Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/airflow/sdk/bases/timetable.py: 63%

1# Licensed to the Apache Software Foundation (ASF) under one 

2# or more contributor license agreements. See the NOTICE file 

3# distributed with this work for additional information 

4# regarding copyright ownership. The ASF licenses this file 

5# to you under the Apache License, Version 2.0 (the 

6# "License"); you may not use this file except in compliance 

7# with the License. You may obtain a copy of the License at 

8# 

9# http://www.apache.org/licenses/LICENSE-2.0 

10# 

11# Unless required by applicable law or agreed to in writing, 

12# software distributed under the License is distributed on an 

13# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 

14# KIND, either express or implied. See the License for the 

15# specific language governing permissions and limitations 

16# under the License. 

17 

18from __future__ import annotations 

19 

20from collections.abc import Iterator 

21from typing import TYPE_CHECKING, Any 

22 

23from airflow.sdk.definitions.asset import AssetUniqueKey, BaseAsset 

24 

25if TYPE_CHECKING: 

26 from sqlalchemy.orm import Session 

27 

28 from airflow.sdk.definitions.asset import Asset, AssetAlias, AssetRef 

29 from airflow.serialization.dag_dependency import DagDependency 

30 

31 

32class NullAsset(BaseAsset): 

33 """ 

34 Sentinel type that represents "no assets". 

35 

36 This is only implemented to make typing easier in timetables, and not 

37 expected to be used anywhere else. 

38 

39 :meta private: 

40 """ 

41 

42 def __bool__(self) -> bool: 

43 return False 

44 

45 def __or__(self, other: BaseAsset) -> BaseAsset: 

46 return NotImplemented 

47 

48 def __and__(self, other: BaseAsset) -> BaseAsset: 

49 return NotImplemented 

50 

51 def as_expression(self) -> Any: 

52 return None 

53 

54 def evaluate(self, statuses: dict[AssetUniqueKey, bool], *, session: Session | None = None) -> bool: 

55 return False 

56 

57 def iter_assets(self) -> Iterator[tuple[AssetUniqueKey, Asset]]: 

58 return iter(()) 

59 

60 def iter_asset_aliases(self) -> Iterator[tuple[str, AssetAlias]]: 

61 return iter(()) 

62 

63 def iter_asset_refs(self) -> Iterator[AssetRef]: 

64 return iter(()) 

65 

66 def iter_dag_dependencies(self, source, target) -> Iterator[DagDependency]: 

67 return iter(()) 

68 

69 

70class BaseTimetable: 

71 """Base class inherited by all user-facing timetables.""" 

72 

73 can_be_scheduled: bool = True 

74 """ 

75 Whether this timetable can actually schedule runs in an automated manner. 

76 

77 This defaults to and should generally be *True* (including non periodic 

78 execution types like *@once* and data triggered tables), but 

79 ``NullTimetable`` sets this to *False*. 

80 """ 

81 

82 active_runs_limit: int | None = None 

83 """ 

84 Maximum active runs that can be active at one time for a DAG. 

85 

86 This is called during DAG initialization, and the return value is used as 

87 the DAG's default ``max_active_runs`` if not set on the DAG explicitly. This 

88 should generally return *None* (no limit), but some timetables may limit 

89 parallelism, such as ``ContinuousTimetable``. 

90 """ 

91 

92 asset_condition: BaseAsset = NullAsset() 

93 

94 def validate(self) -> None: 

95 """ 

96 Validate the timetable is correctly specified. 

97 

98 Override this method to provide run-time validation raised when a DAG 

99 is put into a dagbag. The default implementation does nothing. 

100 

101 :raises: :class:`~airflow.sdk.exceptions.AirflowTimetableInvalid` on validation failure. 

102 """