Coverage for python/lsst/daf/butler/core/storageClass.py: 44%

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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/>. 

21 

22from __future__ import annotations 

23 

24"""Support for Storage Classes.""" 

25 

26__all__ = ("StorageClass", "StorageClassFactory", "StorageClassConfig") 

27 

28import builtins 

29import copy 

30import itertools 

31import logging 

32from typing import ( 

33 Any, 

34 Collection, 

35 Dict, 

36 ItemsView, 

37 Iterator, 

38 KeysView, 

39 List, 

40 Mapping, 

41 Optional, 

42 Sequence, 

43 Set, 

44 Tuple, 

45 Type, 

46 Union, 

47 ValuesView, 

48) 

49 

50from lsst.utils import doImportType 

51from lsst.utils.classes import Singleton 

52from lsst.utils.introspection import get_full_type_name 

53 

54from .config import Config, ConfigSubset 

55from .configSupport import LookupKey 

56from .storageClassDelegate import StorageClassDelegate 

57 

58log = logging.getLogger(__name__) 

59 

60 

61class StorageClassConfig(ConfigSubset): 

62 """Configuration class for defining Storage Classes.""" 

63 

64 component = "storageClasses" 

65 defaultConfigFile = "storageClasses.yaml" 

66 

67 

68class StorageClass: 

69 """Class describing how a label maps to a particular Python type. 

70 

71 Parameters 

72 ---------- 

73 name : `str` 

74 Name to use for this class. 

75 pytype : `type` or `str` 

76 Python type (or name of type) to associate with the `StorageClass` 

77 components : `dict`, optional 

78 `dict` mapping name of a component to another `StorageClass`. 

79 derivedComponents : `dict`, optional 

80 `dict` mapping name of a derived component to another `StorageClass`. 

81 parameters : `~collections.abc.Sequence` or `~collections.abc.Set` 

82 Parameters understood by this `StorageClass` that can control 

83 reading of data from datastores. 

84 delegate : `str`, optional 

85 Fully qualified name of class supporting assembly and disassembly 

86 of a `pytype` instance. 

87 converters : `dict` [`str`, `str`], optional 

88 Mapping of python type to function that can be called to convert 

89 that python type to the valid type of this storage class. 

90 """ 

91 

92 _cls_name: str = "BaseStorageClass" 

93 _cls_components: Optional[Dict[str, StorageClass]] = None 

94 _cls_derivedComponents: Optional[Dict[str, StorageClass]] = None 

95 _cls_parameters: Optional[Union[Set[str], Sequence[str]]] = None 

96 _cls_delegate: Optional[str] = None 

97 _cls_pytype: Optional[Union[Type, str]] = None 

98 _cls_converters: Optional[Dict[str, str]] = None 

99 defaultDelegate: Type = StorageClassDelegate 

100 defaultDelegateName: str = get_full_type_name(defaultDelegate) 

101 

102 def __init__( 

103 self, 

104 name: Optional[str] = None, 

105 pytype: Optional[Union[Type, str]] = None, 

106 components: Optional[Dict[str, StorageClass]] = None, 

107 derivedComponents: Optional[Dict[str, StorageClass]] = None, 

108 parameters: Optional[Union[Sequence, Set]] = None, 

109 delegate: Optional[str] = None, 

110 converters: Optional[Dict[str, str]] = None, 

111 ): 

112 if name is None: 

113 name = self._cls_name 

114 if pytype is None: 114 ↛ 116line 114 didn't jump to line 116, because the condition on line 114 was never false

115 pytype = self._cls_pytype 

116 if components is None: 116 ↛ 118line 116 didn't jump to line 118, because the condition on line 116 was never false

117 components = self._cls_components 

118 if derivedComponents is None: 118 ↛ 120line 118 didn't jump to line 120, because the condition on line 118 was never false

119 derivedComponents = self._cls_derivedComponents 

120 if parameters is None: 120 ↛ 122line 120 didn't jump to line 122, because the condition on line 120 was never false

121 parameters = self._cls_parameters 

122 if delegate is None: 122 ↛ 126line 122 didn't jump to line 126, because the condition on line 122 was never false

123 delegate = self._cls_delegate 

124 

125 # Merge converters with class defaults. 

126 self._converters = {} 

127 if self._cls_converters is not None: 

128 self._converters.update(self._cls_converters) 

129 if converters: 129 ↛ 130line 129 didn't jump to line 130, because the condition on line 129 was never true

130 self._converters.update(converters) 

131 

132 # Version of converters where the python types have been 

133 # Do not try to import anything until needed. 

134 self._converters_by_type: Optional[Dict[Type, Type]] = None 

135 

136 self.name = name 

137 

138 if pytype is None: 

139 pytype = object 

140 

141 self._pytype: Optional[Type] 

142 if not isinstance(pytype, str): 

143 # Already have a type so store it and get the name 

144 self._pytypeName = get_full_type_name(pytype) 

145 self._pytype = pytype 

146 else: 

147 # Store the type name and defer loading of type 

148 self._pytypeName = pytype 

149 self._pytype = None 

150 

151 if components is not None: 

152 if len(components) == 1: 152 ↛ 153line 152 didn't jump to line 153, because the condition on line 152 was never true

153 raise ValueError( 

154 f"Composite storage class {name} is not allowed to have" 

155 f" only one component '{next(iter(components))}'." 

156 " Did you mean it to be a derived component?" 

157 ) 

158 self._components = components 

159 else: 

160 self._components = {} 

161 self._derivedComponents = derivedComponents if derivedComponents is not None else {} 

162 self._parameters = frozenset(parameters) if parameters is not None else frozenset() 

163 # if the delegate is not None also set it and clear the default 

164 # delegate 

165 self._delegate: Optional[Type] 

166 self._delegateClassName: Optional[str] 

167 if delegate is not None: 

168 self._delegateClassName = delegate 

169 self._delegate = None 

170 elif components is not None: 170 ↛ 173line 170 didn't jump to line 173, because the condition on line 170 was never true

171 # We set a default delegate for composites so that a class is 

172 # guaranteed to support something if it is a composite. 

173 log.debug("Setting default delegate for %s", self.name) 

174 self._delegate = self.defaultDelegate 

175 self._delegateClassName = self.defaultDelegateName 

176 else: 

177 self._delegate = None 

178 self._delegateClassName = None 

179 

180 @property 

181 def components(self) -> Dict[str, StorageClass]: 

182 """Return the components associated with this `StorageClass`.""" 

183 return self._components 

184 

185 @property 

186 def derivedComponents(self) -> Dict[str, StorageClass]: 

187 """Return derived components associated with `StorageClass`.""" 

188 return self._derivedComponents 

189 

190 @property 

191 def converters(self) -> Dict[str, str]: 

192 """Return the type converters supported by this `StorageClass`.""" 

193 return self._converters 

194 

195 @property 

196 def converters_by_type(self) -> Dict[Type, Type]: 

197 """Return the type converters as python types.""" 

198 if self._converters_by_type is None: 

199 self._converters_by_type = {} 

200 

201 # Loop over list because the dict can be edited in loop. 

202 for candidate_type_str, converter_str in list(self.converters.items()): 

203 if hasattr(builtins, candidate_type_str): 

204 candidate_type = getattr(builtins, candidate_type_str) 

205 else: 

206 try: 

207 candidate_type = doImportType(candidate_type_str) 

208 except ImportError as e: 

209 log.warning( 

210 "Unable to import type %s associated with storage class %s (%s)", 

211 candidate_type_str, 

212 self.name, 

213 e, 

214 ) 

215 del self.converters[candidate_type_str] 

216 continue 

217 

218 try: 

219 converter = doImportType(converter_str) 

220 except ImportError as e: 

221 log.warning( 

222 "Unable to import conversion function %s associated with storage class %s " 

223 "required to convert type %s (%s)", 

224 converter_str, 

225 self.name, 

226 candidate_type_str, 

227 e, 

228 ) 

229 del self.converters[candidate_type_str] 

230 continue 

231 if not callable(converter): 

232 # doImportType is annotated to return a Type but in actual 

233 # fact it can return Any except ModuleType because package 

234 # variables can be accessed. This make mypy believe it 

235 # is impossible for the return value to not be a callable 

236 # so we must ignore the warning. 

237 log.warning( # type: ignore 

238 "Conversion function %s associated with storage class " 

239 "%s to convert type %s is not a callable.", 

240 converter_str, 

241 self.name, 

242 candidate_type_str, 

243 ) 

244 del self.converters[candidate_type_str] 

245 continue 

246 self._converters_by_type[candidate_type] = converter 

247 return self._converters_by_type 

248 

249 @property 

250 def parameters(self) -> Set[str]: 

251 """Return `set` of names of supported parameters.""" 

252 return set(self._parameters) 

253 

254 @property 

255 def pytype(self) -> Type: 

256 """Return Python type associated with this `StorageClass`.""" 

257 if self._pytype is not None: 

258 return self._pytype 

259 

260 if hasattr(builtins, self._pytypeName): 

261 pytype = getattr(builtins, self._pytypeName) 

262 else: 

263 pytype = doImportType(self._pytypeName) 

264 self._pytype = pytype 

265 return self._pytype 

266 

267 @property 

268 def delegateClass(self) -> Optional[Type]: 

269 """Class to use to delegate type-specific actions.""" 

270 if self._delegate is not None: 

271 return self._delegate 

272 if self._delegateClassName is None: 

273 return None 

274 delegate_class = doImportType(self._delegateClassName) 

275 self._delegate = delegate_class 

276 return self._delegate 

277 

278 def allComponents(self) -> Mapping[str, StorageClass]: 

279 """Return all defined components. 

280 

281 This mapping includes all the derived and read/write components 

282 for the corresponding storage class. 

283 

284 Returns 

285 ------- 

286 comp : `dict` of [`str`, `StorageClass`] 

287 The component name to storage class mapping. 

288 """ 

289 components = copy.copy(self.components) 

290 components.update(self.derivedComponents) 

291 return components 

292 

293 def delegate(self) -> StorageClassDelegate: 

294 """Return an instance of a storage class delegate. 

295 

296 Returns 

297 ------- 

298 delegate : `StorageClassDelegate` 

299 Instance of the delegate associated with this `StorageClass`. 

300 The delegate is constructed with this `StorageClass`. 

301 

302 Raises 

303 ------ 

304 TypeError 

305 This StorageClass has no associated delegate. 

306 """ 

307 cls = self.delegateClass 

308 if cls is None: 

309 raise TypeError(f"No delegate class is associated with StorageClass {self.name}") 

310 return cls(storageClass=self) 

311 

312 def isComposite(self) -> bool: 

313 """Return Boolean indicating whether this is a composite or not. 

314 

315 Returns 

316 ------- 

317 isComposite : `bool` 

318 `True` if this `StorageClass` is a composite, `False` 

319 otherwise. 

320 """ 

321 if self.components: 

322 return True 

323 return False 

324 

325 def _lookupNames(self) -> Tuple[LookupKey, ...]: 

326 """Keys to use when looking up this DatasetRef in a configuration. 

327 

328 The names are returned in order of priority. 

329 

330 Returns 

331 ------- 

332 names : `tuple` of `LookupKey` 

333 Tuple of a `LookupKey` using the `StorageClass` name. 

334 """ 

335 return (LookupKey(name=self.name),) 

336 

337 def knownParameters(self) -> Set[str]: 

338 """Return set of all parameters known to this `StorageClass`. 

339 

340 The set includes parameters understood by components of a composite. 

341 

342 Returns 

343 ------- 

344 known : `set` 

345 All parameter keys of this `StorageClass` and the component 

346 storage classes. 

347 """ 

348 known = set(self._parameters) 

349 for sc in self.components.values(): 

350 known.update(sc.knownParameters()) 

351 return known 

352 

353 def validateParameters(self, parameters: Collection = None) -> None: 

354 """Check that the parameters are known to this `StorageClass`. 

355 

356 Does not check the values. 

357 

358 Parameters 

359 ---------- 

360 parameters : `~collections.abc.Collection`, optional 

361 Collection containing the parameters. Can be `dict`-like or 

362 `set`-like. The parameter values are not checked. 

363 If no parameters are supplied, always returns without error. 

364 

365 Raises 

366 ------ 

367 KeyError 

368 Some parameters are not understood by this `StorageClass`. 

369 """ 

370 # No parameters is always okay 

371 if not parameters: 

372 return 

373 

374 # Extract the important information into a set. Works for dict and 

375 # list. 

376 external = set(parameters) 

377 

378 diff = external - self.knownParameters() 

379 if diff: 

380 s = "s" if len(diff) > 1 else "" 

381 unknown = "', '".join(diff) 

382 raise KeyError(f"Parameter{s} '{unknown}' not understood by StorageClass {self.name}") 

383 

384 def filterParameters(self, parameters: Mapping[str, Any], subset: Collection = None) -> Mapping[str, Any]: 

385 """Filter out parameters that are not known to this `StorageClass`. 

386 

387 Parameters 

388 ---------- 

389 parameters : `Mapping`, optional 

390 Candidate parameters. Can be `None` if no parameters have 

391 been provided. 

392 subset : `~collections.abc.Collection`, optional 

393 Subset of supported parameters that the caller is interested 

394 in using. The subset must be known to the `StorageClass` 

395 if specified. If `None` the supplied parameters will all 

396 be checked, else only the keys in this set will be checked. 

397 

398 Returns 

399 ------- 

400 filtered : `Mapping` 

401 Valid parameters. Empty `dict` if none are suitable. 

402 

403 Raises 

404 ------ 

405 ValueError 

406 Raised if the provided subset is not a subset of the supported 

407 parameters or if it is an empty set. 

408 """ 

409 if not parameters: 

410 return {} 

411 

412 known = self.knownParameters() 

413 

414 if subset is not None: 

415 if not subset: 

416 raise ValueError("Specified a parameter subset but it was empty") 

417 subset = set(subset) 

418 if not subset.issubset(known): 

419 raise ValueError(f"Requested subset ({subset}) is not a subset of known parameters ({known})") 

420 wanted = subset 

421 else: 

422 wanted = known 

423 

424 return {k: parameters[k] for k in wanted if k in parameters} 

425 

426 def validateInstance(self, instance: Any) -> bool: 

427 """Check that the supplied Python object has the expected Python type. 

428 

429 Parameters 

430 ---------- 

431 instance : `object` 

432 Object to check. 

433 

434 Returns 

435 ------- 

436 isOk : `bool` 

437 True if the supplied instance object can be handled by this 

438 `StorageClass`, False otherwise. 

439 """ 

440 return isinstance(instance, self.pytype) 

441 

442 def is_type(self, other: Type, compare_types: bool = False) -> bool: 

443 """Return Boolean indicating whether the supplied type matches 

444 the type in this `StorageClass`. 

445 

446 Parameters 

447 ---------- 

448 other : `Type` 

449 The type to be checked. 

450 compare_types : `bool`, optional 

451 If `True` the python type will be used in the comparison 

452 if the type names do not match. This may trigger an import 

453 of code and so can be slower. 

454 

455 Returns 

456 ------- 

457 match : `bool` 

458 `True` if the types are equal. 

459 

460 Notes 

461 ----- 

462 If this `StorageClass` has not yet imported the Python type the 

463 check is done against the full type name, this prevents an attempt 

464 to import the type when it will likely not match. 

465 """ 

466 if self._pytype: 

467 return self._pytype is other 

468 

469 other_name = get_full_type_name(other) 

470 if self._pytypeName == other_name: 

471 return True 

472 

473 if compare_types: 

474 # Must protect against the import failing. 

475 try: 

476 return self.pytype is other 

477 except Exception: 

478 pass 

479 

480 return False 

481 

482 def can_convert(self, other: StorageClass) -> bool: 

483 """Return `True` if this storage class can convert python types 

484 in the other storage class. 

485 

486 Parameters 

487 ---------- 

488 other : `StorageClass` 

489 The storage class to check. 

490 

491 Returns 

492 ------- 

493 can : `bool` 

494 `True` if this storage class has a registered converter for 

495 the python type associated with the other storage class. That 

496 converter will convert the other python type to the one associated 

497 with this storage class. 

498 """ 

499 if other.name == self.name: 

500 # Identical storage classes are compatible. 

501 return True 

502 

503 # It may be that the storage class being compared is not 

504 # available because the python type can't be imported. In that 

505 # case conversion must be impossible. 

506 try: 

507 other_pytype = other.pytype 

508 except Exception: 

509 return False 

510 

511 # Or even this storage class itself can not have the type imported. 

512 try: 

513 self_pytype = self.pytype 

514 except Exception: 

515 return False 

516 

517 if issubclass(other_pytype, self_pytype): 

518 # Storage classes have different names but the same python type. 

519 return True 

520 

521 for candidate_type in self.converters_by_type: 

522 if issubclass(other_pytype, candidate_type): 

523 return True 

524 return False 

525 

526 def coerce_type(self, incorrect: Any) -> Any: 

527 """Coerce the supplied incorrect instance to the python type 

528 associated with this `StorageClass`. 

529 

530 Parameters 

531 ---------- 

532 incorrect : `object` 

533 An object that might be the incorrect type. 

534 

535 Returns 

536 ------- 

537 correct : `object` 

538 An object that matches the python type of this `StorageClass`. 

539 Can be the same object as given. If `None`, `None` will be 

540 returned. 

541 

542 Raises 

543 ------ 

544 TypeError 

545 Raised if no conversion can be found. 

546 """ 

547 if incorrect is None: 

548 return None 

549 

550 # Possible this is the correct type already. 

551 if self.validateInstance(incorrect): 

552 return incorrect 

553 

554 # Check each registered converter. 

555 for candidate_type, converter in self.converters_by_type.items(): 

556 if isinstance(incorrect, candidate_type): 

557 try: 

558 return converter(incorrect) 

559 except Exception: 

560 log.error( 

561 "Converter %s failed to convert type %s", 

562 get_full_type_name(converter), 

563 get_full_type_name(incorrect), 

564 ) 

565 raise 

566 raise TypeError( 

567 "Type does not match and no valid converter found to convert" 

568 f" '{type(incorrect)}' to '{self.pytype}'" 

569 ) 

570 

571 def __eq__(self, other: Any) -> bool: 

572 """Equality checks name, pytype name, delegate name, and components.""" 

573 if not isinstance(other, StorageClass): 

574 return NotImplemented 

575 

576 if self.name != other.name: 

577 return False 

578 

579 # We must compare pytype and delegate by name since we do not want 

580 # to trigger an import of external module code here 

581 if self._delegateClassName != other._delegateClassName: 

582 return False 

583 if self._pytypeName != other._pytypeName: 

584 return False 

585 

586 # Ensure we have the same component keys in each 

587 if set(self.components.keys()) != set(other.components.keys()): 

588 return False 

589 

590 # Same parameters 

591 if self.parameters != other.parameters: 

592 return False 

593 

594 # Ensure that all the components have the same type 

595 for k in self.components: 

596 if self.components[k] != other.components[k]: 

597 return False 

598 

599 # If we got to this point everything checks out 

600 return True 

601 

602 def __hash__(self) -> int: 

603 return hash(self.name) 

604 

605 def __repr__(self) -> str: 

606 optionals: Dict[str, Any] = {} 

607 if self._pytypeName != "object": 

608 optionals["pytype"] = self._pytypeName 

609 if self._delegateClassName is not None: 

610 optionals["delegate"] = self._delegateClassName 

611 if self._parameters: 

612 optionals["parameters"] = self._parameters 

613 if self.components: 

614 optionals["components"] = self.components 

615 if self.converters: 

616 optionals["converters"] = self.converters 

617 

618 # order is preserved in the dict 

619 options = ", ".join(f"{k}={v!r}" for k, v in optionals.items()) 

620 

621 # Start with mandatory fields 

622 r = f"{self.__class__.__name__}({self.name!r}" 

623 if options: 

624 r = r + ", " + options 

625 r = r + ")" 

626 return r 

627 

628 def __str__(self) -> str: 

629 return self.name 

630 

631 

632class StorageClassFactory(metaclass=Singleton): 

633 """Factory for `StorageClass` instances. 

634 

635 This class is a singleton, with each instance sharing the pool of 

636 StorageClasses. Since code can not know whether it is the first 

637 time the instance has been created, the constructor takes no arguments. 

638 To populate the factory with storage classes, a call to 

639 `~StorageClassFactory.addFromConfig()` should be made. 

640 

641 Parameters 

642 ---------- 

643 config : `StorageClassConfig` or `str`, optional 

644 Load configuration. In a ButlerConfig` the relevant configuration 

645 is located in the ``storageClasses`` section. 

646 """ 

647 

648 def __init__(self, config: Optional[Union[StorageClassConfig, str]] = None): 

649 self._storageClasses: Dict[str, StorageClass] = {} 

650 self._configs: List[StorageClassConfig] = [] 

651 

652 # Always seed with the default config 

653 self.addFromConfig(StorageClassConfig()) 

654 

655 if config is not None: 655 ↛ 656line 655 didn't jump to line 656, because the condition on line 655 was never true

656 self.addFromConfig(config) 

657 

658 def __str__(self) -> str: 

659 """Return summary of factory. 

660 

661 Returns 

662 ------- 

663 summary : `str` 

664 Summary of the factory status. 

665 """ 

666 sep = "\n" 

667 return f"""Number of registered StorageClasses: {len(self._storageClasses)} 

668 

669StorageClasses 

670-------------- 

671{sep.join(f"{s}: {self._storageClasses[s]}" for s in self._storageClasses)} 

672""" 

673 

674 def __contains__(self, storageClassOrName: Union[StorageClass, str]) -> bool: 

675 """Indicate whether the storage class exists in the factory. 

676 

677 Parameters 

678 ---------- 

679 storageClassOrName : `str` or `StorageClass` 

680 If `str` is given existence of the named StorageClass 

681 in the factory is checked. If `StorageClass` is given 

682 existence and equality are checked. 

683 

684 Returns 

685 ------- 

686 in : `bool` 

687 True if the supplied string is present, or if the supplied 

688 `StorageClass` is present and identical. 

689 

690 Notes 

691 ----- 

692 The two different checks (one for "key" and one for "value") based on 

693 the type of the given argument mean that it is possible for 

694 StorageClass.name to be in the factory but StorageClass to not be 

695 in the factory. 

696 """ 

697 if isinstance(storageClassOrName, str): 697 ↛ 699line 697 didn't jump to line 699, because the condition on line 697 was never false

698 return storageClassOrName in self._storageClasses 

699 elif isinstance(storageClassOrName, StorageClass): 

700 if storageClassOrName.name in self._storageClasses: 

701 return storageClassOrName == self._storageClasses[storageClassOrName.name] 

702 return False 

703 

704 def __len__(self) -> int: 

705 return len(self._storageClasses) 

706 

707 def __iter__(self) -> Iterator[str]: 

708 return iter(self._storageClasses) 

709 

710 def values(self) -> ValuesView[StorageClass]: 

711 return self._storageClasses.values() 

712 

713 def keys(self) -> KeysView[str]: 

714 return self._storageClasses.keys() 

715 

716 def items(self) -> ItemsView[str, StorageClass]: 

717 return self._storageClasses.items() 

718 

719 def addFromConfig(self, config: Union[StorageClassConfig, Config, str]) -> None: 

720 """Add more `StorageClass` definitions from a config file. 

721 

722 Parameters 

723 ---------- 

724 config : `StorageClassConfig`, `Config` or `str` 

725 Storage class configuration. Can contain a ``storageClasses`` 

726 key if part of a global configuration. 

727 """ 

728 sconfig = StorageClassConfig(config) 

729 self._configs.append(sconfig) 

730 

731 # Since we can not assume that we will get definitions of 

732 # components or parents before their classes are defined 

733 # we have a helper function that we can call recursively 

734 # to extract definitions from the configuration. 

735 def processStorageClass(name: str, sconfig: StorageClassConfig, msg: str = "") -> None: 

736 # Maybe we've already processed this through recursion 

737 if name not in sconfig: 

738 return 

739 info = sconfig.pop(name) 

740 

741 # Always create the storage class so we can ensure that 

742 # we are not trying to overwrite with a different definition 

743 components = None 

744 

745 # Extract scalar items from dict that are needed for 

746 # StorageClass Constructor 

747 storageClassKwargs = {k: info[k] for k in ("pytype", "delegate", "parameters") if k in info} 

748 

749 if "converters" in info: 

750 storageClassKwargs["converters"] = info["converters"].toDict() 

751 

752 for compName in ("components", "derivedComponents"): 

753 if compName not in info: 

754 continue 

755 components = {} 

756 for cname, ctype in info[compName].items(): 

757 if ctype not in self: 

758 processStorageClass(ctype, sconfig, msg) 

759 components[cname] = self.getStorageClass(ctype) 

760 

761 # Fill in other items 

762 storageClassKwargs[compName] = components 

763 

764 # Create the new storage class and register it 

765 baseClass = None 

766 if "inheritsFrom" in info: 

767 baseName = info["inheritsFrom"] 

768 if baseName not in self: 768 ↛ 769line 768 didn't jump to line 769, because the condition on line 768 was never true

769 processStorageClass(baseName, sconfig, msg) 

770 baseClass = type(self.getStorageClass(baseName)) 

771 

772 newStorageClassType = self.makeNewStorageClass(name, baseClass, **storageClassKwargs) 

773 newStorageClass = newStorageClassType() 

774 self.registerStorageClass(newStorageClass, msg=msg) 

775 

776 # In case there is a problem, construct a context message for any 

777 # error reporting. 

778 files = [str(f) for f in itertools.chain([sconfig.configFile], sconfig.filesRead) if f] 

779 context = f"when adding definitions from {', '.join(files)}" if files else "" 

780 log.debug("Adding definitions from config %s", ", ".join(files)) 

781 

782 for name in list(sconfig.keys()): 

783 processStorageClass(name, sconfig, context) 

784 

785 @staticmethod 

786 def makeNewStorageClass( 

787 name: str, baseClass: Optional[Type[StorageClass]] = StorageClass, **kwargs: Any 

788 ) -> Type[StorageClass]: 

789 """Create a new Python class as a subclass of `StorageClass`. 

790 

791 Parameters 

792 ---------- 

793 name : `str` 

794 Name to use for this class. 

795 baseClass : `type`, optional 

796 Base class for this `StorageClass`. Must be either `StorageClass` 

797 or a subclass of `StorageClass`. If `None`, `StorageClass` will 

798 be used. 

799 

800 Returns 

801 ------- 

802 newtype : `type` subclass of `StorageClass` 

803 Newly created Python type. 

804 """ 

805 if baseClass is None: 

806 baseClass = StorageClass 

807 if not issubclass(baseClass, StorageClass): 807 ↛ 808line 807 didn't jump to line 808, because the condition on line 807 was never true

808 raise ValueError(f"Base class must be a StorageClass not {baseClass}") 

809 

810 # convert the arguments to use different internal names 

811 clsargs = {f"_cls_{k}": v for k, v in kwargs.items() if v is not None} 

812 clsargs["_cls_name"] = name 

813 

814 # Some container items need to merge with the base class values 

815 # so that a child can inherit but override one bit. 

816 # lists (which you get from configs) are treated as sets for this to 

817 # work consistently. 

818 for k in ("components", "parameters", "derivedComponents", "converters"): 

819 classKey = f"_cls_{k}" 

820 if classKey in clsargs: 

821 baseValue = getattr(baseClass, classKey, None) 

822 if baseValue is not None: 

823 currentValue = clsargs[classKey] 

824 if isinstance(currentValue, dict): 824 ↛ 827line 824 didn't jump to line 827, because the condition on line 824 was never false

825 newValue = baseValue.copy() 

826 else: 

827 newValue = set(baseValue) 

828 newValue.update(currentValue) 

829 clsargs[classKey] = newValue 

830 

831 # If we have parameters they should be a frozen set so that the 

832 # parameters in the class can not be modified. 

833 pk = "_cls_parameters" 

834 if pk in clsargs: 

835 clsargs[pk] = frozenset(clsargs[pk]) 

836 

837 return type(f"StorageClass{name}", (baseClass,), clsargs) 

838 

839 def getStorageClass(self, storageClassName: str) -> StorageClass: 

840 """Get a StorageClass instance associated with the supplied name. 

841 

842 Parameters 

843 ---------- 

844 storageClassName : `str` 

845 Name of the storage class to retrieve. 

846 

847 Returns 

848 ------- 

849 instance : `StorageClass` 

850 Instance of the correct `StorageClass`. 

851 

852 Raises 

853 ------ 

854 KeyError 

855 The requested storage class name is not registered. 

856 """ 

857 return self._storageClasses[storageClassName] 

858 

859 def findStorageClass(self, pytype: Type, compare_types: bool = False) -> StorageClass: 

860 """Find the storage class associated with this python type. 

861 

862 Parameters 

863 ---------- 

864 pytype : `type` 

865 The Python type to be matched. 

866 compare_types : `bool`, optional 

867 If `False`, the type will be checked against name of the python 

868 type. This comparison is always done first. If `True` and the 

869 string comparison failed, each candidate storage class will be 

870 forced to have its type imported. This can be significantly slower. 

871 

872 Returns 

873 ------- 

874 storageClass : `StorageClass` 

875 The matching storage class. 

876 

877 Raises 

878 ------ 

879 KeyError 

880 Raised if no match could be found. 

881 

882 Notes 

883 ----- 

884 It is possible for a python type to be associated with multiple 

885 storage classes. This method will currently return the first that 

886 matches. 

887 """ 

888 result = self._find_storage_class(pytype, False) 

889 if result: 

890 return result 

891 

892 if compare_types: 

893 # The fast comparison failed and we were asked to try the 

894 # variant that might involve code imports. 

895 result = self._find_storage_class(pytype, True) 

896 if result: 

897 return result 

898 

899 raise KeyError(f"Unable to find a StorageClass associated with type {get_full_type_name(pytype)!r}") 

900 

901 def _find_storage_class(self, pytype: Type, compare_types: bool) -> Optional[StorageClass]: 

902 """Iterate through all storage classes to find a match. 

903 

904 Parameters 

905 ---------- 

906 pytype : `type` 

907 The Python type to be matched. 

908 compare_types : `bool`, optional 

909 Whether to use type name matching or explicit type matching. 

910 The latter can be slower. 

911 

912 Returns 

913 ------- 

914 storageClass : `StorageClass` or `None` 

915 The matching storage class, or `None` if no match was found. 

916 

917 Notes 

918 ----- 

919 Helper method for ``findStorageClass``. 

920 """ 

921 for storageClass in self.values(): 

922 if storageClass.is_type(pytype, compare_types=compare_types): 

923 return storageClass 

924 return None 

925 

926 def registerStorageClass(self, storageClass: StorageClass, msg: Optional[str] = None) -> None: 

927 """Store the `StorageClass` in the factory. 

928 

929 Will be indexed by `StorageClass.name` and will return instances 

930 of the supplied `StorageClass`. 

931 

932 Parameters 

933 ---------- 

934 storageClass : `StorageClass` 

935 Type of the Python `StorageClass` to register. 

936 msg : `str`, optional 

937 Additional message string to be included in any error message. 

938 

939 Raises 

940 ------ 

941 ValueError 

942 If a storage class has already been registered with 

943 that storage class name and the previous definition differs. 

944 """ 

945 if storageClass.name in self._storageClasses: 945 ↛ 946line 945 didn't jump to line 946, because the condition on line 945 was never true

946 existing = self.getStorageClass(storageClass.name) 

947 if existing != storageClass: 

948 errmsg = f" {msg}" if msg else "" 

949 raise ValueError( 

950 f"New definition for StorageClass {storageClass.name} ({storageClass!r}) " 

951 f"differs from current definition ({existing!r}){errmsg}" 

952 ) 

953 else: 

954 self._storageClasses[storageClass.name] = storageClass 

955 

956 def _unregisterStorageClass(self, storageClassName: str) -> None: 

957 """Remove the named StorageClass from the factory. 

958 

959 Parameters 

960 ---------- 

961 storageClassName : `str` 

962 Name of storage class to remove. 

963 

964 Raises 

965 ------ 

966 KeyError 

967 The named storage class is not registered. 

968 

969 Notes 

970 ----- 

971 This method is intended to simplify testing of StorageClassFactory 

972 functionality and it is not expected to be required for normal usage. 

973 """ 

974 del self._storageClasses[storageClassName]