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1 | ;;; tq.el --- utility to maintain a transaction queue |
2 | ||
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3 | ;; Copyright (C) 1985, 1986, 1987, 1992 Free Software Foundation, Inc. |
4 | ||
83023647 | 5 | ;; Author: Scott Draves <spot@cs.cmu.edu> |
e29b94be | 6 | ;; Maintainer: FSF |
83023647 | 7 | ;; Adapted-By: ESR |
d7b4d18f | 8 | ;; Keywords: extensions |
83023647 | 9 | |
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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 | |
14 | ;; the Free Software Foundation; either version 2, or (at your option) | |
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 | |
b578f267 EN |
23 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
24 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
25 | ;; Boston, MA 02111-1307, USA. | |
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26 | |
27 | ;;; Commentary: | |
83023647 | 28 | |
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29 | ;;; manages receiving a stream asynchronously, |
30 | ;;; parsing it into transactions, and then calling | |
31 | ;;; handler functions | |
32 | ||
abeffda9 ER |
33 | ;;; Our basic structure is the queue/process/buffer triple. Each entry |
34 | ;;; of the queue is a regexp/closure/function triple. We buffer | |
35 | ;;; bytes from the process until we see the regexp at the head of the | |
36 | ;;; queue. Then we call the function with the closure and the | |
37 | ;;; collected bytes. | |
38 | ||
83023647 | 39 | ;;; Code: |
abeffda9 | 40 | |
09f11993 | 41 | ;;;###autoload |
abeffda9 | 42 | (defun tq-create (process) |
09f11993 RS |
43 | "Create and return a transaction queue communicating with PROCESS. |
44 | PROCESS should be a subprocess capable of sending and receiving | |
45 | streams of bytes. It may be a local process, or it may be connected | |
46 | to a tcp server on another machine." | |
abeffda9 ER |
47 | (let ((tq (cons nil (cons process |
48 | (generate-new-buffer | |
49 | (concat " tq-temp-" | |
50 | (process-name process))))))) | |
51 | (set-process-filter process | |
52 | (`(lambda (proc string) | |
53 | (tq-filter '(, tq) string)))) | |
54 | tq)) | |
55 | ||
56 | ;;; accessors | |
57 | (defun tq-queue (tq) (car tq)) | |
58 | (defun tq-process (tq) (car (cdr tq))) | |
59 | (defun tq-buffer (tq) (cdr (cdr tq))) | |
60 | ||
61 | (defun tq-queue-add (tq re closure fn) | |
62 | (setcar tq (nconc (tq-queue tq) | |
63 | (cons (cons re (cons closure fn)) nil))) | |
64 | 'ok) | |
65 | ||
66 | (defun tq-queue-head-regexp (tq) (car (car (tq-queue tq)))) | |
67 | (defun tq-queue-head-fn (tq) (cdr (cdr (car (tq-queue tq))))) | |
68 | (defun tq-queue-head-closure (tq) (car (cdr (car (tq-queue tq))))) | |
69 | (defun tq-queue-empty (tq) (not (tq-queue tq))) | |
70 | (defun tq-queue-pop (tq) (setcar tq (cdr (car tq))) (null (car tq))) | |
71 | ||
72 | ||
73 | ;;; must add to queue before sending! | |
74 | (defun tq-enqueue (tq question regexp closure fn) | |
09f11993 RS |
75 | "Add a transaction to transaction queue TQ. |
76 | This sends the string QUESTION to the process that TQ communicates with. | |
77 | When the corresponding answer comes back, we call FN | |
78 | with two arguments: CLOSURE, and the answer to the question. | |
79 | REGEXP is a regular expression to match the entire answer; | |
80 | that's how we tell where the answer ends." | |
abeffda9 ER |
81 | (tq-queue-add tq regexp closure fn) |
82 | (process-send-string (tq-process tq) question)) | |
83 | ||
84 | (defun tq-close (tq) | |
09f11993 | 85 | "Shut down transaction queue TQ, terminating the process." |
abeffda9 ER |
86 | (delete-process (tq-process tq)) |
87 | (kill-buffer (tq-buffer tq))) | |
88 | ||
89 | (defun tq-filter (tq string) | |
90 | "Append STRING to the TQ's buffer; then process the new data." | |
09841f8d RS |
91 | (with-current-buffer (tq-buffer tq) |
92 | (goto-char (point-max)) | |
93 | (insert string) | |
94 | (tq-process-buffer tq))) | |
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95 | |
96 | (defun tq-process-buffer (tq) | |
97 | "Check TQ's buffer for the regexp at the head of the queue." | |
98 | (set-buffer (tq-buffer tq)) | |
99 | (if (= 0 (buffer-size)) () | |
100 | (if (tq-queue-empty tq) | |
101 | (let ((buf (generate-new-buffer "*spurious*"))) | |
102 | (copy-to-buffer buf (point-min) (point-max)) | |
103 | (delete-region (point-min) (point)) | |
104 | (pop-to-buffer buf nil) | |
e8a74167 KH |
105 | (error "Spurious communication from process %s, see buffer %s" |
106 | (process-name (tq-process tq)) | |
107 | (buffer-name buf))) | |
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108 | (goto-char (point-min)) |
109 | (if (re-search-forward (tq-queue-head-regexp tq) nil t) | |
110 | (let ((answer (buffer-substring (point-min) (point)))) | |
111 | (delete-region (point-min) (point)) | |
941e78a7 RS |
112 | (unwind-protect |
113 | (condition-case nil | |
114 | (funcall (tq-queue-head-fn tq) | |
115 | (tq-queue-head-closure tq) | |
116 | answer) | |
117 | (error nil)) | |
118 | (tq-queue-pop tq)) | |
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119 | (tq-process-buffer tq)))))) |
120 | ||
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121 | (provide 'tq) |
122 | ||
abeffda9 | 123 | ;;; tq.el ends here |