daphne/channels/delay/worker.py
Andrew Godwin 558d66a6b2 Fixed #512: Give rundelay a configurable sleep interval
Also reduced the default interval to 1s.
2017-01-30 17:13:30 -08:00

92 lines
3.0 KiB
Python

from __future__ import unicode_literals
import json
import logging
import signal
import sys
import time
from django.core.exceptions import ValidationError
from .models import DelayedMessage
logger = logging.getLogger('django.channels')
class Worker(object):
"""Worker class that listens to channels.delay messages and dispatches messages"""
def __init__(
self,
channel_layer,
signal_handlers=True,
database_sleep_duration=1,
):
self.channel_layer = channel_layer
self.signal_handlers = signal_handlers
self.termed = False
self.in_job = False
self.database_sleep_duration = database_sleep_duration
def install_signal_handler(self):
signal.signal(signal.SIGTERM, self.sigterm_handler)
signal.signal(signal.SIGINT, self.sigterm_handler)
def sigterm_handler(self, signo, stack_frame):
self.termed = True
if self.in_job:
logger.info("Shutdown signal received while busy, waiting for loop termination")
else:
logger.info("Shutdown signal received while idle, terminating immediately")
sys.exit(0)
def run(self):
if self.signal_handlers:
self.install_signal_handler()
logger.info("Listening on asgi.delay")
last_delay_check = 0
while not self.termed:
self.in_job = False
channel, content = self.channel_layer.receive(['asgi.delay'], block=False)
self.in_job = True
if channel is not None:
logger.debug("Got message on asgi.delay")
if 'channel' not in content or \
'content' not in content or \
'delay' not in content:
logger.error("Invalid message received, it must contain keys 'channel', 'content', "
"and 'delay'.")
break
message = DelayedMessage(
content=json.dumps(content['content']),
channel_name=content['channel'],
delay=content['delay']
)
try:
message.full_clean()
except ValidationError as err:
logger.error("Invalid message received: %s:%s", err.error_dict.keys(), err.messages)
break
message.save()
else:
# Sleep for a short interval so we don't idle hot.
time.sleep(0.1)
# check for messages to send
if time.time() - last_delay_check > self.database_sleep_duration:
if DelayedMessage.objects.is_due().exists():
for message in DelayedMessage.objects.is_due().all():
logger.info("Sending delayed message to channel %s", message.channel_name)
message.send(channel_layer=self.channel_layer)
else:
logger.debug("No delayed messages waiting.")
last_delay_check = time.time()