Coverage for python / lsst / daf / butler / queries / _dataset_query_results.py: 54%

1# This file is part of daf_butler. 

2# 

3# Developed for the LSST Data Management System. 

4# This product includes software developed by the LSST Project 

5# (http://www.lsst.org). 

6# See the COPYRIGHT file at the top-level directory of this distribution 

7# for details of code ownership. 

8# 

9# This software is dual licensed under the GNU General Public License and also 

10# under a 3-clause BSD license. Recipients may choose which of these licenses 

11# to use; please see the files gpl-3.0.txt and/or bsd_license.txt, 

12# respectively. If you choose the GPL option then the following text applies 

13# (but note that there is still no warranty even if you opt for BSD instead): 

14# 

15# This program is free software: you can redistribute it and/or modify 

16# it under the terms of the GNU General Public License as published by 

17# the Free Software Foundation, either version 3 of the License, or 

18# (at your option) any later version. 

19# 

20# This program is distributed in the hope that it will be useful, 

21# but WITHOUT ANY WARRANTY; without even the implied warranty of 

22# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

23# GNU General Public License for more details. 

24# 

25# You should have received a copy of the GNU General Public License 

26# along with this program. If not, see <http://www.gnu.org/licenses/>. 

27 

28from __future__ import annotations 

29 

30__all__ = ("DatasetRefQueryResults",) 

31 

32from collections.abc import Iterator 

33from typing import TYPE_CHECKING, Any, final 

34 

35from .._dataset_ref import DatasetRef 

36from .._dataset_type import DatasetType 

37from ..dimensions import DimensionGroup 

38from ._base import QueryResultsBase 

39from .driver import QueryDriver 

40from .result_specs import DataCoordinateResultSpec, DatasetRefResultSpec 

41from .tree import QueryTree 

42 

43if TYPE_CHECKING: 

44 from ._data_coordinate_query_results import DataCoordinateQueryResults 

45 

46 

47@final 

48class DatasetRefQueryResults(QueryResultsBase): 

49 """A query for `DatasetRef` results with a single dataset type. 

50 

51 Parameters 

52 ---------- 

53 driver : `QueryDriver` 

54 Implementation object that knows how to actually execute queries. 

55 tree : `QueryTree` 

56 Description of the query as a tree of joins and column expressions. The 

57 instance returned directly by the `Butler._query` entry point should be 

58 constructed via `make_unit_query_tree`. 

59 spec : `DatasetRefResultSpec` 

60 Specification of the query result rows, including output columns, 

61 ordering, and slicing. 

62 

63 Notes 

64 ----- 

65 This class should never be constructed directly by users; use 

66 `Query.datasets` instead. 

67 """ 

68 

69 def __init__(self, driver: QueryDriver, tree: QueryTree, spec: DatasetRefResultSpec): 

70 spec.validate_tree(tree) 

71 super().__init__(driver, tree) 

72 self._spec = spec 

73 

74 def __iter__(self) -> Iterator[DatasetRef]: 

75 for page in self._iter_pages(): 

76 yield from page 

77 

78 def _iter_pages(self) -> Iterator[list[DatasetRef]]: 

79 """Return the results from the query in batches as they are returned 

80 from the database. 

81 """ 

82 # This method is used outside this class in other daf_butler-internal 

83 # functions. 

84 for page in self._driver.execute(self._spec, self._tree): 

85 yield page.rows 

86 

87 @property 

88 def dimensions(self) -> DimensionGroup: 

89 # Docstring inherited 

90 return self._spec.dimensions 

91 

92 @property 

93 def dataset_type(self) -> DatasetType: 

94 # Docstring inherited. 

95 return DatasetType(self._spec.dataset_type_name, self._spec.dimensions, self._spec.storage_class_name) 

96 

97 @property 

98 def data_ids(self) -> DataCoordinateQueryResults: 

99 # Docstring inherited. 

100 from ._data_coordinate_query_results import DataCoordinateQueryResults 

101 

102 return DataCoordinateQueryResults( 

103 self._driver, 

104 tree=self._tree, 

105 spec=DataCoordinateResultSpec.model_construct( 

106 dimensions=self.dataset_type.dimensions, 

107 include_dimension_records=self._spec.include_dimension_records, 

108 ), 

109 ) 

110 

111 @property 

112 def has_dimension_records(self) -> bool: 

113 """Whether all data IDs in this iterable contain dimension records.""" 

114 return self._spec.include_dimension_records 

115 

116 def with_dimension_records(self) -> DatasetRefQueryResults: 

117 """Return a results object for which `has_dimension_records` is 

118 `True`. 

119 """ 

120 if self.has_dimension_records: 

121 return self 

122 return self._copy(tree=self._tree, include_dimension_records=True) 

123 

124 def count(self, *, exact: bool = True, discard: bool = False) -> int: 

125 # Docstring inherited. 

126 return self._driver.count(self._tree, self._spec, exact=exact, discard=discard) 

127 

128 def _copy(self, tree: QueryTree, **kwargs: Any) -> DatasetRefQueryResults: 

129 # Docstring inherited. 

130 return DatasetRefQueryResults(self._driver, tree, self._spec.model_copy(update=kwargs)) 

131 

132 def _get_datasets(self) -> frozenset[str]: 

133 # Docstring inherited. 

134 return frozenset({self.dataset_type.name})