Source code for wishbone.module.switch

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#  Copyright 2018 Jelle Smet <>
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 3 of the License, or
#  (at your option) any later version.
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  GNU General Public License for more details.
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.

from import Actor
from wishbone.module import FlowModule
from wishbone.error import ModuleInitFailure, ReservedName

[docs]class Switch(FlowModule): '''**Switch outgoing queues while forwarding events.** Forwards events to the desired outgoing queue based on the value of <outgoing>. The value of <outgoing> can be dynamically set in 2 ways: - Using a template function. - By sending an event to the <switch> queue with the value of <outgoing> stored under *data*. Parameters:: - outgoing(str)("outbox")* | The name of the queue to submit incoming events to. Queues:: - inbox | incoming events - switch | incoming events to alter outgoing queue. - outbox* | outgoing events - <connected_queue_1> | outgoing events - <connected_queue_n> | outgoing events ''' def __init__(self, actor_config, outgoing="outbox"): Actor.__init__(self, actor_config) self.pool.createQueue("inbox") self.pool.createQueue("switch") self.pool.createQueue("outbox") self.pool.queue.switch.disableFallThrough() self.registerConsumer(self.consume, "inbox") self.registerConsumer(self.switch, "switch") self.forbidden = ["inbox", "switch"] def preHook(self): if self.kwargs.outgoing in self.forbidden: raise ModuleInitFailure("Module parameter <outgoing> cannot have value '%s'." % (self.kwargs.outgoing)) self.destination = self.kwargs.outgoing self._destination = self.kwargs.outgoing def consume(self, event): if self.kwargs.outgoing != self._destination: self._destination = self.kwargs.outgoing self.destination = self.kwargs.outgoing if self.destination in self.forbidden: raise ReservedName("Cannot forward incoming events to queue '%s'." % (self.destination)) else: self.submit(event, self.destination) def switch(self, event): prefix = "<switch> queue received event" try: name = event.get("data") if self.pool.hasQueue(name): self.destination = name"%s. Outgoing messages forwarded to queue '%s'." % (prefix, name)) else: self.logging.error("%s but module has no queue named '%s'." % (prefix, name)) except KeyError: self.logging.error("%s but has no value key data." % (prefix))