X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/76b17c0b664daf4f941ec3a4d45e7c3e92d3003d..a7be409c6b9884611e1269b1a41b41046effcca8:/lisp/emacs-lisp/tq.el diff --git a/lisp/emacs-lisp/tq.el b/lisp/emacs-lisp/tq.el index 5dc77a36f6..1ee6a12c5c 100644 --- a/lisp/emacs-lisp/tq.el +++ b/lisp/emacs-lisp/tq.el @@ -1,17 +1,19 @@ ;;; tq.el --- utility to maintain a transaction queue -;; Copyright (C) 1985, 1986, 1987, 1992 Free Software Foundation, Inc. +;; Copyright (C) 1985, 1986, 1987, 1992, 2001, 2002, 2003, 2004, +;; 2005, 2006, 2007, 2008 Free Software Foundation, Inc. ;; Author: Scott Draves +;; Maintainer: FSF ;; Adapted-By: ESR ;; Keywords: extensions ;; This file is part of GNU Emacs. -;; GNU Emacs is free software; you can redistribute it and/or modify +;; 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. +;; the Free Software Foundation, either version 3 of the License, 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 @@ -19,23 +21,60 @@ ;; 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, 675 Mass Ave, Cambridge, MA 02139, USA. +;; along with GNU Emacs. If not, see . ;;; Commentary: - -;;; manages receiving a stream asynchronously, -;;; parsing it into transactions, and then calling -;;; handler functions -;;; Our basic structure is the queue/process/buffer triple. Each entry -;;; of the queue is a regexp/closure/function triple. We buffer -;;; bytes from the process until we see the regexp at the head of the -;;; queue. Then we call the function with the closure and the -;;; collected bytes. +;; This file manages receiving a stream asynchronously, parsing it +;; into transactions, and then calling the associated handler function +;; upon the completion of each transaction. + +;; Our basic structure is the queue/process/buffer triple. Each entry +;; of the queue part is a list of question, regexp, closure, and +;; function that is consed to the last element. + +;; A transaction queue may be created by calling `tq-create'. + +;; A request may be added to the queue by calling `tq-enqueue'. If +;; the `delay-question' argument is non-nil, we will wait to send the +;; question to the process until it has finished sending other input. +;; Otherwise, once a request is enqueued, we send the given question +;; immediately to the process. + +;; We then buffer bytes from the process until we see the regexp that +;; was provided in the call to `tq-enqueue'. Then we call the +;; provided function with the closure and the collected bytes. If we +;; have indicated that the question from the next transaction was not +;; sent immediately, send it at this point, awaiting the response. ;;; Code: +;;; Accessors + +;; This part looks like (queue . (process . buffer)) +(defun tq-queue (tq) (car tq)) +(defun tq-process (tq) (car (cdr tq))) +(defun tq-buffer (tq) (cdr (cdr tq))) + +;; The structure of `queue' is as follows +;; ((question regexp closure . fn) +;; ) +;; question: string to send to the process +(defun tq-queue-head-question (tq) (car (car (tq-queue tq)))) +;; regexp: regular expression that matches the end of a response from +;; the process +(defun tq-queue-head-regexp (tq) (car (cdr (car (tq-queue tq))))) +;; closure: additional data to pass to the function +(defun tq-queue-head-closure (tq) (car (cdr (cdr (car (tq-queue tq)))))) +;; fn: function to call upon receiving a complete response from the +;; process +(defun tq-queue-head-fn (tq) (cdr (cdr (cdr (car (tq-queue tq)))))) + +;; Determine whether queue is empty +(defun tq-queue-empty (tq) (not (tq-queue tq))) + +;;; Core functionality + ;;;###autoload (defun tq-create (process) "Create and return a transaction queue communicating with PROCESS. @@ -46,38 +85,44 @@ to a tcp server on another machine." (generate-new-buffer (concat " tq-temp-" (process-name process))))))) + (buffer-disable-undo (tq-buffer tq)) (set-process-filter process - (`(lambda (proc string) - (tq-filter '(, tq) string)))) + `(lambda (proc string) + (tq-filter ',tq string))) tq)) -;;; accessors -(defun tq-queue (tq) (car tq)) -(defun tq-process (tq) (car (cdr tq))) -(defun tq-buffer (tq) (cdr (cdr tq))) - -(defun tq-queue-add (tq re closure fn) +(defun tq-queue-add (tq question re closure fn) (setcar tq (nconc (tq-queue tq) - (cons (cons re (cons closure fn)) nil))) + (cons (cons question (cons re (cons closure fn))) nil))) 'ok) -(defun tq-queue-head-regexp (tq) (car (car (tq-queue tq)))) -(defun tq-queue-head-fn (tq) (cdr (cdr (car (tq-queue tq))))) -(defun tq-queue-head-closure (tq) (car (cdr (car (tq-queue tq))))) -(defun tq-queue-empty (tq) (not (tq-queue tq))) -(defun tq-queue-pop (tq) (setcar tq (cdr (car tq))) (null (car tq))) - +(defun tq-queue-pop (tq) + (setcar tq (cdr (car tq))) + (let ((question (tq-queue-head-question tq))) + (condition-case nil + (process-send-string (tq-process tq) question) + (error nil))) + (null (car tq))) -;;; must add to queue before sending! -(defun tq-enqueue (tq question regexp closure fn) +(defun tq-enqueue (tq question regexp closure fn &optional delay-question) "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. + +When the corresponding answer comes back, we call FN with two +arguments: CLOSURE, which may contain additional data that FN +needs, 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)) +that's how we tell where the answer ends. + +If DELAY-QUESTION is non-nil, delay sending this question until +the process has finished replying to any previous questions. +This produces more reliable results with some processes." + (let ((sendp (or (not delay-question) + (not (tq-queue tq))))) + (tq-queue-add tq (unless sendp question) regexp closure fn) + (when sendp + (process-send-string (tq-process tq) question)))) (defun tq-close (tq) "Shut down transaction queue TQ, terminating the process." @@ -86,33 +131,41 @@ that's how we tell where the answer ends." (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)) + (let ((buffer (tq-buffer tq))) + (when (buffer-live-p buffer) + (with-current-buffer buffer + (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." - (set-buffer (tq-buffer tq)) - (if (= 0 (buffer-size)) () - (if (tq-queue-empty tq) - (let ((buf (generate-new-buffer "*spurious*"))) - (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 " (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) - (tq-process-buffer tq)))))) + (let ((buffer (tq-buffer tq))) + (when (buffer-live-p buffer) + (set-buffer buffer) + (if (= 0 (buffer-size)) () + (if (tq-queue-empty tq) + (let ((buf (generate-new-buffer "*spurious*"))) + (copy-to-buffer buf (point-min) (point-max)) + (delete-region (point-min) (point)) + (pop-to-buffer buf nil) + (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)) + (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) +;; arch-tag: 65dea08c-4edd-4cde-83a5-e8a15b993b79 ;;; tq.el ends here