from __future__ import absolute_import, unicode_literals
import logging
import re
import pykka
from mopidy.mpd import exceptions, protocol, tokenize
logger = logging.getLogger(__name__)
protocol.load_protocol_modules()
[docs]class MpdDispatcher(object):
"""
The MPD session feeds the MPD dispatcher with requests. The dispatcher
finds the correct handler, processes the request and sends the response
back to the MPD session.
"""
_noidle = re.compile(r'^noidle$')
def __init__(self, session=None, config=None, core=None, uri_map=None):
self.config = config
self.authenticated = False
self.command_list_receiving = False
self.command_list_ok = False
self.command_list = []
self.command_list_index = None
self.context = MpdContext(
self, session=session, config=config, core=core, uri_map=uri_map)
[docs] def handle_request(self, request, current_command_list_index=None):
"""Dispatch incoming requests to the correct handler."""
self.command_list_index = current_command_list_index
response = []
filter_chain = [
self._catch_mpd_ack_errors_filter,
self._authenticate_filter,
self._command_list_filter,
self._idle_filter,
self._add_ok_filter,
self._call_handler_filter,
]
return self._call_next_filter(request, response, filter_chain)
def handle_idle(self, subsystem):
# TODO: validate against mopidy/mpd/protocol/status.SUBSYSTEMS
self.context.events.add(subsystem)
subsystems = self.context.subscriptions.intersection(
self.context.events)
if not subsystems:
return
response = []
for subsystem in subsystems:
response.append('changed: %s' % subsystem)
response.append('OK')
self.context.subscriptions = set()
self.context.events = set()
self.context.session.send_lines(response)
def _call_next_filter(self, request, response, filter_chain):
if filter_chain:
next_filter = filter_chain.pop(0)
return next_filter(request, response, filter_chain)
else:
return response
# Filter: catch MPD ACK errors
def _catch_mpd_ack_errors_filter(self, request, response, filter_chain):
try:
return self._call_next_filter(request, response, filter_chain)
except exceptions.MpdAckError as mpd_ack_error:
if self.command_list_index is not None:
mpd_ack_error.index = self.command_list_index
return [mpd_ack_error.get_mpd_ack()]
# Filter: authenticate
def _authenticate_filter(self, request, response, filter_chain):
if self.authenticated:
return self._call_next_filter(request, response, filter_chain)
elif self.config['mpd']['password'] is None:
self.authenticated = True
return self._call_next_filter(request, response, filter_chain)
else:
command_name = request.split(' ')[0]
command = protocol.commands.handlers.get(command_name)
if command and not command.auth_required:
return self._call_next_filter(request, response, filter_chain)
else:
raise exceptions.MpdPermissionError(command=command_name)
# Filter: command list
def _command_list_filter(self, request, response, filter_chain):
if self._is_receiving_command_list(request):
self.command_list.append(request)
return []
else:
response = self._call_next_filter(request, response, filter_chain)
if (self._is_receiving_command_list(request) or
self._is_processing_command_list(request)):
if response and response[-1] == 'OK':
response = response[:-1]
return response
def _is_receiving_command_list(self, request):
return (
self.command_list_receiving and request != 'command_list_end')
def _is_processing_command_list(self, request):
return (
self.command_list_index is not None and
request != 'command_list_end')
# Filter: idle
def _idle_filter(self, request, response, filter_chain):
if self._is_currently_idle() and not self._noidle.match(request):
logger.debug(
'Client sent us %s, only %s is allowed while in '
'the idle state', repr(request), repr('noidle'))
self.context.session.close()
return []
if not self._is_currently_idle() and self._noidle.match(request):
return [] # noidle was called before idle
response = self._call_next_filter(request, response, filter_chain)
if self._is_currently_idle():
return []
else:
return response
def _is_currently_idle(self):
return bool(self.context.subscriptions)
# Filter: add OK
def _add_ok_filter(self, request, response, filter_chain):
response = self._call_next_filter(request, response, filter_chain)
if not self._has_error(response):
response.append('OK')
return response
def _has_error(self, response):
return response and response[-1].startswith('ACK')
# Filter: call handler
def _call_handler_filter(self, request, response, filter_chain):
try:
response = self._format_response(self._call_handler(request))
return self._call_next_filter(request, response, filter_chain)
except pykka.ActorDeadError as e:
logger.warning('Tried to communicate with dead actor.')
raise exceptions.MpdSystemError(e)
def _call_handler(self, request):
tokens = tokenize.split(request)
# TODO: check that blacklist items are valid commands?
blacklist = self.config['mpd'].get('command_blacklist', [])
if tokens and tokens[0] in blacklist:
logger.warning(
'MPD client used blacklisted command: %s', tokens[0])
raise exceptions.MpdDisabled(command=tokens[0])
try:
return protocol.commands.call(tokens, context=self.context)
except exceptions.MpdAckError as exc:
if exc.command is None:
exc.command = tokens[0]
raise
def _format_response(self, response):
formatted_response = []
for element in self._listify_result(response):
formatted_response.extend(self._format_lines(element))
return formatted_response
def _listify_result(self, result):
if result is None:
return []
if isinstance(result, set):
return self._flatten(list(result))
if not isinstance(result, list):
return [result]
return self._flatten(result)
def _flatten(self, the_list):
result = []
for element in the_list:
if isinstance(element, list):
result.extend(self._flatten(element))
else:
result.append(element)
return result
def _format_lines(self, line):
if isinstance(line, dict):
return ['%s: %s' % (key, value) for (key, value) in line.items()]
if isinstance(line, tuple):
(key, value) = line
return ['%s: %s' % (key, value)]
return [line]
[docs]class MpdContext(object):
"""
This object is passed as the first argument to all MPD command handlers to
give the command handlers access to important parts of Mopidy.
"""
#: The current :class:`MpdDispatcher`.
dispatcher = None
#: The current :class:`mopidy.mpd.MpdSession`.
session = None
#: The MPD password
password = None
#: The Mopidy core API. An instance of :class:`mopidy.core.Core`.
core = None
#: The active subsystems that have pending events.
events = None
#: The subsytems that we want to be notified about in idle mode.
subscriptions = None
_uri_map = None
def __init__(self, dispatcher, session=None, config=None, core=None,
uri_map=None):
self.dispatcher = dispatcher
self.session = session
if config is not None:
self.password = config['mpd']['password']
self.core = core
self.events = set()
self.subscriptions = set()
self._uri_map = uri_map
[docs] def lookup_playlist_uri_from_name(self, name):
"""
Helper function to retrieve a playlist from its unique MPD name.
"""
return self._uri_map.playlist_uri_from_name(name)
[docs] def lookup_playlist_name_from_uri(self, uri):
"""
Helper function to retrieve the unique MPD playlist name from its uri.
"""
return self._uri_map.playlist_name_from_uri(uri)
[docs] def browse(self, path, recursive=True, lookup=True):
"""
Browse the contents of a given directory path.
Returns a sequence of two-tuples ``(path, data)``.
If ``recursive`` is true, it returns results for all entries in the
given path.
If ``lookup`` is true and the ``path`` is to a track, the returned
``data`` is a future which will contain the results from looking up
the URI with :meth:`mopidy.core.LibraryController.lookup`. If
``lookup`` is false and the ``path`` is to a track, the returned
``data`` will be a :class:`mopidy.models.Ref` for the track.
For all entries that are not tracks, the returned ``data`` will be
:class:`None`.
"""
path_parts = re.findall(r'[^/]+', path or '')
root_path = '/'.join([''] + path_parts)
uri = self._uri_map.uri_from_name(root_path)
if uri is None:
for part in path_parts:
for ref in self.core.library.browse(uri).get():
if ref.type != ref.TRACK and ref.name == part:
uri = ref.uri
break
else:
raise exceptions.MpdNoExistError('Not found')
root_path = self._uri_map.insert(root_path, uri)
if recursive:
yield (root_path, None)
path_and_futures = [(root_path, self.core.library.browse(uri))]
while path_and_futures:
base_path, future = path_and_futures.pop()
for ref in future.get():
path = '/'.join([base_path, ref.name.replace('/', '')])
path = self._uri_map.insert(path, ref.uri)
if ref.type == ref.TRACK:
if lookup:
# TODO: can we lookup all the refs at once now?
yield (path, self.core.library.lookup(uris=[ref.uri]))
else:
yield (path, ref)
else:
yield (path, None)
if recursive:
path_and_futures.append(
(path, self.core.library.browse(ref.uri)))