musicpd.py

   1 # python-musicpd: Python MPD client library
   2 # Copyright (C) 2008-2010  J. Alexander Treuman <jat@spatialrift.net>
   3 # Copyright (C) 2012-2014  Kaliko Jack <kaliko@azylum.org>
   4 #
   5 # python-musicpd is free software: you can redistribute it and/or modify
   6 # it under the terms of the GNU Lesser General Public License as published by
   7 # the Free Software Foundation, either version 3 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # python-musicpd is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU Lesser General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU Lesser General Public License
  16 # along with python-musicpd.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 # pylint: disable=C0111
  19
  20 import socket
  21
  22
  23 HELLO_PREFIX = "OK MPD "
  24 ERROR_PREFIX = "ACK "
  25 SUCCESS = "OK"
  26 NEXT = "list_OK"
  27 VERSION = '0.4.2'
  28
  29
  30 class MPDError(Exception):
  31     pass
  32
  33 class ConnectionError(MPDError):
  34     pass
  35
  36 class ProtocolError(MPDError):
  37     pass
  38
  39 class CommandError(MPDError):
  40     pass
  41
  42 class CommandListError(MPDError):
  43     pass
  44
  45 class PendingCommandError(MPDError):
  46     pass
  47
  48 class IteratingError(MPDError):
  49     pass
  50
  51 class Range:
  52
  53     def __init__(self, tpl):
  54         self.tpl = tpl
  55         self._check()
  56
  57     def __str__(self):
  58         if len(self.tpl) == 1:
  59             return '{0}:'.format(self.tpl[0])
  60         return '{0[0]}:{0[1]}'.format(self.tpl)
  61
  62     def __repr__(self):
  63         return 'Range({0})'.format(self.tpl)
  64
  65     def _check(self):
  66         if not isinstance(self.tpl, tuple):
  67             raise CommandError('Wrong type, provide a tuple')
  68         if len(self.tpl) not in [1, 2]:
  69             raise CommandError('length not in [1, 2]')
  70         for index in self.tpl:
  71             try:
  72                 index = int(index)
  73             except (TypeError, ValueError):
  74                 raise CommandError('Not a tuple of int')
  75
  76
  77 class _NotConnected:
  78     def __getattr__(self, attr):
  79         return self._dummy
  80
  81     def _dummy(*args):
  82         raise ConnectionError("Not connected")
  83
  84 class MPDClient:
  85     def __init__(self):
  86         self.iterate = False
  87         self._reset()
  88         self._commands = {
  89             # Status Commands
  90             "clearerror":         self._fetch_nothing,
  91             "currentsong":        self._fetch_object,
  92             "idle":               self._fetch_list,
  93             #"noidle":             None,
  94             "status":             self._fetch_object,
  95             "stats":              self._fetch_object,
  96             # Playback Option Commands
  97             "consume":            self._fetch_nothing,
  98             "crossfade":          self._fetch_nothing,
  99             "mixrampdb":          self._fetch_nothing,
 100             "mixrampdelay":       self._fetch_nothing,
 101             "random":             self._fetch_nothing,
 102             "repeat":             self._fetch_nothing,
 103             "setvol":             self._fetch_nothing,
 104             "single":             self._fetch_nothing,
 105             "replay_gain_mode":   self._fetch_nothing,
 106             "replay_gain_status": self._fetch_item,
 107             "volume":             self._fetch_nothing,
 108             # Playback Control Commands
 109             "next":               self._fetch_nothing,
 110             "pause":              self._fetch_nothing,
 111             "play":               self._fetch_nothing,
 112             "playid":             self._fetch_nothing,
 113             "previous":           self._fetch_nothing,
 114             "seek":               self._fetch_nothing,
 115             "seekid":             self._fetch_nothing,
 116             "seekcur":            self._fetch_nothing,
 117             "stop":               self._fetch_nothing,
 118             # Playlist Commands
 119             "add":                self._fetch_nothing,
 120             "addid":              self._fetch_item,
 121             "clear":              self._fetch_nothing,
 122             "delete":             self._fetch_nothing,
 123             "deleteid":           self._fetch_nothing,
 124             "move":               self._fetch_nothing,
 125             "moveid":             self._fetch_nothing,
 126             "playlist":           self._fetch_playlist,
 127             "playlistfind":       self._fetch_songs,
 128             "playlistid":         self._fetch_songs,
 129             "playlistinfo":       self._fetch_songs,
 130             "playlistsearch":     self._fetch_songs,
 131             "plchanges":          self._fetch_songs,
 132             "plchangesposid":     self._fetch_changes,
 133             "shuffle":            self._fetch_nothing,
 134             "swap":               self._fetch_nothing,
 135             "swapid":             self._fetch_nothing,
 136             # Stored Playlist Commands
 137             "listplaylist":       self._fetch_list,
 138             "listplaylistinfo":   self._fetch_songs,
 139             "listplaylists":      self._fetch_playlists,
 140             "load":               self._fetch_nothing,
 141             "playlistadd":        self._fetch_nothing,
 142             "playlistclear":      self._fetch_nothing,
 143             "playlistdelete":     self._fetch_nothing,
 144             "playlistmove":       self._fetch_nothing,
 145             "rename":             self._fetch_nothing,
 146             "rm":                 self._fetch_nothing,
 147             "save":               self._fetch_nothing,
 148             # Database Commands
 149             "count":              self._fetch_object,
 150             "find":               self._fetch_songs,
 151             "findadd":            self._fetch_nothing,
 152             "list":               self._fetch_list,
 153             "listall":            self._fetch_database,
 154             "listallinfo":        self._fetch_database,
 155             "lsinfo":             self._fetch_database,
 156             "search":             self._fetch_songs,
 157             "searchadd":          self._fetch_nothing,
 158             "searchaddpl":        self._fetch_nothing,
 159             "update":             self._fetch_item,
 160             "rescan":             self._fetch_item,
 161             "readcomments":       self._fetch_object,
 162             # Mounts and neighbors
 163             "mount":              self._fetch_nothing,
 164             "unmount":            self._fetch_nothing,
 165             "listmounts":         self._fetch_mounts,
 166             "listneighbors":      self._fetch_neighbors,
 167             # Sticker Commands
 168             "sticker get":        self._fetch_item,
 169             "sticker set":        self._fetch_nothing,
 170             "sticker delete":     self._fetch_nothing,
 171             "sticker list":       self._fetch_list,
 172             "sticker find":       self._fetch_songs,
 173             # Connection Commands
 174             "close":              None,
 175             "kill":               None,
 176             "password":           self._fetch_nothing,
 177             "ping":               self._fetch_nothing,
 178             # Audio Output Commands
 179             "disableoutput":      self._fetch_nothing,
 180             "enableoutput":       self._fetch_nothing,
 181             "toggleoutput":       self._fetch_nothing,
 182             "outputs":            self._fetch_outputs,
 183             # Reflection Commands
 184             "commands":           self._fetch_list,
 185             "notcommands":        self._fetch_list,
 186             "tagtypes":           self._fetch_list,
 187             "urlhandlers":        self._fetch_list,
 188             "decoders":           self._fetch_plugins,
 189             # Client to Client
 190             "subscribe":          self._fetch_nothing,
 191             "unsubscribe":        self._fetch_nothing,
 192             "channels":           self._fetch_list,
 193             "readmessages":       self._fetch_messages,
 194             "sendmessage":        self._fetch_nothing,
 195         }
 196
 197     def __getattr__(self, attr):
 198         if attr == 'send_noidle':  # have send_noidle to cancel idle as well as noidle
 199             return self.noidle()
 200         if attr.startswith("send_"):
 201             command = attr.replace("send_", "", 1)
 202             wrapper = self._send
 203         elif attr.startswith("fetch_"):
 204             command = attr.replace("fetch_", "", 1)
 205             wrapper = self._fetch
 206         else:
 207             command = attr
 208             wrapper = self._execute
 209         if command not in self._commands:
 210             command = command.replace("_", " ")
 211             if command not in self._commands:
 212                 raise AttributeError("'%s' object has no attribute '%s'" %
 213                                      (self.__class__.__name__, attr))
 214         return lambda *args: wrapper(command, args)
 215
 216     def _send(self, command, args):
 217         if self._command_list is not None:
 218             raise CommandListError("Cannot use send_%s in a command list" %
 219                                    command.replace(" ", "_"))
 220         self._write_command(command, args)
 221         retval = self._commands[command]
 222         if retval is not None:
 223             self._pending.append(command)
 224
 225     def _fetch(self, command, args=None):
 226         if self._command_list is not None:
 227             raise CommandListError("Cannot use fetch_%s in a command list" %
 228                                    command.replace(" ", "_"))
 229         if self._iterating:
 230             raise IteratingError("Cannot use fetch_%s while iterating" %
 231                                  command.replace(" ", "_"))
 232         if not self._pending:
 233             raise PendingCommandError("No pending commands to fetch")
 234         if self._pending[0] != command:
 235             raise PendingCommandError("'%s' is not the currently "
 236                                       "pending command" % command)
 237         del self._pending[0]
 238         retval = self._commands[command]
 239         if callable(retval):
 240             return retval()
 241         return retval
 242
 243     def _execute(self, command, args):
 244         if self._iterating:
 245             raise IteratingError("Cannot execute '%s' while iterating" %
 246                                  command)
 247         if self._pending:
 248             raise PendingCommandError("Cannot execute '%s' with "
 249                                       "pending commands" % command)
 250         retval = self._commands[command]
 251         if self._command_list is not None:
 252             if not callable(retval):
 253                 raise CommandListError("'%s' not allowed in command list" %
 254                                         command)
 255             self._write_command(command, args)
 256             self._command_list.append(retval)
 257         else:
 258             self._write_command(command, args)
 259             if callable(retval):
 260                 return retval()
 261             return retval
 262
 263     def _write_line(self, line):
 264         self._wfile.write("%s\n" % line)
 265         self._wfile.flush()
 266
 267     def _write_command(self, command, args=None):
 268         if args is None:
 269             args = []
 270         parts = [command]
 271         for arg in args:
 272             if isinstance(arg, tuple):
 273                 parts.append('{0!s}'.format(Range(arg)))
 274             else:
 275                 parts.append('"%s"' % escape(str(arg)))
 276         self._write_line(" ".join(parts))
 277
 278     def _read_line(self):
 279         line = self._rfile.readline()
 280         if not line.endswith("\n"):
 281             self.disconnect()
 282             raise ConnectionError("Connection lost while reading line")
 283         line = line.rstrip("\n")
 284         if line.startswith(ERROR_PREFIX):
 285             error = line[len(ERROR_PREFIX):].strip()
 286             raise CommandError(error)
 287         if self._command_list is not None:
 288             if line == NEXT:
 289                 return
 290             if line == SUCCESS:
 291                 raise ProtocolError("Got unexpected '%s'" % SUCCESS)
 292         elif line == SUCCESS:
 293             return
 294         return line
 295
 296     def _read_pair(self, separator):
 297         line = self._read_line()
 298         if line is None:
 299             return
 300         pair = line.split(separator, 1)
 301         if len(pair) < 2:
 302             raise ProtocolError("Could not parse pair: '%s'" % line)
 303         return pair
 304
 305     def _read_pairs(self, separator=": "):
 306         pair = self._read_pair(separator)
 307         while pair:
 308             yield pair
 309             pair = self._read_pair(separator)
 310
 311     def _read_list(self):
 312         seen = None
 313         for key, value in self._read_pairs():
 314             if key != seen:
 315                 if seen is not None:
 316                     raise ProtocolError("Expected key '%s', got '%s'" %
 317                                         (seen, key))
 318                 seen = key
 319             yield value
 320
 321     def _read_playlist(self):
 322         for _, value in self._read_pairs(":"):
 323             yield value
 324
 325     def _read_objects(self, delimiters=None):
 326         obj = {}
 327         if delimiters is None:
 328             delimiters = []
 329         for key, value in self._read_pairs():
 330             key = key.lower()
 331             if obj:
 332                 if key in delimiters:
 333                     yield obj
 334                     obj = {}
 335                 elif key in obj:
 336                     if not isinstance(obj[key], list):
 337                         obj[key] = [obj[key], value]
 338                     else:
 339                         obj[key].append(value)
 340                     continue
 341             obj[key] = value
 342         if obj:
 343             yield obj
 344
 345     def _read_command_list(self):
 346         try:
 347             for retval in self._command_list:
 348                 yield retval()
 349         finally:
 350             self._command_list = None
 351         self._fetch_nothing()
 352
 353     def _iterator_wrapper(self, iterator):
 354         try:
 355             for item in iterator:
 356                 yield item
 357         finally:
 358             self._iterating = False
 359
 360     def _wrap_iterator(self, iterator):
 361         if not self.iterate:
 362             return list(iterator)
 363         self._iterating = True
 364         return self._iterator_wrapper(iterator)
 365
 366     def _fetch_nothing(self):
 367         line = self._read_line()
 368         if line is not None:
 369             raise ProtocolError("Got unexpected return value: '%s'" % line)
 370
 371     def _fetch_item(self):
 372         pairs = list(self._read_pairs())
 373         if len(pairs) != 1:
 374             return
 375         return pairs[0][1]
 376
 377     def _fetch_list(self):
 378         return self._wrap_iterator(self._read_list())
 379
 380     def _fetch_playlist(self):
 381         return self._wrap_iterator(self._read_playlist())
 382
 383     def _fetch_object(self):
 384         objs = list(self._read_objects())
 385         if not objs:
 386             return {}
 387         return objs[0]
 388
 389     def _fetch_objects(self, delimiters):
 390         return self._wrap_iterator(self._read_objects(delimiters))
 391
 392     def _fetch_changes(self):
 393         return self._fetch_objects(["cpos"])
 394
 395     def _fetch_songs(self):
 396         return self._fetch_objects(["file"])
 397
 398     def _fetch_playlists(self):
 399         return self._fetch_objects(["playlist"])
 400
 401     def _fetch_database(self):
 402         return self._fetch_objects(["file", "directory", "playlist"])
 403
 404     def _fetch_outputs(self):
 405         return self._fetch_objects(["outputid"])
 406
 407     def _fetch_plugins(self):
 408         return self._fetch_objects(["plugin"])
 409
 410     def _fetch_messages(self):
 411         return self._fetch_objects(["channel"])
 412
 413     def _fetch_mounts(self):
 414         return self._fetch_objects(["mount"])
 415
 416     def _fetch_neighbors(self):
 417         return self._fetch_objects(["neighbor"])
 418
 419     def _fetch_command_list(self):
 420         return self._wrap_iterator(self._read_command_list())
 421
 422     def _hello(self):
 423         line = self._rfile.readline()
 424         if not line.endswith("\n"):
 425             raise ConnectionError("Connection lost while reading MPD hello")
 426         line = line.rstrip("\n")
 427         if not line.startswith(HELLO_PREFIX):
 428             raise ProtocolError("Got invalid MPD hello: '%s'" % line)
 429         self.mpd_version = line[len(HELLO_PREFIX):].strip()
 430
 431     def _reset(self):
 432         # pylint: disable=w0201
 433         self.mpd_version = None
 434         self._iterating = False
 435         self._pending = []
 436         self._command_list = None
 437         self._sock = None
 438         self._rfile = _NotConnected()
 439         self._wfile = _NotConnected()
 440
 441     def _connect_unix(self, path):
 442         if not hasattr(socket, "AF_UNIX"):
 443             raise ConnectionError("Unix domain sockets not supported "
 444                                   "on this platform")
 445         sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
 446         sock.connect(path)
 447         return sock
 448
 449     def _connect_tcp(self, host, port):
 450         try:
 451             flags = socket.AI_ADDRCONFIG
 452         except AttributeError:
 453             flags = 0
 454         err = None
 455         for res in socket.getaddrinfo(host, port, socket.AF_UNSPEC,
 456                                       socket.SOCK_STREAM, socket.IPPROTO_TCP,
 457                                       flags):
 458             af, socktype, proto, _, sa = res
 459             sock = None
 460             try:
 461                 sock = socket.socket(af, socktype, proto)
 462                 sock.connect(sa)
 463                 return sock
 464             except socket.error as socket_err:
 465                 err = socket_err
 466                 if sock is not None:
 467                     sock.close()
 468         if err is not None:
 469             raise ConnectionError(str(err))
 470         else:
 471             raise ConnectionError("getaddrinfo returns an empty list")
 472
 473     def noidle(self):
 474         # noidle's special case
 475         if not self._pending or self._pending[0] != 'idle':
 476             raise CommandError('cannot send noidle if send_idle was not called')
 477         del self._pending[0]
 478         self._write_command("noidle")
 479         return self._fetch_list()
 480
 481     def connect(self, host, port):
 482         if self._sock is not None:
 483             raise ConnectionError("Already connected")
 484         if host.startswith("/"):
 485             self._sock = self._connect_unix(host)
 486         else:
 487             self._sock = self._connect_tcp(host, port)
 488         self._rfile = self._sock.makefile("r", encoding='utf-8')
 489         self._wfile = self._sock.makefile("w", encoding='utf-8')
 490         try:
 491             self._hello()
 492         except:
 493             self.disconnect()
 494             raise
 495
 496     def disconnect(self):
 497         if hasattr(self._rfile, 'close'):
 498             self._rfile.close()
 499         if hasattr(self._wfile, 'close'):
 500             self._wfile.close()
 501         if hasattr(self._sock, 'close'):
 502             self._sock.close()
 503         self._reset()
 504
 505     def fileno(self):
 506         if self._sock is None:
 507             raise ConnectionError("Not connected")
 508         return self._sock.fileno()
 509
 510     def command_list_ok_begin(self):
 511         if self._command_list is not None:
 512             raise CommandListError("Already in command list")
 513         if self._iterating:
 514             raise IteratingError("Cannot begin command list while iterating")
 515         if self._pending:
 516             raise PendingCommandError("Cannot begin command list "
 517                                       "with pending commands")
 518         self._write_command("command_list_ok_begin")
 519         self._command_list = []
 520
 521     def command_list_end(self):
 522         if self._command_list is None:
 523             raise CommandListError("Not in command list")
 524         if self._iterating:
 525             raise IteratingError("Already iterating over a command list")
 526         self._write_command("command_list_end")
 527         return self._fetch_command_list()
 528
 529
 530 def escape(text):
 531     return text.replace("\\", "\\\\").replace('"', '\\"')
 532
 533
 534 # vim: set expandtab shiftwidth=4 softtabstop=4 textwidth=79: