diff options
| -rw-r--r-- | emms-player-mpd.el | 119 | ||||
| -rw-r--r-- | tq.el | 171 |
2 files changed, 180 insertions, 110 deletions
diff --git a/emms-player-mpd.el b/emms-player-mpd.el index a748c62..603a0f8 100644 --- a/emms-player-mpd.el +++ b/emms-player-mpd.el @@ -102,6 +102,7 @@ (require 'emms-player-simple) (require 'emms-source-playlist) ; for emms-source-file-parse-playlist +(require 'tq) (defgroup emms-player-mpd nil "EMMS player for MusicPD." @@ -224,107 +225,6 @@ If your EMMS playlist contains stored playlists, set this to nil." 'seek 'emms-player-mpd-seek) -;;; Transaction Queue (with some improvements) based on tq.el - -(defun emms-player-mpd-tq-create (process) - "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 " emms-player-mpd-tq-temp-" - (process-name process))))))) - (set-process-filter process - `(lambda (proc string) - (emms-player-mpd-tq-filter ',tq string))) - tq)) - -;; accessors -(defun emms-player-mpd-tq-queue (tq) - (car tq)) -(defun emms-player-mpd-tq-process (tq) - (car (cdr tq))) -(defun emms-player-mpd-tq-buffer (tq) - (cdr (cdr tq))) -(defun emms-player-mpd-tq-queue-head-question (tq) - (car (car (emms-player-mpd-tq-queue tq)))) -(defun emms-player-mpd-tq-queue-head-regexp (tq) - (car (cdr (car (emms-player-mpd-tq-queue tq))))) -(defun emms-player-mpd-tq-queue-head-closure (tq) - (car (cdr (cdr (car (emms-player-mpd-tq-queue tq)))))) -(defun emms-player-mpd-tq-queue-head-fn (tq) - (cdr (cdr (cdr (car (emms-player-mpd-tq-queue tq)))))) - -(defun emms-player-mpd-tq-queue-empty (tq) - (not (emms-player-mpd-tq-queue tq))) - -(defun emms-player-mpd-tq-queue-add (tq question re closure fn) - (setcar tq (nconc (emms-player-mpd-tq-queue tq) - (cons (cons question (cons re (cons closure fn))) nil))) - 'ok) - -(defun emms-player-mpd-tq-queue-pop (tq) - (setcar tq (cdr (car tq))) - (let ((question (emms-player-mpd-tq-queue-head-question tq))) - (when question - (process-send-string (emms-player-mpd-tq-process tq) question))) - (null (car tq))) - -(defun emms-player-mpd-tq-enqueue (tq question regexp closure fn) - "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." - (let ((sendp (not (emms-player-mpd-tq-queue-head-question tq)))) - (emms-player-mpd-tq-queue-add tq question regexp closure fn) - (when sendp - (process-send-string (emms-player-mpd-tq-process tq) question)))) - -(defun emms-player-mpd-tq-close (tq) - "Shut down transaction queue TQ, terminating the process." - (delete-process (emms-player-mpd-tq-process tq)) - (kill-buffer (emms-player-mpd-tq-buffer tq))) - -(defun emms-player-mpd-tq-filter (tq string) - "Append STRING to the TQ's buffer; then process the new data." - (let ((buffer (emms-player-mpd-tq-buffer tq))) - (when (buffer-live-p buffer) - (with-current-buffer buffer - (goto-char (point-max)) - (insert string) - (emms-player-mpd-tq-process-buffer tq))))) - -(defun emms-player-mpd-tq-process-buffer (tq) - "Check TQ's buffer for the regexp at the head of the queue." - (let ((buffer (emms-player-mpd-tq-buffer tq))) - (when (buffer-live-p buffer) - (set-buffer buffer) - (if (= 0 (buffer-size)) () - (if (emms-player-mpd-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 (emms-player-mpd-tq-process tq)) - (buffer-name buf))) - (goto-char (point-min)) - (if (re-search-forward (emms-player-mpd-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 (emms-player-mpd-tq-queue-head-fn tq) - (emms-player-mpd-tq-queue-head-closure tq) - answer) - (error nil)) - (emms-player-mpd-tq-queue-pop tq)) - (emms-player-mpd-tq-process-buffer tq)))))))) - ;;; Dealing with the MusicPD network process (defvar emms-player-mpd-process nil) @@ -375,16 +275,15 @@ return at the end of a request.") (set-process-sentinel emms-player-mpd-process 'emms-player-mpd-sentinel) (setq emms-player-mpd-queue - (emms-player-mpd-tq-create emms-player-mpd-process)) + (tq-create emms-player-mpd-process)) (if (fboundp 'set-process-query-on-exit-flag) (set-process-query-on-exit-flag emms-player-mpd-process nil) (process-kill-without-query emms-player-mpd-process)) ;; send password (when (stringp emms-player-mpd-server-password) - (emms-player-mpd-tq-enqueue - emms-player-mpd-queue - (concat "password " emms-player-mpd-server-password "\n") - emms-player-mpd-status-regexp nil #'ignore)))) + (tq-enqueue emms-player-mpd-queue + (concat "password " emms-player-mpd-server-password "\n") + emms-player-mpd-status-regexp nil #'ignore t)))) (defun emms-player-mpd-close-process (&optional from-sentinel) "Terminate the current MusicPD client process. @@ -393,7 +292,7 @@ in which case certain checks should not be made." (when (or from-sentinel (and (processp emms-player-mpd-process) (memq (process-status emms-player-mpd-process) '(run open)))) - (emms-player-mpd-tq-close emms-player-mpd-queue) + (tq-close emms-player-mpd-queue) (setq emms-player-mpd-queue nil) (setq emms-player-mpd-process nil))) @@ -403,9 +302,9 @@ When a reply comes, call FN with CLOSURE and the result." (emms-player-mpd-ensure-process) (unless (string= (substring question -1) "\n") (setq question (concat question "\n"))) - (emms-player-mpd-tq-enqueue emms-player-mpd-queue question - emms-player-mpd-status-regexp - closure fn)) + (tq-enqueue emms-player-mpd-queue question + emms-player-mpd-status-regexp + closure fn t)) ;;; Helper functions @@ -0,0 +1,171 @@ +;;; tq.el --- utility to maintain a transaction queue + +;; Copyright (C) 1985, 1986, 1987, 1992, 2002, 2003, 2004, +;; 2005, 2006 Free Software Foundation, Inc. + +;; Author: Scott Draves <spot@cs.cmu.edu> +;; 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 +;; 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., 51 Franklin Street, Fifth Floor, +;; Boston, MA 02110-1301, USA. + +;;; Commentary: + +;; 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) +;; <other queue entries>) +;; 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. +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-" + (process-name process))))))) + (set-process-filter process + `(lambda (proc string) + (tq-filter ',tq string))) + tq)) + +(defun tq-queue-add (tq question re closure fn) + (setcar tq (nconc (tq-queue tq) + (cons (cons question (cons re (cons closure fn))) nil))) + 'ok) + +(defun tq-queue-pop (tq) + (setcar tq (cdr (car tq))) + (let ((question (tq-queue-head-question tq))) + (when question + (process-send-string (tq-process tq) question))) + (null (car tq))) + +(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, 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. + +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." + (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." + (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." + (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 |