#!/usr/bin/env python
#
# -*- coding: utf-8 -*-
#
# roundrobin.py
#
# Copyright 2018 Jelle Smet <development@smetj.net>
#
# 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
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# 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 wishbone.actor import Actor
from wishbone.module import FlowModule
from itertools import cycle
from random import randint
[docs]class RoundRobin(FlowModule):
'''**Round-robins incoming events to all connected queues.**
Create a "1 to n" relationship between queues. Events arriving in inbox
are then submitted in a roundrobin (or randomized) fashion to the
connected queues. The outbox queue is non existent.
Parameters::
- randomize(bool)(False)
| Randomizes the queue selection instead of going round-robin
| over all queues.
Queues::
- inbox
| Incoming events
'''
def __init__(self, actor_config, randomize=False):
Actor.__init__(self, actor_config)
self.pool.createQueue("inbox")
self.registerConsumer(self.consume, "inbox")
def preHook(self):
self.destination_queues = []
for queue in self.pool.listQueues(names=True):
if queue not in ["_failed", "_success", "_metrics", "_logs"]:
self.destination_queues.append(queue)
if not self.kwargs.randomize:
self.cycle = cycle(self.destination_queues)
self.chooseQueue = self.__chooseNextQueue
else:
self.chooseQueue = self.__chooseRandomQueue
def consume(self, event):
queue = self.chooseQueue()
self.submit(event, queue)
def __chooseNextQueue(self):
return next(self.cycle)
def __chooseRandomQueue(self):
index = randint(0, len(self.destination_queues) - 1)
return self.destination_queues[index]