--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lisp/packages/server.el	Mon Aug 13 08:45:50 2007 +0200
@@ -0,0 +1,418 @@
+;;; server.el --- Lisp code for GNU Emacs running as server process.
+
+;; Copyright (C) 1986, 1987, 1992, 1994, 1995 Free Software Foundation, Inc.
+
+;; Author: William Sommerfeld <wesommer@athena.mit.edu>
+;; Keywords: processes
+
+;; Changes by peck@sun.com and by rms.
+
+;; This file is part of XEmacs.
+
+;; XEmacs 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 2, or (at your option)
+;; any later version.
+
+;; XEmacs 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 XEmacs; see the file COPYING.  If not, write to the Free
+;; Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+;;; Synched up with FSF 19.30.
+
+;;; Commentary:
+
+;;; This Lisp code is run in Emacs when it is to operate as
+;;; a server for other processes.
+
+;;; Load this library and do M-x server-edit to enable Emacs as a server.
+;;; Emacs runs the program ../etc/emacsserver as a subprocess
+;;; for communication with clients.  If there are no client buffers to edit, 
+;;; server-edit acts like (switch-to-buffer (other-buffer))
+
+;;; When some other program runs "the editor" to edit a file,
+;;; "the editor" can be the Emacs client program ../etc/emacsclient.
+;;; This program transmits the file names to Emacs through
+;;; the server subprocess, and Emacs visits them and lets you edit them.
+
+;;; Note that any number of clients may dispatch files to emacs to be edited.
+
+;;; When you finish editing a Server buffer, again call server-edit
+;;; to mark that buffer as done for the client and switch to the next 
+;;; Server buffer.  When all the buffers for a client have been edited 
+;;; and exited with server-edit, the client "editor" will return
+;;; to the program that invoked it.  
+
+;;; Your editing commands and Emacs's display output go to and from
+;;; the terminal in the usual way.  Thus, server operation is possible
+;;; only when Emacs can talk to the terminal at the time you invoke
+;;; the client.  This is possible in four cases:
+
+;;; 1. On a window system, where Emacs runs in one window and the
+;;; program that wants to use "the editor" runs in another.
+
+;;; 2. On a multi-terminal system, where Emacs runs on one terminal and the
+;;; program that wants to use "the editor" runs on another.
+
+;;; 3. When the program that wants to use "the editor" is running
+;;; as a subprocess of Emacs.
+
+;;; 4. On a system with job control, when Emacs is suspended, the program
+;;; that wants to use "the editor" will stop and display
+;;; "Waiting for Emacs...".  It can then be suspended, and Emacs can be
+;;; brought into the foreground for editing.  When done editing, Emacs is
+;;; suspended again, and the client program is brought into the foreground.
+
+;;; The buffer local variable "server-buffer-clients" lists 
+;;; the clients who are waiting for this buffer to be edited.  
+;;; The global variable "server-clients" lists all the waiting clients,
+;;; and which files are yet to be edited for each.
+
+;;; Code:
+
+(defvar server-program (expand-file-name "emacsserver" exec-directory)
+  "*The program to use as the edit server.")
+
+(defvar server-visit-hook nil
+  "*List of hooks to call when visiting a file for the Emacs server.")
+
+(defvar server-switch-hook nil
+  "*List of hooks to call when switching to a buffer for the Emacs server.")
+
+(defvar server-done-hook nil
+  "*List of hooks to call when done editing a buffer for the Emacs server.")
+
+(defvar server-process nil 
+  "the current server process")
+
+(defvar server-previous-string "")
+
+(defvar server-clients nil
+  "List of current server clients.
+Each element is (CLIENTID BUFFERS...) where CLIENTID is a string
+that can be given to the server process to identify a client.
+When a buffer is marked as \"done\", it is removed from this list.")
+
+(defvar server-buffer-clients nil
+  "List of clientids for clients requesting editing of current buffer.")
+(make-variable-buffer-local 'server-buffer-clients)
+;; Changing major modes should not erase this local.
+(put 'server-buffer-clients 'permanent-local t)
+
+(defvar server-window nil
+  "*The window to use for selecting Emacs server buffers.
+If nil, use the selected window.
+If it is a frame, use the frame's selected window.")
+
+(defvar server-temp-file-regexp "^/tmp/Re\\|/draft$"
+  "*Regexp which should match filenames of temporary files
+which are deleted and reused after each edit
+by the programs that invoke the emacs server.")
+
+(or (assq 'server-buffer-clients minor-mode-alist)
+    (setq minor-mode-alist (cons '(server-buffer-clients " Server") minor-mode-alist)))
+
+;; If a *server* buffer exists,
+;; write STRING to it for logging purposes.
+(defun server-log (string)
+  (if (get-buffer "*server*")
+      (save-excursion
+	(set-buffer "*server*")
+	(goto-char (point-max))
+	(insert (current-time-string) " " string)
+	(or (bolp) (newline)))))
+
+(defun server-sentinel (proc msg)
+  (cond ((eq (process-status proc) 'exit)
+	 (server-log (message "Server subprocess exited")))
+	((eq (process-status proc) 'signal)
+	 (server-log (message "Server subprocess killed")))))
+
+;;;###autoload
+(make-obsolete 'server-start 'gnuserv-start)
+(defun server-start (&optional leave-dead)
+  "Use `gnuserv-start' instead of this function.
+Allow this Emacs process to be a server for client processes.
+This starts a server communications subprocess through which
+client \"editors\" can send your editing commands to this Emacs job.
+To use the server, set up the program `emacsclient' in the
+Emacs distribution as your standard \"editor\".
+
+Prefix arg means just kill any existing server communications subprocess."
+  (interactive "P")
+  ;; kill it dead!
+  (if server-process
+      (progn
+	(set-process-sentinel server-process nil)
+	(condition-case () (delete-process server-process) (error nil))))
+  (condition-case () (delete-file "~/.emacs_server") (error nil))
+  (let* ((sysname (system-name))
+	 (dot-index (string-match "\\." sysname)))
+    (condition-case ()
+	(delete-file (format "/tmp/esrv%d-%s" (user-uid) sysname))
+      (error nil))
+    ;; In case the server file name was made with a domainless hostname,
+    ;; try deleting that name too.
+    (if dot-index
+	(condition-case ()
+	    (delete-file (format "/tmp/esrv%d-%s" (user-uid)
+				 (substring sysname 0 dot-index)))
+	  (error nil))))
+  ;; If we already had a server, clear out associated status.
+  (while server-clients
+    (let ((buffer (nth 1 (car server-clients))))
+      (server-buffer-done buffer)))
+  (if leave-dead
+      nil
+    (if server-process
+	(server-log (message "Restarting server")))
+    ;; Using a pty is wasteful, and the separate session causes
+    ;; annoyance sometimes (some systems kill idle sessions).
+    (let ((process-connection-type nil))
+      (setq server-process (start-process "server" nil server-program)))
+    (set-process-sentinel server-process 'server-sentinel)
+    (set-process-filter server-process 'server-process-filter)
+    (process-kill-without-query server-process)))
+
+;Process a request from the server to edit some files.
+;Format of STRING is "Client: CLIENTID PATH PATH PATH... \n"
+(defun server-process-filter (proc string)
+  (server-log string)
+  (setq string (concat server-previous-string string))
+  ;; If the input is multiple lines,
+  ;; process each line individually.
+  (while (string-match "\n" string)
+    (let ((request (substring string 0 (match-beginning 0)))
+	  client
+	  (files nil)
+	  (lineno 1))
+      ;; Remove this line from STRING.
+      (setq string (substring string (match-end 0)))	  
+      (if (string-match "^Error: " request)
+	  (message (concat "Server error: " (substring request (match-end 0))))
+	(if (string-match "^Client: " request)
+	    (progn
+	      (setq request (substring request (match-end 0)))
+	      (setq client (list (substring request 0 (string-match " " request))))
+	      (setq request (substring request (match-end 0)))
+	      (while (string-match "[^ ]+ " request)
+		(let ((arg
+		       (substring request (match-beginning 0) (1- (match-end 0)))))
+		  (setq request (substring request (match-end 0)))
+		  (if (string-match "\\`\\+[0-9]+\\'" arg)
+		      (setq lineno (read (substring arg 1)))
+		    (setq files
+			  (cons (list arg lineno)
+				files))
+		    (setq lineno 1))))
+	      (server-visit-files files client)
+	      ;; CLIENT is now a list (CLIENTNUM BUFFERS...)
+	      (setq server-clients (cons client server-clients))
+	      (server-switch-buffer (nth 1 client))
+	      (run-hooks 'server-switch-hook)
+	      (message (substitute-command-keys
+			"When done with a buffer, type \\[server-edit]")))))))
+  ;; Save for later any partial line that remains.
+  (setq server-previous-string string))
+
+(defun server-visit-files (files client)
+  "Finds FILES and returns the list CLIENT with the buffers nconc'd.
+FILES is an alist whose elements are (FILENAME LINENUMBER)."
+  (let (client-record (obuf (current-buffer)))
+    ;; Restore the current buffer afterward, but not using save-excursion,
+    ;; because we don't want to save point in this buffer
+    ;; if it happens to be one of those specified by the server.
+    (unwind-protect
+	(while files
+	  ;; If there is an existing buffer modified or the file is modified,
+	  ;; revert it.
+	  ;; If there is an existing buffer with deleted file, offer to write it.
+	  (let* ((filen (car (car files)))
+		 (obuf (get-file-buffer filen)))
+	    (if (and obuf (set-buffer obuf))
+		(if (file-exists-p filen)
+		    (if (or (not (verify-visited-file-modtime obuf))
+			    (buffer-modified-p obuf))
+			(revert-buffer t nil))
+		  (if (y-or-n-p
+		       (concat "File no longer exists: "
+			       filen
+			       ", write buffer to file? "))
+		      (write-file filen)))
+	      (set-buffer (find-file-noselect filen))
+	      (run-hooks 'server-visit-hook)))
+	  (goto-line (nth 1 (car files)))
+	  (setq server-buffer-clients (cons (car client) server-buffer-clients))
+	  (setq client-record (cons (current-buffer) client-record))
+	  (setq files (cdr files)))
+      (set-buffer obuf))
+    (nconc client client-record)))
+
+(defun server-buffer-done (buffer)
+  "Mark BUFFER as \"done\" for its client(s).
+This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
+NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
+or nil.  KILLED is t if we killed BUFFER (because it was a temp file)."
+  (let ((running (eq (process-status server-process) 'run))
+	(next-buffer nil)
+	(killed nil)
+	(first t)
+	(old-clients server-clients))
+    (while old-clients
+      (let ((client (car old-clients)))
+	(or next-buffer 
+	    (setq next-buffer (nth 1 (memq buffer client))))
+	(delq buffer client)
+	;; Delete all dead buffers from CLIENT.
+	(let ((tail client))
+	  (while tail
+	    (and (bufferp (car tail))
+		 (null (buffer-name (car tail)))
+		 (delq (car tail) client))
+	    (setq tail (cdr tail))))
+	;; If client now has no pending buffers,
+	;; tell it that it is done, and forget it entirely.
+	(if (cdr client) nil
+	  (if running
+	      (progn
+		;; Don't send emacsserver two commands in close succession.
+		;; It cannot handle that.
+		(or first (sit-for 1))
+		(setq first nil)
+		(process-send-string server-process 
+				     (format "Close: %s Done\n" (car client)))
+		(server-log (format "Close: %s Done\n" (car client)))))
+	  (setq server-clients (delq client server-clients))))
+      (setq old-clients (cdr old-clients)))
+    (if (and (bufferp buffer) (buffer-name buffer))
+	(progn
+	  (save-excursion
+	    (set-buffer buffer)
+	    (setq server-buffer-clients nil)
+	    (run-hooks 'server-done-hook))
+	  (if (server-temp-file-p buffer)
+	      (progn (kill-buffer buffer)
+		     (setq killed t))
+	    (bury-buffer buffer))))
+    (list next-buffer killed)))
+
+(defun server-temp-file-p (buffer)
+  "Return non-nil if BUFFER contains a file considered temporary.
+These are files whose names suggest they are repeatedly
+reused to pass information to another program.
+
+The variable `server-temp-file-regexp' controls which filenames
+are considered temporary."
+  (and (buffer-file-name buffer)
+       (string-match server-temp-file-regexp (buffer-file-name buffer))))
+
+(defun server-done ()
+  "Offer to save current buffer, mark it as \"done\" for clients.
+This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
+NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
+or nil.  KILLED is t if we killed the BUFFER (because it was a temp file)."
+  (let ((buffer (current-buffer)))
+    (if server-buffer-clients
+	(progn
+ 	  (if (server-temp-file-p buffer)
+	      ;; For a temp file, save, and do make a non-numeric backup
+	      ;; (unless make-backup-files is nil).
+	      (let ((version-control nil)
+		    (buffer-backed-up nil))
+		(save-buffer))
+	    (if (and (buffer-modified-p)
+		     (y-or-n-p (concat "Save file " buffer-file-name "? ")))
+		(save-buffer buffer)))
+	  (server-buffer-done buffer)))))
+
+;; Ask before killing a server buffer.
+;; It was suggested to release its client instead,
+;; but I think that is dangerous--the client would proceed
+;; using whatever is on disk in that file. -- rms.
+(defun server-kill-buffer-query-function ()
+  (or (not server-buffer-clients)
+      (yes-or-no-p (format "Buffer `%s' still has clients; kill it? "
+			   (buffer-name (current-buffer))))))
+
+(add-hook 'kill-buffer-query-functions
+ 	  'server-kill-buffer-query-function)
+
+(defun server-kill-emacs-query-function ()
+  (let (live-client
+	(tail server-clients))
+    ;; See if any clients have any buffers that are still alive.
+    (while tail
+      (if (memq t (mapcar 'stringp (mapcar 'buffer-name (cdr (car tail)))))
+	  (setq live-client t))
+      (setq tail (cdr tail)))
+    (or (not live-client)
+	(yes-or-no-p "Server buffers still have clients; exit anyway? "))))
+
+(add-hook 'kill-emacs-query-functions 'server-kill-emacs-query-function)
+
+(defun server-edit (&optional arg)
+  "Switch to next server editing buffer; say \"Done\" for current buffer.
+If a server buffer is current, it is marked \"done\" and optionally saved.
+When all of a client's buffers are marked as \"done\", the client is notified.
+
+Temporary files such as MH <draft> files are always saved and backed up,
+no questions asked.  (The variable `make-backup-files', if nil, still
+inhibits a backup; you can set it locally in a particular buffer to
+prevent a backup for it.)  The variable `server-temp-file-regexp' controls
+which filenames are considered temporary.
+
+If invoked with a prefix argument, or if there is no server process running, 
+starts server process and that is all.  Invoked by \\[server-edit]."
+  (interactive "P")
+  (if (or arg
+	  (not server-process)
+	  (memq (process-status server-process) '(signal exit)))
+      (server-start nil)
+    (apply 'server-switch-buffer (server-done))))
+
+(defun server-switch-buffer (&optional next-buffer killed-one)
+  "Switch to another buffer, preferably one that has a client.
+Arg NEXT-BUFFER is a suggestion; if it is a live buffer, use it."
+  ;; KILLED-ONE is t in a recursive call
+  ;; if we have already killed one temp-file server buffer.
+  ;; This means we should avoid the final "switch to some other buffer"
+  ;; since we've already effectively done that.
+  (cond ((and (windowp server-window)
+	      (window-live-p server-window))
+	 (select-window server-window))
+	((framep server-window)
+	 (if (not (frame-live-p server-window))
+	     (setq server-window (make-frame)))
+	 (select-window (frame-selected-window server-window))))
+  (if (window-minibuffer-p (selected-window))
+      (select-window (next-window nil 'nomini 0)))
+  ;; Move to a non-dedicated window, if we have one.
+  (let ((last-window (previous-window nil 'nomini 0)))
+    (while (and (window-dedicated-p (selected-window))
+		(not (eq last-window (selected-window))))
+      (select-window (next-window nil 'nomini 0))))
+  (set-window-dedicated-p (selected-window) nil)
+  (if next-buffer
+      (if (and (bufferp next-buffer)
+	       (buffer-name next-buffer))
+	  (switch-to-buffer next-buffer)
+	;; If NEXT-BUFFER is a dead buffer,
+	;; remove the server records for it
+	;; and try the next surviving server buffer.
+	(apply 'server-switch-buffer
+	       (server-buffer-done next-buffer)))
+    (if server-clients
+	(server-switch-buffer (nth 1 (car server-clients)) killed-one)
+      (if (not killed-one)
+	  (switch-to-buffer (other-buffer))))))
+
+(global-set-key "\C-x#" 'server-edit)
+
+(provide 'server)
+
+;;; server.el ends here