/usr/lib/python3/dist-packages/celery/events/snapshot.py is in python3-celery 4.1.0-2ubuntu1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 | # -*- coding: utf-8 -*-
"""Periodically store events in a database.
Consuming the events as a stream isn't always suitable
so this module implements a system to take snapshots of the
state of a cluster at regular intervals. There's a full
implementation of this writing the snapshots to a database
in :mod:`djcelery.snapshots` in the `django-celery` distribution.
"""
from __future__ import absolute_import, print_function, unicode_literals
from kombu.utils.limits import TokenBucket
from celery import platforms
from celery.app import app_or_default
from celery.utils.timer2 import Timer
from celery.utils.dispatch import Signal
from celery.utils.imports import instantiate
from celery.utils.log import get_logger
from celery.utils.time import rate
__all__ = ['Polaroid', 'evcam']
logger = get_logger('celery.evcam')
class Polaroid(object):
"""Record event snapshots."""
timer = None
shutter_signal = Signal(name='shutter_signal', providing_args={'state'})
cleanup_signal = Signal(name='cleanup_signal')
clear_after = False
_tref = None
_ctref = None
def __init__(self, state, freq=1.0, maxrate=None,
cleanup_freq=3600.0, timer=None, app=None):
self.app = app_or_default(app)
self.state = state
self.freq = freq
self.cleanup_freq = cleanup_freq
self.timer = timer or self.timer or Timer()
self.logger = logger
self.maxrate = maxrate and TokenBucket(rate(maxrate))
def install(self):
self._tref = self.timer.call_repeatedly(self.freq, self.capture)
self._ctref = self.timer.call_repeatedly(
self.cleanup_freq, self.cleanup,
)
def on_shutter(self, state):
pass
def on_cleanup(self):
pass
def cleanup(self):
logger.debug('Cleanup: Running...')
self.cleanup_signal.send(sender=self.state)
self.on_cleanup()
def shutter(self):
if self.maxrate is None or self.maxrate.can_consume():
logger.debug('Shutter: %s', self.state)
self.shutter_signal.send(sender=self.state)
self.on_shutter(self.state)
def capture(self):
self.state.freeze_while(self.shutter, clear_after=self.clear_after)
def cancel(self):
if self._tref:
self._tref() # flush all received events.
self._tref.cancel()
if self._ctref:
self._ctref.cancel()
def __enter__(self):
self.install()
return self
def __exit__(self, *exc_info):
self.cancel()
def evcam(camera, freq=1.0, maxrate=None, loglevel=0,
logfile=None, pidfile=None, timer=None, app=None):
"""Start snapshot recorder."""
app = app_or_default(app)
if pidfile:
platforms.create_pidlock(pidfile)
app.log.setup_logging_subsystem(loglevel, logfile)
print('-> evcam: Taking snapshots with {0} (every {1} secs.)'.format(
camera, freq))
state = app.events.State()
cam = instantiate(camera, state, app=app, freq=freq,
maxrate=maxrate, timer=timer)
cam.install()
conn = app.connection_for_read()
recv = app.events.Receiver(conn, handlers={'*': state.event})
try:
try:
recv.capture(limit=None)
except KeyboardInterrupt:
raise SystemExit
finally:
cam.cancel()
conn.close()
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