vc-dispatcher.el 17.2 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78
;;; vc-dispatcher.el -- generic command-dispatcher facility.

;; Copyright (C) 2008
;;   Free Software Foundation, Inc.

;; Author:     FSF (see below for full credits)
;; Maintainer: Eric S. Raymond <esr@thyrsus.com>
;; Keywords: tools

;; 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.

;;; Credits:

;; Designed and implemented by Eric S. Raymond, originally as part of VC mode.

;;; Commentary:

;; Goals:
;;
;; There is a class of front-ending problems that Emacs might be used
;; to address that involves selecting sets of files, or possibly
;; directories, and passing the selection set to slave commands.  The
;; prototypical example, from which this code is derived, is talking
;; to version-control systems. 
;;
;; vc-dispatcher.el is written to decouple the UI issues in such front
;; ends from their application-specific logic. It also provides a
;; service layer for running the slave commands either synchronously
;; or asynchronously and managing the message/error logs from the
;; command runs.
;;
;; Similar UI problems can be expected to come up in applications
;; areas other than VCSes; IDEs and document search are two obvious ones.
;; This mode is intended to ensure that the Emacs interfaces for all such
;; beasts are consistent and carefully designed.  But even if nothing
;; but VC ever uses it, getting the layer separation right will be
;; a valuable thing.

;; Dispatcher's universe:
;;
;; The universe consists of the file tree rooted at the current
;; directory. The dispatcher's upper layer deduces some subset 
;; of the file tree from the state of the currently visited buffer 
;; and returns that subset, presumably to a client mode.
;;
;; The user may be attempting to select one of three contexts: an
;; explicitly selected fileset, the current working directory, or a
;; global (null) context.  The user may be looking at either of two
;; different views; a buffer visiting a file, or a directory buffer
;; generated by vc-dispatcher.  The main UI problem connected with
;; this mode is that the user may need to be able to select any of
;; these three contexts from either view.
;;
;; The lower layer of this mode runs commands in subprocesses, either
;; synchronously or asynchronously.  Commands may be launched in one
;; of two ways: they may be run immediately, or the calling mode can
;; create a closure associated with a text-entry buffer, to be
;; executed when the user types C-c to ship the buffer contents. In
;; either case the command messages and error (if any) will remain
;; available in a status buffer.

(provide 'vc-dispatcher)

79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101
;; General customization

(defcustom vc-logentry-check-hook nil
  "Normal hook run by `vc-finish-logentry'.
Use this to impose your own rules on the entry in addition to any the
version control backend imposes itself."
  :type 'hook
  :group 'vc)

;; Variables the user doesn't need to know about.
(defvar vc-log-operation nil)
(defvar vc-log-after-operation-hook nil)
(defvar vc-log-fileset)
(defvar vc-log-extra)

;; In a log entry buffer, this is a local variable
;; that points to the buffer for which it was made
;; (either a file, or a VC dired buffer).
(defvar vc-parent-buffer nil)
(put 'vc-parent-buffer 'permanent-local t)
(defvar vc-parent-buffer-name nil)
(put 'vc-parent-buffer-name 'permanent-local t)

102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117
;; Common command execution logic

(defun vc-process-filter (p s)
  "An alternative output filter for async process P.
One difference with the default filter is that this inserts S after markers.
Another is that undo information is not kept."
  (let ((buffer (process-buffer p)))
    (when (buffer-live-p buffer)
      (with-current-buffer buffer
        (save-excursion
          (let ((buffer-undo-list t)
                (inhibit-read-only t))
            (goto-char (process-mark p))
            (insert s)
            (set-marker (process-mark p) (point))))))))

118 119
(defun vc-setup-buffer (buf)
  "Prepare BUF for executing a slave command and make it current."
120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252
  (let ((camefrom (current-buffer))
	(olddir default-directory))
    (set-buffer (get-buffer-create buf))
    (kill-all-local-variables)
    (set (make-local-variable 'vc-parent-buffer) camefrom)
    (set (make-local-variable 'vc-parent-buffer-name)
	 (concat " from " (buffer-name camefrom)))
    (setq default-directory olddir)
    (let ((buffer-undo-list t)
          (inhibit-read-only t))
      (erase-buffer))))

(defvar vc-sentinel-movepoint)          ;Dynamically scoped.

(defun vc-process-sentinel (p s)
  (let ((previous (process-get p 'vc-previous-sentinel))
        (buf (process-buffer p)))
    ;; Impatient users sometime kill "slow" buffers; check liveness
    ;; to avoid "error in process sentinel: Selecting deleted buffer".
    (when (buffer-live-p buf)
      (when previous (funcall previous p s))
      (with-current-buffer buf
        (setq mode-line-process
              (let ((status (process-status p)))
                ;; Leave mode-line uncluttered, normally.
                (unless (eq 'exit status)
                  (format " (%s)" status))))
        (let (vc-sentinel-movepoint)
          ;; Normally, we want async code such as sentinels to not move point.
          (save-excursion
            (goto-char (process-mark p))
            (let ((cmds (process-get p 'vc-sentinel-commands)))
              (process-put p 'vc-sentinel-commands nil)
              (dolist (cmd cmds)
                ;; Each sentinel may move point and the next one should be run
                ;; at that new point.  We could get the same result by having
                ;; each sentinel read&set process-mark, but since `cmd' needs
                ;; to work both for async and sync processes, this would be
                ;; difficult to achieve.
                (vc-exec-after cmd))))
          ;; But sometimes the sentinels really want to move point.
          (when vc-sentinel-movepoint
	    (let ((win (get-buffer-window (current-buffer) 0)))
	      (if (not win)
		  (goto-char vc-sentinel-movepoint)
		(with-selected-window win
		  (goto-char vc-sentinel-movepoint))))))))))

(defun vc-set-mode-line-busy-indicator ()
  (setq mode-line-process
	(concat " " (propertize "[waiting...]"
                                'face 'mode-line-emphasis
                                'help-echo
                                "A VC command is in progress in this buffer"))))

(defun vc-exec-after (code)
  "Eval CODE when the current buffer's process is done.
If the current buffer has no process, just evaluate CODE.
Else, add CODE to the process' sentinel."
  (let ((proc (get-buffer-process (current-buffer))))
    (cond
     ;; If there's no background process, just execute the code.
     ;; We used to explicitly call delete-process on exited processes,
     ;; but this led to timing problems causing process output to be
     ;; lost.  Terminated processes get deleted automatically
     ;; anyway. -- cyd
     ((or (null proc) (eq (process-status proc) 'exit))
      ;; Make sure we've read the process's output before going further.
      (when proc (accept-process-output proc))
      (eval code))
     ;; If a process is running, add CODE to the sentinel
     ((eq (process-status proc) 'run)
      (vc-set-mode-line-busy-indicator)
      (let ((previous (process-sentinel proc)))
        (unless (eq previous 'vc-process-sentinel)
          (process-put proc 'vc-previous-sentinel previous))
        (set-process-sentinel proc 'vc-process-sentinel))
      (process-put proc 'vc-sentinel-commands
                   ;; We keep the code fragments in the order given
                   ;; so that vc-diff-finish's message shows up in
                   ;; the presence of non-nil vc-command-messages.
                   (append (process-get proc 'vc-sentinel-commands)
                           (list code))))
     (t (error "Unexpected process state"))))
  nil)

(defvar vc-post-command-functions nil
  "Hook run at the end of `vc-do-command'.
Each function is called inside the buffer in which the command was run
and is passed 3 arguments: the COMMAND, the FILES and the FLAGS.")

(defvar w32-quote-process-args)

(defun vc-delistify (filelist)
  "Smash a FILELIST into a file list string suitable for info messages."
  ;; FIXME what about file names with spaces?
  (if (not filelist) "."  (mapconcat 'identity filelist " ")))

;;;###autoload
(defun vc-do-command (buffer okstatus command file-or-list &rest flags)
  "Execute a VC command, notifying user and checking for errors.
Output from COMMAND goes to BUFFER, or *vc* if BUFFER is nil or the
current buffer if BUFFER is t.  If the destination buffer is not
already current, set it up properly and erase it.  The command is
considered successful if its exit status does not exceed OKSTATUS (if
OKSTATUS is nil, that means to ignore error status, if it is `async', that
means not to wait for termination of the subprocess; if it is t it means to
ignore all execution errors).  FILE-OR-LIST is the name of a working file;
it may be a list of files or be nil (to execute commands that don't expect
a file name or set of files).  If an optional list of FLAGS is present,
that is inserted into the command line before the filename."
  ;; FIXME: file-relative-name can return a bogus result because
  ;; it doesn't look at the actual file-system to see if symlinks
  ;; come into play.
  (let* ((files
	  (mapcar (lambda (f) (file-relative-name (expand-file-name f)))
		  (if (listp file-or-list) file-or-list (list file-or-list))))
	 (full-command
	  ;; What we're doing here is preparing a version of the command
	  ;; for display in a debug-progess message.  If it's fewer than
	  ;; 20 characters display the entire command (without trailing
	  ;; newline).  Otherwise display the first 20 followed by an ellipsis.
	  (concat (if (string= (substring command -1) "\n")
		      (substring command 0 -1)
		    command)
		  " "
		  (vc-delistify (mapcar (lambda (s) (if (> (length s) 20) (concat (substring s 0 2) "...")  s)) flags))
		  " " (vc-delistify files))))
    (save-current-buffer
      (unless (or (eq buffer t)
		  (and (stringp buffer)
		       (string= (buffer-name) buffer))
		  (eq buffer (current-buffer)))
253
	(vc-setup-buffer (or buffer "*vc*")))
254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312
      ;; If there's some previous async process still running, just kill it.
      (let ((oldproc (get-buffer-process (current-buffer))))
        ;; If we wanted to wait for oldproc to finish before doing
        ;; something, we'd have used vc-eval-after.
        ;; Use `delete-process' rather than `kill-process' because we don't
        ;; want any of its output to appear from now on.
        (if oldproc (delete-process oldproc)))
      (let ((squeezed (remq nil flags))
	    (inhibit-read-only t)
	    (status 0))
	(when files
	  (setq squeezed (nconc squeezed files)))
	(let ((exec-path (append vc-path exec-path))
	      ;; Add vc-path to PATH for the execution of this command.
	      (process-environment
	       (cons (concat "PATH=" (getenv "PATH")
			     path-separator
			     (mapconcat 'identity vc-path path-separator))
		     process-environment))
	      (w32-quote-process-args t))
	  (when (and (eq okstatus 'async) (file-remote-p default-directory))
	    ;; start-process does not support remote execution
	    (setq okstatus nil))
	  (if (eq okstatus 'async)
	      ;; Run asynchronously.
	      (let ((proc
		     (let ((process-connection-type nil))
		       (apply 'start-file-process command (current-buffer)
                              command squeezed))))
		(if vc-command-messages
		    (message "Running %s in background..." full-command))
		;;(set-process-sentinel proc (lambda (p msg) (delete-process p)))
		(set-process-filter proc 'vc-process-filter)
		(vc-exec-after
		 `(if vc-command-messages
		      (message "Running %s in background... done" ',full-command))))
	    ;; Run synchrously
	    (when vc-command-messages
	      (message "Running %s in foreground..." full-command))
	    (let ((buffer-undo-list t))
	      (setq status (apply 'process-file command nil t nil squeezed)))
	    (when (and (not (eq t okstatus))
		       (or (not (integerp status))
			   (and okstatus (< okstatus status))))
              (unless (eq ?\s (aref (buffer-name (current-buffer)) 0))
                (pop-to-buffer (current-buffer))
                (goto-char (point-min))
                (shrink-window-if-larger-than-buffer))
	      (error "Running %s...FAILED (%s)" full-command
		     (if (integerp status) (format "status %d" status) status))))
	  ;; We're done.  But don't emit a status message if running
	  ;; asychronously, it would just mislead.
	  (if (and vc-command-messages (not (eq okstatus 'async)))
	      (message "Running %s...OK = %d" full-command status)))
	(vc-exec-after
	 `(run-hook-with-args 'vc-post-command-functions
			      ',command ',file-or-list ',flags))
	status))))

313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410
;; Command closures

(defun vc-start-logentry (files extra comment initial-contents msg action &optional after-hook)
  "Accept a comment for an operation on FILES with extra data EXTRA.
If COMMENT is nil, pop up a VC-log buffer, emit MSG, and set the
action on close to ACTION.  If COMMENT is a string and
INITIAL-CONTENTS is non-nil, then COMMENT is used as the initial
contents of the log entry buffer.  If COMMENT is a string and
INITIAL-CONTENTS is nil, do action immediately as if the user had
entered COMMENT.  If COMMENT is t, also do action immediately with an
empty comment.  Remember the file's buffer in `vc-parent-buffer'
\(current one if no file).  AFTER-HOOK specifies the local value
for `vc-log-after-operation-hook'."
  (let ((parent
         (if (or (eq major-mode 'vc-dired-mode) (eq major-mode 'vc-dir-mode))
             ;; If we are called from VC dired, the parent buffer is
             ;; the current buffer.
             (current-buffer)
           (if (and files (equal (length files) 1))
               (get-file-buffer (car files))
             (current-buffer)))))
    (when vc-before-checkin-hook
      (if files
	  (with-current-buffer parent
	    (run-hooks 'vc-before-checkin-hook))
	(run-hooks 'vc-before-checkin-hook)))
    (if (and comment (not initial-contents))
	(set-buffer (get-buffer-create "*VC-log*"))
      (pop-to-buffer (get-buffer-create "*VC-log*")))
    (set (make-local-variable 'vc-parent-buffer) parent)
    (set (make-local-variable 'vc-parent-buffer-name)
	 (concat " from " (buffer-name vc-parent-buffer)))
    ;;(if file (vc-mode-line file))
    (vc-log-edit files)
    (make-local-variable 'vc-log-after-operation-hook)
    (when after-hook
      (setq vc-log-after-operation-hook after-hook))
    (setq vc-log-operation action)
    (setq vc-log-extra extra)
    (when comment
      (erase-buffer)
      (when (stringp comment) (insert comment)))
    (if (or (not comment) initial-contents)
	(message "%s  Type C-c C-c when done" msg)
      (vc-finish-logentry (eq comment t)))))

(defun vc-finish-logentry (&optional nocomment)
  "Complete the operation implied by the current log entry.
Use the contents of the current buffer as a check-in or registration
comment.  If the optional arg NOCOMMENT is non-nil, then don't check
the buffer contents as a comment."
  (interactive)
  ;; Check and record the comment, if any.
  (unless nocomment
    (run-hooks 'vc-logentry-check-hook))
  ;; Sync parent buffer in case the user modified it while editing the comment.
  ;; But not if it is a vc-dired buffer.
  (with-current-buffer vc-parent-buffer
    (or vc-dired-mode (eq major-mode 'vc-dir-mode) (vc-buffer-sync)))
  (unless vc-log-operation
    (error "No log operation is pending"))
  ;; save the parameters held in buffer-local variables
  (let ((log-operation vc-log-operation)
	(log-fileset vc-log-fileset)
	(log-extra vc-log-extra)
	(log-entry (buffer-string))
	(after-hook vc-log-after-operation-hook)
	(tmp-vc-parent-buffer vc-parent-buffer))
    (pop-to-buffer vc-parent-buffer)
    ;; OK, do it to it
    (save-excursion
      (funcall log-operation
	       log-fileset
	       log-extra
	       log-entry))
    ;; Remove checkin window (after the checkin so that if that fails
    ;; we don't zap the *VC-log* buffer and the typing therein).
    ;; -- IMO this should be replaced with quit-window
    (let ((logbuf (get-buffer "*VC-log*")))
      (cond ((and logbuf vc-delete-logbuf-window)
	     (delete-windows-on logbuf (selected-frame))
	     ;; Kill buffer and delete any other dedicated windows/frames.
	     (kill-buffer logbuf))
	    (logbuf (pop-to-buffer "*VC-log*")
		    (bury-buffer)
		    (pop-to-buffer tmp-vc-parent-buffer))))
    ;; Now make sure we see the expanded headers
    (when log-fileset
      (mapc
       (lambda (file) (vc-resynch-buffer file vc-keep-workfiles t))
       log-fileset))
    (when vc-dired-mode
      (dired-move-to-filename))
    (when (eq major-mode 'vc-dir-mode)
      (vc-dir-move-to-goal-column))
    (run-hooks after-hook 'vc-finish-logentry-hook)))


411
;;; vc-dispatcher.el ends here