Current File : //usr/lib/python3/dist-packages/dbus/connection.py
# Copyright (C) 2007 Collabora Ltd. <http://www.collabora.co.uk/>
#
# SPDX-License-Identifier: MIT
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use, copy,
# modify, merge, publish, distribute, sublicense, and/or sell copies
# of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
__all__ = ('Connection', 'SignalMatch')
__docformat__ = 'reStructuredText'
import logging
import threading
import weakref
from _dbus_bindings import (
Connection as _Connection, LOCAL_IFACE, LOCAL_PATH, validate_bus_name,
validate_interface_name, validate_member_name, validate_object_path)
from dbus.exceptions import DBusException
from dbus.lowlevel import (
ErrorMessage, HANDLER_RESULT_NOT_YET_HANDLED, MethodCallMessage,
MethodReturnMessage, SignalMessage)
from dbus.proxies import ProxyObject
from dbus._compat import is_py2, is_py3
from _dbus_bindings import String
_logger = logging.getLogger('dbus.connection')
def _noop(*args, **kwargs):
pass
class SignalMatch(object):
_slots = ['_sender_name_owner', '_member', '_interface', '_sender',
'_path', '_handler', '_args_match', '_rule',
'_byte_arrays', '_conn_weakref',
'_destination_keyword', '_interface_keyword',
'_message_keyword', '_member_keyword',
'_sender_keyword', '_path_keyword', '_int_args_match']
__slots__ = tuple(_slots)
def __init__(self, conn, sender, object_path, dbus_interface,
member, handler, byte_arrays=False,
sender_keyword=None, path_keyword=None,
interface_keyword=None, member_keyword=None,
message_keyword=None, destination_keyword=None,
**kwargs):
if member is not None:
validate_member_name(member)
if dbus_interface is not None:
validate_interface_name(dbus_interface)
if sender is not None:
validate_bus_name(sender)
if object_path is not None:
validate_object_path(object_path)
self._rule = None
self._conn_weakref = weakref.ref(conn)
self._sender = sender
self._interface = dbus_interface
self._member = member
self._path = object_path
self._handler = handler
# if the connection is actually a bus, it's responsible for changing
# this later
self._sender_name_owner = sender
if 'utf8_strings' in kwargs:
raise TypeError("unexpected keyword argument 'utf8_strings'")
self._byte_arrays = byte_arrays
self._sender_keyword = sender_keyword
self._path_keyword = path_keyword
self._member_keyword = member_keyword
self._interface_keyword = interface_keyword
self._message_keyword = message_keyword
self._destination_keyword = destination_keyword
self._args_match = kwargs
if not kwargs:
self._int_args_match = None
else:
self._int_args_match = {}
for kwarg in kwargs:
if not kwarg.startswith('arg'):
raise TypeError('SignalMatch: unknown keyword argument %s'
% kwarg)
try:
index = int(kwarg[3:])
except ValueError:
raise TypeError('SignalMatch: unknown keyword argument %s'
% kwarg)
if index < 0 or index > 63:
raise TypeError('SignalMatch: arg match index must be in '
'range(64), not %d' % index)
self._int_args_match[index] = kwargs[kwarg]
def __hash__(self):
"""SignalMatch objects are compared by identity."""
return hash(id(self))
def __eq__(self, other):
"""SignalMatch objects are compared by identity."""
return self is other
def __ne__(self, other):
"""SignalMatch objects are compared by identity."""
return self is not other
sender = property(lambda self: self._sender)
def __str__(self):
if self._rule is None:
rule = ["type='signal'"]
if self._sender is not None:
rule.append("sender='%s'" % self._sender)
if self._path is not None:
rule.append("path='%s'" % self._path)
if self._interface is not None:
rule.append("interface='%s'" % self._interface)
if self._member is not None:
rule.append("member='%s'" % self._member)
if self._int_args_match is not None:
for index, value in self._int_args_match.items():
rule.append("arg%d='%s'" % (index, value))
self._rule = ','.join(rule)
return self._rule
def __repr__(self):
return ('<%s at %x "%s" on conn %r>'
% (self.__class__, id(self), self._rule, self._conn_weakref()))
def set_sender_name_owner(self, new_name):
self._sender_name_owner = new_name
def matches_removal_spec(self, sender, object_path,
dbus_interface, member, handler, **kwargs):
if handler not in (None, self._handler):
return False
if sender != self._sender:
return False
if object_path != self._path:
return False
if dbus_interface != self._interface:
return False
if member != self._member:
return False
if kwargs != self._args_match:
return False
return True
def maybe_handle_message(self, message):
args = None
# these haven't been checked yet by the match tree
if self._sender_name_owner not in (None, message.get_sender()):
return False
if self._int_args_match is not None:
# extracting args with byte_arrays is less work
kwargs = dict(byte_arrays=True)
args = message.get_args_list(**kwargs)
for index, value in self._int_args_match.items():
if (index >= len(args)
or not isinstance(args[index], String)
or args[index] != value):
return False
# these have likely already been checked by the match tree
if self._member not in (None, message.get_member()):
return False
if self._interface not in (None, message.get_interface()):
return False
if self._path not in (None, message.get_path()):
return False
try:
# minor optimization: if we already extracted the args with the
# right calling convention to do the args match, don't bother
# doing so again
if args is None or not self._byte_arrays:
args = message.get_args_list(byte_arrays=self._byte_arrays)
kwargs = {}
if self._sender_keyword is not None:
kwargs[self._sender_keyword] = message.get_sender()
if self._destination_keyword is not None:
kwargs[self._destination_keyword] = message.get_destination()
if self._path_keyword is not None:
kwargs[self._path_keyword] = message.get_path()
if self._member_keyword is not None:
kwargs[self._member_keyword] = message.get_member()
if self._interface_keyword is not None:
kwargs[self._interface_keyword] = message.get_interface()
if self._message_keyword is not None:
kwargs[self._message_keyword] = message
self._handler(*args, **kwargs)
except:
# basicConfig is a no-op if logging is already configured
logging.basicConfig()
_logger.error('Exception in handler for D-Bus signal:', exc_info=1)
return True
def remove(self):
conn = self._conn_weakref()
# do nothing if the connection has already vanished
if conn is not None:
conn.remove_signal_receiver(self, self._member,
self._interface, self._sender,
self._path,
**self._args_match)
class Connection(_Connection):
"""A connection to another application. In this base class there is
assumed to be no bus daemon.
:Since: 0.81.0
"""
ProxyObjectClass = ProxyObject
def __init__(self, *args, **kwargs):
super(Connection, self).__init__(*args, **kwargs)
# this if-block is needed because shared bus connections can be
# __init__'ed more than once
if not hasattr(self, '_dbus_Connection_initialized'):
self._dbus_Connection_initialized = 1
self.__call_on_disconnection = []
self._signal_recipients_by_object_path = {}
"""Map from object path to dict mapping dbus_interface to dict
mapping member to list of SignalMatch objects."""
self._signals_lock = threading.Lock()
"""Lock used to protect signal data structures"""
self.add_message_filter(self.__class__._signal_func)
def activate_name_owner(self, bus_name):
"""Return the unique name for the given bus name, activating it
if necessary and possible.
If the name is already unique or this connection is not to a
bus daemon, just return it.
:Returns: a bus name. If the given `bus_name` exists, the returned
name identifies its current owner; otherwise the returned name
does not exist.
:Raises DBusException: if the implementation has failed
to activate the given bus name.
:Since: 0.81.0
"""
return bus_name
def get_object(self, bus_name=None, object_path=None, introspect=True,
**kwargs):
"""Return a local proxy for the given remote object.
Method calls on the proxy are translated into method calls on the
remote object.
:Parameters:
`bus_name` : str
A bus name (either the unique name or a well-known name)
of the application owning the object. The keyword argument
named_service is a deprecated alias for this.
`object_path` : str
The object path of the desired object
`introspect` : bool
If true (default), attempt to introspect the remote
object to find out supported methods and their signatures
:Returns: a `dbus.proxies.ProxyObject`
"""
named_service = kwargs.pop('named_service', None)
if named_service is not None:
if bus_name is not None:
raise TypeError('bus_name and named_service cannot both '
'be specified')
from warnings import warn
warn('Passing the named_service parameter to get_object by name '
'is deprecated: please use positional parameters',
DeprecationWarning, stacklevel=2)
bus_name = named_service
if kwargs:
raise TypeError('get_object does not take these keyword '
'arguments: %s' % ', '.join(kwargs.keys()))
return self.ProxyObjectClass(self, bus_name, object_path,
introspect=introspect)
def add_signal_receiver(self, handler_function,
signal_name=None,
dbus_interface=None,
bus_name=None,
path=None,
**keywords):
"""Arrange for the given function to be called when a signal matching
the parameters is received.
:Parameters:
`handler_function` : callable
The function to be called. Its positional arguments will
be the arguments of the signal. By default it will receive
no keyword arguments, but see the description of
the optional keyword arguments below.
`signal_name` : str
The signal name; None (the default) matches all names
`dbus_interface` : str
The D-Bus interface name with which to qualify the signal;
None (the default) matches all interface names
`bus_name` : str
A bus name for the sender, which will be resolved to a
unique name if it is not already; None (the default) matches
any sender.
`path` : str
The object path of the object which must have emitted the
signal; None (the default) matches any object path
:Keywords:
`utf8_strings` : bool
If True, the handler function will receive any string
arguments as dbus.UTF8String objects (a subclass of str
guaranteed to be UTF-8). If False (default) it will receive
any string arguments as dbus.String objects (a subclass of
unicode).
`byte_arrays` : bool
If True, the handler function will receive any byte-array
arguments as dbus.ByteArray objects (a subclass of str).
If False (default) it will receive any byte-array
arguments as a dbus.Array of dbus.Byte (subclasses of:
a list of ints).
`sender_keyword` : str
If not None (the default), the handler function will receive
the unique name of the sending endpoint as a keyword
argument with this name.
`destination_keyword` : str
If not None (the default), the handler function will receive
the bus name of the destination (or None if the signal is a
broadcast, as is usual) as a keyword argument with this name.
`interface_keyword` : str
If not None (the default), the handler function will receive
the signal interface as a keyword argument with this name.
`member_keyword` : str
If not None (the default), the handler function will receive
the signal name as a keyword argument with this name.
`path_keyword` : str
If not None (the default), the handler function will receive
the object-path of the sending object as a keyword argument
with this name.
`message_keyword` : str
If not None (the default), the handler function will receive
the `dbus.lowlevel.SignalMessage` as a keyword argument with
this name.
`arg...` : unicode or UTF-8 str
If there are additional keyword parameters of the form
``arg``\\ *n*, match only signals where the *n*\\ th argument
is the value given for that keyword parameter. As of this
time only string arguments can be matched (in particular,
object paths and signatures can't).
`named_service` : str
A deprecated alias for `bus_name`.
"""
self._require_main_loop()
named_service = keywords.pop('named_service', None)
if named_service is not None:
if bus_name is not None:
raise TypeError('bus_name and named_service cannot both be '
'specified')
bus_name = named_service
from warnings import warn
warn('Passing the named_service parameter to add_signal_receiver '
'by name is deprecated: please use positional parameters',
DeprecationWarning, stacklevel=2)
match = SignalMatch(self, bus_name, path, dbus_interface,
signal_name, handler_function, **keywords)
self._signals_lock.acquire()
try:
by_interface = self._signal_recipients_by_object_path.setdefault(
path, {})
by_member = by_interface.setdefault(dbus_interface, {})
matches = by_member.setdefault(signal_name, [])
matches.append(match)
finally:
self._signals_lock.release()
return match
def _iter_easy_matches(self, path, dbus_interface, member):
if path is not None:
path_keys = (None, path)
else:
path_keys = (None,)
if dbus_interface is not None:
interface_keys = (None, dbus_interface)
else:
interface_keys = (None,)
if member is not None:
member_keys = (None, member)
else:
member_keys = (None,)
for path in path_keys:
by_interface = self._signal_recipients_by_object_path.get(path)
if by_interface is None:
continue
for dbus_interface in interface_keys:
by_member = by_interface.get(dbus_interface, None)
if by_member is None:
continue
for member in member_keys:
matches = by_member.get(member, None)
if matches is None:
continue
for m in matches:
yield m
def remove_signal_receiver(self, handler_or_match,
signal_name=None,
dbus_interface=None,
bus_name=None,
path=None,
**keywords):
named_service = keywords.pop('named_service', None)
if named_service is not None:
if bus_name is not None:
raise TypeError('bus_name and named_service cannot both be '
'specified')
bus_name = named_service
from warnings import warn
warn('Passing the named_service parameter to '
'remove_signal_receiver by name is deprecated: please use '
'positional parameters',
DeprecationWarning, stacklevel=2)
new = []
deletions = []
self._signals_lock.acquire()
try:
by_interface = self._signal_recipients_by_object_path.get(path,
None)
if by_interface is None:
return
by_member = by_interface.get(dbus_interface, None)
if by_member is None:
return
matches = by_member.get(signal_name, None)
if matches is None:
return
for match in matches:
if (handler_or_match is match
or match.matches_removal_spec(bus_name,
path,
dbus_interface,
signal_name,
handler_or_match,
**keywords)):
deletions.append(match)
else:
new.append(match)
if new:
by_member[signal_name] = new
else:
del by_member[signal_name]
if not by_member:
del by_interface[dbus_interface]
if not by_interface:
del self._signal_recipients_by_object_path[path]
finally:
self._signals_lock.release()
for match in deletions:
self._clean_up_signal_match(match)
def _clean_up_signal_match(self, match):
# Now called without the signals lock held (it was held in <= 0.81.0)
pass
def _signal_func(self, message):
"""D-Bus filter function. Handle signals by dispatching to Python
callbacks kept in the match-rule tree.
"""
if not isinstance(message, SignalMessage):
return HANDLER_RESULT_NOT_YET_HANDLED
dbus_interface = message.get_interface()
path = message.get_path()
signal_name = message.get_member()
for match in self._iter_easy_matches(path, dbus_interface,
signal_name):
match.maybe_handle_message(message)
if (dbus_interface == LOCAL_IFACE and
path == LOCAL_PATH and
signal_name == 'Disconnected'):
for cb in self.__call_on_disconnection:
try:
cb(self)
except Exception:
# basicConfig is a no-op if logging is already configured
logging.basicConfig()
_logger.error('Exception in handler for Disconnected '
'signal:', exc_info=1)
return HANDLER_RESULT_NOT_YET_HANDLED
def call_async(self, bus_name, object_path, dbus_interface, method,
signature, args, reply_handler, error_handler,
timeout=-1.0, byte_arrays=False,
require_main_loop=True, **kwargs):
"""Call the given method, asynchronously.
If the reply_handler is None, successful replies will be ignored.
If the error_handler is None, failures will be ignored. If both
are None, the implementation may request that no reply is sent.
:Returns: The dbus.lowlevel.PendingCall.
:Since: 0.81.0
"""
if object_path == LOCAL_PATH:
raise DBusException('Methods may not be called on the reserved '
'path %s' % LOCAL_PATH)
if dbus_interface == LOCAL_IFACE:
raise DBusException('Methods may not be called on the reserved '
'interface %s' % LOCAL_IFACE)
# no need to validate other args - MethodCallMessage ctor will do
get_args_opts = dict(byte_arrays=byte_arrays)
if 'utf8_strings' in kwargs:
raise TypeError("unexpected keyword argument 'utf8_strings'")
message = MethodCallMessage(destination=bus_name,
path=object_path,
interface=dbus_interface,
method=method)
# Add the arguments to the function
try:
message.append(signature=signature, *args)
except Exception as e:
logging.basicConfig()
_logger.error('Unable to set arguments %r according to '
'signature %r: %s: %s',
args, signature, e.__class__, e)
raise
if reply_handler is None and error_handler is None:
# we don't care what happens, so just send it
self.send_message(message)
return
if reply_handler is None:
reply_handler = _noop
if error_handler is None:
error_handler = _noop
def msg_reply_handler(message):
if isinstance(message, MethodReturnMessage):
reply_handler(*message.get_args_list(**get_args_opts))
elif isinstance(message, ErrorMessage):
error_handler(DBusException(name=message.get_error_name(),
*message.get_args_list()))
else:
error_handler(TypeError('Unexpected type for reply '
'message: %r' % message))
return self.send_message_with_reply(message, msg_reply_handler,
timeout,
require_main_loop=require_main_loop)
def call_blocking(self, bus_name, object_path, dbus_interface, method,
signature, args, timeout=-1.0,
byte_arrays=False, **kwargs):
"""Call the given method, synchronously.
:Since: 0.81.0
"""
if object_path == LOCAL_PATH:
raise DBusException('Methods may not be called on the reserved '
'path %s' % LOCAL_PATH)
if dbus_interface == LOCAL_IFACE:
raise DBusException('Methods may not be called on the reserved '
'interface %s' % LOCAL_IFACE)
# no need to validate other args - MethodCallMessage ctor will do
get_args_opts = dict(byte_arrays=byte_arrays)
if 'utf8_strings' in kwargs:
raise TypeError("unexpected keyword argument 'utf8_strings'")
message = MethodCallMessage(destination=bus_name,
path=object_path,
interface=dbus_interface,
method=method)
# Add the arguments to the function
try:
message.append(signature=signature, *args)
except Exception as e:
logging.basicConfig()
_logger.error('Unable to set arguments %r according to '
'signature %r: %s: %s',
args, signature, e.__class__, e)
raise
# make a blocking call
reply_message = self.send_message_with_reply_and_block(
message, timeout)
args_list = reply_message.get_args_list(**get_args_opts)
if len(args_list) == 0:
return None
elif len(args_list) == 1:
return args_list[0]
else:
return tuple(args_list)
def call_on_disconnection(self, callable):
"""Arrange for `callable` to be called with one argument (this
Connection object) when the Connection becomes
disconnected.
:Since: 0.83.0
"""
self.__call_on_disconnection.append(callable)
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