Source code for mopidy.frontends.mpd.protocol
"""
This is Mopidy's MPD protocol implementation.
This is partly based upon the `MPD protocol documentation
<http://www.musicpd.org/doc/protocol/>`_, which is a useful resource, but it is
rather incomplete with regards to data formats, both for requests and
responses. Thus, we have had to talk a great deal with the the original `MPD
server <http://mpd.wikia.com/>`_ using telnet to get the details we need to
implement our own MPD server which is compatible with the numerous existing
`MPD clients <http://mpd.wikia.com/wiki/Clients>`_.
"""
from __future__ import unicode_literals
from collections import namedtuple
import re
#: The MPD protocol uses UTF-8 for encoding all data.
ENCODING = 'UTF-8'
#: The MPD protocol uses ``\n`` as line terminator.
LINE_TERMINATOR = '\n'
#: The MPD protocol version is 0.17.0.
VERSION = '0.17.0'
MpdCommand = namedtuple('MpdCommand', ['name', 'auth_required'])
#: Set of all available commands, represented as :class:`MpdCommand` objects.
mpd_commands = set()
#: Map between request matchers and request handler functions.
request_handlers = {}
[docs]def handle_request(pattern, auth_required=True):
"""
Decorator for connecting command handlers to command requests.
If you use named groups in the pattern, the decorated method will get the
groups as keyword arguments. If the group is optional, remember to give the
argument a default value.
For example, if the command is ``do that thing`` the ``what`` argument will
be ``this thing``::
@handle_request('do\ (?P<what>.+)$')
def do(what):
...
Note that the patterns are compiled with the :attr:`re.VERBOSE` flag. Thus,
you must escape any space characters you want to match, but you're also
free to add non-escaped whitespace to format the pattern for easier
reading.
:param pattern: regexp pattern for matching commands
:type pattern: string
"""
def decorator(func):
match = re.search('([a-z_]+)', pattern)
if match is not None:
mpd_commands.add(
MpdCommand(name=match.group(), auth_required=auth_required))
compiled_pattern = re.compile(pattern, flags=(re.UNICODE | re.VERBOSE))
if compiled_pattern in request_handlers:
raise ValueError('Tried to redefine handler for %s with %s' % (
pattern, func))
request_handlers[compiled_pattern] = func
func.__doc__ = ' - *Pattern:* ``%s``\n\n%s' % (
pattern, func.__doc__ or '')
return func
return decorator
[docs]def load_protocol_modules():
"""
The protocol modules must be imported to get them registered in
:attr:`request_handlers` and :attr:`mpd_commands`.
"""
from . import ( # noqa
audio_output, channels, command_list, connection, current_playlist,
empty, music_db, playback, reflection, status, stickers,
stored_playlists)