Coverage for python/lsst/daf/butler/dimensions/_group.py: 37%
178 statements
« prev ^ index » next coverage.py v7.4.0, created at 2024-01-25 10:50 +0000
« prev ^ index » next coverage.py v7.4.0, created at 2024-01-25 10:50 +0000
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/>.
28from __future__ import annotations
30__all__ = ["DimensionGroup"]
32import itertools
33from collections.abc import Iterable, Iterator, Mapping, Set
34from types import MappingProxyType
35from typing import TYPE_CHECKING, Any
37from lsst.utils.classes import cached_getter, immutable
39from .._named import NamedValueAbstractSet, NamedValueSet
40from .._topology import TopologicalFamily, TopologicalSpace
42if TYPE_CHECKING: # Imports needed only for type annotations; may be circular.
43 from ._elements import DimensionElement
44 from ._graph import DimensionGraph
45 from ._universe import DimensionUniverse
48class SortedSequenceSet(Set[str]):
49 """A set-like interface wrapper around a tuple.
51 This delegates directly to ``tuple.__contains__``, so there is an implicit
52 assumption that `len` is small and hence O(N) lookups are not a problem, as
53 is the case for sets of dimension names.
55 Parameters
56 ----------
57 seq : `tuple` [`str`, ...]
58 Strings to see the set.
59 """
61 def __init__(self, seq: tuple[str, ...]):
62 self._seq = seq
64 __slots__ = ("_seq",)
66 def __contains__(self, x: object) -> bool:
67 return x in self._seq
69 def __iter__(self) -> Iterator[str]:
70 return iter(self._seq)
72 def __len__(self) -> int:
73 return len(self._seq)
75 def __hash__(self) -> int:
76 return hash(self._seq)
78 def __eq__(self, other: object) -> bool:
79 if seq := getattr(other, "_seq", None):
80 return seq == self._seq
81 return super().__eq__(other)
83 @classmethod
84 def _from_iterable(cls, iterable: Iterable[str]) -> set[str]:
85 # This is used by collections.abc.Set mixin methods when they need
86 # to return a new object (e.g. in `__and__`).
87 return set(iterable)
89 def __repr__(self) -> str:
90 return f"{{{', '.join(str(k) for k in self._seq)}}}"
92 def as_tuple(self) -> tuple[str, ...]:
93 """Return the underlying tuple.
95 Returns
96 -------
97 t : `tuple`
98 A tuple of all the values.
99 """
100 return self._seq
102 @property
103 def names(self) -> Set[str]:
104 """An alias to ``self``.
106 This is a backwards-compatibility API that allows `DimensionGroup`
107 to mimic the `DimensionGraph` object it is intended to replace, by
108 permitting expressions like ``x.required.names`` when ``x`` can be
109 an object of either type.
110 """
111 return self
114@immutable
115class DimensionGroup: # numpydoc ignore=PR02
116 """An immutable, dependency-complete collection of dimensions.
118 `DimensionGroup` behaves in many respects like a set of `str` dimension
119 names that maintains several special subsets and supersets of related
120 dimension elements. It does not fully implement the `collections.abc.Set`
121 interface, because it defines a few different iteration orders and does not
122 privilege any one of them by implementing ``__iter__``.
124 Parameters
125 ----------
126 universe : `DimensionUniverse`
127 Object that manages all known dimensions.
128 names : iterable of `str`, optional
129 An iterable of the names of dimensions that must be included in the
130 group. All (recursive) dependencies of these dimensions will also be
131 included. At most one of ``dimensions`` and ``names`` must be
132 provided.
133 _conform : `bool`, optional
134 If `True` (default), expand to include dependencies. `False` should
135 only be used for callers that can guarantee that other arguments are
136 already correctly expanded, and is for internal use only.
138 Notes
139 -----
140 `DimensionGroup` should be used instead of other collections in most
141 contexts where a collection of dimensions is required and a
142 `DimensionUniverse` is available. Exceptions include cases where order
143 matters (and is different from the consistent ordering defined by the
144 `DimensionUniverse`), or complete `~collection.abc.Set` semantics are
145 required.
146 """
148 def __new__(
149 cls,
150 universe: DimensionUniverse,
151 names: Iterable[str] | DimensionGroup = frozenset(),
152 _conform: bool = True,
153 ) -> DimensionGroup:
154 if isinstance(names, DimensionGroup):
155 if names.universe is universe:
156 return names
157 else:
158 names = names.names
159 if _conform:
160 # Expand dimension names to include all required and implied
161 # dependencies.
162 to_expand = set(names)
163 names = set()
164 while to_expand:
165 dimension = universe[to_expand.pop()]
166 names.add(dimension.name)
167 to_expand.update(dimension.required.names)
168 to_expand.update(dimension.implied.names)
169 to_expand.difference_update(names)
170 else:
171 names = frozenset(names)
172 # Look in the cache of existing groups, with the expanded set of names.
173 cache_key = frozenset(names)
174 self = universe._cached_groups.get(cache_key)
175 if self is not None:
176 return self
177 # This is apparently a new group. Create it, and add it to the cache.
178 self = super().__new__(cls)
179 self.universe = universe
180 # Reorder dimensions by iterating over the universe (which is
181 # ordered already) and extracting the ones in the set.
182 self.names = SortedSequenceSet(tuple(d.name for d in universe.sorted(names)))
183 # Make a set that includes both the dimensions and any
184 # DimensionElements whose dependencies are in self.dimensions.
185 self.elements = SortedSequenceSet(
186 tuple(e.name for e in universe.elements if e.required.names <= self.names)
187 )
188 self.governors = SortedSequenceSet(
189 tuple(d for d in self.names if d in universe.governor_dimensions.names)
190 )
191 self.skypix = SortedSequenceSet(tuple(d for d in self.names if d in universe.skypix_dimensions.names))
192 # Split dependencies up into "required" and "implied" subsets.
193 # Note that a dimension may be required in one group and implied in
194 # another.
195 required: list[str] = []
196 implied: list[str] = []
197 for dim1 in self.names:
198 for dim2 in self.names:
199 if dim1 in universe[dim2].implied.names:
200 implied.append(dim1)
201 break
202 else:
203 # If no other dimension implies dim1, it's required.
204 required.append(dim1)
205 self.required = SortedSequenceSet(tuple(required))
206 self.implied = SortedSequenceSet(tuple(implied))
208 self._space_families = MappingProxyType(
209 {
210 space: NamedValueSet(
211 universe[e].topology[space] for e in self.elements if space in universe[e].topology
212 ).freeze()
213 for space in TopologicalSpace.__members__.values()
214 }
215 )
217 # Build mappings from dimension to index; this is really for
218 # DataCoordinate, but we put it in DimensionGroup because many (many!)
219 # DataCoordinates will share the same DimensionGroup, and we want them
220 # to be lightweight. The order here is what's convenient for
221 # DataCoordinate: all required dimensions before all implied
222 # dimensions.
223 self._data_coordinate_indices = {
224 name: i for i, name in enumerate(itertools.chain(self.required, self.implied))
225 }
226 return universe._cached_groups.set_or_get(cache_key, self)
228 def __getnewargs__(self) -> tuple:
229 return (self.universe, self.names._seq, False)
231 def __deepcopy__(self, memo: dict) -> DimensionGroup:
232 # DimensionGroup is recursively immutable; see note in @immutable
233 # decorator.
234 return self
236 def __len__(self) -> int:
237 return len(self.names)
239 def __contains__(self, element: str) -> bool:
240 if element in self.elements:
241 return True
242 else:
243 from ._elements import DimensionElement
245 if isinstance(element, DimensionElement): # type: ignore[unreachable]
246 raise TypeError(
247 "DimensionGroup does not support membership tests using DimensionElement "
248 "instances; use their names instead."
249 )
250 return False
252 def __str__(self) -> str:
253 return str(self.names)
255 def __repr__(self) -> str:
256 return f"DimensionGroup({self.names})"
258 def as_group(self) -> DimensionGroup:
259 """Return ``self``.
261 Returns
262 -------
263 group : `DimensionGroup`
264 Returns itself.
266 Notes
267 -----
268 This is a backwards-compatibility API that allows both `DimensionGraph`
269 and `DimensionGroup` to be coerced to the latter.
270 """
271 return self
273 @cached_getter
274 def _as_graph(self) -> DimensionGraph:
275 """Return a view of ``self`` as a `DimensionGraph`.
277 Returns
278 -------
279 graph : `DimensionGraph`
280 The deprecated form of `DimensionGroup`.
282 Notes
283 -----
284 This is provided as a convenience for methods and properties that must
285 return a `DimensionGraph` for backwards compatibility (until v27). It
286 is the only way of making a `DimensionGraph` that does not produce
287 a warning.
288 """
289 from ._graph import DimensionGraph
291 result = object.__new__(DimensionGraph)
292 result._group = self
293 return result
295 def isdisjoint(self, other: DimensionGroup) -> bool:
296 """Test whether the intersection of two groups is empty.
298 Parameters
299 ----------
300 other : `DimensionGroup`
301 Other group to compare with.
303 Returns
304 -------
305 is_disjoin : `bool`
306 Returns `True` if either operand is the empty.
307 """
308 return self.names.isdisjoint(other.names)
310 def issubset(self, other: DimensionGroup) -> bool:
311 """Test whether all dimensions in ``self`` are also in ``other``.
313 Parameters
314 ----------
315 other : `DimensionGroup`
316 Other group to compare with.
318 Returns
319 -------
320 is_subset : `bool`
321 Returns `True` if ``self`` is empty.
322 """
323 return self.names <= other.names
325 def issuperset(self, other: DimensionGroup) -> bool:
326 """Test whether all dimensions in ``other`` are also in ``self``.
328 Parameters
329 ----------
330 other : `DimensionGroup`
331 Other group to compare with.
333 Returns
334 -------
335 is_superset : `bool`
336 Returns `True` if ``other`` is empty.
337 """
338 return self.names >= other.names
340 def __eq__(self, other: Any) -> bool:
341 from ._graph import DimensionGraph
343 # TODO: Drop DimensionGraph support here on DM-41326.
344 if isinstance(other, (DimensionGroup, DimensionGraph)):
345 return self.names == other.names
346 else:
347 return False
349 def __hash__(self) -> int:
350 return hash(self.required._seq)
352 def __le__(self, other: DimensionGroup) -> bool:
353 return self.names <= other.names
355 def __ge__(self, other: DimensionGroup) -> bool:
356 return self.names >= other.names
358 def __lt__(self, other: DimensionGroup) -> bool:
359 return self.names < other.names
361 def __gt__(self, other: DimensionGroup) -> bool:
362 return self.names > other.names
364 def union(self, *others: DimensionGroup) -> DimensionGroup:
365 """Construct a new group with all dimensions in any of the operands.
367 Parameters
368 ----------
369 *others : `DimensionGroup`
370 Other groups to join with.
372 Returns
373 -------
374 union : `DimensionGroup`
375 Union of all the groups.
377 Notes
378 -----
379 The elements of the returned group may exceed the naive union of their
380 elements, as some dimension elements are included in groups whenever
381 multiple dimensions are present, and those dependency dimensions could
382 have been provided by different operands.
383 """
384 names = set(self.names).union(*[other.names for other in others])
385 return DimensionGroup(self.universe, names)
387 def intersection(self, *others: DimensionGroup) -> DimensionGroup:
388 """Construct a new group with only dimensions in all of the operands.
390 Parameters
391 ----------
392 *others : `DimensionGroup`
393 Other groups to compare with.
395 Returns
396 -------
397 inter : `DimensionGroup`
398 Intersection of all the groups.
400 Notes
401 -----
402 See also `union`.
403 """
404 names = set(self.names).intersection(*[other.names for other in others])
405 return DimensionGroup(self.universe, names=names)
407 def __or__(self, other: DimensionGroup) -> DimensionGroup:
408 return self.union(other)
410 def __and__(self, other: DimensionGroup) -> DimensionGroup:
411 return self.intersection(other)
413 @property
414 def data_coordinate_keys(self) -> Set[str]:
415 """A set of dimensions ordered like `DataCoordinate.mapping`.
417 This order is defined as all required dimensions followed by all
418 implied dimensions.
419 """
420 return self._data_coordinate_indices.keys()
422 @property
423 @cached_getter
424 def lookup_order(self) -> tuple[str, ...]:
425 """A tuple of all elements in the order needed to find their records.
427 Unlike the table definition/topological order (which is what
428 `DimensionUniverse.sorted` gives you), when dimension A implies
429 dimension B, dimension A appears first.
430 """
431 done: set[str] = set()
432 order: list[str] = []
434 def add_to_order(element: DimensionElement) -> None:
435 if element.name in done:
436 return
437 predecessors = set(element.required.names)
438 predecessors.discard(element.name)
439 if not done.issuperset(predecessors):
440 return
441 order.append(element.name)
442 done.add(element.name)
443 for other in element.implied:
444 add_to_order(other)
446 while not done.issuperset(self.required):
447 for dimension in self.required:
448 add_to_order(self.universe[dimension])
450 order.extend(element for element in self.elements if element not in done)
451 return tuple(order)
453 @property
454 def spatial(self) -> NamedValueAbstractSet[TopologicalFamily]:
455 """Families represented by the spatial elements in this graph."""
456 return self._space_families[TopologicalSpace.SPATIAL]
458 @property
459 def temporal(self) -> NamedValueAbstractSet[TopologicalFamily]:
460 """Families represented by the temporal elements in this graph."""
461 return self._space_families[TopologicalSpace.TEMPORAL]
463 # Class attributes below are shadowed by instance attributes, and are
464 # present just to hold the docstrings for those instance attributes.
466 universe: DimensionUniverse
467 """The set of all known dimensions, of which this group is a subset
468 (`DimensionUniverse`).
469 """
471 names: SortedSequenceSet
472 """A true `~collections.abc.Set` of the dimension names.
474 Iteration order is consist with `DimensionUniverse.sorted`: each dimension
475 is preceded by its required and implied dependencies.
476 """
478 elements: SortedSequenceSet
479 """A true `~collections.abc.Set` of all dimension element names in the
480 group; a superset of `dimensions`.
481 """
483 governors: SortedSequenceSet
484 """A true `~collections.abc.Set` of all governor dimension names in the
485 group.
486 """
488 skypix: SortedSequenceSet
489 """A true `~collections.abc.Set` of all skypix dimension names in the "
490 group.
491 """
493 required: SortedSequenceSet
494 """The dimensions that must be directly identified via their primary keys
495 in a data ID in order to identify the rest of the elements in the group.
496 """
498 implied: SortedSequenceSet
499 """The dimensions that need not be directly identified via their primary
500 keys in a data ID.
501 """
503 _space_families: Mapping[TopologicalSpace, NamedValueAbstractSet[TopologicalFamily]]
504 """Families of elements in this graph that exist in topological spaces
505 relationships (`~collections.abc.Mapping` from `TopologicalSpace` to
506 `NamedValueAbstractSet` of `TopologicalFamily`).
507 """
509 _data_coordinate_indices: dict[str, int]