platypush/platypush/cron/scheduler.py

125 lines
3.6 KiB
Python

import enum
import logging
import threading
import time
import croniter
from platypush.procedure import Procedure
from platypush.utils import is_functional_cron
logger = logging.getLogger('platypush:cron')
class CronjobState(enum.IntEnum):
IDLE = 0
WAIT = 1
RUNNING = 2
DONE = 3
ERROR = 4
class Cronjob(threading.Thread):
def __init__(self, name, cron_expression, actions):
super().__init__()
self.cron_expression = cron_expression
self.name = name
self.state = CronjobState.IDLE
self._should_stop = threading.Event()
if isinstance(actions, dict) or isinstance(actions, list):
self.actions = Procedure.build(name=name + '__Cron', _async=False, requests=actions)
else:
self.actions = actions
def run(self):
self.state = CronjobState.WAIT
self.wait()
if self.should_stop():
return
self.state = CronjobState.RUNNING
try:
logger.info('Running cronjob {}'.format(self.name))
context = {}
if isinstance(self.actions, Procedure):
response = self.actions.execute(_async=False, **context)
else:
response = self.actions(**context)
logger.info('Response from cronjob {}: {}'.format(self.name, response))
self.state = CronjobState.DONE
except Exception as e:
logger.exception(e)
self.state = CronjobState.ERROR
def wait(self):
now = int(time.time())
cron = croniter.croniter(self.cron_expression, now)
next_run = int(cron.get_next())
self._should_stop.wait(next_run - now)
def should_run(self):
now = int(time.time())
cron = croniter.croniter(self.cron_expression, now)
next_run = int(cron.get_next())
return now == next_run
def stop(self):
self._should_stop.set()
def should_stop(self):
return self._should_stop.is_set()
class CronScheduler(threading.Thread):
def __init__(self, jobs):
super().__init__()
self.jobs_config = jobs
self._jobs = {}
self._should_stop = threading.Event()
logger.info('Cron scheduler initialized with {} jobs'.
format(len(self.jobs_config.keys())))
def _get_job(self, name, config):
job = self._jobs.get(name)
if job and job.state not in [CronjobState.DONE, CronjobState.ERROR]:
return job
if isinstance(config, dict):
self._jobs[name] = Cronjob(name=name, cron_expression=config['cron_expression'],
actions=config['actions'])
elif is_functional_cron(config):
self._jobs[name] = Cronjob(name=name, cron_expression=config.cron_expression,
actions=config)
else:
raise AssertionError('Expected type dict or function for cron {}, got {}'.format(
name, type(config)))
return self._jobs[name]
def stop(self):
for job in self._jobs.values():
job.stop()
self._should_stop.set()
def should_stop(self):
return self._should_stop.is_set()
def run(self):
logger.info('Running cron scheduler')
while not self.should_stop():
for (job_name, job_config) in self.jobs_config.items():
job = self._get_job(name=job_name, config=job_config)
if job.state == CronjobState.IDLE:
job.start()
time.sleep(0.5)
logger.info('Terminating cron scheduler')
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