Coverage for python/lsst/daf/butler/core/storageClass.py: 46%
322 statements
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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 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/>.
22from __future__ import annotations
24"""Support for Storage Classes."""
26__all__ = ("StorageClass", "StorageClassFactory", "StorageClassConfig")
28import builtins
29import copy
30import logging
31from typing import Any, Collection, Dict, List, Mapping, Optional, Sequence, Set, Tuple, Type, Union
33from lsst.utils import doImportType
34from lsst.utils.classes import Singleton
35from lsst.utils.introspection import get_full_type_name
37from .config import Config, ConfigSubset
38from .configSupport import LookupKey
39from .storageClassDelegate import StorageClassDelegate
41log = logging.getLogger(__name__)
44class StorageClassConfig(ConfigSubset):
45 """Configuration class for defining Storage Classes."""
47 component = "storageClasses"
48 defaultConfigFile = "storageClasses.yaml"
51class StorageClass:
52 """Class describing how a label maps to a particular Python type.
54 Parameters
55 ----------
56 name : `str`
57 Name to use for this class.
58 pytype : `type` or `str`
59 Python type (or name of type) to associate with the `StorageClass`
60 components : `dict`, optional
61 `dict` mapping name of a component to another `StorageClass`.
62 derivedComponents : `dict`, optional
63 `dict` mapping name of a derived component to another `StorageClass`.
64 parameters : `~collections.abc.Sequence` or `~collections.abc.Set`
65 Parameters understood by this `StorageClass` that can control
66 reading of data from datastores.
67 delegate : `str`, optional
68 Fully qualified name of class supporting assembly and disassembly
69 of a `pytype` instance.
70 converters : `dict` [`str`, `str`], optional
71 Mapping of python type to function that can be called to convert
72 that python type to the valid type of this storage class.
73 """
75 _cls_name: str = "BaseStorageClass"
76 _cls_components: Optional[Dict[str, StorageClass]] = None
77 _cls_derivedComponents: Optional[Dict[str, StorageClass]] = None
78 _cls_parameters: Optional[Union[Set[str], Sequence[str]]] = None
79 _cls_delegate: Optional[str] = None
80 _cls_pytype: Optional[Union[Type, str]] = None
81 _cls_converters: Optional[Dict[str, str]] = None
82 defaultDelegate: Type = StorageClassDelegate
83 defaultDelegateName: str = get_full_type_name(defaultDelegate)
85 def __init__(
86 self,
87 name: Optional[str] = None,
88 pytype: Optional[Union[Type, str]] = None,
89 components: Optional[Dict[str, StorageClass]] = None,
90 derivedComponents: Optional[Dict[str, StorageClass]] = None,
91 parameters: Optional[Union[Sequence, Set]] = None,
92 delegate: Optional[str] = None,
93 converters: Optional[Dict[str, str]] = None,
94 ):
95 if name is None:
96 name = self._cls_name
97 if pytype is None: 97 ↛ 99line 97 didn't jump to line 99, because the condition on line 97 was never false
98 pytype = self._cls_pytype
99 if components is None: 99 ↛ 101line 99 didn't jump to line 101, because the condition on line 99 was never false
100 components = self._cls_components
101 if derivedComponents is None: 101 ↛ 103line 101 didn't jump to line 103, because the condition on line 101 was never false
102 derivedComponents = self._cls_derivedComponents
103 if parameters is None: 103 ↛ 105line 103 didn't jump to line 105, because the condition on line 103 was never false
104 parameters = self._cls_parameters
105 if delegate is None: 105 ↛ 109line 105 didn't jump to line 109, because the condition on line 105 was never false
106 delegate = self._cls_delegate
108 # Merge converters with class defaults.
109 self._converters = {}
110 if self._cls_converters is not None:
111 self._converters.update(self._cls_converters)
112 if converters: 112 ↛ 113line 112 didn't jump to line 113, because the condition on line 112 was never true
113 self._converters.update(converters)
115 # Version of converters where the python types have been
116 # Do not try to import anything until needed.
117 self._converters_by_type: Optional[Dict[Type, Type]] = None
119 self.name = name
121 if pytype is None:
122 pytype = object
124 self._pytype: Optional[Type]
125 if not isinstance(pytype, str):
126 # Already have a type so store it and get the name
127 self._pytypeName = get_full_type_name(pytype)
128 self._pytype = pytype
129 else:
130 # Store the type name and defer loading of type
131 self._pytypeName = pytype
132 self._pytype = None
134 if components is not None:
135 if len(components) == 1: 135 ↛ 136line 135 didn't jump to line 136, because the condition on line 135 was never true
136 raise ValueError(
137 f"Composite storage class {name} is not allowed to have"
138 f" only one component '{next(iter(components))}'."
139 " Did you mean it to be a derived component?"
140 )
141 self._components = components
142 else:
143 self._components = {}
144 self._derivedComponents = derivedComponents if derivedComponents is not None else {}
145 self._parameters = frozenset(parameters) if parameters is not None else frozenset()
146 # if the delegate is not None also set it and clear the default
147 # delegate
148 self._delegate: Optional[Type]
149 self._delegateClassName: Optional[str]
150 if delegate is not None:
151 self._delegateClassName = delegate
152 self._delegate = None
153 elif components is not None: 153 ↛ 156line 153 didn't jump to line 156, because the condition on line 153 was never true
154 # We set a default delegate for composites so that a class is
155 # guaranteed to support something if it is a composite.
156 log.debug("Setting default delegate for %s", self.name)
157 self._delegate = self.defaultDelegate
158 self._delegateClassName = self.defaultDelegateName
159 else:
160 self._delegate = None
161 self._delegateClassName = None
163 @property
164 def components(self) -> Dict[str, StorageClass]:
165 """Return the components associated with this `StorageClass`."""
166 return self._components
168 @property
169 def derivedComponents(self) -> Dict[str, StorageClass]:
170 """Return derived components associated with `StorageClass`."""
171 return self._derivedComponents
173 @property
174 def converters(self) -> Dict[str, str]:
175 """Return the type converters supported by this `StorageClass`."""
176 return self._converters
178 @property
179 def converters_by_type(self) -> Dict[Type, Type]:
180 """Return the type converters as python types."""
181 if self._converters_by_type is None:
182 self._converters_by_type = {}
184 # Loop over list because the dict can be edited in loop.
185 for candidate_type_str, converter_str in list(self.converters.items()):
186 if hasattr(builtins, candidate_type_str):
187 candidate_type = getattr(builtins, candidate_type_str)
188 else:
189 try:
190 candidate_type = doImportType(candidate_type_str)
191 except ImportError as e:
192 log.warning(
193 "Unable to import type %s associated with storage class %s (%s)",
194 candidate_type_str,
195 self.name,
196 e,
197 )
198 del self.converters[candidate_type_str]
199 continue
201 try:
202 converter = doImportType(converter_str)
203 except ImportError as e:
204 log.warning(
205 "Unable to import conversion function %s associated with storage class %s "
206 "required to convert type %s (%s)",
207 converter_str,
208 self.name,
209 candidate_type_str,
210 e,
211 )
212 del self.converters[candidate_type_str]
213 continue
214 if not callable(converter):
215 # doImportType is annotated to return a Type but in actual
216 # fact it can return Any except ModuleType because package
217 # variables can be accessed. This make mypy believe it
218 # is impossible for the return value to not be a callable
219 # so we must ignore the warning.
220 log.warning( # type: ignore
221 "Conversion function %s associated with storage class "
222 "%s to convert type %s is not a callable.",
223 converter_str,
224 self.name,
225 candidate_type_str,
226 )
227 del self.converters[candidate_type_str]
228 continue
229 self._converters_by_type[candidate_type] = converter
230 return self._converters_by_type
232 @property
233 def parameters(self) -> Set[str]:
234 """Return `set` of names of supported parameters."""
235 return set(self._parameters)
237 @property
238 def pytype(self) -> Type:
239 """Return Python type associated with this `StorageClass`."""
240 if self._pytype is not None:
241 return self._pytype
243 if hasattr(builtins, self._pytypeName):
244 pytype = getattr(builtins, self._pytypeName)
245 else:
246 pytype = doImportType(self._pytypeName)
247 self._pytype = pytype
248 return self._pytype
250 @property
251 def delegateClass(self) -> Optional[Type]:
252 """Class to use to delegate type-specific actions."""
253 if self._delegate is not None:
254 return self._delegate
255 if self._delegateClassName is None:
256 return None
257 delegate_class = doImportType(self._delegateClassName)
258 self._delegate = delegate_class
259 return self._delegate
261 def allComponents(self) -> Mapping[str, StorageClass]:
262 """Return all defined components.
264 This mapping includes all the derived and read/write components
265 for the corresponding storage class.
267 Returns
268 -------
269 comp : `dict` of [`str`, `StorageClass`]
270 The component name to storage class mapping.
271 """
272 components = copy.copy(self.components)
273 components.update(self.derivedComponents)
274 return components
276 def delegate(self) -> StorageClassDelegate:
277 """Return an instance of a storage class delegate.
279 Returns
280 -------
281 delegate : `StorageClassDelegate`
282 Instance of the delegate associated with this `StorageClass`.
283 The delegate is constructed with this `StorageClass`.
285 Raises
286 ------
287 TypeError
288 This StorageClass has no associated delegate.
289 """
290 cls = self.delegateClass
291 if cls is None:
292 raise TypeError(f"No delegate class is associated with StorageClass {self.name}")
293 return cls(storageClass=self)
295 def isComposite(self) -> bool:
296 """Return Boolean indicating whether this is a composite or not.
298 Returns
299 -------
300 isComposite : `bool`
301 `True` if this `StorageClass` is a composite, `False`
302 otherwise.
303 """
304 if self.components:
305 return True
306 return False
308 def _lookupNames(self) -> Tuple[LookupKey, ...]:
309 """Keys to use when looking up this DatasetRef in a configuration.
311 The names are returned in order of priority.
313 Returns
314 -------
315 names : `tuple` of `LookupKey`
316 Tuple of a `LookupKey` using the `StorageClass` name.
317 """
318 return (LookupKey(name=self.name),)
320 def knownParameters(self) -> Set[str]:
321 """Return set of all parameters known to this `StorageClass`.
323 The set includes parameters understood by components of a composite.
325 Returns
326 -------
327 known : `set`
328 All parameter keys of this `StorageClass` and the component
329 storage classes.
330 """
331 known = set(self._parameters)
332 for sc in self.components.values():
333 known.update(sc.knownParameters())
334 return known
336 def validateParameters(self, parameters: Collection = None) -> None:
337 """Check that the parameters are known to this `StorageClass`.
339 Does not check the values.
341 Parameters
342 ----------
343 parameters : `~collections.abc.Collection`, optional
344 Collection containing the parameters. Can be `dict`-like or
345 `set`-like. The parameter values are not checked.
346 If no parameters are supplied, always returns without error.
348 Raises
349 ------
350 KeyError
351 Some parameters are not understood by this `StorageClass`.
352 """
353 # No parameters is always okay
354 if not parameters:
355 return
357 # Extract the important information into a set. Works for dict and
358 # list.
359 external = set(parameters)
361 diff = external - self.knownParameters()
362 if diff:
363 s = "s" if len(diff) > 1 else ""
364 unknown = "', '".join(diff)
365 raise KeyError(f"Parameter{s} '{unknown}' not understood by StorageClass {self.name}")
367 def filterParameters(self, parameters: Mapping[str, Any], subset: Collection = None) -> Mapping[str, Any]:
368 """Filter out parameters that are not known to this `StorageClass`.
370 Parameters
371 ----------
372 parameters : `Mapping`, optional
373 Candidate parameters. Can be `None` if no parameters have
374 been provided.
375 subset : `~collections.abc.Collection`, optional
376 Subset of supported parameters that the caller is interested
377 in using. The subset must be known to the `StorageClass`
378 if specified. If `None` the supplied parameters will all
379 be checked, else only the keys in this set will be checked.
381 Returns
382 -------
383 filtered : `Mapping`
384 Valid parameters. Empty `dict` if none are suitable.
386 Raises
387 ------
388 ValueError
389 Raised if the provided subset is not a subset of the supported
390 parameters or if it is an empty set.
391 """
392 if not parameters:
393 return {}
395 known = self.knownParameters()
397 if subset is not None:
398 if not subset:
399 raise ValueError("Specified a parameter subset but it was empty")
400 subset = set(subset)
401 if not subset.issubset(known):
402 raise ValueError(f"Requested subset ({subset}) is not a subset of known parameters ({known})")
403 wanted = subset
404 else:
405 wanted = known
407 return {k: parameters[k] for k in wanted if k in parameters}
409 def validateInstance(self, instance: Any) -> bool:
410 """Check that the supplied Python object has the expected Python type.
412 Parameters
413 ----------
414 instance : `object`
415 Object to check.
417 Returns
418 -------
419 isOk : `bool`
420 True if the supplied instance object can be handled by this
421 `StorageClass`, False otherwise.
422 """
423 return isinstance(instance, self.pytype)
425 def can_convert(self, other: StorageClass) -> bool:
426 """Return `True` if this storage class can convert python types
427 in the other storage class.
429 Parameters
430 ----------
431 other : `StorageClass`
432 The storage class to check.
434 Returns
435 -------
436 can : `bool`
437 `True` if this storage class has a registered converter for
438 the python type associated with the other storage class. That
439 converter will convert the other python type to the one associated
440 with this storage class.
441 """
442 if other.name == self.name:
443 # Identical storage classes are compatible.
444 return True
446 # It may be that the storage class being compared is not
447 # available because the python type can't be imported. In that
448 # case conversion must be impossible.
449 try:
450 other_pytype = other.pytype
451 except Exception:
452 return False
454 # Or even this storage class itself can not have the type imported.
455 try:
456 self_pytype = self.pytype
457 except Exception:
458 return False
460 if issubclass(other_pytype, self_pytype):
461 # Storage classes have different names but the same python type.
462 return True
464 for candidate_type in self.converters_by_type:
465 if issubclass(other_pytype, candidate_type):
466 return True
467 return False
469 def coerce_type(self, incorrect: Any) -> Any:
470 """Coerce the supplied incorrect instance to the python type
471 associated with this `StorageClass`.
473 Parameters
474 ----------
475 incorrect : `object`
476 An object that might be the incorrect type.
478 Returns
479 -------
480 correct : `object`
481 An object that matches the python type of this `StorageClass`.
482 Can be the same object as given. If `None`, `None` will be
483 returned.
485 Raises
486 ------
487 TypeError
488 Raised if no conversion can be found.
489 """
490 if incorrect is None:
491 return None
493 # Possible this is the correct type already.
494 if self.validateInstance(incorrect):
495 return incorrect
497 # Check each registered converter.
498 for candidate_type, converter in self.converters_by_type.items():
499 if isinstance(incorrect, candidate_type):
500 try:
501 return converter(incorrect)
502 except Exception:
503 log.error(
504 "Converter %s failed to convert type %s",
505 get_full_type_name(converter),
506 get_full_type_name(incorrect),
507 )
508 raise
509 raise TypeError(
510 "Type does not match and no valid converter found to convert"
511 f" '{type(incorrect)}' to '{self.pytype}'"
512 )
514 def __eq__(self, other: Any) -> bool:
515 """Equality checks name, pytype name, delegate name, and components."""
516 if not isinstance(other, StorageClass):
517 return NotImplemented
519 if self.name != other.name:
520 return False
522 # We must compare pytype and delegate by name since we do not want
523 # to trigger an import of external module code here
524 if self._delegateClassName != other._delegateClassName:
525 return False
526 if self._pytypeName != other._pytypeName:
527 return False
529 # Ensure we have the same component keys in each
530 if set(self.components.keys()) != set(other.components.keys()):
531 return False
533 # Same parameters
534 if self.parameters != other.parameters:
535 return False
537 # Ensure that all the components have the same type
538 for k in self.components:
539 if self.components[k] != other.components[k]:
540 return False
542 # If we got to this point everything checks out
543 return True
545 def __hash__(self) -> int:
546 return hash(self.name)
548 def __repr__(self) -> str:
549 optionals: Dict[str, Any] = {}
550 if self._pytypeName != "object":
551 optionals["pytype"] = self._pytypeName
552 if self._delegateClassName is not None:
553 optionals["delegate"] = self._delegateClassName
554 if self._parameters:
555 optionals["parameters"] = self._parameters
556 if self.components:
557 optionals["components"] = self.components
558 if self.converters:
559 optionals["converters"] = self.converters
561 # order is preserved in the dict
562 options = ", ".join(f"{k}={v!r}" for k, v in optionals.items())
564 # Start with mandatory fields
565 r = f"{self.__class__.__name__}({self.name!r}"
566 if options:
567 r = r + ", " + options
568 r = r + ")"
569 return r
571 def __str__(self) -> str:
572 return self.name
575class StorageClassFactory(metaclass=Singleton):
576 """Factory for `StorageClass` instances.
578 This class is a singleton, with each instance sharing the pool of
579 StorageClasses. Since code can not know whether it is the first
580 time the instance has been created, the constructor takes no arguments.
581 To populate the factory with storage classes, a call to
582 `~StorageClassFactory.addFromConfig()` should be made.
584 Parameters
585 ----------
586 config : `StorageClassConfig` or `str`, optional
587 Load configuration. In a ButlerConfig` the relevant configuration
588 is located in the ``storageClasses`` section.
589 """
591 def __init__(self, config: Optional[Union[StorageClassConfig, str]] = None):
592 self._storageClasses: Dict[str, StorageClass] = {}
593 self._configs: List[StorageClassConfig] = []
595 # Always seed with the default config
596 self.addFromConfig(StorageClassConfig())
598 if config is not None: 598 ↛ 599line 598 didn't jump to line 599, because the condition on line 598 was never true
599 self.addFromConfig(config)
601 def __str__(self) -> str:
602 """Return summary of factory.
604 Returns
605 -------
606 summary : `str`
607 Summary of the factory status.
608 """
609 sep = "\n"
610 return f"""Number of registered StorageClasses: {len(self._storageClasses)}
612StorageClasses
613--------------
614{sep.join(f"{s}: {self._storageClasses[s]}" for s in self._storageClasses)}
615"""
617 def __contains__(self, storageClassOrName: Union[StorageClass, str]) -> bool:
618 """Indicate whether the storage class exists in the factory.
620 Parameters
621 ----------
622 storageClassOrName : `str` or `StorageClass`
623 If `str` is given existence of the named StorageClass
624 in the factory is checked. If `StorageClass` is given
625 existence and equality are checked.
627 Returns
628 -------
629 in : `bool`
630 True if the supplied string is present, or if the supplied
631 `StorageClass` is present and identical.
633 Notes
634 -----
635 The two different checks (one for "key" and one for "value") based on
636 the type of the given argument mean that it is possible for
637 StorageClass.name to be in the factory but StorageClass to not be
638 in the factory.
639 """
640 if isinstance(storageClassOrName, str): 640 ↛ 642line 640 didn't jump to line 642, because the condition on line 640 was never false
641 return storageClassOrName in self._storageClasses
642 elif isinstance(storageClassOrName, StorageClass):
643 if storageClassOrName.name in self._storageClasses:
644 return storageClassOrName == self._storageClasses[storageClassOrName.name]
645 return False
647 def addFromConfig(self, config: Union[StorageClassConfig, Config, str]) -> None:
648 """Add more `StorageClass` definitions from a config file.
650 Parameters
651 ----------
652 config : `StorageClassConfig`, `Config` or `str`
653 Storage class configuration. Can contain a ``storageClasses``
654 key if part of a global configuration.
655 """
656 sconfig = StorageClassConfig(config)
657 self._configs.append(sconfig)
659 # Since we can not assume that we will get definitions of
660 # components or parents before their classes are defined
661 # we have a helper function that we can call recursively
662 # to extract definitions from the configuration.
663 def processStorageClass(name: str, sconfig: StorageClassConfig) -> None:
664 # Maybe we've already processed this through recursion
665 if name not in sconfig:
666 return
667 info = sconfig.pop(name)
669 # Always create the storage class so we can ensure that
670 # we are not trying to overwrite with a different definition
671 components = None
673 # Extract scalar items from dict that are needed for
674 # StorageClass Constructor
675 storageClassKwargs = {k: info[k] for k in ("pytype", "delegate", "parameters") if k in info}
677 if "converters" in info:
678 storageClassKwargs["converters"] = info["converters"].toDict()
680 for compName in ("components", "derivedComponents"):
681 if compName not in info:
682 continue
683 components = {}
684 for cname, ctype in info[compName].items():
685 if ctype not in self:
686 processStorageClass(ctype, sconfig)
687 components[cname] = self.getStorageClass(ctype)
689 # Fill in other items
690 storageClassKwargs[compName] = components
692 # Create the new storage class and register it
693 baseClass = None
694 if "inheritsFrom" in info:
695 baseName = info["inheritsFrom"]
696 if baseName not in self: 696 ↛ 697line 696 didn't jump to line 697, because the condition on line 696 was never true
697 processStorageClass(baseName, sconfig)
698 baseClass = type(self.getStorageClass(baseName))
700 newStorageClassType = self.makeNewStorageClass(name, baseClass, **storageClassKwargs)
701 newStorageClass = newStorageClassType()
702 self.registerStorageClass(newStorageClass)
704 for name in list(sconfig.keys()):
705 processStorageClass(name, sconfig)
707 @staticmethod
708 def makeNewStorageClass(
709 name: str, baseClass: Optional[Type[StorageClass]] = StorageClass, **kwargs: Any
710 ) -> Type[StorageClass]:
711 """Create a new Python class as a subclass of `StorageClass`.
713 Parameters
714 ----------
715 name : `str`
716 Name to use for this class.
717 baseClass : `type`, optional
718 Base class for this `StorageClass`. Must be either `StorageClass`
719 or a subclass of `StorageClass`. If `None`, `StorageClass` will
720 be used.
722 Returns
723 -------
724 newtype : `type` subclass of `StorageClass`
725 Newly created Python type.
726 """
727 if baseClass is None:
728 baseClass = StorageClass
729 if not issubclass(baseClass, StorageClass): 729 ↛ 730line 729 didn't jump to line 730, because the condition on line 729 was never true
730 raise ValueError(f"Base class must be a StorageClass not {baseClass}")
732 # convert the arguments to use different internal names
733 clsargs = {f"_cls_{k}": v for k, v in kwargs.items() if v is not None}
734 clsargs["_cls_name"] = name
736 # Some container items need to merge with the base class values
737 # so that a child can inherit but override one bit.
738 # lists (which you get from configs) are treated as sets for this to
739 # work consistently.
740 for k in ("components", "parameters", "derivedComponents", "converters"):
741 classKey = f"_cls_{k}"
742 if classKey in clsargs:
743 baseValue = getattr(baseClass, classKey, None)
744 if baseValue is not None:
745 currentValue = clsargs[classKey]
746 if isinstance(currentValue, dict): 746 ↛ 749line 746 didn't jump to line 749, because the condition on line 746 was never false
747 newValue = baseValue.copy()
748 else:
749 newValue = set(baseValue)
750 newValue.update(currentValue)
751 clsargs[classKey] = newValue
753 # If we have parameters they should be a frozen set so that the
754 # parameters in the class can not be modified.
755 pk = "_cls_parameters"
756 if pk in clsargs:
757 clsargs[pk] = frozenset(clsargs[pk])
759 return type(f"StorageClass{name}", (baseClass,), clsargs)
761 def getStorageClass(self, storageClassName: str) -> StorageClass:
762 """Get a StorageClass instance associated with the supplied name.
764 Parameters
765 ----------
766 storageClassName : `str`
767 Name of the storage class to retrieve.
769 Returns
770 -------
771 instance : `StorageClass`
772 Instance of the correct `StorageClass`.
774 Raises
775 ------
776 KeyError
777 The requested storage class name is not registered.
778 """
779 return self._storageClasses[storageClassName]
781 def registerStorageClass(self, storageClass: StorageClass) -> None:
782 """Store the `StorageClass` in the factory.
784 Will be indexed by `StorageClass.name` and will return instances
785 of the supplied `StorageClass`.
787 Parameters
788 ----------
789 storageClass : `StorageClass`
790 Type of the Python `StorageClass` to register.
792 Raises
793 ------
794 ValueError
795 If a storage class has already been registered with
796 storageClassName and the previous definition differs.
797 """
798 if storageClass.name in self._storageClasses: 798 ↛ 799line 798 didn't jump to line 799, because the condition on line 798 was never true
799 existing = self.getStorageClass(storageClass.name)
800 if existing != storageClass:
801 raise ValueError(
802 f"New definition for StorageClass {storageClass.name} ({storageClass}) "
803 f"differs from current definition ({existing})"
804 )
805 else:
806 self._storageClasses[storageClass.name] = storageClass
808 def _unregisterStorageClass(self, storageClassName: str) -> None:
809 """Remove the named StorageClass from the factory.
811 Parameters
812 ----------
813 storageClassName : `str`
814 Name of storage class to remove.
816 Raises
817 ------
818 KeyError
819 The named storage class is not registered.
821 Notes
822 -----
823 This method is intended to simplify testing of StorageClassFactory
824 functionality and it is not expected to be required for normal usage.
825 """
826 del self._storageClasses[storageClassName]