73 lines
2.5 KiB
Python
73 lines
2.5 KiB
Python
"""Timezone aware Cron schedule Implementation."""
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from collections import namedtuple
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from datetime import datetime, timezone
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from celery import schedules
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schedstate = namedtuple('schedstate', ('is_due', 'next'))
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class TzAwareCrontab(schedules.crontab):
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"""Timezone Aware Crontab."""
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def __init__(
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self, minute='*', hour='*', day_of_week='*',
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day_of_month='*', month_of_year='*', tz=timezone.utc, app=None
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):
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"""Overwrite Crontab constructor to include a timezone argument."""
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self.tz = tz
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nowfun = self.nowfunc
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super().__init__(
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minute=minute, hour=hour, day_of_week=day_of_week,
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day_of_month=day_of_month,
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month_of_year=month_of_year, nowfun=nowfun, app=app
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)
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def nowfunc(self):
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return datetime.now(self.tz)
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def is_due(self, last_run_at):
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"""Calculate when the next run will take place.
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Return tuple of ``(is_due, next_time_to_check)``.
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The ``last_run_at`` argument needs to be timezone aware.
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"""
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# convert last_run_at to the schedule timezone
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last_run_at = last_run_at.astimezone(self.tz)
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rem_delta = self.remaining_estimate(last_run_at)
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rem = max(rem_delta.total_seconds(), 0)
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due = rem == 0
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if due:
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rem_delta = self.remaining_estimate(self.now())
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rem = max(rem_delta.total_seconds(), 0)
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return schedstate(due, rem)
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# Needed to support pickling
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def __repr__(self):
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return """<crontab: {0._orig_minute} {0._orig_hour}
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{0._orig_day_of_week} {0._orig_day_of_month}
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{0._orig_month_of_year} (m/h/d/dM/MY), {0.tz}>
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""".format(self)
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def __reduce__(self):
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return (self.__class__, (self._orig_minute,
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self._orig_hour,
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self._orig_day_of_week,
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self._orig_day_of_month,
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self._orig_month_of_year,
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self.tz), None)
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def __eq__(self, other):
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if isinstance(other, schedules.crontab):
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return (other.month_of_year == self.month_of_year
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and other.day_of_month == self.day_of_month
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and other.day_of_week == self.day_of_week
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and other.hour == self.hour
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and other.minute == self.minute
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and other.tz == self.tz)
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return NotImplemented
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