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) == 0:
  59             return ':'
  60         if len(self.tpl) == 1:
  61             return '{0}:'.format(self.tpl[0])
  62         return '{0[0]}:{0[1]}'.format(self.tpl)
  63
  64     def __repr__(self):
  65         return 'Range({0})'.format(self.tpl)
  66
  67     def _check(self):
  68         if not isinstance(self.tpl, tuple):
  69             raise CommandError('Wrong type, provide a tuple')
  70         if len(self.tpl) not in [0, 1, 2]:
  71             raise CommandError('length not in [0, 1, 2]')
  72         for index in self.tpl:
  73             try:
  74                 index = int(index)
  75             except (TypeError, ValueError):
  76                 raise CommandError('Not a tuple of int')
  77
  78
  79 class _NotConnected:
  80     def __getattr__(self, attr):
  81         return self._dummy
  82
  83     def _dummy(*args):
  84         raise ConnectionError("Not connected")
  85
  86 class MPDClient:
  87     def __init__(self):
  88         self.iterate = False
  89         self._reset()
  90         self._commands = {
  91             # Status Commands
  92             "clearerror":         self._fetch_nothing,
  93             "currentsong":        self._fetch_object,
  94             "idle":               self._fetch_list,
  95             #"noidle":             None,
  96             "status":             self._fetch_object,
  97             "stats":              self._fetch_object,
  98             # Playback Option Commands
  99             "consume":            self._fetch_nothing,
 100             "crossfade":          self._fetch_nothing,
 101             "mixrampdb":          self._fetch_nothing,
 102             "mixrampdelay":       self._fetch_nothing,
 103             "random":             self._fetch_nothing,
 104             "repeat":             self._fetch_nothing,
 105             "setvol":             self._fetch_nothing,
 106             "single":             self._fetch_nothing,
 107             "replay_gain_mode":   self._fetch_nothing,
 108             "replay_gain_status": self._fetch_item,
 109             "volume":             self._fetch_nothing,
 110             # Playback Control Commands
 111             "next":               self._fetch_nothing,
 112             "pause":              self._fetch_nothing,
 113             "play":               self._fetch_nothing,
 114             "playid":             self._fetch_nothing,
 115             "previous":           self._fetch_nothing,
 116             "seek":               self._fetch_nothing,
 117             "seekid":             self._fetch_nothing,
 118             "seekcur":            self._fetch_nothing,
 119             "stop":               self._fetch_nothing,
 120             # Playlist Commands
 121             "add":                self._fetch_nothing,
 122             "addid":              self._fetch_item,
 123             "clear":              self._fetch_nothing,
 124             "delete":             self._fetch_nothing,
 125             "deleteid":           self._fetch_nothing,
 126             "move":               self._fetch_nothing,
 127             "moveid":             self._fetch_nothing,
 128             "playlist":           self._fetch_playlist,
 129             "playlistfind":       self._fetch_songs,
 130             "playlistid":         self._fetch_songs,
 131             "playlistinfo":       self._fetch_songs,
 132             "playlistsearch":     self._fetch_songs,
 133             "plchanges":          self._fetch_songs,
 134             "plchangesposid":     self._fetch_changes,
 135             "prio":               self._fetch_nothing,
 136             "prioid":             self._fetch_nothing,
 137             "rangeid":            self._fetch_nothing,
 138             "shuffle":            self._fetch_nothing,
 139             "swap":               self._fetch_nothing,
 140             "swapid":             self._fetch_nothing,
 141             "addtagid":           self._fetch_nothing,
 142             "cleartagid":         self._fetch_nothing,
 143             # Stored Playlist Commands
 144             "listplaylist":       self._fetch_list,
 145             "listplaylistinfo":   self._fetch_songs,
 146             "listplaylists":      self._fetch_playlists,
 147             "load":               self._fetch_nothing,
 148             "playlistadd":        self._fetch_nothing,
 149             "playlistclear":      self._fetch_nothing,
 150             "playlistdelete":     self._fetch_nothing,
 151             "playlistmove":       self._fetch_nothing,
 152             "rename":             self._fetch_nothing,
 153             "rm":                 self._fetch_nothing,
 154             "save":               self._fetch_nothing,
 155             # Database Commands
 156             "count":              self._fetch_object,
 157             "find":               self._fetch_songs,
 158             "findadd":            self._fetch_nothing,
 159             "list":               self._fetch_list,
 160             "listall":            self._fetch_database,
 161             "listallinfo":        self._fetch_database,
 162             "lsinfo":             self._fetch_database,
 163             "search":             self._fetch_songs,
 164             "searchadd":          self._fetch_nothing,
 165             "searchaddpl":        self._fetch_nothing,
 166             "update":             self._fetch_item,
 167             "rescan":             self._fetch_item,
 168             "readcomments":       self._fetch_object,
 169             # Mounts and neighbors
 170             "mount":              self._fetch_nothing,
 171             "unmount":            self._fetch_nothing,
 172             "listmounts":         self._fetch_mounts,
 173             "listneighbors":      self._fetch_neighbors,
 174             # Sticker Commands
 175             "sticker get":        self._fetch_item,
 176             "sticker set":        self._fetch_nothing,
 177             "sticker delete":     self._fetch_nothing,
 178             "sticker list":       self._fetch_list,
 179             "sticker find":       self._fetch_songs,
 180             # Connection Commands
 181             "close":              None,
 182             "kill":               None,
 183             "password":           self._fetch_nothing,
 184             "ping":               self._fetch_nothing,
 185             # Audio Output Commands
 186             "disableoutput":      self._fetch_nothing,
 187             "enableoutput":       self._fetch_nothing,
 188             "toggleoutput":       self._fetch_nothing,
 189             "outputs":            self._fetch_outputs,
 190             # Reflection Commands
 191             "commands":           self._fetch_list,
 192             "notcommands":        self._fetch_list,
 193             "tagtypes":           self._fetch_list,
 194             "urlhandlers":        self._fetch_list,
 195             "decoders":           self._fetch_plugins,
 196             # Client to Client
 197             "subscribe":          self._fetch_nothing,
 198             "unsubscribe":        self._fetch_nothing,
 199             "channels":           self._fetch_list,
 200             "readmessages":       self._fetch_messages,
 201             "sendmessage":        self._fetch_nothing,
 202         }
 203
 204     def __getattr__(self, attr):
 205         if attr == 'send_noidle':  # have send_noidle to cancel idle as well as noidle
 206             return self.noidle()
 207         if attr.startswith("send_"):
 208             command = attr.replace("send_", "", 1)
 209             wrapper = self._send
 210         elif attr.startswith("fetch_"):
 211             command = attr.replace("fetch_", "", 1)
 212             wrapper = self._fetch
 213         else:
 214             command = attr
 215             wrapper = self._execute
 216         if command not in self._commands:
 217             command = command.replace("_", " ")
 218             if command not in self._commands:
 219                 raise AttributeError("'%s' object has no attribute '%s'" %
 220                                      (self.__class__.__name__, attr))
 221         return lambda *args: wrapper(command, args)
 222
 223     def _send(self, command, args):
 224         if self._command_list is not None:
 225             raise CommandListError("Cannot use send_%s in a command list" %
 226                                    command.replace(" ", "_"))
 227         self._write_command(command, args)
 228         retval = self._commands[command]
 229         if retval is not None:
 230             self._pending.append(command)
 231
 232     def _fetch(self, command, args=None):
 233         if self._command_list is not None:
 234             raise CommandListError("Cannot use fetch_%s in a command list" %
 235                                    command.replace(" ", "_"))
 236         if self._iterating:
 237             raise IteratingError("Cannot use fetch_%s while iterating" %
 238                                  command.replace(" ", "_"))
 239         if not self._pending:
 240             raise PendingCommandError("No pending commands to fetch")
 241         if self._pending[0] != command:
 242             raise PendingCommandError("'%s' is not the currently "
 243                                       "pending command" % command)
 244         del self._pending[0]
 245         retval = self._commands[command]
 246         if callable(retval):
 247             return retval()
 248         return retval
 249
 250     def _execute(self, command, args):
 251         if self._iterating:
 252             raise IteratingError("Cannot execute '%s' while iterating" %
 253                                  command)
 254         if self._pending:
 255             raise PendingCommandError("Cannot execute '%s' with "
 256                                       "pending commands" % command)
 257         retval = self._commands[command]
 258         if self._command_list is not None:
 259             if not callable(retval):
 260                 raise CommandListError("'%s' not allowed in command list" %
 261                                         command)
 262             self._write_command(command, args)
 263             self._command_list.append(retval)
 264         else:
 265             self._write_command(command, args)
 266             if callable(retval):
 267                 return retval()
 268             return retval
 269
 270     def _write_line(self, line):
 271         self._wfile.write("%s\n" % line)
 272         self._wfile.flush()
 273
 274     def _write_command(self, command, args=None):
 275         if args is None:
 276             args = []
 277         parts = [command]
 278         for arg in args:
 279             if isinstance(arg, tuple):
 280                 parts.append('{0!s}'.format(Range(arg)))
 281             else:
 282                 parts.append('"%s"' % escape(str(arg)))
 283         self._write_line(" ".join(parts))
 284
 285     def _read_line(self):
 286         line = self._rfile.readline()
 287         if not line.endswith("\n"):
 288             self.disconnect()
 289             raise ConnectionError("Connection lost while reading line")
 290         line = line.rstrip("\n")
 291         if line.startswith(ERROR_PREFIX):
 292             error = line[len(ERROR_PREFIX):].strip()
 293             raise CommandError(error)
 294         if self._command_list is not None:
 295             if line == NEXT:
 296                 return
 297             if line == SUCCESS:
 298                 raise ProtocolError("Got unexpected '%s'" % SUCCESS)
 299         elif line == SUCCESS:
 300             return
 301         return line
 302
 303     def _read_pair(self, separator):
 304         line = self._read_line()
 305         if line is None:
 306             return
 307         pair = line.split(separator, 1)
 308         if len(pair) < 2:
 309             raise ProtocolError("Could not parse pair: '%s'" % line)
 310         return pair
 311
 312     def _read_pairs(self, separator=": "):
 313         pair = self._read_pair(separator)
 314         while pair:
 315             yield pair
 316             pair = self._read_pair(separator)
 317
 318     def _read_list(self):
 319         seen = None
 320         for key, value in self._read_pairs():
 321             if key != seen:
 322                 if seen is not None:
 323                     raise ProtocolError("Expected key '%s', got '%s'" %
 324                                         (seen, key))
 325                 seen = key
 326             yield value
 327
 328     def _read_playlist(self):
 329         for _, value in self._read_pairs(":"):
 330             yield value
 331
 332     def _read_objects(self, delimiters=None):
 333         obj = {}
 334         if delimiters is None:
 335             delimiters = []
 336         for key, value in self._read_pairs():
 337             key = key.lower()
 338             if obj:
 339                 if key in delimiters:
 340                     yield obj
 341                     obj = {}
 342                 elif key in obj:
 343                     if not isinstance(obj[key], list):
 344                         obj[key] = [obj[key], value]
 345                     else:
 346                         obj[key].append(value)
 347                     continue
 348             obj[key] = value
 349         if obj:
 350             yield obj
 351
 352     def _read_command_list(self):
 353         try:
 354             for retval in self._command_list:
 355                 yield retval()
 356         finally:
 357             self._command_list = None
 358         self._fetch_nothing()
 359
 360     def _iterator_wrapper(self, iterator):
 361         try:
 362             for item in iterator:
 363                 yield item
 364         finally:
 365             self._iterating = False
 366
 367     def _wrap_iterator(self, iterator):
 368         if not self.iterate:
 369             return list(iterator)
 370         self._iterating = True
 371         return self._iterator_wrapper(iterator)
 372
 373     def _fetch_nothing(self):
 374         line = self._read_line()
 375         if line is not None:
 376             raise ProtocolError("Got unexpected return value: '%s'" % line)
 377
 378     def _fetch_item(self):
 379         pairs = list(self._read_pairs())
 380         if len(pairs) != 1:
 381             return
 382         return pairs[0][1]
 383
 384     def _fetch_list(self):
 385         return self._wrap_iterator(self._read_list())
 386
 387     def _fetch_playlist(self):
 388         return self._wrap_iterator(self._read_playlist())
 389
 390     def _fetch_object(self):
 391         objs = list(self._read_objects())
 392         if not objs:
 393             return {}
 394         return objs[0]
 395
 396     def _fetch_objects(self, delimiters):
 397         return self._wrap_iterator(self._read_objects(delimiters))
 398
 399     def _fetch_changes(self):
 400         return self._fetch_objects(["cpos"])
 401
 402     def _fetch_songs(self):
 403         return self._fetch_objects(["file"])
 404
 405     def _fetch_playlists(self):
 406         return self._fetch_objects(["playlist"])
 407
 408     def _fetch_database(self):
 409         return self._fetch_objects(["file", "directory", "playlist"])
 410
 411     def _fetch_outputs(self):
 412         return self._fetch_objects(["outputid"])
 413
 414     def _fetch_plugins(self):
 415         return self._fetch_objects(["plugin"])
 416
 417     def _fetch_messages(self):
 418         return self._fetch_objects(["channel"])
 419
 420     def _fetch_mounts(self):
 421         return self._fetch_objects(["mount"])
 422
 423     def _fetch_neighbors(self):
 424         return self._fetch_objects(["neighbor"])
 425
 426     def _fetch_command_list(self):
 427         return self._wrap_iterator(self._read_command_list())
 428
 429     def _hello(self):
 430         line = self._rfile.readline()
 431         if not line.endswith("\n"):
 432             raise ConnectionError("Connection lost while reading MPD hello")
 433         line = line.rstrip("\n")
 434         if not line.startswith(HELLO_PREFIX):
 435             raise ProtocolError("Got invalid MPD hello: '%s'" % line)
 436         self.mpd_version = line[len(HELLO_PREFIX):].strip()
 437
 438     def _reset(self):
 439         # pylint: disable=w0201
 440         self.mpd_version = None
 441         self._iterating = False
 442         self._pending = []
 443         self._command_list = None
 444         self._sock = None
 445         self._rfile = _NotConnected()
 446         self._wfile = _NotConnected()
 447
 448     def _connect_unix(self, path):
 449         if not hasattr(socket, "AF_UNIX"):
 450             raise ConnectionError("Unix domain sockets not supported "
 451                                   "on this platform")
 452         sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
 453         sock.connect(path)
 454         return sock
 455
 456     def _connect_tcp(self, host, port):
 457         try:
 458             flags = socket.AI_ADDRCONFIG
 459         except AttributeError:
 460             flags = 0
 461         err = None
 462         for res in socket.getaddrinfo(host, port, socket.AF_UNSPEC,
 463                                       socket.SOCK_STREAM, socket.IPPROTO_TCP,
 464                                       flags):
 465             af, socktype, proto, _, sa = res
 466             sock = None
 467             try:
 468                 sock = socket.socket(af, socktype, proto)
 469                 sock.connect(sa)
 470                 return sock
 471             except socket.error as socket_err:
 472                 err = socket_err
 473                 if sock is not None:
 474                     sock.close()
 475         if err is not None:
 476             raise ConnectionError(str(err))
 477         else:
 478             raise ConnectionError("getaddrinfo returns an empty list")
 479
 480     def noidle(self):
 481         # noidle's special case
 482         if not self._pending or self._pending[0] != 'idle':
 483             raise CommandError('cannot send noidle if send_idle was not called')
 484         del self._pending[0]
 485         self._write_command("noidle")
 486         return self._fetch_list()
 487
 488     def connect(self, host, port):
 489         if self._sock is not None:
 490             raise ConnectionError("Already connected")
 491         if host.startswith("/"):
 492             self._sock = self._connect_unix(host)
 493         else:
 494             self._sock = self._connect_tcp(host, port)
 495         self._rfile = self._sock.makefile("r", encoding='utf-8')
 496         self._wfile = self._sock.makefile("w", encoding='utf-8')
 497         try:
 498             self._hello()
 499         except:
 500             self.disconnect()
 501             raise
 502
 503     def disconnect(self):
 504         if hasattr(self._rfile, 'close'):
 505             self._rfile.close()
 506         if hasattr(self._wfile, 'close'):
 507             self._wfile.close()
 508         if hasattr(self._sock, 'close'):
 509             self._sock.close()
 510         self._reset()
 511
 512     def fileno(self):
 513         if self._sock is None:
 514             raise ConnectionError("Not connected")
 515         return self._sock.fileno()
 516
 517     def command_list_ok_begin(self):
 518         if self._command_list is not None:
 519             raise CommandListError("Already in command list")
 520         if self._iterating:
 521             raise IteratingError("Cannot begin command list while iterating")
 522         if self._pending:
 523             raise PendingCommandError("Cannot begin command list "
 524                                       "with pending commands")
 525         self._write_command("command_list_ok_begin")
 526         self._command_list = []
 527
 528     def command_list_end(self):
 529         if self._command_list is None:
 530             raise CommandListError("Not in command list")
 531         if self._iterating:
 532             raise IteratingError("Already iterating over a command list")
 533         self._write_command("command_list_end")
 534         return self._fetch_command_list()
 535
 536
 537 def escape(text):
 538     return text.replace("\\", "\\\\").replace('"', '\\"')
 539
 540
 541 # vim: set expandtab shiftwidth=4 softtabstop=4 textwidth=79: