Coverage for python/lsst/pipe/base/pipeline_graph/_mapping_views.py: 53%
59 statements
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« prev ^ index » next coverage.py v7.3.0, created at 2023-08-31 09:39 +0000
1# This file is part of pipe_base.
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 program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program. If not, see <http://www.gnu.org/licenses/>.
21from __future__ import annotations
23from collections.abc import Iterable, Iterator, Mapping, Sequence
24from typing import Any, ClassVar, TypeVar, cast, overload
26import networkx
28from ._dataset_types import DatasetTypeNode
29from ._exceptions import UnresolvedGraphError
30from ._nodes import NodeKey, NodeType
31from ._tasks import TaskInitNode, TaskNode
33_N = TypeVar("_N", covariant=True)
34_T = TypeVar("_T")
37class MappingView(Mapping[str, _N]):
38 """Base class for mapping views into nodes of certain types in a
39 `PipelineGraph`.
42 Parameters
43 ----------
44 parent_xgraph : `networkx.MultiDiGraph`
45 Backing networkx graph for the `PipelineGraph` instance.
47 Notes
48 -----
49 Instances should only be constructed by `PipelineGraph` and its helper
50 classes.
52 Iteration order is topologically sorted if and only if the backing
53 `PipelineGraph` has been sorted since its last modification.
54 """
56 def __init__(self, parent_xgraph: networkx.MultiDiGraph) -> None:
57 self._parent_xgraph = parent_xgraph
58 self._keys: list[str] | None = None
60 _NODE_TYPE: ClassVar[NodeType] # defined by derived classes
62 def __contains__(self, key: object) -> bool:
63 # The given key may not be a str, but if it isn't it'll just fail the
64 # check, which is what we want anyway.
65 return NodeKey(self._NODE_TYPE, cast(str, key)) in self._parent_xgraph
67 def __iter__(self) -> Iterator[str]:
68 if self._keys is None:
69 self._keys = self._make_keys(self._parent_xgraph)
70 return iter(self._keys)
72 def __getitem__(self, key: str) -> _N:
73 return self._parent_xgraph.nodes[NodeKey(self._NODE_TYPE, key)]["instance"]
75 def __len__(self) -> int:
76 if self._keys is None:
77 self._keys = self._make_keys(self._parent_xgraph)
78 return len(self._keys)
80 def __repr__(self) -> str:
81 return f"{type(self).__name__}({self!s})"
83 def __str__(self) -> str:
84 return f"{{{', '.join(iter(self))}}}"
86 def _reorder(self, parent_keys: Sequence[NodeKey]) -> None:
87 """Set this view's iteration order according to the given iterable of
88 parent keys.
90 Parameters
91 ----------
92 parent_keys : `~collections.abc.Sequence` [ `NodeKey` ]
93 Superset of the keys in this view, in the new order.
94 """
95 self._keys = self._make_keys(parent_keys)
97 def _reset(self) -> None:
98 """Reset all cached content.
100 This should be called by the parent graph after any changes that could
101 invalidate the view, causing it to be reconstructed when next
102 requested.
103 """
104 self._keys = None
106 def _make_keys(self, parent_keys: Iterable[NodeKey]) -> list[str]:
107 """Make a sequence of keys for this view from an iterable of parent
108 keys.
110 Parameters
111 ----------
112 parent_keys : `~collections.abc.Iterable` [ `NodeKey` ]
113 Superset of the keys in this view.
114 """
115 return [str(k) for k in parent_keys if k.node_type is self._NODE_TYPE]
118class TaskMappingView(MappingView[TaskNode]):
119 """A mapping view of the tasks in a `PipelineGraph`.
121 Notes
122 -----
123 Mapping keys are task labels and values are `TaskNode` instances.
124 Iteration order is topological if and only if the `PipelineGraph` has been
125 sorted since its last modification.
126 """
128 _NODE_TYPE = NodeType.TASK
131class TaskInitMappingView(MappingView[TaskInitNode]):
132 """A mapping view of the nodes representing task initialization in a
133 `PipelineGraph`.
135 Notes
136 -----
137 Mapping keys are task labels and values are `TaskInitNode` instances.
138 Iteration order is topological if and only if the `PipelineGraph` has been
139 sorted since its last modification.
140 """
142 _NODE_TYPE = NodeType.TASK_INIT
145class DatasetTypeMappingView(MappingView[DatasetTypeNode]):
146 """A mapping view of the nodes representing task initialization in a
147 `PipelineGraph`.
149 Notes
150 -----
151 Mapping keys are parent dataset type names and values are `DatasetTypeNode`
152 instances, but values are only available for nodes that have been resolved
153 (see `PipelineGraph.resolve`). Attempting to access an unresolved value
154 will result in `UnresolvedGraphError` being raised. Keys for unresolved
155 nodes are always present and iterable.
157 Iteration order is topological if and only if the `PipelineGraph` has been
158 sorted since its last modification.
159 """
161 _NODE_TYPE = NodeType.DATASET_TYPE
163 def __getitem__(self, key: str) -> DatasetTypeNode:
164 if (result := super().__getitem__(key)) is None:
165 raise UnresolvedGraphError(f"Node for dataset type {key!r} has not been resolved.")
166 return result
168 def is_resolved(self, key: str) -> bool:
169 """Test whether a node has been resolved."""
170 return super().__getitem__(key) is not None
172 @overload
173 def get_if_resolved(self, key: str) -> DatasetTypeNode | None:
174 ... # pragma: nocover
176 @overload
177 def get_if_resolved(self, key: str, default: _T) -> DatasetTypeNode | _T:
178 ... # pragma: nocover
180 def get_if_resolved(self, key: str, default: Any = None) -> DatasetTypeNode | Any:
181 """Get a node or return a default if it has not been resolved.
183 Parameters
184 ----------
185 key : `str`
186 Parent dataset type name.
187 default
188 Value to return if this dataset type has not been resolved.
190 Raises
191 ------
192 KeyError
193 Raised if the node is not present in the graph at all.
194 """
195 if (result := super().__getitem__(key)) is None:
196 return default # type: ignore
197 return result