't modify the buffer\n" yield t] | |
| 184 nil | |
| 185 ["No\n\nDon't modify the buffer\nbut revert it" revert t] | |
| 186 )) | |
| 428 | 187 (catch 'auast-done |
| 188 (while t | |
| 189 (let ((event (next-command-event))) | |
| 190 (cond ((and (misc-user-event-p event) (eq (event-object event) 'proceed)) | |
| 191 (throw 'auast-done nil)) | |
| 192 ((and (misc-user-event-p event) (eq (event-object event) 'yield)) | |
| 444 | 193 (signal 'file-supersession (list filename))) |
| 428 | 194 ((and (misc-user-event-p event) (eq (event-object event) 'revert)) |
| 444 | 195 (or (equal filename (buffer-file-name)) |
| 428 | 196 (error |
| 197 "ask-user-about-supersession-threat called bogusly")) | |
| 198 (revert-buffer nil t) | |
| 199 (signal 'file-supersession | |
| 444 | 200 (list filename "(reverted)"))) |
| 428 | 201 ((and (misc-user-event-p event) |
| 202 (eq (event-object event) 'menu-no-selection-hook)) | |
| 203 (signal 'quit nil)) | |
| 442 | 204 ;; safety check, so we're not endlessly stuck when no |
| 205 ;; dialog box up | |
| 206 ((not (popup-up-p)) | |
| 207 (signal 'quit nil)) | |
| 428 | 208 ((button-release-event-p event) ;; don't beep twice |
| 209 nil) | |
| 210 (t | |
| 211 (beep) | |
| 212 (message "please answer the dialog box")))))))) | |
| 213 | |
| 214 | |
| 215 ;;; top-level | |
| 216 | |
| 217 ;;;###autoload | |
| 444 | 218 (defun ask-user-about-lock (filename other-user) |
| 219 "Ask user wanting to edit FILENAME, locked by OTHER-USER, what to do. | |
| 428 | 220 This function has a choice of three things to do: |
| 444 | 221 do (signal 'file-locked (list FILENAME OTHER-USER)) |
| 428 | 222 to refrain from editing the file |
| 223 return t (grab the lock on the file) | |
| 224 return nil (edit the file even though it is locked). | |
| 444 | 225 You can rewrite it to use any criteria you like to choose which one to do." |
| 428 | 226 (discard-input) |
| 442 | 227 (if (should-use-dialog-box-p) |
| 444 | 228 (ask-user-about-lock-dbox filename other-user) |
| 229 (ask-user-about-lock-minibuf filename other-user))) | |
| 428 | 230 |
| 231 ;;;###autoload | |
| 444 | 232 (defun ask-user-about-supersession-threat (filename) |
| 233 "Ask user who is about to modify an obsolete buffer what to do. | |
| 428 | 234 This function has two choices: it can return, in which case the modification |
| 444 | 235 of the buffer will proceed, or it can (signal 'file-supersession (FILENAME)), |
| 428 | 236 in which case the proposed buffer modification will not be made. |
| 237 | |
| 444 | 238 You can rewrite this to use any criteria you like to choose which one to do. |
| 428 | 239 The buffer in question is current when this function is called." |
| 240 (discard-input) | |
| 442 | 241 (if (should-use-dialog-box-p) |
| 444 | 242 (ask-user-about-supersession-threat-dbox filename) |
| 243 (ask-user-about-supersession-threat-minibuf filename))) | |
| 428 | 244 |
| 245 ;;; userlock.el ends here |