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             "prio":               self._fetch_nothing,
 134             "prioid":             self._fetch_nothing,
 135             "shuffle":            self._fetch_nothing,
 136             "swap":               self._fetch_nothing,
 137             "swapid":             self._fetch_nothing,
 138             "addtagid":           self._fetch_nothing,
 139             "cleartagid":         self._fetch_nothing,
 140             # Stored Playlist Commands
 141             "listplaylist":       self._fetch_list,
 142             "listplaylistinfo":   self._fetch_songs,
 143             "listplaylists":      self._fetch_playlists,
 144             "load":               self._fetch_nothing,
 145             "playlistadd":        self._fetch_nothing,
 146             "playlistclear":      self._fetch_nothing,
 147             "playlistdelete":     self._fetch_nothing,
 148             "playlistmove":       self._fetch_nothing,
 149             "rename":             self._fetch_nothing,
 150             "rm":                 self._fetch_nothing,
 151             "save":               self._fetch_nothing,
 152             # Database Commands
 153             "count":              self._fetch_object,
 154             "find":               self._fetch_songs,
 155             "findadd":            self._fetch_nothing,
 156             "list":               self._fetch_list,
 157             "listall":            self._fetch_database,
 158             "listallinfo":        self._fetch_database,
 159             "lsinfo":             self._fetch_database,
 160             "search":             self._fetch_songs,
 161             "searchadd":          self._fetch_nothing,
 162             "searchaddpl":        self._fetch_nothing,
 163             "update":             self._fetch_item,
 164             "rescan":             self._fetch_item,
 165             "readcomments":       self._fetch_object,
 166             # Mounts and neighbors
 167             "mount":              self._fetch_nothing,
 168             "unmount":            self._fetch_nothing,
 169             "listmounts":         self._fetch_mounts,
 170             "listneighbors":      self._fetch_neighbors,
 171             # Sticker Commands
 172             "sticker get":        self._fetch_item,
 173             "sticker set":        self._fetch_nothing,
 174             "sticker delete":     self._fetch_nothing,
 175             "sticker list":       self._fetch_list,
 176             "sticker find":       self._fetch_songs,
 177             # Connection Commands
 178             "close":              None,
 179             "kill":               None,
 180             "password":           self._fetch_nothing,
 181             "ping":               self._fetch_nothing,
 182             # Audio Output Commands
 183             "disableoutput":      self._fetch_nothing,
 184             "enableoutput":       self._fetch_nothing,
 185             "toggleoutput":       self._fetch_nothing,
 186             "outputs":            self._fetch_outputs,
 187             # Reflection Commands
 188             "commands":           self._fetch_list,
 189             "notcommands":        self._fetch_list,
 190             "tagtypes":           self._fetch_list,
 191             "urlhandlers":        self._fetch_list,
 192             "decoders":           self._fetch_plugins,
 193             # Client to Client
 194             "subscribe":          self._fetch_nothing,
 195             "unsubscribe":        self._fetch_nothing,
 196             "channels":           self._fetch_list,
 197             "readmessages":       self._fetch_messages,
 198             "sendmessage":        self._fetch_nothing,
 199         }
 200
 201     def __getattr__(self, attr):
 202         if attr == 'send_noidle':  # have send_noidle to cancel idle as well as noidle
 203             return self.noidle()
 204         if attr.startswith("send_"):
 205             command = attr.replace("send_", "", 1)
 206             wrapper = self._send
 207         elif attr.startswith("fetch_"):
 208             command = attr.replace("fetch_", "", 1)
 209             wrapper = self._fetch
 210         else:
 211             command = attr
 212             wrapper = self._execute
 213         if command not in self._commands:
 214             command = command.replace("_", " ")
 215             if command not in self._commands:
 216                 raise AttributeError("'%s' object has no attribute '%s'" %
 217                                      (self.__class__.__name__, attr))
 218         return lambda *args: wrapper(command, args)
 219
 220     def _send(self, command, args):
 221         if self._command_list is not None:
 222             raise CommandListError("Cannot use send_%s in a command list" %
 223                                    command.replace(" ", "_"))
 224         self._write_command(command, args)
 225         retval = self._commands[command]
 226         if retval is not None:
 227             self._pending.append(command)
 228
 229     def _fetch(self, command, args=None):
 230         if self._command_list is not None:
 231             raise CommandListError("Cannot use fetch_%s in a command list" %
 232                                    command.replace(" ", "_"))
 233         if self._iterating:
 234             raise IteratingError("Cannot use fetch_%s while iterating" %
 235                                  command.replace(" ", "_"))
 236         if not self._pending:
 237             raise PendingCommandError("No pending commands to fetch")
 238         if self._pending[0] != command:
 239             raise PendingCommandError("'%s' is not the currently "
 240                                       "pending command" % command)
 241         del self._pending[0]
 242         retval = self._commands[command]
 243         if callable(retval):
 244             return retval()
 245         return retval
 246
 247     def _execute(self, command, args):
 248         if self._iterating:
 249             raise IteratingError("Cannot execute '%s' while iterating" %
 250                                  command)
 251         if self._pending:
 252             raise PendingCommandError("Cannot execute '%s' with "
 253                                       "pending commands" % command)
 254         retval = self._commands[command]
 255         if self._command_list is not None:
 256             if not callable(retval):
 257                 raise CommandListError("'%s' not allowed in command list" %
 258                                         command)
 259             self._write_command(command, args)
 260             self._command_list.append(retval)
 261         else:
 262             self._write_command(command, args)
 263             if callable(retval):
 264                 return retval()
 265             return retval
 266
 267     def _write_line(self, line):
 268         self._wfile.write("%s\n" % line)
 269         self._wfile.flush()
 270
 271     def _write_command(self, command, args=None):
 272         if args is None:
 273             args = []
 274         parts = [command]
 275         for arg in args:
 276             if isinstance(arg, tuple):
 277                 parts.append('{0!s}'.format(Range(arg)))
 278             else:
 279                 parts.append('"%s"' % escape(str(arg)))
 280         self._write_line(" ".join(parts))
 281
 282     def _read_line(self):
 283         line = self._rfile.readline()
 284         if not line.endswith("\n"):
 285             self.disconnect()
 286             raise ConnectionError("Connection lost while reading line")
 287         line = line.rstrip("\n")
 288         if line.startswith(ERROR_PREFIX):
 289             error = line[len(ERROR_PREFIX):].strip()
 290             raise CommandError(error)
 291         if self._command_list is not None:
 292             if line == NEXT:
 293                 return
 294             if line == SUCCESS:
 295                 raise ProtocolError("Got unexpected '%s'" % SUCCESS)
 296         elif line == SUCCESS:
 297             return
 298         return line
 299
 300     def _read_pair(self, separator):
 301         line = self._read_line()
 302         if line is None:
 303             return
 304         pair = line.split(separator, 1)
 305         if len(pair) < 2:
 306             raise ProtocolError("Could not parse pair: '%s'" % line)
 307         return pair
 308
 309     def _read_pairs(self, separator=": "):
 310         pair = self._read_pair(separator)
 311         while pair:
 312             yield pair
 313             pair = self._read_pair(separator)
 314
 315     def _read_list(self):
 316         seen = None
 317         for key, value in self._read_pairs():
 318             if key != seen:
 319                 if seen is not None:
 320                     raise ProtocolError("Expected key '%s', got '%s'" %
 321                                         (seen, key))
 322                 seen = key
 323             yield value
 324
 325     def _read_playlist(self):
 326         for _, value in self._read_pairs(":"):
 327             yield value
 328
 329     def _read_objects(self, delimiters=None):
 330         obj = {}
 331         if delimiters is None:
 332             delimiters = []
 333         for key, value in self._read_pairs():
 334             key = key.lower()
 335             if obj:
 336                 if key in delimiters:
 337                     yield obj
 338                     obj = {}
 339                 elif key in obj:
 340                     if not isinstance(obj[key], list):
 341                         obj[key] = [obj[key], value]
 342                     else:
 343                         obj[key].append(value)
 344                     continue
 345             obj[key] = value
 346         if obj:
 347             yield obj
 348
 349     def _read_command_list(self):
 350         try:
 351             for retval in self._command_list:
 352                 yield retval()
 353         finally:
 354             self._command_list = None
 355         self._fetch_nothing()
 356
 357     def _iterator_wrapper(self, iterator):
 358         try:
 359             for item in iterator:
 360                 yield item
 361         finally:
 362             self._iterating = False
 363
 364     def _wrap_iterator(self, iterator):
 365         if not self.iterate:
 366             return list(iterator)
 367         self._iterating = True
 368         return self._iterator_wrapper(iterator)
 369
 370     def _fetch_nothing(self):
 371         line = self._read_line()
 372         if line is not None:
 373             raise ProtocolError("Got unexpected return value: '%s'" % line)
 374
 375     def _fetch_item(self):
 376         pairs = list(self._read_pairs())
 377         if len(pairs) != 1:
 378             return
 379         return pairs[0][1]
 380
 381     def _fetch_list(self):
 382         return self._wrap_iterator(self._read_list())
 383
 384     def _fetch_playlist(self):
 385         return self._wrap_iterator(self._read_playlist())
 386
 387     def _fetch_object(self):
 388         objs = list(self._read_objects())
 389         if not objs:
 390             return {}
 391         return objs[0]
 392
 393     def _fetch_objects(self, delimiters):
 394         return self._wrap_iterator(self._read_objects(delimiters))
 395
 396     def _fetch_changes(self):
 397         return self._fetch_objects(["cpos"])
 398
 399     def _fetch_songs(self):
 400         return self._fetch_objects(["file"])
 401
 402     def _fetch_playlists(self):
 403         return self._fetch_objects(["playlist"])
 404
 405     def _fetch_database(self):
 406         return self._fetch_objects(["file", "directory", "playlist"])
 407
 408     def _fetch_outputs(self):
 409         return self._fetch_objects(["outputid"])
 410
 411     def _fetch_plugins(self):
 412         return self._fetch_objects(["plugin"])
 413
 414     def _fetch_messages(self):
 415         return self._fetch_objects(["channel"])
 416
 417     def _fetch_mounts(self):
 418         return self._fetch_objects(["mount"])
 419
 420     def _fetch_neighbors(self):
 421         return self._fetch_objects(["neighbor"])
 422
 423     def _fetch_command_list(self):
 424         return self._wrap_iterator(self._read_command_list())
 425
 426     def _hello(self):
 427         line = self._rfile.readline()
 428         if not line.endswith("\n"):
 429             raise ConnectionError("Connection lost while reading MPD hello")
 430         line = line.rstrip("\n")
 431         if not line.startswith(HELLO_PREFIX):
 432             raise ProtocolError("Got invalid MPD hello: '%s'" % line)
 433         self.mpd_version = line[len(HELLO_PREFIX):].strip()
 434
 435     def _reset(self):
 436         # pylint: disable=w0201
 437         self.mpd_version = None
 438         self._iterating = False
 439         self._pending = []
 440         self._command_list = None
 441         self._sock = None
 442         self._rfile = _NotConnected()
 443         self._wfile = _NotConnected()
 444
 445     def _connect_unix(self, path):
 446         if not hasattr(socket, "AF_UNIX"):
 447             raise ConnectionError("Unix domain sockets not supported "
 448                                   "on this platform")
 449         sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
 450         sock.connect(path)
 451         return sock
 452
 453     def _connect_tcp(self, host, port):
 454         try:
 455             flags = socket.AI_ADDRCONFIG
 456         except AttributeError:
 457             flags = 0
 458         err = None
 459         for res in socket.getaddrinfo(host, port, socket.AF_UNSPEC,
 460                                       socket.SOCK_STREAM, socket.IPPROTO_TCP,
 461                                       flags):
 462             af, socktype, proto, _, sa = res
 463             sock = None
 464             try:
 465                 sock = socket.socket(af, socktype, proto)
 466                 sock.connect(sa)
 467                 return sock
 468             except socket.error as socket_err:
 469                 err = socket_err
 470                 if sock is not None:
 471                     sock.close()
 472         if err is not None:
 473             raise ConnectionError(str(err))
 474         else:
 475             raise ConnectionError("getaddrinfo returns an empty list")
 476
 477     def noidle(self):
 478         # noidle's special case
 479         if not self._pending or self._pending[0] != 'idle':
 480             raise CommandError('cannot send noidle if send_idle was not called')
 481         del self._pending[0]
 482         self._write_command("noidle")
 483         return self._fetch_list()
 484
 485     def connect(self, host, port):
 486         if self._sock is not None:
 487             raise ConnectionError("Already connected")
 488         if host.startswith("/"):
 489             self._sock = self._connect_unix(host)
 490         else:
 491             self._sock = self._connect_tcp(host, port)
 492         self._rfile = self._sock.makefile("r", encoding='utf-8')
 493         self._wfile = self._sock.makefile("w", encoding='utf-8')
 494         try:
 495             self._hello()
 496         except:
 497             self.disconnect()
 498             raise
 499
 500     def disconnect(self):
 501         if hasattr(self._rfile, 'close'):
 502             self._rfile.close()
 503         if hasattr(self._wfile, 'close'):
 504             self._wfile.close()
 505         if hasattr(self._sock, 'close'):
 506             self._sock.close()
 507         self._reset()
 508
 509     def fileno(self):
 510         if self._sock is None:
 511             raise ConnectionError("Not connected")
 512         return self._sock.fileno()
 513
 514     def command_list_ok_begin(self):
 515         if self._command_list is not None:
 516             raise CommandListError("Already in command list")
 517         if self._iterating:
 518             raise IteratingError("Cannot begin command list while iterating")
 519         if self._pending:
 520             raise PendingCommandError("Cannot begin command list "
 521                                       "with pending commands")
 522         self._write_command("command_list_ok_begin")
 523         self._command_list = []
 524
 525     def command_list_end(self):
 526         if self._command_list is None:
 527             raise CommandListError("Not in command list")
 528         if self._iterating:
 529             raise IteratingError("Already iterating over a command list")
 530         self._write_command("command_list_end")
 531         return self._fetch_command_list()
 532
 533
 534 def escape(text):
 535     return text.replace("\\", "\\\\").replace('"', '\\"')
 536
 537
 538 # vim: set expandtab shiftwidth=4 softtabstop=4 textwidth=79: