Coverage for python/lsst/daf/butler/core/config.py : 43%

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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"""Configuration control."""
26__all__ = ("Config", "ConfigSubset")
28import collections
29import copy
30import json
31import logging
32import pprint
33import os
34import yaml
35import sys
36from yaml.representer import Representer
37import io
38from typing import Sequence, Optional, ClassVar, IO, Union
40from lsst.utils import doImport
41from ._butlerUri import ButlerURI
43yaml.add_representer(collections.defaultdict, Representer.represent_dict)
46# Config module logger
47log = logging.getLogger(__name__)
49# PATH-like environment variable to use for defaults.
50CONFIG_PATH = "DAF_BUTLER_CONFIG_PATH"
52try:
53 yamlLoader = yaml.CSafeLoader
54except AttributeError:
55 # Not all installations have the C library
56 yamlLoader = yaml.SafeLoader
59class Loader(yamlLoader):
60 """YAML Loader that supports file include directives
62 Uses ``!include`` directive in a YAML file to point to another
63 YAML file to be included. The path in the include directive is relative
64 to the file containing that directive.
66 storageClasses: !include storageClasses.yaml
68 Examples
69 --------
70 >>> with open("document.yaml", "r") as f:
71 data = yaml.load(f, Loader=Loader)
73 Notes
74 -----
75 See https://davidchall.github.io/yaml-includes.html
76 """
78 def __init__(self, stream):
79 super().__init__(stream)
80 # if this is a string and not a stream we may well lack a name
81 try:
82 self._root = ButlerURI(stream.name)
83 except AttributeError:
84 # No choice but to assume a local filesystem
85 self._root = ButlerURI("no-file.yaml")
86 Loader.add_constructor("!include", Loader.include)
88 def include(self, node):
89 if isinstance(node, yaml.ScalarNode):
90 return self.extractFile(self.construct_scalar(node))
92 elif isinstance(node, yaml.SequenceNode):
93 result = []
94 for filename in self.construct_sequence(node):
95 result.append(self.extractFile(filename))
96 return result
98 elif isinstance(node, yaml.MappingNode):
99 result = {}
100 for k, v in self.construct_mapping(node).items():
101 result[k] = self.extractFile(v)
102 return result
104 else:
105 print("Error:: unrecognised node type in !include statement", file=sys.stderr)
106 raise yaml.constructor.ConstructorError
108 def extractFile(self, filename):
109 # It is possible for the !include to point to an explicit URI
110 # instead of a relative URI, therefore we first see if it is
111 # scheme-less or not. If it has a scheme we use it directly
112 # if it is scheme-less we use it relative to the file root.
113 requesteduri = ButlerURI(filename, forceAbsolute=False)
115 if requesteduri.scheme:
116 fileuri = requesteduri
117 else:
118 fileuri = copy.copy(self._root)
119 fileuri.updateFile(filename)
121 log.debug("Opening YAML file via !include: %s", fileuri)
123 # Read all the data from the resource
124 data = fileuri.read()
126 # Store the bytes into a BytesIO so we can attach a .name
127 stream = io.BytesIO(data)
128 stream.name = fileuri.geturl()
129 return yaml.load(stream, Loader)
132class Config(collections.abc.MutableMapping):
133 r"""Implements a datatype that is used by `Butler` for configuration
134 parameters.
136 It is essentially a `dict` with key/value pairs, including nested dicts
137 (as values). In fact, it can be initialized with a `dict`.
138 This is explained next:
140 Config extends the `dict` api so that hierarchical values may be accessed
141 with delimited notation or as a tuple. If a string is given the delimiter
142 is picked up from the first character in that string. For example,
143 ``foo.getValue(".a.b.c")``, ``foo["a"]["b"]["c"]``, ``foo["a", "b", "c"]``,
144 ``foo[".a.b.c"]``, and ``foo["/a/b/c"]`` all achieve the same outcome.
145 If the first character is alphanumeric, no delimiter will be used.
146 ``foo["a.b.c"]`` will be a single key ``a.b.c`` as will ``foo[":a.b.c"]``.
147 Unicode characters can be used as the delimiter for distinctiveness if
148 required.
150 If a key in the hierarchy starts with a non-alphanumeric character care
151 should be used to ensure that either the tuple interface is used or
152 a distinct delimiter is always given in string form.
154 Finally, the delimiter can be escaped if it is part of a key and also
155 has to be used as a delimiter. For example, ``foo[r".a.b\.c"]`` results in
156 a two element hierarchy of ``a`` and ``b.c``. For hard-coded strings it is
157 always better to use a different delimiter in these cases.
159 Note that adding a multi-level key implicitly creates any nesting levels
160 that do not exist, but removing multi-level keys does not automatically
161 remove empty nesting levels. As a result:
163 >>> c = Config()
164 >>> c[".a.b"] = 1
165 >>> del c[".a.b"]
166 >>> c["a"]
167 Config({'a': {}})
169 Storage formats supported:
171 - yaml: read and write is supported.
172 - json: read and write is supported but no ``!include`` directive.
174 Parameters
175 ----------
176 other : `str` or `Config` or `dict` or `ButlerURI`
177 Other source of configuration, can be:
179 - (`str` or `ButlerURI`) Treated as a URI to a config file. Must end
180 with ".yaml".
181 - (`Config`) Copies the other Config's values into this one.
182 - (`dict`) Copies the values from the dict into this Config.
184 If `None` is provided an empty `Config` will be created.
185 """
187 _D: ClassVar[str] = "→"
188 """Default internal delimiter to use for components in the hierarchy when
189 constructing keys for external use (see `Config.names()`)."""
191 includeKey: ClassVar[str] = "includeConfigs"
192 """Key used to indicate that another config should be included at this
193 part of the hierarchy."""
195 resourcesPackage: str = "lsst.daf.butler"
196 """Package to search for default configuration data. The resources
197 themselves will be within a ``configs`` resource hierarchy."""
199 def __init__(self, other=None):
200 self._data = {}
201 self.configFile = None
203 if other is None:
204 return
206 if isinstance(other, Config):
207 self._data = copy.deepcopy(other._data)
208 self.configFile = other.configFile
209 elif isinstance(other, collections.abc.Mapping):
210 self.update(other)
211 elif isinstance(other, (str, ButlerURI)): 211 ↛ 218line 211 didn't jump to line 218, because the condition on line 211 was never false
212 # if other is a string, assume it is a file path/URI
213 self.__initFromUri(other)
214 self._processExplicitIncludes()
215 else:
216 # if the config specified by other could not be recognized raise
217 # a runtime error.
218 raise RuntimeError(f"A Config could not be loaded from other: {other}")
220 def ppprint(self):
221 """helper function for debugging, prints a config out in a readable
222 way in the debugger.
224 use: pdb> print(myConfigObject.ppprint())
226 Returns
227 -------
228 s : `str`
229 A prettyprint formatted string representing the config
230 """
231 return pprint.pformat(self._data, indent=2, width=1)
233 def __repr__(self):
234 return f"{type(self).__name__}({self._data!r})"
236 def __str__(self):
237 return self.ppprint()
239 def __len__(self):
240 return len(self._data)
242 def __iter__(self):
243 return iter(self._data)
245 def copy(self):
246 return type(self)(self)
248 @classmethod
249 def fromString(cls, string: str, format: str = "yaml") -> Config:
250 """Create a new Config instance from a serialized string.
252 Parameters
253 ----------
254 string : `str`
255 String containing content in specified format
256 format : `str`, optional
257 Format of the supplied string. Can be ``json`` or ``yaml``.
259 Returns
260 -------
261 c : `Config`
262 Newly-constructed Config.
263 """
264 if format == "yaml":
265 new_config = cls().__initFromYaml(string)
266 elif format == "json":
267 new_config = cls().__initFromJson(string)
268 else:
269 raise ValueError(f"Unexpected format of string: {format}")
270 new_config._processExplicitIncludes()
271 return new_config
273 @classmethod
274 def fromYaml(cls, string: str) -> Config:
275 """Create a new Config instance from a YAML string.
277 Parameters
278 ----------
279 string : `str`
280 String containing content in YAML format
282 Returns
283 -------
284 c : `Config`
285 Newly-constructed Config.
286 """
287 return cls.fromString(string, format="yaml")
289 def __initFromUri(self, path: str) -> None:
290 """Load a file from a path or an URI.
292 Parameters
293 ----------
294 path : `str`
295 Path or a URI to a persisted config file.
296 """
297 uri = ButlerURI(path)
298 ext = uri.getExtension()
299 if ext == ".yaml": 299 ↛ 306line 299 didn't jump to line 306, because the condition on line 299 was never false
300 log.debug("Opening YAML config file: %s", uri.geturl())
301 content = uri.read()
302 # Use a stream so we can name it
303 stream = io.BytesIO(content)
304 stream.name = uri.geturl()
305 self.__initFromYaml(stream)
306 elif ext == ".json":
307 log.debug("Opening JSON config file: %s", uri.geturl())
308 content = uri.read()
309 self.__initFromJson(content)
310 else:
311 raise RuntimeError(f"Unhandled config file type: {uri}")
312 self.configFile = uri
314 def __initFromYaml(self, stream):
315 """Loads a YAML config from any readable stream that contains one.
317 Parameters
318 ----------
319 stream: `IO` or `str`
320 Stream to pass to the YAML loader. Accepts anything that
321 `yaml.load` accepts. This can include a string as well as an
322 IO stream.
324 Raises
325 ------
326 yaml.YAMLError
327 If there is an error loading the file.
328 """
329 content = yaml.load(stream, Loader=Loader)
330 if content is None: 330 ↛ 331line 330 didn't jump to line 331, because the condition on line 330 was never true
331 content = {}
332 self._data = content
333 return self
335 def __initFromJson(self, stream):
336 """Loads a JSON config from any readable stream that contains one.
338 Parameters
339 ----------
340 stream: `IO` or `str`
341 Stream to pass to the JSON loader. This can include a string as
342 well as an IO stream.
344 Raises
345 ------
346 TypeError:
347 Raised if there is an error loading the content.
348 """
349 if isinstance(stream, (bytes, str)):
350 content = json.loads(stream)
351 else:
352 content = json.load(stream)
353 if content is None:
354 content = {}
355 self._data = content
356 return self
358 def _processExplicitIncludes(self):
359 """Scan through the configuration searching for the special
360 includeConfigs directive and process the includes."""
362 # Search paths for config files
363 searchPaths = [ButlerURI(os.path.curdir, forceDirectory=True)]
364 if self.configFile is not None: 364 ↛ 372line 364 didn't jump to line 372, because the condition on line 364 was never false
365 if isinstance(self.configFile, ButlerURI): 365 ↛ 368line 365 didn't jump to line 368, because the condition on line 365 was never false
366 configDir = self.configFile.dirname()
367 else:
368 raise RuntimeError(f"Unexpected type for config file: {self.configFile}")
369 searchPaths.append(configDir)
371 # Ensure we know what delimiter to use
372 names = self.nameTuples()
373 for path in names:
374 if path[-1] == self.includeKey: 374 ↛ 376line 374 didn't jump to line 376, because the condition on line 374 was never true
376 log.debug("Processing file include directive at %s", self._D + self._D.join(path))
377 basePath = path[:-1]
379 # Extract the includes and then delete them from the config
380 includes = self[path]
381 del self[path]
383 # Be consistent and convert to a list
384 if not isinstance(includes, list):
385 includes = [includes]
387 # Read each file assuming it is a reference to a file
388 # The file can be relative to config file or cwd
389 # ConfigSubset search paths are not used
390 subConfigs = []
391 for fileName in includes:
392 # Expand any shell variables -- this could be URI
393 fileName = ButlerURI(os.path.expandvars(fileName), forceAbsolute=False)
394 found = None
395 if fileName.isabs():
396 found = fileName
397 else:
398 for dir in searchPaths:
399 if isinstance(dir, ButlerURI):
400 specific = dir.join(fileName.path)
401 # Remote resource check might be expensive
402 if specific.exists():
403 found = specific
404 else:
405 log.warning("Do not understand search path entry '%s' of type %s",
406 dir, type(dir).__name__)
407 if not found:
408 raise RuntimeError(f"Unable to find referenced include file: {fileName}")
410 # Read the referenced Config as a Config
411 subConfigs.append(type(self)(found))
413 # Now we need to merge these sub configs with the current
414 # information that was present in this node in the config
415 # tree with precedence given to the explicit values
416 newConfig = subConfigs.pop(0)
417 for sc in subConfigs:
418 newConfig.update(sc)
420 # Explicit values take precedence
421 if not basePath:
422 # This is an include at the root config
423 newConfig.update(self)
424 # Replace the current config
425 self._data = newConfig._data
426 else:
427 newConfig.update(self[basePath])
428 # And reattach to the base config
429 self[basePath] = newConfig
431 @staticmethod
432 def _splitIntoKeys(key):
433 r"""Split the argument for get/set/in into a hierarchical list.
435 Parameters
436 ----------
437 key : `str` or iterable
438 Argument given to get/set/in. If an iterable is provided it will
439 be converted to a list. If the first character of the string
440 is not an alphanumeric character then it will be used as the
441 delimiter for the purposes of splitting the remainder of the
442 string. If the delimiter is also in one of the keys then it
443 can be escaped using ``\``. There is no default delimiter.
445 Returns
446 -------
447 keys : `list`
448 Hierarchical keys as a `list`.
449 """
450 if isinstance(key, str):
451 if not key[0].isalnum(): 451 ↛ 452line 451 didn't jump to line 452, because the condition on line 451 was never true
452 d = key[0]
453 key = key[1:]
454 else:
455 return [key, ]
456 escaped = f"\\{d}"
457 temp = None
458 if escaped in key:
459 # Complain at the attempt to escape the escape
460 doubled = fr"\{escaped}"
461 if doubled in key:
462 raise ValueError(f"Escaping an escaped delimiter ({doubled} in {key})"
463 " is not yet supported.")
464 # Replace with a character that won't be in the string
465 temp = "\r"
466 if temp in key or d == temp:
467 raise ValueError(f"Can not use character {temp!r} in hierarchical key or as"
468 " delimiter if escaping the delimiter")
469 key = key.replace(escaped, temp)
470 hierarchy = key.split(d)
471 if temp:
472 hierarchy = [h.replace(temp, d) for h in hierarchy]
473 return hierarchy
474 elif isinstance(key, collections.abc.Iterable): 474 ↛ 478line 474 didn't jump to line 478, because the condition on line 474 was never false
475 return list(key)
476 else:
477 # Not sure what this is so try it anyway
478 return [key, ]
480 def _getKeyHierarchy(self, name):
481 """Retrieve the key hierarchy for accessing the Config
483 Parameters
484 ----------
485 name : `str` or `tuple`
486 Delimited string or `tuple` of hierarchical keys.
488 Returns
489 -------
490 hierarchy : `list` of `str`
491 Hierarchy to use as a `list`. If the name is available directly
492 as a key in the Config it will be used regardless of the presence
493 of any nominal delimiter.
494 """
495 if name in self._data:
496 keys = [name, ]
497 else:
498 keys = self._splitIntoKeys(name)
499 return keys
501 def _findInHierarchy(self, keys, create=False):
502 """Look for hierarchy of keys in Config
504 Parameters
505 ----------
506 keys : `list` or `tuple`
507 Keys to search in hierarchy.
508 create : `bool`, optional
509 If `True`, if a part of the hierarchy does not exist, insert an
510 empty `dict` into the hierarchy.
512 Returns
513 -------
514 hierarchy : `list`
515 List of the value corresponding to each key in the supplied
516 hierarchy. Only keys that exist in the hierarchy will have
517 a value.
518 complete : `bool`
519 `True` if the full hierarchy exists and the final element
520 in ``hierarchy`` is the value of relevant value.
521 """
522 d = self._data
524 def checkNextItem(k, d, create):
525 """See if k is in d and if it is return the new child"""
526 nextVal = None
527 isThere = False
528 if d is None: 528 ↛ 530line 528 didn't jump to line 530, because the condition on line 528 was never true
529 # We have gone past the end of the hierarchy
530 pass
531 elif isinstance(d, collections.abc.Sequence): 531 ↛ 536line 531 didn't jump to line 536, because the condition on line 531 was never true
532 # Check sequence first because for lists
533 # __contains__ checks whether value is found in list
534 # not whether the index exists in list. When we traverse
535 # the hierarchy we are interested in the index.
536 try:
537 nextVal = d[int(k)]
538 isThere = True
539 except IndexError:
540 pass
541 except ValueError:
542 isThere = k in d
543 elif k in d:
544 nextVal = d[k]
545 isThere = True
546 elif create: 546 ↛ 547line 546 didn't jump to line 547, because the condition on line 546 was never true
547 d[k] = {}
548 nextVal = d[k]
549 isThere = True
550 return nextVal, isThere
552 hierarchy = []
553 complete = True
554 for k in keys:
555 d, isThere = checkNextItem(k, d, create)
556 if isThere:
557 hierarchy.append(d)
558 else:
559 complete = False
560 break
562 return hierarchy, complete
564 def __getitem__(self, name):
565 # Override the split for the simple case where there is an exact
566 # match. This allows `Config.items()` to work via a simple
567 # __iter__ implementation that returns top level keys of
568 # self._data.
569 keys = self._getKeyHierarchy(name)
571 hierarchy, complete = self._findInHierarchy(keys)
572 if not complete: 572 ↛ 573line 572 didn't jump to line 573, because the condition on line 572 was never true
573 raise KeyError(f"{name} not found")
574 data = hierarchy[-1]
576 if isinstance(data, collections.abc.Mapping):
577 data = Config(data)
578 # Ensure that child configs inherit the parent internal delimiter
579 if self._D != Config._D: 579 ↛ 580line 579 didn't jump to line 580, because the condition on line 579 was never true
580 data._D = self._D
581 return data
583 def __setitem__(self, name, value):
584 keys = self._getKeyHierarchy(name)
585 last = keys.pop()
586 if isinstance(value, Config):
587 value = copy.deepcopy(value._data)
589 hierarchy, complete = self._findInHierarchy(keys, create=True)
590 if hierarchy:
591 data = hierarchy[-1]
592 else:
593 data = self._data
595 try:
596 data[last] = value
597 except TypeError:
598 data[int(last)] = value
600 def __contains__(self, key):
601 keys = self._getKeyHierarchy(key)
602 hierarchy, complete = self._findInHierarchy(keys)
603 return complete
605 def __delitem__(self, key):
606 keys = self._getKeyHierarchy(key)
607 last = keys.pop()
608 hierarchy, complete = self._findInHierarchy(keys)
609 if complete: 609 ↛ 616line 609 didn't jump to line 616, because the condition on line 609 was never false
610 if hierarchy: 610 ↛ 611line 610 didn't jump to line 611, because the condition on line 610 was never true
611 data = hierarchy[-1]
612 else:
613 data = self._data
614 del data[last]
615 else:
616 raise KeyError(f"{key} not found in Config")
618 def update(self, other):
619 """Like dict.update, but will add or modify keys in nested dicts,
620 instead of overwriting the nested dict entirely.
622 For example, for the given code:
623 foo = {"a": {"b": 1}}
624 foo.update({"a": {"c": 2}})
626 Parameters
627 ----------
628 other : `dict` or `Config`
629 Source of configuration:
631 - If foo is a dict, then after the update foo == {"a": {"c": 2}}
632 - But if foo is a Config, then after the update
633 foo == {"a": {"b": 1, "c": 2}}
634 """
635 def doUpdate(d, u):
636 if not isinstance(u, collections.abc.Mapping) or \ 636 ↛ 638line 636 didn't jump to line 638, because the condition on line 636 was never true
637 not isinstance(d, collections.abc.Mapping):
638 raise RuntimeError("Only call update with Mapping, not {}".format(type(d)))
639 for k, v in u.items():
640 if isinstance(v, collections.abc.Mapping):
641 d[k] = doUpdate(d.get(k, {}), v)
642 else:
643 d[k] = v
644 return d
645 doUpdate(self._data, other)
647 def merge(self, other):
648 """Like Config.update, but will add keys & values from other that
649 DO NOT EXIST in self.
651 Keys and values that already exist in self will NOT be overwritten.
653 Parameters
654 ----------
655 other : `dict` or `Config`
656 Source of configuration:
657 """
658 otherCopy = copy.deepcopy(other)
659 otherCopy.update(self)
660 self._data = otherCopy._data
662 def nameTuples(self, topLevelOnly=False):
663 """Get tuples representing the name hierarchies of all keys.
665 The tuples returned from this method are guaranteed to be usable
666 to access items in the configuration object.
668 Parameters
669 ----------
670 topLevelOnly : `bool`, optional
671 If False, the default, a full hierarchy of names is returned.
672 If True, only the top level are returned.
674 Returns
675 -------
676 names : `list` of `tuple` of `str`
677 List of all names present in the `Config` where each element
678 in the list is a `tuple` of strings representing the hierarchy.
679 """
680 if topLevelOnly: 680 ↛ 681line 680 didn't jump to line 681, because the condition on line 680 was never true
681 return list((k,) for k in self)
683 def getKeysAsTuples(d, keys, base):
684 if isinstance(d, collections.abc.Sequence):
685 theseKeys = range(len(d))
686 else:
687 theseKeys = d.keys()
688 for key in theseKeys:
689 val = d[key]
690 levelKey = base + (key,) if base is not None else (key,)
691 keys.append(levelKey)
692 if isinstance(val, (collections.abc.Mapping, collections.abc.Sequence)) \
693 and not isinstance(val, str):
694 getKeysAsTuples(val, keys, levelKey)
695 keys = []
696 getKeysAsTuples(self._data, keys, None)
697 return keys
699 def names(self, topLevelOnly=False, delimiter=None):
700 """Get a delimited name of all the keys in the hierarchy.
702 The values returned from this method are guaranteed to be usable
703 to access items in the configuration object.
705 Parameters
706 ----------
707 topLevelOnly : `bool`, optional
708 If False, the default, a full hierarchy of names is returned.
709 If True, only the top level are returned.
710 delimiter : `str`, optional
711 Delimiter to use when forming the keys. If the delimiter is
712 present in any of the keys, it will be escaped in the returned
713 names. If `None` given a delimiter will be automatically provided.
714 The delimiter can not be alphanumeric.
716 Returns
717 -------
718 names : `list` of `str`
719 List of all names present in the `Config`.
721 Notes
722 -----
723 This is different than the built-in method `dict.keys`, which will
724 return only the first level keys.
726 Raises
727 ------
728 ValueError:
729 The supplied delimiter is alphanumeric.
730 """
731 if topLevelOnly:
732 return list(self.keys())
734 # Get all the tuples of hierarchical keys
735 nameTuples = self.nameTuples()
737 if delimiter is not None and delimiter.isalnum():
738 raise ValueError(f"Supplied delimiter ({delimiter!r}) must not be alphanumeric.")
740 if delimiter is None:
741 # Start with something, and ensure it does not need to be
742 # escaped (it is much easier to understand if not escaped)
743 delimiter = self._D
745 # Form big string for easy check of delimiter clash
746 combined = "".join("".join(str(s) for s in k) for k in nameTuples)
748 # Try a delimiter and keep trying until we get something that
749 # works.
750 ntries = 0
751 while delimiter in combined:
752 log.debug(f"Delimiter '{delimiter}' could not be used. Trying another.")
753 ntries += 1
755 if ntries > 100:
756 raise ValueError(f"Unable to determine a delimiter for Config {self}")
758 # try another one
759 while True:
760 delimiter = chr(ord(delimiter)+1)
761 if not delimiter.isalnum():
762 break
764 log.debug(f"Using delimiter {delimiter!r}")
766 # Form the keys, escaping the delimiter if necessary
767 strings = [delimiter + delimiter.join(str(s).replace(delimiter, f"\\{delimiter}") for s in k)
768 for k in nameTuples]
769 return strings
771 def asArray(self, name):
772 """Get a value as an array.
774 May contain one or more elements.
776 Parameters
777 ----------
778 name : `str`
779 Key to use to retrieve value.
781 Returns
782 -------
783 array : `collections.abc.Sequence`
784 The value corresponding to name, but guaranteed to be returned
785 as a list with at least one element. If the value is a
786 `~collections.abc.Sequence` (and not a `str`) the value itself
787 will be returned, else the value will be the first element.
788 """
789 val = self.get(name)
790 if isinstance(val, str):
791 val = [val]
792 elif not isinstance(val, collections.abc.Sequence):
793 val = [val]
794 return val
796 def __eq__(self, other):
797 if isinstance(other, Config):
798 other = other._data
799 return self._data == other
801 def __ne__(self, other):
802 if isinstance(other, Config):
803 other = other._data
804 return self._data != other
806 #######
807 # i/o #
809 def dump(self, output: Optional[IO] = None, format: str = "yaml") -> Optional[str]:
810 """Writes the config to an output stream.
812 Parameters
813 ----------
814 output : `IO`, optional
815 The stream to use for output. If `None` the serialized content
816 will be returned.
817 format : `str`, optional
818 The format to use for the output. Can be "yaml" or "json".
820 Returns
821 -------
822 serialized : `str` or `None`
823 If a stream was given the stream will be used and the return
824 value will be `None`. If the stream was `None` the
825 serialization will be returned as a string.
826 """
827 if format == "yaml":
828 return yaml.safe_dump(self._data, output, default_flow_style=False)
829 elif format == "json":
830 if output is not None:
831 json.dump(self._data, output, ensure_ascii=False)
832 return
833 else:
834 return json.dumps(self._data, ensure_ascii=False)
835 raise ValueError(f"Unsupported format for Config serialization: {format}")
837 def dumpToUri(self, uri: Union[ButlerURI, str], updateFile: bool = True,
838 defaultFileName: str = "butler.yaml",
839 overwrite: bool = True) -> None:
840 """Writes the config to location pointed to by given URI.
842 Currently supports 's3' and 'file' URI schemes.
844 Parameters
845 ----------
846 uri: `str` or `ButlerURI`
847 URI of location where the Config will be written.
848 updateFile : bool, optional
849 If True and uri does not end on a filename with extension, will
850 append `defaultFileName` to the target uri. True by default.
851 defaultFileName : bool, optional
852 The file name that will be appended to target uri if updateFile is
853 True and uri does not end on a file with an extension.
854 overwrite : bool, optional
855 If True the configuration will be written even if it already
856 exists at that location.
857 """
858 # Make local copy of URI or create new one
859 uri = ButlerURI(uri)
861 if updateFile and not uri.getExtension():
862 uri.updateFile(defaultFileName)
864 # Try to work out the format from the extension
865 ext = uri.getExtension()
866 format = ext[1:].lower()
868 uri.write(self.dump(format=format).encode(), overwrite=overwrite)
869 self.configFile = uri
871 @staticmethod
872 def updateParameters(configType, config, full, toUpdate=None, toCopy=None, overwrite=True):
873 """Generic helper function for updating specific config parameters.
875 Allows for named parameters to be set to new values in bulk, and
876 for other values to be set by copying from a reference config.
878 Assumes that the supplied config is compatible with ``configType``
879 and will attach the updated values to the supplied config by
880 looking for the related component key. It is assumed that
881 ``config`` and ``full`` are from the same part of the
882 configuration hierarchy.
884 Parameters
885 ----------
886 configType : `ConfigSubset`
887 Config type to use to extract relevant items from ``config``.
888 config : `Config`
889 A `Config` to update. Only the subset understood by
890 the supplied `ConfigSubset` will be modified. Default values
891 will not be inserted and the content will not be validated
892 since mandatory keys are allowed to be missing until
893 populated later by merging.
894 full : `Config`
895 A complete config with all defaults expanded that can be
896 converted to a ``configType``. Read-only and will not be
897 modified by this method. Values are read from here if
898 ``toCopy`` is defined.
900 Repository-specific options that should not be obtained
901 from defaults when Butler instances are constructed
902 should be copied from ``full`` to ``config``.
903 toUpdate : `dict`, optional
904 A `dict` defining the keys to update and the new value to use.
905 The keys and values can be any supported by `Config`
906 assignment.
907 toCopy : `tuple`, optional
908 `tuple` of keys whose values should be copied from ``full``
909 into ``config``.
910 overwrite : `bool`, optional
911 If `False`, do not modify a value in ``config`` if the key
912 already exists. Default is always to overwrite.
914 Raises
915 ------
916 ValueError
917 Neither ``toUpdate`` not ``toCopy`` were defined.
918 """
919 if toUpdate is None and toCopy is None:
920 raise ValueError("One of toUpdate or toCopy parameters must be set.")
922 # If this is a parent configuration then we need to ensure that
923 # the supplied config has the relevant component key in it.
924 # If this is a parent configuration we add in the stub entry
925 # so that the ConfigSubset constructor will do the right thing.
926 # We check full for this since that is guaranteed to be complete.
927 if configType.component in full and configType.component not in config:
928 config[configType.component] = {}
930 # Extract the part of the config we wish to update
931 localConfig = configType(config, mergeDefaults=False, validate=False)
933 if toUpdate:
934 for key, value in toUpdate.items():
935 if key in localConfig and not overwrite:
936 log.debug("Not overriding key '%s' with value '%s' in config %s",
937 key, value, localConfig.__class__.__name__)
938 else:
939 localConfig[key] = value
941 if toCopy:
942 localFullConfig = configType(full, mergeDefaults=False)
943 for key in toCopy:
944 if key in localConfig and not overwrite:
945 log.debug("Not overriding key '%s' from defaults in config %s",
946 key, localConfig.__class__.__name__)
947 else:
948 localConfig[key] = localFullConfig[key]
950 # Reattach to parent if this is a child config
951 if configType.component in config:
952 config[configType.component] = localConfig
953 else:
954 config.update(localConfig)
956 def toDict(self):
957 """Convert a `Config` to a standalone hierarchical `dict`.
959 Returns
960 -------
961 d : `dict`
962 The standalone hierarchical `dict` with any `Config` classes
963 in the hierarchy converted to `dict`.
965 Notes
966 -----
967 This can be useful when passing a Config to some code that
968 expects native Python types.
969 """
970 output = copy.deepcopy(self._data)
971 for k, v in output.items():
972 if isinstance(v, Config):
973 v = v.toDict()
974 output[k] = v
975 return output
978class ConfigSubset(Config):
979 """Config representing a subset of a more general configuration.
981 Subclasses define their own component and when given a configuration
982 that includes that component, the resulting configuration only includes
983 the subset. For example, your config might contain ``dimensions`` if it's
984 part of a global config and that subset will be stored. If ``dimensions``
985 can not be found it is assumed that the entire contents of the
986 configuration should be used.
988 Default values are read from the environment or supplied search paths
989 using the default configuration file name specified in the subclass.
990 This allows a configuration class to be instantiated without any
991 additional arguments.
993 Additional validation can be specified to check for keys that are mandatory
994 in the configuration.
996 Parameters
997 ----------
998 other : `Config` or `str` or `dict`
999 Argument specifying the configuration information as understood
1000 by `Config`
1001 validate : `bool`, optional
1002 If `True` required keys will be checked to ensure configuration
1003 consistency.
1004 mergeDefaults : `bool`, optional
1005 If `True` defaults will be read and the supplied config will
1006 be combined with the defaults, with the supplied valiues taking
1007 precedence.
1008 searchPaths : `list` or `tuple`, optional
1009 Explicit additional paths to search for defaults. They should
1010 be supplied in priority order. These paths have higher priority
1011 than those read from the environment in
1012 `ConfigSubset.defaultSearchPaths()`. Paths can be `str` referring to
1013 the local file system or URIs, `ButlerURI`.
1014 """
1016 component: ClassVar[Optional[str]] = None
1017 """Component to use from supplied config. Can be None. If specified the
1018 key is not required. Can be a full dot-separated path to a component.
1019 """
1021 requiredKeys: ClassVar[Sequence[str]] = ()
1022 """Keys that are required to be specified in the configuration.
1023 """
1025 defaultConfigFile: ClassVar[Optional[str]] = None
1026 """Name of the file containing defaults for this config class.
1027 """
1029 def __init__(self, other=None, validate=True, mergeDefaults=True, searchPaths=None):
1031 # Create a blank object to receive the defaults
1032 # Once we have the defaults we then update with the external values
1033 super().__init__()
1035 # Create a standard Config rather than subset
1036 externalConfig = Config(other)
1038 # Select the part we need from it
1039 # To simplify the use of !include we also check for the existence of
1040 # component.component (since the included files can themselves
1041 # include the component name)
1042 if self.component is not None: 1042 ↛ 1051line 1042 didn't jump to line 1051, because the condition on line 1042 was never false
1043 doubled = (self.component, self.component)
1044 # Must check for double depth first
1045 if doubled in externalConfig: 1045 ↛ 1046line 1045 didn't jump to line 1046, because the condition on line 1045 was never true
1046 externalConfig = externalConfig[doubled]
1047 elif self.component in externalConfig:
1048 externalConfig._data = externalConfig._data[self.component]
1050 # Default files read to create this configuration
1051 self.filesRead = []
1053 # Assume we are not looking up child configurations
1054 containerKey = None
1056 # Sometimes we do not want to merge with defaults.
1057 if mergeDefaults:
1059 # Supplied search paths have highest priority
1060 fullSearchPath = []
1061 if searchPaths: 1061 ↛ 1062line 1061 didn't jump to line 1062, because the condition on line 1061 was never true
1062 fullSearchPath.extend(searchPaths)
1064 # Read default paths from enviroment
1065 fullSearchPath.extend(self.defaultSearchPaths())
1067 # There are two places to find defaults for this particular config
1068 # - The "defaultConfigFile" defined in the subclass
1069 # - The class specified in the "cls" element in the config.
1070 # Read cls after merging in case it changes.
1071 if self.defaultConfigFile is not None: 1071 ↛ 1076line 1071 didn't jump to line 1076, because the condition on line 1071 was never false
1072 self._updateWithConfigsFromPath(fullSearchPath, self.defaultConfigFile)
1074 # Can have a class specification in the external config (priority)
1075 # or from the defaults.
1076 pytype = None
1077 if "cls" in externalConfig: 1077 ↛ 1078line 1077 didn't jump to line 1078, because the condition on line 1077 was never true
1078 pytype = externalConfig["cls"]
1079 elif "cls" in self: 1079 ↛ 1080line 1079 didn't jump to line 1080, because the condition on line 1079 was never true
1080 pytype = self["cls"]
1082 if pytype is not None: 1082 ↛ 1083line 1082 didn't jump to line 1083, because the condition on line 1082 was never true
1083 try:
1084 cls = doImport(pytype)
1085 except ImportError as e:
1086 raise RuntimeError(f"Failed to import cls '{pytype}' for config {type(self)}") from e
1087 defaultsFile = cls.defaultConfigFile
1088 if defaultsFile is not None:
1089 self._updateWithConfigsFromPath(fullSearchPath, defaultsFile)
1091 # Get the container key in case we need it
1092 try:
1093 containerKey = cls.containerKey
1094 except AttributeError:
1095 pass
1097 # Now update this object with the external values so that the external
1098 # values always override the defaults
1099 self.update(externalConfig)
1101 # If this configuration has child configurations of the same
1102 # config class, we need to expand those defaults as well.
1104 if mergeDefaults and containerKey is not None and containerKey in self: 1104 ↛ 1105line 1104 didn't jump to line 1105, because the condition on line 1104 was never true
1105 for idx, subConfig in enumerate(self[containerKey]):
1106 self[containerKey, idx] = type(self)(other=subConfig, validate=validate,
1107 mergeDefaults=mergeDefaults,
1108 searchPaths=searchPaths)
1110 if validate:
1111 self.validate()
1113 @classmethod
1114 def defaultSearchPaths(cls):
1115 """Read the environment to determine search paths to use for global
1116 defaults.
1118 Global defaults, at lowest priority, are found in the ``config``
1119 directory of the butler source tree. Additional defaults can be
1120 defined using the environment variable ``$DAF_BUTLER_CONFIG_PATHS``
1121 which is a PATH-like variable where paths at the front of the list
1122 have priority over those later.
1124 Returns
1125 -------
1126 paths : `list`
1127 Returns a list of paths to search. The returned order is in
1128 priority with the highest priority paths first. The butler config
1129 configuration resources will not be included here but will
1130 always be searched last.
1132 Notes
1133 -----
1134 The environment variable is split on the standard ``:`` path separator.
1135 This currently makes it incompatible with usage of URIs.
1136 """
1137 # We can pick up defaults from multiple search paths
1138 # We fill defaults by using the butler config path and then
1139 # the config path environment variable in reverse order.
1140 defaultsPaths = []
1142 if CONFIG_PATH in os.environ: 1142 ↛ 1143line 1142 didn't jump to line 1143, because the condition on line 1142 was never true
1143 externalPaths = os.environ[CONFIG_PATH].split(os.pathsep)
1144 defaultsPaths.extend(externalPaths)
1146 # Add the package defaults as a resource
1147 defaultsPaths.append(ButlerURI(f"resource://{cls.resourcesPackage}/configs",
1148 forceDirectory=True))
1149 return defaultsPaths
1151 def _updateWithConfigsFromPath(self, searchPaths, configFile):
1152 """Search the supplied paths, merging the configuration values
1154 The values read will override values currently stored in the object.
1155 Every file found in the path will be read, such that the earlier
1156 path entries have higher priority.
1158 Parameters
1159 ----------
1160 searchPaths : `list` of `ButlerURI`, `str`
1161 Paths to search for the supplied configFile. This path
1162 is the priority order, such that files read from the
1163 first path entry will be selected over those read from
1164 a later path. Can contain `str` referring to the local file
1165 system or a URI string.
1166 configFile : `ButlerURI`
1167 File to locate in path. If absolute path it will be read
1168 directly and the search path will not be used. Can be a URI
1169 to an explicit resource (which will ignore the search path)
1170 which is assumed to exist.
1171 """
1172 uri = ButlerURI(configFile)
1173 if uri.isabs() and uri.exists(): 1173 ↛ 1175line 1173 didn't jump to line 1175, because the condition on line 1173 was never true
1174 # Assume this resource exists
1175 self._updateWithOtherConfigFile(configFile)
1176 self.filesRead.append(configFile)
1177 else:
1178 # Reverse order so that high priority entries
1179 # update the object last.
1180 for pathDir in reversed(searchPaths):
1181 if isinstance(pathDir, (str, ButlerURI)): 1181 ↛ 1188line 1181 didn't jump to line 1188, because the condition on line 1181 was never false
1182 pathDir = ButlerURI(pathDir, forceDirectory=True)
1183 file = pathDir.join(configFile)
1184 if file.exists(): 1184 ↛ 1180line 1184 didn't jump to line 1180, because the condition on line 1184 was never false
1185 self.filesRead.append(file)
1186 self._updateWithOtherConfigFile(file)
1187 else:
1188 raise ValueError(f"Unexpected search path type encountered: {pathDir!r}")
1190 def _updateWithOtherConfigFile(self, file):
1191 """Read in some defaults and update.
1193 Update the configuration by reading the supplied file as a config
1194 of this class, and merging such that these values override the
1195 current values. Contents of the external config are not validated.
1197 Parameters
1198 ----------
1199 file : `Config`, `str`, `ButlerURI`, or `dict`
1200 Entity that can be converted to a `ConfigSubset`.
1201 """
1202 # Use this class to read the defaults so that subsetting can happen
1203 # correctly.
1204 externalConfig = type(self)(file, validate=False, mergeDefaults=False)
1205 self.update(externalConfig)
1207 def validate(self):
1208 """Check that mandatory keys are present in this configuration.
1210 Ignored if ``requiredKeys`` is empty."""
1211 # Validation
1212 missing = [k for k in self.requiredKeys if k not in self._data]
1213 if missing: 1213 ↛ 1214line 1213 didn't jump to line 1214, because the condition on line 1213 was never true
1214 raise KeyError(f"Mandatory keys ({missing}) missing from supplied configuration for {type(self)}")