Viewing file:  routing.py (2.76 KB) -rw-r--r--
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from warnings import warn
from .low_level import MessageType, HeaderFields
from .wrappers import DBusErrorResponse
class Router:
"""Routing for messages coming back to a client application.
:param handle_factory: Constructor for an object like asyncio.Future,
with methods *set_result* and *set_exception*. Outgoing method call
messages will get a handle associated with them.
:param on_unhandled: Callback for messages not otherwise dispatched.
"""
def __init__(self, handle_factory, on_unhandled=None):
self.handle_factory = handle_factory
self._on_unhandled = on_unhandled
self.outgoing_serial = 0
self.awaiting_reply = {}
self.signal_callbacks = {}
@property
def on_unhandled(self):
return self._on_unhandled
@on_unhandled.setter
def on_unhandled(self, value):
warn("Setting on_unhandled is deprecated. Please use the filter() "
"method or simple receive() calls instead.", stacklevel=2)
self._on_unhandled = value
def outgoing(self, msg):
"""Set the serial number in the message & make a handle if a method call
"""
self.outgoing_serial += 1
msg.header.serial = self.outgoing_serial
if msg.header.message_type is MessageType.method_call:
self.awaiting_reply[msg.header.serial] = handle = self.handle_factory()
return handle
def subscribe_signal(self, callback, path, interface, member):
"""Add a callback for a signal.
"""
warn("The subscribe_signal() method is deprecated. "
"Please use the filter() API instead.", stacklevel=2)
self.signal_callbacks[(path, interface, member)] = callback
def incoming(self, msg):
"""Route an incoming message.
"""
hdr = msg.header
# Signals:
if hdr.message_type is MessageType.signal:
key = (hdr.fields.get(HeaderFields.path, None),
hdr.fields.get(HeaderFields.interface, None),
hdr.fields.get(HeaderFields.member, None)
)
cb = self.signal_callbacks.get(key, None)
if cb is not None:
cb(msg.body)
return
# Method returns & errors
reply_serial = hdr.fields.get(HeaderFields.reply_serial, -1)
reply_handle = self.awaiting_reply.pop(reply_serial, None)
if reply_handle is not None:
if hdr.message_type is MessageType.method_return:
reply_handle.set_result(msg.body)
return
elif hdr.message_type is MessageType.error:
reply_handle.set_exception(DBusErrorResponse(msg))
return
if self.on_unhandled:
self.on_unhandled(msg)
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