1 ;;;; MPCL -- Common Lisp MPD Client library
3 #-sbcl (error "No known socket interface for ~a" (lisp-implementation-type))
5 (eval-when (:compile-toplevel :load-toplevel :execute)
6 (require 'sb-bsd-sockets)
8 (defpackage :mpcl (:use :cl :sb-bsd-sockets))
13 (defvar *last-command* 0)
14 (defvar *last-server* nil)
16 #+sbcl (defvar *conn-lock* (sb-thread:make-mutex))
19 (defmacro concat (&rest strings)
20 `(concatenate 'string ,@strings))
22 (defun assert-type (type val)
23 (assert (typep val type))
26 (defun clipnum (num min max)
27 (cond ((< num min) min)
31 (defmacro regex-cond (key &body clauses)
32 (let ((match (gensym))
36 (flet ((ctrans (clause)
37 (if (eq (first clause) 'otherwise)
38 `(return-from ,block-nm
39 (progn ,@(rest clause)))
40 (destructuring-bind (regex arglist &body body)
42 `(multiple-value-bind (,match ,sub)
43 (ppcre:scan-to-strings ,regex ,val)
45 `((declare (ignore ,sub))))
47 (return-from ,block-nm
48 (let ,(let ((argno 0))
49 (mapcar #'(lambda (arg)
50 (prog1 `(,arg (aref ,sub ,argno))
55 (let ((,val (the string ,key)))
56 ,@(mapcar #'ctrans clauses))))))
59 (define-condition protocol-error (error)
60 ((message :reader protocol-error-message
63 (real-error :reader protocol-error-cause
67 (retries :reader protocol-error-retries
71 (:report (lambda (c s)
72 (if (protocol-error-cause c)
73 (format s "~A: ~A" (protocol-error-message c) (protocol-error-cause c))
74 (format s "Protocol error occurred on mpd socket: ~A" (protocol-error-message c))))))
76 (define-condition protocol-input-error (protocol-error)
77 ((inputs :reader protocol-error-inputs
79 (:report (lambda (c s)
80 (apply #'format s (protocol-error-message c) (protocol-error-inputs c)))))
82 (define-condition command-error (error)
83 ((err-code :reader command-error-code
86 (message :reader command-error-message
89 (:report (lambda (c s)
90 (format s "mpd error response: ~A" (command-error-message c)))))
92 (defvar *command-error-types* (make-hash-table))
94 (defmacro def-command-error-type (code name desc)
95 (let ((cond-sym (intern (concat "COMMAND-ERROR-" (symbol-name name)))))
96 `(progn (define-condition ,cond-sym (command-error)
98 (:report (lambda (c s)
99 (format s "mpd error response: ~A (message was: `~A')" ,desc (command-error-message c)))))
100 (setf (gethash ,code *command-error-types*) ',cond-sym)
101 (export '(,cond-sym)))))
102 ;; The following are fetched from libmpdclient.h. In all honesty, I
103 ;; can't really figure out what they mean just from their names, so
104 ;; the descriptions aren't optimal in every conceivable way.
105 (def-command-error-type 1 not-list "not list")
106 (def-command-error-type 2 arg "argument")
107 (def-command-error-type 3 password "bad password")
108 (def-command-error-type 4 permission "permission denied")
109 (def-command-error-type 5 unknown-cmd "unknown command")
110 (def-command-error-type 50 no-exist "item does not exist")
111 (def-command-error-type 51 playlist-max "playlist overload") ; ?!
112 (def-command-error-type 52 system "system error")
113 (def-command-error-type 53 playlist-load "could not load playlist")
114 (def-command-error-type 54 update-already "already updated") ; ?!
115 (def-command-error-type 55 player-sync "player sync") ; ?!
116 (def-command-error-type 56 exist "item already exists")
118 (export '(protocol-error reconnect command-error
119 protocol-error-retries command-error-code
120 command-error-message))
122 ;;; Struct definitions
124 (file "" :type string)
125 (id -1 :type integer)
126 (pos -1 :type integer)
127 (length -1 :type integer)
128 (track -1 :type integer)
129 artist title album genre composer date)
132 song-file song-id song-pos song-length song-track
133 song-artist song-title song-album song-genre
134 song-composer song-date))
137 (volume 0 :type integer)
138 (playlist-version -1 :type integer)
139 (num-songs 0 :type integer)
140 (song -1 :type integer)
141 (songid -1 :type integer)
142 (pos -1 :type integer)
143 (song-len -1 :type integer)
144 repeat repeat-song random state)
146 ;;; Basic protocol management
147 #+sbcl (defmacro with-conn-lock (&body body)
148 `(sb-thread:with-recursive-lock (*conn-lock*) ,@body))
149 #-sbcl (defmacro with-conn-lock (&body body)
153 "Disconnect from MPD."
155 (let ((sk (prog1 *socket* (setf *socket* nil))))
156 (if sk (ignore-errors (close sk))))))
158 (defun connection-error (condition-type &rest condition-args)
160 (error (apply #'make-condition condition-type :retries *retries* condition-args)))
162 (defun command-error (code message)
163 (error (funcall #'make-condition (gethash code *command-error-types* 'command-error)
167 (defun get-response ()
168 (let ((ret '()) (last nil))
169 (loop (let ((line (handler-case
172 (connection-error 'protocol-error
173 :message "Socket read error"
179 ("^ACK \\[(\\d+)@(\\d+)\\] \\{([^\\}]*)\\} (.*)$"
180 (code list-pos command rest)
181 (declare (ignore list-pos command))
182 (command-error (parse-integer code) rest))
185 (let ((new (list (cons (intern (string-upcase key) (find-package 'keyword))
188 (setf (cdr last) new last new)
189 (setf ret new last new))))
191 (connection-error 'protocol-input-error
192 :message "Invalid response from mpd: ~A"
193 :inputs (list line))))))))
195 (defun default-host ()
197 #+sbcl (let ((host (sb-posix:getenv "MPD_HOST")))
198 (when host (return host)))
201 (defun default-port ()
203 #+sbcl (let ((port (sb-posix:getenv "MPD_PORT")))
204 (when port (return (parse-integer port))))
207 (defun connect (&key (host (default-host)) (port (default-port)))
208 "Connect to a running MPD."
211 (setf *socket* (block outer
212 (let ((last-err nil))
213 (dolist (address (host-ent-addresses (get-host-by-name host)))
215 (let ((sk (make-instance 'inet-socket :type :stream)))
216 (socket-connect sk address port)
217 (return-from outer (socket-make-stream sk :input t :output t :buffering :none)))
220 (warn "mpd connection failure on address ~A: ~A" address err))))
222 (error "Could not connect to mpd: ~A" last-err)
223 (error "Could not connect to mpd: host name `~A' did not resolve to any addreses" host)))))
224 (setf *last-server* (cons host port))
225 (setf *last-command* (get-universal-time))
228 (defmacro dovector ((var vec) &body body)
230 `(dotimes (,i (length ,vec))
231 (let ((,var (aref ,vec ,i)))
234 (defmacro with-push-vector ((push-fun type &key (init-length 16)) &body body)
235 (let ((vec (gensym)))
236 `(let ((,vec (make-array (list ,init-length) :element-type ',type :adjustable t :fill-pointer 0)))
237 (flet ((,push-fun (el)
238 (declare (type ,type el))
239 (vector-push-extend el ,vec)))
243 (defun quote-argument (arg)
244 (declare (type string arg))
245 (if (= (length arg) 0)
248 (res (with-push-vector (add character)
252 (setf quote t) (add elt))
254 (setf quote t) (add #\\) (add #\"))
256 (error "Cannot send strings containing newlines to mpd: ~S" arg))
259 (concat "\"" res "\"")
262 (defun arg-to-string (arg)
266 (t (write-to-string arg :escape nil)))))
268 (defun mpd-command (&rest words)
273 (progn (if (null *socket*)
274 (connection-error 'protocol-error
275 :message "Not connected to mpd"))
277 (progn (write-string (reduce #'(lambda (a b) (concat a " " b))
278 (mapcar #'arg-to-string words))
281 (force-output *socket*))
283 (connection-error 'protocol-error
284 :message "Socket write error"
286 (setf *last-command* (get-universal-time))
287 (return (get-response)))
289 :test (lambda (c) (and (typep c 'protocol-error) (not (null *last-server*))))
291 (format s "Reconnect to ~A:~D and try again (~D retries so far)" (car *last-server*) (cdr *last-server*) *retries*))
293 (connect :host (car *last-server*)
294 :port (cdr *last-server*))))))))
296 (export '(connect disconnect))
299 ;; These, and the structures themselves, should probably be rewritten
300 ;; using macros instead. There's a lot of redundancy.
301 (defun cons-status (info)
302 (let ((ret (make-status)))
303 (dolist (line info ret)
307 (let ((pos (assert-type '(integer 0 *) (position #\: (cdr line)))))
308 (setf (status-pos ret) (parse-integer (subseq (cdr line) 0 pos))
309 (status-song-len ret) (parse-integer (subseq (cdr line) (1+ pos))))))
310 ((:state) (setf (status-state ret) (intern (string-upcase (cdr line)) (find-package 'keyword))))
311 ((:repeat) (setf (status-repeat ret) (not (equal (cdr line) "0"))))
312 ((:repeatsong) (setf (status-repeat-song ret) (not (equal (cdr line) "0"))))
313 ((:random) (setf (status-random ret) (not (equal (cdr line) "0"))))
314 ((:volume) (setf (status-volume ret) (parse-integer (cdr line))))
315 ((:playlistlength) (setf (status-num-songs ret) (parse-integer (cdr line))))
316 ((:song) (setf (status-song ret) (parse-integer (cdr line))))
317 ((:songid) (setf (status-songid ret) (parse-integer (cdr line))))
318 ((:playlist) (setf (status-playlist-version ret) (parse-integer (cdr line))))
320 ((:xfade :bitrate :audio))
321 (t (warn "Unknown status slot ~A" (car line))))
323 (warn "Status slot parse error in ~S, slot was ~S" ret line))))))
325 (defun song-list (info)
326 (let ((ret '()) (cur nil))
327 (dolist (line info ret)
331 (setf cur (make-song :file (cdr line)))
332 (setf ret (nconc ret (list cur))))
333 ((:time) (setf (song-length cur) (parse-integer (cdr line))))
334 ((:id) (setf (song-id cur) (parse-integer (cdr line))))
335 ((:pos) (setf (song-pos cur) (parse-integer (cdr line))))
336 ((:track) (setf (song-track cur) (parse-integer (cdr line))))
337 ((:title) (setf (song-title cur) (cdr line)))
338 ((:album) (setf (song-album cur) (cdr line)))
339 ((:artist) (setf (song-artist cur) (cdr line)))
340 ((:genre) (setf (song-genre cur) (cdr line)))
341 ((:composer) (setf (song-composer cur) (cdr line)))
342 ((:date) (setf (song-date cur) (cdr line)))
343 (t (warn "Unknown song slot ~A" (car line))))
345 (warn "Song slot parse error in ~A, slot was ~A" cur line))))))
347 ;;; Functions for individual commands
349 "Fetch and return the current status of the MPD as a STATUS structure."
350 (cons-status (mpd-command "status")))
352 (defmacro with-status (slots &body body)
353 "Fetch the current status of the MPD, and then run BODY with the
354 variables in the SLOTS bound to their curresponding status items.
358 The current state of the MPD
359 Known values are :STOP, :PAUSE and :PLAY
360 VOLUME (INTEGER 0 100)
361 Current output volume
362 PLAYLIST-VERSION (INTEGER 0 *)
363 Increases by one each time the playlist changes
364 NUM-SONGS (INTEGER 0 *)
365 Number of songs in the playlist
366 SONG (INTEGER 0 NUM-SONGS)
367 Index, in the playlist, of the currently playing song
369 ID of the currently playing song
370 SONG-LEN (INTEGER 0 *)
371 Length, in seconds, of currently playing song
372 POS (INTEGER 0 SONG-LEN)
373 Current time position of the currently playing song, in seconds
375 Non-NIL if the MPD is in repeat mode
376 REPEAT-SONG (NIL or T)
377 Non-NIL if the MPD is repeating the current song
378 (not available without patching)
380 Non-NIL if the MPD is in random mode"
381 (let ((status (gensym "STATUS")))
382 `(let* ((,status (status))
383 ;; This is kinda ugly, but I don't really know any better
384 ;; way to do it with structs.
385 ,@(mapcar #'(lambda (slot-sym)
386 (let ((slot-fun (intern (concat "STATUS-" (symbol-name slot-sym))
387 (find-package 'mpcl))))
388 `(,slot-sym (,slot-fun ,status))))
392 (defun play-song (song)
393 "Switch to a new song. SONG can be either an integer, indicating the
394 position in the playlist of the song to be played, or a SONG structure
395 instance (as received from the PLAYLIST function, for example),
396 reflecting the song to be played."
398 (song (mpd-command "playid" (song-id song)))
399 (integer (mpd-command "play" song))))
402 "Go to the next song in the playlist."
403 (mpd-command "next"))
406 "Go to the previous song in the playlist."
407 (mpd-command "previous"))
409 (defun toggle-pause ()
410 "Toggle between the :PAUSE and :PLAY states. Has no effect if the
411 MPD is in the :STOP state."
412 (mpd-command "pause"))
415 "Pause the playback, but only in the :PLAY state."
416 (if (eq (status-state (status)) :play)
420 "Ping the MPD, so as to keep connection open."
421 (mpd-command "ping"))
424 "Ping the MPD, but only if more than 10 seconds have elapsed since a
425 command was last sent to it."
427 (> (- (get-universal-time) *last-command*) 10))
433 (mpd-command "stop"))
436 "Start playback of the current song."
437 (mpd-command "play"))
439 (defun current-song ()
440 "Returns a SONG structure instance reflecting the currently playing song."
441 (first (song-list (mpd-command "currentsong"))))
443 (defun song-info (song-num)
444 "Returns a SONG structure instance describing the song with the
445 number SONG-NUM in the playlist"
446 (declare (type (integer 0 *) song-num))
447 (first (song-list (mpd-command "playlistinfo" song-num))))
450 "Return a list of SONG structure instances, reflecting the songs in
451 the current playlist."
452 (song-list (mpd-command "playlistinfo")))
454 (defun search-song (type datum)
455 "Search the entire song database for songs matching DATUM. TYPE
456 specifies what data to search among, and can be one of the following
468 This function returns a list of SONG instances describing the search
469 results, but meaningful information in the ID and POS slots, whether
470 or not the songs are actually part of the current playlist."
471 (song-list (mpd-command "search" (string-downcase (symbol-name type)) datum)))
473 (defun search-playlist (type datum)
474 "Works like the SEARCH-SONG function, but limits the search to the
475 currently loaded playlist, and will return meaningful ID and POS
476 information. See the documentation for the SEARCH-SONG function for
477 further information."
478 (song-list (mpd-command "playlistsearch" (string-downcase (symbol-name type)) datum)))
480 (defun seek (sec &optional relative)
481 "Seek in the currently playing song. If RELATIVE is NIL (the
482 default), seeks to SEC seconds from the start; otherwise, seeks to SEC
483 seconds from the current position (may be negative)."
484 (with-status (songid pos)
486 (setf sec (+ pos sec)))
487 (mpd-command "seekid" songid sec)))
489 (defun set-volume (value &optional relative)
490 "Tells the MPD to change the audio system volume to VALUE, ranging
491 from 0 to 100. If RELATIVE is non-NIL, change the current volume by
492 VALUE (which may be negative) instead."
493 (mpd-command "setvol"
494 (clipnum (if relative
495 (with-status (volume)
500 (export '(current-song song-info playlist status with-status ping maybe-ping
501 play-song next prev toggle-pause pause play stop seek set-volume
502 search-song search-playlist))