;;; tq.el --- utility to maintain a transaction queue
+;; Copyright (C) 1985, 1986, 1987, 1992 Free Software Foundation, Inc.
+
;; Author: Scott Draves <spot@cs.cmu.edu>
;; Adapted-By: ESR
+;; Keywords: extensions
+
+;; 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 2, 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., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
-;; Commentary:
+;;; Commentary:
;;; manages receiving a stream asynchronously,
;;; parsing it into transactions, and then calling
;;; Code:
-(provide 'tq)
-
+;;;###autoload
(defun tq-create (process)
- "Create and return a transaction queue. PROCESS should be capable
-of sending and receiving streams of bytes. It may be a local process,
-or it may be connected to a tcp server on another machine."
+ "Create and return a transaction queue communicating with PROCESS.
+PROCESS should be a subprocess capable of sending and receiving
+streams of bytes. It may be a local process, or it may be connected
+to a tcp server on another machine."
(let ((tq (cons nil (cons process
(generate-new-buffer
(concat " tq-temp-"
;;; must add to queue before sending!
(defun tq-enqueue (tq question regexp closure fn)
- "Add a transaction to TQ. Send question to the process, and call FN
-with CLOSURE and and the answer, when it appears. The end of the
-answer is identified by REGEXP."
+ "Add a transaction to transaction queue TQ.
+This sends the string QUESTION to the process that TQ communicates with.
+When the corresponding answer comes back, we call FN
+with two arguments: CLOSURE, and the answer to the question.
+REGEXP is a regular expression to match the entire answer;
+that's how we tell where the answer ends."
(tq-queue-add tq regexp closure fn)
(process-send-string (tq-process tq) question))
(defun tq-close (tq)
- "Shut down the process, and destroy the evidence."
+ "Shut down transaction queue TQ, terminating the process."
(delete-process (tq-process tq))
(kill-buffer (tq-buffer tq)))
(defun tq-filter (tq string)
"Append STRING to the TQ's buffer; then process the new data."
- (set-buffer (tq-buffer tq))
- (goto-char (point-max))
- (insert string)
- (tq-process-buffer tq))
+ (with-current-buffer (tq-buffer tq)
+ (goto-char (point-max))
+ (insert string)
+ (tq-process-buffer tq)))
(defun tq-process-buffer (tq)
"Check TQ's buffer for the regexp at the head of the queue."
(copy-to-buffer buf (point-min) (point-max))
(delete-region (point-min) (point))
(pop-to-buffer buf nil)
- (error (concat "Spurious communication from process "
- (process-name (tq-process tq))
- ", see buffer *spurious*.")))
+ (error "Spurious communication from process %s, see buffer %s"
+ (process-name (tq-process tq))
+ (buffer-name buf)))
(goto-char (point-min))
(if (re-search-forward (tq-queue-head-regexp tq) nil t)
(let ((answer (buffer-substring (point-min) (point))))
(delete-region (point-min) (point))
- (funcall (tq-queue-head-fn tq)
- (tq-queue-head-closure tq)
- answer)
- (tq-queue-pop tq)
+ (unwind-protect
+ (condition-case nil
+ (funcall (tq-queue-head-fn tq)
+ (tq-queue-head-closure tq)
+ answer)
+ (error nil))
+ (tq-queue-pop tq))
(tq-process-buffer tq))))))
+(provide 'tq)
+
;;; tq.el ends here