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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"""Configuration control.""" 

25 

26__all__ = ("Config", "ConfigSubset") 

27 

28import collections 

29import copy 

30import logging 

31import pprint 

32import os 

33import yaml 

34import sys 

35from yaml.representer import Representer 

36import io 

37from typing import Sequence, Optional, ClassVar, IO, Union 

38 

39from lsst.utils import doImport 

40from ._butlerUri import ButlerURI 

41 

42yaml.add_representer(collections.defaultdict, Representer.represent_dict) 

43 

44 

45# Config module logger 

46log = logging.getLogger(__name__) 

47 

48# PATH-like environment variable to use for defaults. 

49CONFIG_PATH = "DAF_BUTLER_CONFIG_PATH" 

50 

51try: 

52 yamlLoader = yaml.CSafeLoader 

53except AttributeError: 

54 # Not all installations have the C library 

55 yamlLoader = yaml.SafeLoader 

56 

57 

58class Loader(yamlLoader): 

59 """YAML Loader that supports file include directives 

60 

61 Uses ``!include`` directive in a YAML file to point to another 

62 YAML file to be included. The path in the include directive is relative 

63 to the file containing that directive. 

64 

65 storageClasses: !include storageClasses.yaml 

66 

67 Examples 

68 -------- 

69 >>> with open("document.yaml", "r") as f: 

70 data = yaml.load(f, Loader=Loader) 

71 

72 Notes 

73 ----- 

74 See https://davidchall.github.io/yaml-includes.html 

75 """ 

76 

77 def __init__(self, stream): 

78 super().__init__(stream) 

79 # if this is a string and not a stream we may well lack a name 

80 try: 

81 self._root = ButlerURI(stream.name) 

82 except AttributeError: 

83 # No choice but to assume a local filesystem 

84 self._root = ButlerURI("no-file.yaml") 

85 Loader.add_constructor("!include", Loader.include) 

86 

87 def include(self, node): 

88 if isinstance(node, yaml.ScalarNode): 

89 return self.extractFile(self.construct_scalar(node)) 

90 

91 elif isinstance(node, yaml.SequenceNode): 

92 result = [] 

93 for filename in self.construct_sequence(node): 

94 result.append(self.extractFile(filename)) 

95 return result 

96 

97 elif isinstance(node, yaml.MappingNode): 

98 result = {} 

99 for k, v in self.construct_mapping(node).items(): 

100 result[k] = self.extractFile(v) 

101 return result 

102 

103 else: 

104 print("Error:: unrecognised node type in !include statement", file=sys.stderr) 

105 raise yaml.constructor.ConstructorError 

106 

107 def extractFile(self, filename): 

108 # It is possible for the !include to point to an explicit URI 

109 # instead of a relative URI, therefore we first see if it is 

110 # scheme-less or not. If it has a scheme we use it directly 

111 # if it is scheme-less we use it relative to the file root. 

112 requesteduri = ButlerURI(filename, forceAbsolute=False) 

113 

114 if requesteduri.scheme: 

115 fileuri = requesteduri 

116 else: 

117 fileuri = copy.copy(self._root) 

118 fileuri.updateFile(filename) 

119 

120 log.debug("Opening YAML file via !include: %s", fileuri) 

121 

122 # Read all the data from the resource 

123 data = fileuri.read() 

124 

125 # Store the bytes into a BytesIO so we can attach a .name 

126 stream = io.BytesIO(data) 

127 stream.name = fileuri.geturl() 

128 return yaml.load(stream, Loader) 

129 

130 

131class Config(collections.abc.MutableMapping): 

132 r"""Implements a datatype that is used by `Butler` for configuration 

133 parameters. 

134 

135 It is essentially a `dict` with key/value pairs, including nested dicts 

136 (as values). In fact, it can be initialized with a `dict`. 

137 This is explained next: 

138 

139 Config extends the `dict` api so that hierarchical values may be accessed 

140 with delimited notation or as a tuple. If a string is given the delimiter 

141 is picked up from the first character in that string. For example, 

142 ``foo.getValue(".a.b.c")``, ``foo["a"]["b"]["c"]``, ``foo["a", "b", "c"]``, 

143 ``foo[".a.b.c"]``, and ``foo["/a/b/c"]`` all achieve the same outcome. 

144 If the first character is alphanumeric, no delimiter will be used. 

145 ``foo["a.b.c"]`` will be a single key ``a.b.c`` as will ``foo[":a.b.c"]``. 

146 Unicode characters can be used as the delimiter for distinctiveness if 

147 required. 

148 

149 If a key in the hierarchy starts with a non-alphanumeric character care 

150 should be used to ensure that either the tuple interface is used or 

151 a distinct delimiter is always given in string form. 

152 

153 Finally, the delimiter can be escaped if it is part of a key and also 

154 has to be used as a delimiter. For example, ``foo[r".a.b\.c"]`` results in 

155 a two element hierarchy of ``a`` and ``b.c``. For hard-coded strings it is 

156 always better to use a different delimiter in these cases. 

157 

158 Note that adding a multi-level key implicitly creates any nesting levels 

159 that do not exist, but removing multi-level keys does not automatically 

160 remove empty nesting levels. As a result: 

161 

162 >>> c = Config() 

163 >>> c[".a.b"] = 1 

164 >>> del c[".a.b"] 

165 >>> c["a"] 

166 Config({'a': {}}) 

167 

168 Storage formats supported: 

169 

170 - yaml: read and write is supported. 

171 

172 

173 Parameters 

174 ---------- 

175 other : `str` or `Config` or `dict` 

176 Other source of configuration, can be: 

177 

178 - (`str`) Treated as a path to a config file on disk. Must end with 

179 ".yaml". 

180 - (`Config`) Copies the other Config's values into this one. 

181 - (`dict`) Copies the values from the dict into this Config. 

182 

183 If `None` is provided an empty `Config` will be created. 

184 """ 

185 

186 _D: ClassVar[str] = "→" 

187 """Default internal delimiter to use for components in the hierarchy when 

188 constructing keys for external use (see `Config.names()`).""" 

189 

190 includeKey: ClassVar[str] = "includeConfigs" 

191 """Key used to indicate that another config should be included at this 

192 part of the hierarchy.""" 

193 

194 resourcesPackage: str = "lsst.daf.butler" 

195 """Package to search for default configuration data. The resources 

196 themselves will be within a ``configs`` resource hierarchy.""" 

197 

198 def __init__(self, other=None): 

199 self._data = {} 

200 self.configFile = None 

201 

202 if other is None: 

203 return 

204 

205 if isinstance(other, Config): 

206 self._data = copy.deepcopy(other._data) 

207 self.configFile = other.configFile 

208 elif isinstance(other, collections.abc.Mapping): 

209 self.update(other) 

210 elif isinstance(other, (str, ButlerURI)): 

211 # if other is a string, assume it is a file path/URI 

212 self.__initFromUri(other) 

213 self._processExplicitIncludes() 

214 else: 

215 # if the config specified by other could not be recognized raise 

216 # a runtime error. 

217 raise RuntimeError(f"A Config could not be loaded from other: {other}") 

218 

219 def ppprint(self): 

220 """helper function for debugging, prints a config out in a readable 

221 way in the debugger. 

222 

223 use: pdb> print(myConfigObject.ppprint()) 

224 

225 Returns 

226 ------- 

227 s : `str` 

228 A prettyprint formatted string representing the config 

229 """ 

230 return pprint.pformat(self._data, indent=2, width=1) 

231 

232 def __repr__(self): 

233 return f"{type(self).__name__}({self._data!r})" 

234 

235 def __str__(self): 

236 return self.ppprint() 

237 

238 def __len__(self): 

239 return len(self._data) 

240 

241 def __iter__(self): 

242 return iter(self._data) 

243 

244 def copy(self): 

245 return type(self)(self) 

246 

247 @classmethod 

248 def fromYaml(cls, string: str) -> Config: 

249 """Create a new Config instance from a YAML string. 

250 

251 Parameters 

252 ---------- 

253 string : `str` 

254 String containing content in YAML format 

255 

256 Returns 

257 ------- 

258 c : `Config` 

259 Newly-constructed Config. 

260 """ 

261 new_config = cls().__initFromYaml(string) 

262 new_config._processExplicitIncludes() 

263 return new_config 

264 

265 def __initFromUri(self, path: str) -> None: 

266 """Load a file from a path or an URI. 

267 

268 Parameters 

269 ---------- 

270 path : `str` 

271 Path or a URI to a persisted config file. 

272 """ 

273 uri = ButlerURI(path) 

274 if uri.getExtension() == ".yaml": 

275 log.debug("Opening YAML config file: %s", uri.geturl()) 

276 content = uri.read() 

277 # Use a stream so we can name it 

278 stream = io.BytesIO(content) 

279 stream.name = uri.geturl() 

280 self.__initFromYaml(stream) 

281 else: 

282 raise RuntimeError(f"Unhandled config file type: {uri}") 

283 self.configFile = uri 

284 

285 def __initFromYaml(self, stream): 

286 """Loads a YAML config from any readable stream that contains one. 

287 

288 Parameters 

289 ---------- 

290 stream: `IO` or `str` 

291 Stream to pass to the YAML loader. Accepts anything that 

292 `yaml.load` accepts. This can include a string as well as an 

293 IO stream. 

294 

295 Raises 

296 ------ 

297 yaml.YAMLError 

298 If there is an error loading the file. 

299 """ 

300 content = yaml.load(stream, Loader=Loader) 

301 if content is None: 

302 content = {} 

303 self._data = content 

304 return self 

305 

306 def _processExplicitIncludes(self): 

307 """Scan through the configuration searching for the special 

308 includeConfigs directive and process the includes.""" 

309 

310 # Search paths for config files 

311 searchPaths = [ButlerURI(os.path.curdir, forceDirectory=True)] 

312 if self.configFile is not None: 

313 if isinstance(self.configFile, ButlerURI): 

314 configDir = self.configFile.dirname() 

315 else: 

316 raise RuntimeError(f"Unexpected type for config file: {self.configFile}") 

317 searchPaths.append(configDir) 

318 

319 # Ensure we know what delimiter to use 

320 names = self.nameTuples() 

321 for path in names: 

322 if path[-1] == self.includeKey: 

323 

324 log.debug("Processing file include directive at %s", self._D + self._D.join(path)) 

325 basePath = path[:-1] 

326 

327 # Extract the includes and then delete them from the config 

328 includes = self[path] 

329 del self[path] 

330 

331 # Be consistent and convert to a list 

332 if not isinstance(includes, list): 

333 includes = [includes] 

334 

335 # Read each file assuming it is a reference to a file 

336 # The file can be relative to config file or cwd 

337 # ConfigSubset search paths are not used 

338 subConfigs = [] 

339 for fileName in includes: 

340 # Expand any shell variables -- this could be URI 

341 fileName = ButlerURI(os.path.expandvars(fileName), forceAbsolute=False) 

342 found = None 

343 if fileName.isabs(): 

344 found = fileName 

345 else: 

346 for dir in searchPaths: 

347 if isinstance(dir, ButlerURI): 

348 specific = dir.join(fileName.path) 

349 # Remote resource check might be expensive 

350 if specific.exists(): 

351 found = specific 

352 else: 

353 log.warning("Do not understand search path entry '%s' of type %s", 

354 dir, type(dir).__name__) 

355 if not found: 

356 raise RuntimeError(f"Unable to find referenced include file: {fileName}") 

357 

358 # Read the referenced Config as a Config 

359 subConfigs.append(type(self)(found)) 

360 

361 # Now we need to merge these sub configs with the current 

362 # information that was present in this node in the config 

363 # tree with precedence given to the explicit values 

364 newConfig = subConfigs.pop(0) 

365 for sc in subConfigs: 

366 newConfig.update(sc) 

367 

368 # Explicit values take precedence 

369 if not basePath: 

370 # This is an include at the root config 

371 newConfig.update(self) 

372 # Replace the current config 

373 self._data = newConfig._data 

374 else: 

375 newConfig.update(self[basePath]) 

376 # And reattach to the base config 

377 self[basePath] = newConfig 

378 

379 @staticmethod 

380 def _splitIntoKeys(key): 

381 r"""Split the argument for get/set/in into a hierarchical list. 

382 

383 Parameters 

384 ---------- 

385 key : `str` or iterable 

386 Argument given to get/set/in. If an iterable is provided it will 

387 be converted to a list. If the first character of the string 

388 is not an alphanumeric character then it will be used as the 

389 delimiter for the purposes of splitting the remainder of the 

390 string. If the delimiter is also in one of the keys then it 

391 can be escaped using ``\``. There is no default delimiter. 

392 

393 Returns 

394 ------- 

395 keys : `list` 

396 Hierarchical keys as a `list`. 

397 """ 

398 if isinstance(key, str): 

399 if not key[0].isalnum(): 

400 d = key[0] 

401 key = key[1:] 

402 else: 

403 return [key, ] 

404 escaped = f"\\{d}" 

405 temp = None 

406 if escaped in key: 

407 # Complain at the attempt to escape the escape 

408 doubled = fr"\{escaped}" 

409 if doubled in key: 

410 raise ValueError(f"Escaping an escaped delimiter ({doubled} in {key})" 

411 " is not yet supported.") 

412 # Replace with a character that won't be in the string 

413 temp = "\r" 

414 if temp in key or d == temp: 

415 raise ValueError(f"Can not use character {temp!r} in hierarchical key or as" 

416 " delimiter if escaping the delimiter") 

417 key = key.replace(escaped, temp) 

418 hierarchy = key.split(d) 

419 if temp: 

420 hierarchy = [h.replace(temp, d) for h in hierarchy] 

421 return hierarchy 

422 elif isinstance(key, collections.abc.Iterable): 

423 return list(key) 

424 else: 

425 # Not sure what this is so try it anyway 

426 return [key, ] 

427 

428 def _getKeyHierarchy(self, name): 

429 """Retrieve the key hierarchy for accessing the Config 

430 

431 Parameters 

432 ---------- 

433 name : `str` or `tuple` 

434 Delimited string or `tuple` of hierarchical keys. 

435 

436 Returns 

437 ------- 

438 hierarchy : `list` of `str` 

439 Hierarchy to use as a `list`. If the name is available directly 

440 as a key in the Config it will be used regardless of the presence 

441 of any nominal delimiter. 

442 """ 

443 if name in self._data: 

444 keys = [name, ] 

445 else: 

446 keys = self._splitIntoKeys(name) 

447 return keys 

448 

449 def _findInHierarchy(self, keys, create=False): 

450 """Look for hierarchy of keys in Config 

451 

452 Parameters 

453 ---------- 

454 keys : `list` or `tuple` 

455 Keys to search in hierarchy. 

456 create : `bool`, optional 

457 If `True`, if a part of the hierarchy does not exist, insert an 

458 empty `dict` into the hierarchy. 

459 

460 Returns 

461 ------- 

462 hierarchy : `list` 

463 List of the value corresponding to each key in the supplied 

464 hierarchy. Only keys that exist in the hierarchy will have 

465 a value. 

466 complete : `bool` 

467 `True` if the full hierarchy exists and the final element 

468 in ``hierarchy`` is the value of relevant value. 

469 """ 

470 d = self._data 

471 

472 def checkNextItem(k, d, create): 

473 """See if k is in d and if it is return the new child""" 

474 nextVal = None 

475 isThere = False 

476 if d is None: 

477 # We have gone past the end of the hierarchy 

478 pass 

479 elif isinstance(d, collections.abc.Sequence): 

480 # Check sequence first because for lists 

481 # __contains__ checks whether value is found in list 

482 # not whether the index exists in list. When we traverse 

483 # the hierarchy we are interested in the index. 

484 try: 

485 nextVal = d[int(k)] 

486 isThere = True 

487 except IndexError: 

488 pass 

489 except ValueError: 

490 isThere = k in d 

491 elif k in d: 

492 nextVal = d[k] 

493 isThere = True 

494 elif create: 

495 d[k] = {} 

496 nextVal = d[k] 

497 isThere = True 

498 return nextVal, isThere 

499 

500 hierarchy = [] 

501 complete = True 

502 for k in keys: 

503 d, isThere = checkNextItem(k, d, create) 

504 if isThere: 

505 hierarchy.append(d) 

506 else: 

507 complete = False 

508 break 

509 

510 return hierarchy, complete 

511 

512 def __getitem__(self, name): 

513 # Override the split for the simple case where there is an exact 

514 # match. This allows `Config.items()` to work via a simple 

515 # __iter__ implementation that returns top level keys of 

516 # self._data. 

517 keys = self._getKeyHierarchy(name) 

518 

519 hierarchy, complete = self._findInHierarchy(keys) 

520 if not complete: 

521 raise KeyError(f"{name} not found") 

522 data = hierarchy[-1] 

523 

524 if isinstance(data, collections.abc.Mapping): 

525 data = Config(data) 

526 # Ensure that child configs inherit the parent internal delimiter 

527 if self._D != Config._D: 

528 data._D = self._D 

529 return data 

530 

531 def __setitem__(self, name, value): 

532 keys = self._getKeyHierarchy(name) 

533 last = keys.pop() 

534 if isinstance(value, Config): 

535 value = copy.deepcopy(value._data) 

536 

537 hierarchy, complete = self._findInHierarchy(keys, create=True) 

538 if hierarchy: 

539 data = hierarchy[-1] 

540 else: 

541 data = self._data 

542 

543 try: 

544 data[last] = value 

545 except TypeError: 

546 data[int(last)] = value 

547 

548 def __contains__(self, key): 

549 keys = self._getKeyHierarchy(key) 

550 hierarchy, complete = self._findInHierarchy(keys) 

551 return complete 

552 

553 def __delitem__(self, key): 

554 keys = self._getKeyHierarchy(key) 

555 last = keys.pop() 

556 hierarchy, complete = self._findInHierarchy(keys) 

557 if complete: 

558 if hierarchy: 

559 data = hierarchy[-1] 

560 else: 

561 data = self._data 

562 del data[last] 

563 else: 

564 raise KeyError(f"{key} not found in Config") 

565 

566 def update(self, other): 

567 """Like dict.update, but will add or modify keys in nested dicts, 

568 instead of overwriting the nested dict entirely. 

569 

570 For example, for the given code: 

571 foo = {"a": {"b": 1}} 

572 foo.update({"a": {"c": 2}}) 

573 

574 Parameters 

575 ---------- 

576 other : `dict` or `Config` 

577 Source of configuration: 

578 

579 - If foo is a dict, then after the update foo == {"a": {"c": 2}} 

580 - But if foo is a Config, then after the update 

581 foo == {"a": {"b": 1, "c": 2}} 

582 """ 

583 def doUpdate(d, u): 

584 if not isinstance(u, collections.abc.Mapping) or \ 

585 not isinstance(d, collections.abc.Mapping): 

586 raise RuntimeError("Only call update with Mapping, not {}".format(type(d))) 

587 for k, v in u.items(): 

588 if isinstance(v, collections.abc.Mapping): 

589 d[k] = doUpdate(d.get(k, {}), v) 

590 else: 

591 d[k] = v 

592 return d 

593 doUpdate(self._data, other) 

594 

595 def merge(self, other): 

596 """Like Config.update, but will add keys & values from other that 

597 DO NOT EXIST in self. 

598 

599 Keys and values that already exist in self will NOT be overwritten. 

600 

601 Parameters 

602 ---------- 

603 other : `dict` or `Config` 

604 Source of configuration: 

605 """ 

606 otherCopy = copy.deepcopy(other) 

607 otherCopy.update(self) 

608 self._data = otherCopy._data 

609 

610 def nameTuples(self, topLevelOnly=False): 

611 """Get tuples representing the name hierarchies of all keys. 

612 

613 The tuples returned from this method are guaranteed to be usable 

614 to access items in the configuration object. 

615 

616 Parameters 

617 ---------- 

618 topLevelOnly : `bool`, optional 

619 If False, the default, a full hierarchy of names is returned. 

620 If True, only the top level are returned. 

621 

622 Returns 

623 ------- 

624 names : `list` of `tuple` of `str` 

625 List of all names present in the `Config` where each element 

626 in the list is a `tuple` of strings representing the hierarchy. 

627 """ 

628 if topLevelOnly: 

629 return list((k,) for k in self) 

630 

631 def getKeysAsTuples(d, keys, base): 

632 if isinstance(d, collections.abc.Sequence): 

633 theseKeys = range(len(d)) 

634 else: 

635 theseKeys = d.keys() 

636 for key in theseKeys: 

637 val = d[key] 

638 levelKey = base + (key,) if base is not None else (key,) 

639 keys.append(levelKey) 

640 if isinstance(val, (collections.abc.Mapping, collections.abc.Sequence)) \ 

641 and not isinstance(val, str): 

642 getKeysAsTuples(val, keys, levelKey) 

643 keys = [] 

644 getKeysAsTuples(self._data, keys, None) 

645 return keys 

646 

647 def names(self, topLevelOnly=False, delimiter=None): 

648 """Get a delimited name of all the keys in the hierarchy. 

649 

650 The values returned from this method are guaranteed to be usable 

651 to access items in the configuration object. 

652 

653 Parameters 

654 ---------- 

655 topLevelOnly : `bool`, optional 

656 If False, the default, a full hierarchy of names is returned. 

657 If True, only the top level are returned. 

658 delimiter : `str`, optional 

659 Delimiter to use when forming the keys. If the delimiter is 

660 present in any of the keys, it will be escaped in the returned 

661 names. If `None` given a delimiter will be automatically provided. 

662 The delimiter can not be alphanumeric. 

663 

664 Returns 

665 ------- 

666 names : `list` of `str` 

667 List of all names present in the `Config`. 

668 

669 Notes 

670 ----- 

671 This is different than the built-in method `dict.keys`, which will 

672 return only the first level keys. 

673 

674 Raises 

675 ------ 

676 ValueError: 

677 The supplied delimiter is alphanumeric. 

678 """ 

679 if topLevelOnly: 

680 return list(self.keys()) 

681 

682 # Get all the tuples of hierarchical keys 

683 nameTuples = self.nameTuples() 

684 

685 if delimiter is not None and delimiter.isalnum(): 

686 raise ValueError(f"Supplied delimiter ({delimiter!r}) must not be alphanumeric.") 

687 

688 if delimiter is None: 

689 # Start with something, and ensure it does not need to be 

690 # escaped (it is much easier to understand if not escaped) 

691 delimiter = self._D 

692 

693 # Form big string for easy check of delimiter clash 

694 combined = "".join("".join(str(s) for s in k) for k in nameTuples) 

695 

696 # Try a delimiter and keep trying until we get something that 

697 # works. 

698 ntries = 0 

699 while delimiter in combined: 

700 log.debug(f"Delimiter '{delimiter}' could not be used. Trying another.") 

701 ntries += 1 

702 

703 if ntries > 100: 

704 raise ValueError(f"Unable to determine a delimiter for Config {self}") 

705 

706 # try another one 

707 while True: 

708 delimiter = chr(ord(delimiter)+1) 

709 if not delimiter.isalnum(): 

710 break 

711 

712 log.debug(f"Using delimiter {delimiter!r}") 

713 

714 # Form the keys, escaping the delimiter if necessary 

715 strings = [delimiter + delimiter.join(str(s).replace(delimiter, f"\\{delimiter}") for s in k) 

716 for k in nameTuples] 

717 return strings 

718 

719 def asArray(self, name): 

720 """Get a value as an array. 

721 

722 May contain one or more elements. 

723 

724 Parameters 

725 ---------- 

726 name : `str` 

727 Key to use to retrieve value. 

728 

729 Returns 

730 ------- 

731 array : `collections.abc.Sequence` 

732 The value corresponding to name, but guaranteed to be returned 

733 as a list with at least one element. If the value is a 

734 `~collections.abc.Sequence` (and not a `str`) the value itself 

735 will be returned, else the value will be the first element. 

736 """ 

737 val = self.get(name) 

738 if isinstance(val, str): 

739 val = [val] 

740 elif not isinstance(val, collections.abc.Sequence): 

741 val = [val] 

742 return val 

743 

744 def __eq__(self, other): 

745 if isinstance(other, Config): 

746 other = other._data 

747 return self._data == other 

748 

749 def __ne__(self, other): 

750 if isinstance(other, Config): 

751 other = other._data 

752 return self._data != other 

753 

754 ####### 

755 # i/o # 

756 

757 def dump(self, output: Optional[IO] = None) -> Optional[str]: 

758 """Writes the config to a yaml stream. 

759 

760 Parameters 

761 ---------- 

762 output : `IO`, optional 

763 The YAML stream to use for output. If `None` the YAML content 

764 will be returned. 

765 

766 Returns 

767 ------- 

768 yaml : `str` or `None` 

769 If a stream was given the stream will be used and the return 

770 value will be `None`. If the stream was `None` the YAML 

771 serialization will be returned as a string. 

772 """ 

773 return yaml.safe_dump(self._data, output, default_flow_style=False) 

774 

775 def dumpToUri(self, uri: Union[ButlerURI, str], updateFile: bool = True, 

776 defaultFileName: str = "butler.yaml", 

777 overwrite: bool = True) -> None: 

778 """Writes the config to location pointed to by given URI. 

779 

780 Currently supports 's3' and 'file' URI schemes. 

781 

782 Parameters 

783 ---------- 

784 uri: `str` or `ButlerURI` 

785 URI of location where the Config will be written. 

786 updateFile : bool, optional 

787 If True and uri does not end on a filename with extension, will 

788 append `defaultFileName` to the target uri. True by default. 

789 defaultFileName : bool, optional 

790 The file name that will be appended to target uri if updateFile is 

791 True and uri does not end on a file with an extension. 

792 overwrite : bool, optional 

793 If True the configuration will be written even if it already 

794 exists at that location. 

795 """ 

796 # Make local copy of URI or create new one 

797 uri = ButlerURI(uri) 

798 

799 if updateFile and not uri.getExtension(): 

800 uri.updateFile(defaultFileName) 

801 

802 uri.write(self.dump().encode(), overwrite=overwrite) 

803 self.configFile = uri 

804 

805 @staticmethod 

806 def updateParameters(configType, config, full, toUpdate=None, toCopy=None, overwrite=True): 

807 """Generic helper function for updating specific config parameters. 

808 

809 Allows for named parameters to be set to new values in bulk, and 

810 for other values to be set by copying from a reference config. 

811 

812 Assumes that the supplied config is compatible with ``configType`` 

813 and will attach the updated values to the supplied config by 

814 looking for the related component key. It is assumed that 

815 ``config`` and ``full`` are from the same part of the 

816 configuration hierarchy. 

817 

818 Parameters 

819 ---------- 

820 configType : `ConfigSubset` 

821 Config type to use to extract relevant items from ``config``. 

822 config : `Config` 

823 A `Config` to update. Only the subset understood by 

824 the supplied `ConfigSubset` will be modified. Default values 

825 will not be inserted and the content will not be validated 

826 since mandatory keys are allowed to be missing until 

827 populated later by merging. 

828 full : `Config` 

829 A complete config with all defaults expanded that can be 

830 converted to a ``configType``. Read-only and will not be 

831 modified by this method. Values are read from here if 

832 ``toCopy`` is defined. 

833 

834 Repository-specific options that should not be obtained 

835 from defaults when Butler instances are constructed 

836 should be copied from ``full`` to ``config``. 

837 toUpdate : `dict`, optional 

838 A `dict` defining the keys to update and the new value to use. 

839 The keys and values can be any supported by `Config` 

840 assignment. 

841 toCopy : `tuple`, optional 

842 `tuple` of keys whose values should be copied from ``full`` 

843 into ``config``. 

844 overwrite : `bool`, optional 

845 If `False`, do not modify a value in ``config`` if the key 

846 already exists. Default is always to overwrite. 

847 

848 Raises 

849 ------ 

850 ValueError 

851 Neither ``toUpdate`` not ``toCopy`` were defined. 

852 """ 

853 if toUpdate is None and toCopy is None: 

854 raise ValueError("One of toUpdate or toCopy parameters must be set.") 

855 

856 # If this is a parent configuration then we need to ensure that 

857 # the supplied config has the relevant component key in it. 

858 # If this is a parent configuration we add in the stub entry 

859 # so that the ConfigSubset constructor will do the right thing. 

860 # We check full for this since that is guaranteed to be complete. 

861 if configType.component in full and configType.component not in config: 

862 config[configType.component] = {} 

863 

864 # Extract the part of the config we wish to update 

865 localConfig = configType(config, mergeDefaults=False, validate=False) 

866 

867 if toUpdate: 

868 for key, value in toUpdate.items(): 

869 if key in localConfig and not overwrite: 

870 log.debug("Not overriding key '%s' with value '%s' in config %s", 

871 key, value, localConfig.__class__.__name__) 

872 else: 

873 localConfig[key] = value 

874 

875 if toCopy: 

876 localFullConfig = configType(full, mergeDefaults=False) 

877 for key in toCopy: 

878 if key in localConfig and not overwrite: 

879 log.debug("Not overriding key '%s' from defaults in config %s", 

880 key, localConfig.__class__.__name__) 

881 else: 

882 localConfig[key] = localFullConfig[key] 

883 

884 # Reattach to parent if this is a child config 

885 if configType.component in config: 

886 config[configType.component] = localConfig 

887 else: 

888 config.update(localConfig) 

889 

890 def toDict(self): 

891 """Convert a `Config` to a standalone hierarchical `dict`. 

892 

893 Returns 

894 ------- 

895 d : `dict` 

896 The standalone hierarchical `dict` with any `Config` classes 

897 in the hierarchy converted to `dict`. 

898 

899 Notes 

900 ----- 

901 This can be useful when passing a Config to some code that 

902 expects native Python types. 

903 """ 

904 output = copy.deepcopy(self._data) 

905 for k, v in output.items(): 

906 if isinstance(v, Config): 

907 v = v.toDict() 

908 output[k] = v 

909 return output 

910 

911 

912class ConfigSubset(Config): 

913 """Config representing a subset of a more general configuration. 

914 

915 Subclasses define their own component and when given a configuration 

916 that includes that component, the resulting configuration only includes 

917 the subset. For example, your config might contain ``dimensions`` if it's 

918 part of a global config and that subset will be stored. If ``dimensions`` 

919 can not be found it is assumed that the entire contents of the 

920 configuration should be used. 

921 

922 Default values are read from the environment or supplied search paths 

923 using the default configuration file name specified in the subclass. 

924 This allows a configuration class to be instantiated without any 

925 additional arguments. 

926 

927 Additional validation can be specified to check for keys that are mandatory 

928 in the configuration. 

929 

930 Parameters 

931 ---------- 

932 other : `Config` or `str` or `dict` 

933 Argument specifying the configuration information as understood 

934 by `Config` 

935 validate : `bool`, optional 

936 If `True` required keys will be checked to ensure configuration 

937 consistency. 

938 mergeDefaults : `bool`, optional 

939 If `True` defaults will be read and the supplied config will 

940 be combined with the defaults, with the supplied valiues taking 

941 precedence. 

942 searchPaths : `list` or `tuple`, optional 

943 Explicit additional paths to search for defaults. They should 

944 be supplied in priority order. These paths have higher priority 

945 than those read from the environment in 

946 `ConfigSubset.defaultSearchPaths()`. Paths can be `str` referring to 

947 the local file system or URIs, `ButlerURI`. 

948 """ 

949 

950 component: ClassVar[Optional[str]] = None 

951 """Component to use from supplied config. Can be None. If specified the 

952 key is not required. Can be a full dot-separated path to a component. 

953 """ 

954 

955 requiredKeys: ClassVar[Sequence[str]] = () 

956 """Keys that are required to be specified in the configuration. 

957 """ 

958 

959 defaultConfigFile: ClassVar[Optional[str]] = None 

960 """Name of the file containing defaults for this config class. 

961 """ 

962 

963 def __init__(self, other=None, validate=True, mergeDefaults=True, searchPaths=None): 

964 

965 # Create a blank object to receive the defaults 

966 # Once we have the defaults we then update with the external values 

967 super().__init__() 

968 

969 # Create a standard Config rather than subset 

970 externalConfig = Config(other) 

971 

972 # Select the part we need from it 

973 # To simplify the use of !include we also check for the existence of 

974 # component.component (since the included files can themselves 

975 # include the component name) 

976 if self.component is not None: 

977 doubled = (self.component, self.component) 

978 # Must check for double depth first 

979 if doubled in externalConfig: 

980 externalConfig = externalConfig[doubled] 

981 elif self.component in externalConfig: 

982 externalConfig._data = externalConfig._data[self.component] 

983 

984 # Default files read to create this configuration 

985 self.filesRead = [] 

986 

987 # Assume we are not looking up child configurations 

988 containerKey = None 

989 

990 # Sometimes we do not want to merge with defaults. 

991 if mergeDefaults: 

992 

993 # Supplied search paths have highest priority 

994 fullSearchPath = [] 

995 if searchPaths: 

996 fullSearchPath.extend(searchPaths) 

997 

998 # Read default paths from enviroment 

999 fullSearchPath.extend(self.defaultSearchPaths()) 

1000 

1001 # There are two places to find defaults for this particular config 

1002 # - The "defaultConfigFile" defined in the subclass 

1003 # - The class specified in the "cls" element in the config. 

1004 # Read cls after merging in case it changes. 

1005 if self.defaultConfigFile is not None: 

1006 self._updateWithConfigsFromPath(fullSearchPath, self.defaultConfigFile) 

1007 

1008 # Can have a class specification in the external config (priority) 

1009 # or from the defaults. 

1010 pytype = None 

1011 if "cls" in externalConfig: 

1012 pytype = externalConfig["cls"] 

1013 elif "cls" in self: 

1014 pytype = self["cls"] 

1015 

1016 if pytype is not None: 

1017 try: 

1018 cls = doImport(pytype) 

1019 except ImportError as e: 

1020 raise RuntimeError(f"Failed to import cls '{pytype}' for config {type(self)}") from e 

1021 defaultsFile = cls.defaultConfigFile 

1022 if defaultsFile is not None: 

1023 self._updateWithConfigsFromPath(fullSearchPath, defaultsFile) 

1024 

1025 # Get the container key in case we need it 

1026 try: 

1027 containerKey = cls.containerKey 

1028 except AttributeError: 

1029 pass 

1030 

1031 # Now update this object with the external values so that the external 

1032 # values always override the defaults 

1033 self.update(externalConfig) 

1034 

1035 # If this configuration has child configurations of the same 

1036 # config class, we need to expand those defaults as well. 

1037 

1038 if mergeDefaults and containerKey is not None and containerKey in self: 

1039 for idx, subConfig in enumerate(self[containerKey]): 

1040 self[containerKey, idx] = type(self)(other=subConfig, validate=validate, 

1041 mergeDefaults=mergeDefaults, 

1042 searchPaths=searchPaths) 

1043 

1044 if validate: 

1045 self.validate() 

1046 

1047 @classmethod 

1048 def defaultSearchPaths(cls): 

1049 """Read the environment to determine search paths to use for global 

1050 defaults. 

1051 

1052 Global defaults, at lowest priority, are found in the ``config`` 

1053 directory of the butler source tree. Additional defaults can be 

1054 defined using the environment variable ``$DAF_BUTLER_CONFIG_PATHS`` 

1055 which is a PATH-like variable where paths at the front of the list 

1056 have priority over those later. 

1057 

1058 Returns 

1059 ------- 

1060 paths : `list` 

1061 Returns a list of paths to search. The returned order is in 

1062 priority with the highest priority paths first. The butler config 

1063 configuration resources will not be included here but will 

1064 always be searched last. 

1065 

1066 Notes 

1067 ----- 

1068 The environment variable is split on the standard ``:`` path separator. 

1069 This currently makes it incompatible with usage of URIs. 

1070 """ 

1071 # We can pick up defaults from multiple search paths 

1072 # We fill defaults by using the butler config path and then 

1073 # the config path environment variable in reverse order. 

1074 defaultsPaths = [] 

1075 

1076 if CONFIG_PATH in os.environ: 

1077 externalPaths = os.environ[CONFIG_PATH].split(os.pathsep) 

1078 defaultsPaths.extend(externalPaths) 

1079 

1080 # Add the package defaults as a resource 

1081 defaultsPaths.append(ButlerURI(f"resource://{cls.resourcesPackage}/configs", 

1082 forceDirectory=True)) 

1083 return defaultsPaths 

1084 

1085 def _updateWithConfigsFromPath(self, searchPaths, configFile): 

1086 """Search the supplied paths, merging the configuration values 

1087 

1088 The values read will override values currently stored in the object. 

1089 Every file found in the path will be read, such that the earlier 

1090 path entries have higher priority. 

1091 

1092 Parameters 

1093 ---------- 

1094 searchPaths : `list` of `ButlerURI`, `str` 

1095 Paths to search for the supplied configFile. This path 

1096 is the priority order, such that files read from the 

1097 first path entry will be selected over those read from 

1098 a later path. Can contain `str` referring to the local file 

1099 system or a URI string. 

1100 configFile : `ButlerURI` 

1101 File to locate in path. If absolute path it will be read 

1102 directly and the search path will not be used. Can be a URI 

1103 to an explicit resource (which will ignore the search path) 

1104 which is assumed to exist. 

1105 """ 

1106 uri = ButlerURI(configFile) 

1107 if uri.isabs() and uri.exists(): 

1108 # Assume this resource exists 

1109 self._updateWithOtherConfigFile(configFile) 

1110 self.filesRead.append(configFile) 

1111 else: 

1112 # Reverse order so that high priority entries 

1113 # update the object last. 

1114 for pathDir in reversed(searchPaths): 

1115 if isinstance(pathDir, (str, ButlerURI)): 

1116 pathDir = ButlerURI(pathDir, forceDirectory=True) 

1117 file = pathDir.join(configFile) 

1118 if file.exists(): 

1119 self.filesRead.append(file) 

1120 self._updateWithOtherConfigFile(file) 

1121 else: 

1122 raise ValueError(f"Unexpected search path type encountered: {pathDir!r}") 

1123 

1124 def _updateWithOtherConfigFile(self, file): 

1125 """Read in some defaults and update. 

1126 

1127 Update the configuration by reading the supplied file as a config 

1128 of this class, and merging such that these values override the 

1129 current values. Contents of the external config are not validated. 

1130 

1131 Parameters 

1132 ---------- 

1133 file : `Config`, `str`, `ButlerURI`, or `dict` 

1134 Entity that can be converted to a `ConfigSubset`. 

1135 """ 

1136 # Use this class to read the defaults so that subsetting can happen 

1137 # correctly. 

1138 externalConfig = type(self)(file, validate=False, mergeDefaults=False) 

1139 self.update(externalConfig) 

1140 

1141 def validate(self): 

1142 """Check that mandatory keys are present in this configuration. 

1143 

1144 Ignored if ``requiredKeys`` is empty.""" 

1145 # Validation 

1146 missing = [k for k in self.requiredKeys if k not in self._data] 

1147 if missing: 

1148 raise KeyError(f"Mandatory keys ({missing}) missing from supplied configuration for {type(self)}")