collinmcnulty commented on code in PR #22332: URL: https://github.com/apache/airflow/pull/22332#discussion_r843864320
########## airflow/timetables/events.py: ########## @@ -0,0 +1,111 @@ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. +import itertools +from typing import Iterable, Optional + +import pendulum +from pendulum import DateTime + +from airflow.timetables.base import DagRunInfo, DataInterval, TimeRestriction, Timetable + + +class EventsTimetable(Timetable): + """ + Timetable that schedules DAG runs at specific listed datetimes. Suitable for + predictable but truly irregular scheduling such as sporting events. + + :param event_dates: List of datetimes for the DAG to run at. Duplicates will be ignored. + :param restrict_to_events: Whether manual runs should use the most recent event or + the current time + :param description: A name for the timetable to display in the UI. Default None will be shown as + "X Events" where X is the len of event_dates + """ + + def __init__( + self, + event_dates: Iterable[DateTime], + restrict_to_events: bool = False, + presorted: bool = False, + description: Optional[str] = None, + ): + + self.event_dates = list(event_dates) # Must be reversible and indexable + if not presorted: + # For long lists this could take a while, so only want to do it once + self.event_dates = sorted(self.event_dates) + self.restrict_to_events = restrict_to_events + if description is None: + self.description = ( + f"{len(self.event_dates)} Events between {self.event_dates[0]} and {self.event_dates[-1]}" + ) + self._summary = f"{len(self.event_dates)} Events" + else: + self._summary = description + self.description = description + + @property + def summary(self) -> str: + return self._summary + + def __repr__(self): + return self.summary + + def next_dagrun_info( + self, + *, + last_automated_data_interval: Optional[DataInterval], + restriction: TimeRestriction, + ) -> Optional[DagRunInfo]: + if last_automated_data_interval is None: + next_event = self.event_dates[0] + else: + future_dates = itertools.dropwhile( + lambda when: when <= last_automated_data_interval.end, self.event_dates # type: ignore + ) + next_event = next(future_dates, None) # type: ignore + if next_event is None: + return None + + return DagRunInfo.exact(next_event) + + def infer_manual_data_interval(self, *, run_after: DateTime) -> DataInterval: + # If Timetable not restricted to events, run for the time specified + if not self.restrict_to_events: + return DataInterval.exact(run_after) + + # If restricted to events, run for the most recent past event + # or for the first event if all events are in the future + if run_after < self.event_dates[0]: + return DataInterval.exact(self.event_dates[0]) + else: + past_events = itertools.dropwhile(lambda when: when > run_after, self.event_dates[::-1]) + most_recent_event = next(past_events) + return DataInterval.exact(most_recent_event) + + def serialize(self): + return { + "event_dates": [str(x) for x in self.event_dates], + "restrict_to_events": self.restrict_to_events, + } + + @classmethod + def deserialize(cls, data) -> Timetable: + return cls( + [pendulum.parse(x) for x in data["event_dates"]], # type: ignore Review Comment: Otherwise mypy thinks there could be a None in there. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
