Source code for airflow.timetables.simple

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from __future__ import annotations

from collections.abc import Sequence
from typing import TYPE_CHECKING, Any

from airflow._shared.timezones import timezone
from airflow.timetables.base import DagRunInfo, DataInterval, Timetable

if TYPE_CHECKING:
    from pendulum import DateTime

    from airflow.sdk.definitions.asset import BaseAsset
    from airflow.timetables.base import TimeRestriction
    from airflow.utils.types import DagRunType


class _TrivialTimetable(Timetable):
    """Some code reuse for "trivial" timetables that has nothing complex."""

    periodic = False
    run_ordering: Sequence[str] = ("logical_date",)

    @classmethod
    def deserialize(cls, data: dict[str, Any]) -> Timetable:
        return cls()

    def __eq__(self, other: object) -> bool:
        """
        As long as *other* is of the same type.

        This is only for testing purposes and should not be relied on otherwise.
        """
        if not isinstance(other, type(self)):
            return NotImplemented
        return True

    def serialize(self) -> dict[str, Any]:
        return {}

    def infer_manual_data_interval(self, *, run_after: DateTime) -> DataInterval:
        return DataInterval.exact(run_after)



[docs]
class NullTimetable(_TrivialTimetable):
    """
    Timetable that never schedules anything.

    This corresponds to ``schedule=None``.
    """


[docs]
    can_be_scheduled = False


[docs]
    description: str = "Never, external triggers only"


    @property

[docs]
    def summary(self) -> str:
        return "None"



[docs]
    def next_dagrun_info(
        self,
        *,
        last_automated_data_interval: DataInterval | None,
        restriction: TimeRestriction,
    ) -> DagRunInfo | None:
        return None





[docs]
class OnceTimetable(_TrivialTimetable):
    """
    Timetable that schedules the execution once as soon as possible.

    This corresponds to ``schedule="@once"``.
    """


[docs]
    description: str = "Once, as soon as possible"


    @property

[docs]
    def summary(self) -> str:
        return "@once"



[docs]
    def next_dagrun_info(
        self,
        *,
        last_automated_data_interval: DataInterval | None,
        restriction: TimeRestriction,
    ) -> DagRunInfo | None:
        if last_automated_data_interval is not None:
            return None  # Already run, no more scheduling.
        # If the user does not specify an explicit start_date, the dag is ready.
        run_after = restriction.earliest or timezone.coerce_datetime(timezone.utcnow())
        # "@once" always schedule to the start_date determined by the DAG and
        # tasks, regardless of catchup or not. This has been the case since 1.10
        # and we're inheriting it.
        if restriction.latest is not None and run_after > restriction.latest:
            return None
        return DagRunInfo.exact(run_after)





[docs]
class ContinuousTimetable(_TrivialTimetable):
    """
    Timetable that schedules continually, while still respecting start_date and end_date.

    This corresponds to ``schedule="@continuous"``.
    """


[docs]
    description: str = "As frequently as possible, but only one run at a time."



[docs]
    active_runs_limit = 1  # Continuous DAGRuns should be constrained to one run at a time


    @property

[docs]
    def summary(self) -> str:
        return "@continuous"



[docs]
    def next_dagrun_info(
        self,
        *,
        last_automated_data_interval: DataInterval | None,
        restriction: TimeRestriction,
    ) -> DagRunInfo | None:
        if restriction.earliest is None:  # No start date, won't run.
            return None

        current_time = timezone.coerce_datetime(timezone.utcnow())

        if last_automated_data_interval is not None:  # has already run once
            if last_automated_data_interval.end > current_time:  # start date is future
                start = restriction.earliest
                elapsed = last_automated_data_interval.end - last_automated_data_interval.start

                end = start + elapsed.as_timedelta()
            else:
                start = last_automated_data_interval.end
                end = current_time
        else:  # first run
            start = restriction.earliest
            end = max(restriction.earliest, current_time)

        if restriction.latest is not None and end > restriction.latest:
            return None

        return DagRunInfo.interval(start, end)




class AssetTriggeredTimetable(_TrivialTimetable):
    """
    Timetable that never schedules anything.

    This should not be directly used anywhere, but only set if a DAG is triggered by assets.

    :meta private:
    """

    description: str = "Triggered by assets"

    def __init__(self, assets: BaseAsset) -> None:
        super().__init__()
        self.asset_condition = assets

    @classmethod
    def deserialize(cls, data: dict[str, Any]) -> Timetable:
        from airflow.serialization.serialized_objects import decode_asset_condition

        return cls(decode_asset_condition(data["asset_condition"]))

    @property
    def summary(self) -> str:
        return "Asset"

    def serialize(self) -> dict[str, Any]:
        from airflow.serialization.serialized_objects import encode_asset_condition

        return {"asset_condition": encode_asset_condition(self.asset_condition)}

    def generate_run_id(
        self,
        *,
        run_type: DagRunType,
        data_interval: DataInterval | None,
        run_after: DateTime,
        **extra,
    ) -> str:
        """
        Generate Run ID based on Run Type, run_after and logical Date.

        :param run_type: type of DagRun
        :param data_interval: the data interval
        :param run_after: the date before which dag run won't start.
        """
        from airflow.models.dagrun import DagRun

        logical_date = data_interval.start if data_interval is not None else run_after

        return DagRun.generate_run_id(run_type=run_type, logical_date=logical_date, run_after=run_after)

    def next_dagrun_info(
        self,
        *,
        last_automated_data_interval: DataInterval | None,
        restriction: TimeRestriction,
    ) -> DagRunInfo | None:
        return None