platypush/platypush/backend/redis.py
2018-05-14 20:09:25 +02:00

53 lines
1.5 KiB
Python

import logging
import json
from redis import Redis
from platypush.backend import Backend
from platypush.message import Message
class RedisBackend(Backend):
"""
Backend that reads messages from a configured Redis queue
(default: `platypush_bus_mq`) and posts them to the application bus.
Very useful when you have plugin whose code is executed in another process
and can't post events or requests to the application bus.
"""
def __init__(self, queue='platypush_bus_mq', redis_args={}, *args, **kwargs):
"""
Params:
queue -- Queue to poll for new messages
redis_args -- Arguments that will be passed to the redis-py
constructor (e.g. host, port, password),
see http://redis-py.readthedocs.io/en/latest/
"""
super().__init__(*args, **kwargs)
self.queue = queue
self.redis_args = redis_args
self.redis = Redis(**self.redis_args)
def send_message(self, msg):
self.redis.rpush(self.queue, msg)
def run(self):
super().run()
logging.info('Initialized Redis backend on queue {} with arguments {}'.
format(self.queue, self.redis_args))
while not self.should_stop():
try:
msg = self.redis.blpop(self.queue)
msg = Message.build(json.loads(msg[1].decode('utf-8')))
self.bus.post(msg)
except Exception as e:
logging.exception(e)
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