Coverage for python/lsst/daf/butler/core/_butlerUri/_butlerUri.py : 52%

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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
24import contextlib
25import urllib.parse
26import posixpath
27import copy
28import logging
29import re
31from pathlib import Path, PurePath, PurePosixPath
33__all__ = ('ButlerURI',)
35from typing import (
36 TYPE_CHECKING,
37 Any,
38 Iterable,
39 Iterator,
40 List,
41 Optional,
42 Tuple,
43 Type,
44 Union,
45)
47from .utils import NoTransaction
49if TYPE_CHECKING: 49 ↛ 50line 49 didn't jump to line 50, because the condition on line 49 was never true
50 from ..datastore import DatastoreTransaction
53log = logging.getLogger(__name__)
55# Regex for looking for URI escapes
56ESCAPES_RE = re.compile(r"%[A-F0-9]{2}")
58# Precomputed escaped hash
59ESCAPED_HASH = urllib.parse.quote("#")
62class ButlerURI:
63 """Convenience wrapper around URI parsers.
65 Provides access to URI components and can convert file
66 paths into absolute path URIs. Scheme-less URIs are treated as if
67 they are local file system paths and are converted to absolute URIs.
69 A specialist subclass is created for each supported URI scheme.
71 Parameters
72 ----------
73 uri : `str` or `urllib.parse.ParseResult`
74 URI in string form. Can be scheme-less if referring to a local
75 filesystem path.
76 root : `str` or `ButlerURI`, optional
77 When fixing up a relative path in a ``file`` scheme or if scheme-less,
78 use this as the root. Must be absolute. If `None` the current
79 working directory will be used. Can be a file URI.
80 forceAbsolute : `bool`, optional
81 If `True`, scheme-less relative URI will be converted to an absolute
82 path using a ``file`` scheme. If `False` scheme-less URI will remain
83 scheme-less and will not be updated to ``file`` or absolute path.
84 forceDirectory: `bool`, optional
85 If `True` forces the URI to end with a separator, otherwise given URI
86 is interpreted as is.
87 isTemporary : `bool`, optional
88 If `True` indicates that this URI points to a temporary resource.
89 """
91 _pathLib: Type[PurePath] = PurePosixPath
92 """Path library to use for this scheme."""
94 _pathModule = posixpath
95 """Path module to use for this scheme."""
97 transferModes: Tuple[str, ...] = ("copy", "auto", "move")
98 """Transfer modes supported by this implementation.
100 Move is special in that it is generally a copy followed by an unlink.
101 Whether that unlink works depends critically on whether the source URI
102 implements unlink. If it does not the move will be reported as a failure.
103 """
105 transferDefault: str = "copy"
106 """Default mode to use for transferring if ``auto`` is specified."""
108 quotePaths = True
109 """True if path-like elements modifying a URI should be quoted.
111 All non-schemeless URIs have to internally use quoted paths. Therefore
112 if a new file name is given (e.g. to updatedFile or join) a decision must
113 be made whether to quote it to be consistent.
114 """
116 isLocal = False
117 """If `True` this URI refers to a local file."""
119 # This is not an ABC with abstract methods because the __new__ being
120 # a factory confuses mypy such that it assumes that every constructor
121 # returns a ButlerURI and then determines that all the abstract methods
122 # are still abstract. If they are not marked abstract but just raise
123 # mypy is fine with it.
125 # mypy is confused without these
126 _uri: urllib.parse.ParseResult
127 isTemporary: bool
128 dirLike: bool
130 def __new__(cls, uri: Union[str, urllib.parse.ParseResult, ButlerURI, Path],
131 root: Optional[Union[str, ButlerURI]] = None, forceAbsolute: bool = True,
132 forceDirectory: bool = False, isTemporary: bool = False) -> ButlerURI:
133 """Create and return new specialist ButlerURI subclass."""
134 parsed: urllib.parse.ParseResult
135 dirLike: bool = False
136 subclass: Optional[Type[ButlerURI]] = None
138 if isinstance(uri, Path): 138 ↛ 139line 138 didn't jump to line 139, because the condition on line 138 was never true
139 uri = str(uri)
141 # Record if we need to post process the URI components
142 # or if the instance is already fully configured
143 if isinstance(uri, str):
144 # Since local file names can have special characters in them
145 # we need to quote them for the parser but we can unquote
146 # later. Assume that all other URI schemes are quoted.
147 # Since sometimes people write file:/a/b and not file:///a/b
148 # we should not quote in the explicit case of file:
149 if "://" not in uri and not uri.startswith("file:"):
150 if ESCAPES_RE.search(uri): 150 ↛ 151line 150 didn't jump to line 151, because the condition on line 150 was never true
151 log.warning("Possible double encoding of %s", uri)
152 else:
153 uri = urllib.parse.quote(uri)
154 # Special case hash since we must support fragments
155 # even in schemeless URIs -- although try to only replace
156 # them in file part and not directory part
157 if ESCAPED_HASH in uri: 157 ↛ 158line 157 didn't jump to line 158, because the condition on line 157 was never true
158 dirpos = uri.rfind("/")
159 # Do replacement after this /
160 uri = uri[:dirpos+1] + uri[dirpos+1:].replace(ESCAPED_HASH, "#")
162 parsed = urllib.parse.urlparse(uri)
163 elif isinstance(uri, urllib.parse.ParseResult):
164 parsed = copy.copy(uri)
165 # If we are being instantiated with a subclass, rather than
166 # ButlerURI, ensure that that subclass is used directly.
167 # This could lead to inconsistencies if this constructor
168 # is used externally outside of the ButlerURI.replace() method.
169 # ButlerS3URI(urllib.parse.urlparse("file://a/b.txt"))
170 # will be a problem.
171 # This is needed to prevent a schemeless absolute URI become
172 # a file URI unexpectedly when calling updatedFile or
173 # updatedExtension
174 if cls is not ButlerURI:
175 parsed, dirLike = cls._fixDirectorySep(parsed, forceDirectory)
176 subclass = cls
178 elif isinstance(uri, ButlerURI): 178 ↛ 183line 178 didn't jump to line 183, because the condition on line 178 was never false
179 # Since ButlerURI is immutable we can return the argument
180 # unchanged.
181 return uri
182 else:
183 raise ValueError("Supplied URI must be string, Path, "
184 f"ButlerURI, or ParseResult but got '{uri!r}'")
186 if subclass is None:
187 # Work out the subclass from the URI scheme
188 if not parsed.scheme:
189 from .schemeless import ButlerSchemelessURI
190 subclass = ButlerSchemelessURI
191 elif parsed.scheme == "file": 191 ↛ 192line 191 didn't jump to line 192, because the condition on line 191 was never true
192 from .file import ButlerFileURI
193 subclass = ButlerFileURI
194 elif parsed.scheme == "s3": 194 ↛ 195line 194 didn't jump to line 195, because the condition on line 194 was never true
195 from .s3 import ButlerS3URI
196 subclass = ButlerS3URI
197 elif parsed.scheme.startswith("http"): 197 ↛ 198line 197 didn't jump to line 198, because the condition on line 197 was never true
198 from .http import ButlerHttpURI
199 subclass = ButlerHttpURI
200 elif parsed.scheme == "resource": 200 ↛ 204line 200 didn't jump to line 204, because the condition on line 200 was never false
201 # Rules for scheme names disallow pkg_resource
202 from .packageresource import ButlerPackageResourceURI
203 subclass = ButlerPackageResourceURI
204 elif parsed.scheme == "mem":
205 # in-memory datastore object
206 from .mem import ButlerInMemoryURI
207 subclass = ButlerInMemoryURI
208 else:
209 raise NotImplementedError(f"No URI support for scheme: '{parsed.scheme}'"
210 " in {parsed.geturl()}")
212 parsed, dirLike = subclass._fixupPathUri(parsed, root=root,
213 forceAbsolute=forceAbsolute,
214 forceDirectory=forceDirectory)
216 # It is possible for the class to change from schemeless
217 # to file so handle that
218 if parsed.scheme == "file": 218 ↛ 219line 218 didn't jump to line 219, because the condition on line 218 was never true
219 from .file import ButlerFileURI
220 subclass = ButlerFileURI
222 # Now create an instance of the correct subclass and set the
223 # attributes directly
224 self = object.__new__(subclass)
225 self._uri = parsed
226 self.dirLike = dirLike
227 self.isTemporary = isTemporary
228 return self
230 @property
231 def scheme(self) -> str:
232 """Return the URI scheme.
234 Notes
235 -----
236 (``://`` is not part of the scheme).
237 """
238 return self._uri.scheme
240 @property
241 def netloc(self) -> str:
242 """Return the URI network location."""
243 return self._uri.netloc
245 @property
246 def path(self) -> str:
247 """Return the path component of the URI."""
248 return self._uri.path
250 @property
251 def unquoted_path(self) -> str:
252 """Return path component of the URI with any URI quoting reversed."""
253 return urllib.parse.unquote(self._uri.path)
255 @property
256 def ospath(self) -> str:
257 """Return the path component of the URI localized to current OS."""
258 raise AttributeError(f"Non-file URI ({self}) has no local OS path.")
260 @property
261 def relativeToPathRoot(self) -> str:
262 """Return path relative to network location.
264 Effectively, this is the path property with posix separator stripped
265 from the left hand side of the path.
267 Always unquotes.
268 """
269 p = self._pathLib(self.path)
270 relToRoot = str(p.relative_to(p.root))
271 if self.dirLike and not relToRoot.endswith("/"): 271 ↛ 272line 271 didn't jump to line 272, because the condition on line 271 was never true
272 relToRoot += "/"
273 return urllib.parse.unquote(relToRoot)
275 @property
276 def is_root(self) -> bool:
277 """Return whether this URI points to the root of the network location.
279 This means that the path components refers to the top level.
280 """
281 relpath = self.relativeToPathRoot
282 if relpath == "./":
283 return True
284 return False
286 @property
287 def fragment(self) -> str:
288 """Return the fragment component of the URI."""
289 return self._uri.fragment
291 @property
292 def params(self) -> str:
293 """Return any parameters included in the URI."""
294 return self._uri.params
296 @property
297 def query(self) -> str:
298 """Return any query strings included in the URI."""
299 return self._uri.query
301 def geturl(self) -> str:
302 """Return the URI in string form.
304 Returns
305 -------
306 url : `str`
307 String form of URI.
308 """
309 return self._uri.geturl()
311 def root_uri(self) -> ButlerURI:
312 """Return the base root URI.
314 Returns
315 -------
316 uri : `ButlerURI`
317 root URI.
318 """
319 return self.replace(path="", forceDirectory=True)
321 def split(self) -> Tuple[ButlerURI, str]:
322 """Split URI into head and tail.
324 Returns
325 -------
326 head: `ButlerURI`
327 Everything leading up to tail, expanded and normalized as per
328 ButlerURI rules.
329 tail : `str`
330 Last `self.path` component. Tail will be empty if path ends on a
331 separator. Tail will never contain separators. It will be
332 unquoted.
334 Notes
335 -----
336 Equivalent to `os.path.split()` where head preserves the URI
337 components.
338 """
339 head, tail = self._pathModule.split(self.path)
340 headuri = self._uri._replace(path=head)
342 # The file part should never include quoted metacharacters
343 tail = urllib.parse.unquote(tail)
345 # Schemeless is special in that it can be a relative path
346 # We need to ensure that it stays that way. All other URIs will
347 # be absolute already.
348 forceAbsolute = self._pathModule.isabs(self.path)
349 return ButlerURI(headuri, forceDirectory=True, forceAbsolute=forceAbsolute), tail
351 def basename(self) -> str:
352 """Return the base name, last element of path, of the URI.
354 Returns
355 -------
356 tail : `str`
357 Last part of the path attribute. Trail will be empty if path ends
358 on a separator.
360 Notes
361 -----
362 If URI ends on a slash returns an empty string. This is the second
363 element returned by `split()`.
365 Equivalent of `os.path.basename()``.
366 """
367 return self.split()[1]
369 def dirname(self) -> ButlerURI:
370 """Return the directory component of the path as a new `ButlerURI`.
372 Returns
373 -------
374 head : `ButlerURI`
375 Everything except the tail of path attribute, expanded and
376 normalized as per ButlerURI rules.
378 Notes
379 -----
380 Equivalent of `os.path.dirname()`.
381 """
382 return self.split()[0]
384 def parent(self) -> ButlerURI:
385 """Return a `ButlerURI` of the parent directory.
387 Returns
388 -------
389 head : `ButlerURI`
390 Everything except the tail of path attribute, expanded and
391 normalized as per `ButlerURI` rules.
393 Notes
394 -----
395 For a file-like URI this will be the same as calling `dirname()`.
396 """
397 # When self is file-like, return self.dirname()
398 if not self.dirLike:
399 return self.dirname()
400 # When self is dir-like, return its parent directory,
401 # regardless of the presence of a trailing separator
402 originalPath = self._pathLib(self.path)
403 parentPath = originalPath.parent
404 return self.replace(path=str(parentPath), forceDirectory=True)
406 def replace(self, forceDirectory: bool = False, **kwargs: Any) -> ButlerURI:
407 """Return new `ButlerURI` with specified components replaced.
409 Parameters
410 ----------
411 forceDirectory : `bool`
412 Parameter passed to ButlerURI constructor to force this
413 new URI to be dir-like.
414 **kwargs
415 Components of a `urllib.parse.ParseResult` that should be
416 modified for the newly-created `ButlerURI`.
418 Returns
419 -------
420 new : `ButlerURI`
421 New `ButlerURI` object with updated values.
423 Notes
424 -----
425 Does not, for now, allow a change in URI scheme.
426 """
427 # Disallow a change in scheme
428 if "scheme" in kwargs: 428 ↛ 429line 428 didn't jump to line 429, because the condition on line 428 was never true
429 raise ValueError(f"Can not use replace() method to change URI scheme for {self}")
430 return self.__class__(self._uri._replace(**kwargs), forceDirectory=forceDirectory)
432 def updatedFile(self, newfile: str) -> ButlerURI:
433 """Return new URI with an updated final component of the path.
435 Parameters
436 ----------
437 newfile : `str`
438 File name with no path component.
440 Returns
441 -------
442 updated : `ButlerURI`
444 Notes
445 -----
446 Forces the ButlerURI.dirLike attribute to be false. The new file path
447 will be quoted if necessary.
448 """
449 if self.quotePaths:
450 newfile = urllib.parse.quote(newfile)
451 dir, _ = self._pathModule.split(self.path)
452 newpath = self._pathModule.join(dir, newfile)
454 updated = self.replace(path=newpath)
455 updated.dirLike = False
456 return updated
458 def updatedExtension(self, ext: Optional[str]) -> ButlerURI:
459 """Return a new `ButlerURI` with updated file extension.
461 All file extensions are replaced.
463 Parameters
464 ----------
465 ext : `str` or `None`
466 New extension. If an empty string is given any extension will
467 be removed. If `None` is given there will be no change.
469 Returns
470 -------
471 updated : `ButlerURI`
472 URI with the specified extension. Can return itself if
473 no extension was specified.
474 """
475 if ext is None:
476 return self
478 # Get the extension
479 current = self.getExtension()
481 # Nothing to do if the extension already matches
482 if current == ext:
483 return self
485 # Remove the current extension from the path
486 # .fits.gz counts as one extension do not use os.path.splitext
487 path = self.path
488 if current:
489 path = path[:-len(current)]
491 # Ensure that we have a leading "." on file extension (and we do not
492 # try to modify the empty string)
493 if ext and not ext.startswith("."):
494 ext = "." + ext
496 return self.replace(path=path + ext)
498 def getExtension(self) -> str:
499 """Return the file extension(s) associated with this URI path.
501 Returns
502 -------
503 ext : `str`
504 The file extension (including the ``.``). Can be empty string
505 if there is no file extension. Usually returns only the last
506 file extension unless there is a special extension modifier
507 indicating file compression, in which case the combined
508 extension (e.g. ``.fits.gz``) will be returned.
509 """
510 special = {".gz", ".bz2", ".xz", ".fz"}
512 # Get the file part of the path so as not to be confused by
513 # "." in directory names.
514 basename = self.basename()
515 extensions = self._pathLib(basename).suffixes
517 if not extensions: 517 ↛ 518line 517 didn't jump to line 518, because the condition on line 517 was never true
518 return ""
520 ext = extensions.pop()
522 # Multiple extensions, decide whether to include the final two
523 if extensions and ext in special: 523 ↛ 524line 523 didn't jump to line 524, because the condition on line 523 was never true
524 ext = f"{extensions[-1]}{ext}"
526 return ext
528 def join(self, path: Union[str, ButlerURI]) -> ButlerURI:
529 """Return new `ButlerURI` with additional path components.
531 Parameters
532 ----------
533 path : `str`, `ButlerURI`
534 Additional file components to append to the current URI. Assumed
535 to include a file at the end. Will be quoted depending on the
536 associated URI scheme. If the path looks like a URI with a scheme
537 referring to an absolute location, it will be returned
538 directly (matching the behavior of `os.path.join()`). It can
539 also be a `ButlerURI`.
541 Returns
542 -------
543 new : `ButlerURI`
544 New URI with any file at the end replaced with the new path
545 components.
547 Notes
548 -----
549 Schemeless URIs assume local path separator but all other URIs assume
550 POSIX separator if the supplied path has directory structure. It
551 may be this never becomes a problem but datastore templates assume
552 POSIX separator is being used.
554 Currently, if the join path is given as an absolute scheme-less
555 URI it will be returned as an absolute ``file:`` URI even if the
556 URI it is being joined to is non-file.
557 """
558 # If we have a full URI in path we will use it directly
559 # but without forcing to absolute so that we can trap the
560 # expected option of relative path.
561 path_uri = ButlerURI(path, forceAbsolute=False)
562 if path_uri.scheme: 562 ↛ 563line 562 didn't jump to line 563, because the condition on line 562 was never true
563 return path_uri
565 # Force back to string
566 path = path_uri.path
568 new = self.dirname() # By definition a directory URI
570 # new should be asked about quoting, not self, since dirname can
571 # change the URI scheme for schemeless -> file
572 if new.quotePaths: 572 ↛ 575line 572 didn't jump to line 575, because the condition on line 572 was never false
573 path = urllib.parse.quote(path)
575 newpath = self._pathModule.normpath(self._pathModule.join(new.path, path))
577 # normpath can strip trailing / so we force directory if the supplied
578 # path ended with a /
579 return new.replace(path=newpath, forceDirectory=path.endswith(self._pathModule.sep))
581 def relative_to(self, other: ButlerURI) -> Optional[str]:
582 """Return the relative path from this URI to the other URI.
584 Parameters
585 ----------
586 other : `ButlerURI`
587 URI to use to calculate the relative path. Must be a parent
588 of this URI.
590 Returns
591 -------
592 subpath : `str`
593 The sub path of this URI relative to the supplied other URI.
594 Returns `None` if there is no parent child relationship.
595 Scheme and netloc must match.
596 """
597 if self.scheme != other.scheme or self.netloc != other.netloc:
598 return None
600 enclosed_path = self._pathLib(self.relativeToPathRoot)
601 parent_path = other.relativeToPathRoot
602 subpath: Optional[str]
603 try:
604 subpath = str(enclosed_path.relative_to(parent_path))
605 except ValueError:
606 subpath = None
607 else:
608 subpath = urllib.parse.unquote(subpath)
609 return subpath
611 def exists(self) -> bool:
612 """Indicate that the resource is available.
614 Returns
615 -------
616 exists : `bool`
617 `True` if the resource exists.
618 """
619 raise NotImplementedError()
621 def remove(self) -> None:
622 """Remove the resource."""
623 raise NotImplementedError()
625 def isabs(self) -> bool:
626 """Indicate that the resource is fully specified.
628 For non-schemeless URIs this is always true.
630 Returns
631 -------
632 isabs : `bool`
633 `True` in all cases except schemeless URI.
634 """
635 return True
637 def abspath(self) -> ButlerURI:
638 """Return URI using an absolute path.
640 Returns
641 -------
642 abs : `ButlerURI`
643 Absolute URI. For non-schemeless URIs this always returns itself.
644 Schemeless URIs are upgraded to file URIs.
645 """
646 return self
648 def _as_local(self) -> Tuple[str, bool]:
649 """Return the location of the (possibly remote) resource as local file.
651 This is a helper function for `as_local` context manager.
653 Returns
654 -------
655 path : `str`
656 If this is a remote resource, it will be a copy of the resource
657 on the local file system, probably in a temporary directory.
658 For a local resource this should be the actual path to the
659 resource.
660 is_temporary : `bool`
661 Indicates if the local path is a temporary file or not.
662 """
663 raise NotImplementedError()
665 @contextlib.contextmanager
666 def as_local(self) -> Iterator[ButlerURI]:
667 """Return the location of the (possibly remote) resource as local file.
669 Yields
670 ------
671 local : `ButlerURI`
672 If this is a remote resource, it will be a copy of the resource
673 on the local file system, probably in a temporary directory.
674 For a local resource this should be the actual path to the
675 resource.
677 Notes
678 -----
679 The context manager will automatically delete any local temporary
680 file.
682 Examples
683 --------
684 Should be used as a context manager:
686 .. code-block:: py
688 with uri.as_local() as local:
689 ospath = local.ospath
690 """
691 local_src, is_temporary = self._as_local()
692 local_uri = ButlerURI(local_src, isTemporary=is_temporary)
694 try:
695 yield local_uri
696 finally:
697 # The caller might have relocated the temporary file
698 if is_temporary and local_uri.exists():
699 local_uri.remove()
701 def read(self, size: int = -1) -> bytes:
702 """Open the resource and return the contents in bytes.
704 Parameters
705 ----------
706 size : `int`, optional
707 The number of bytes to read. Negative or omitted indicates
708 that all data should be read.
709 """
710 raise NotImplementedError()
712 def write(self, data: bytes, overwrite: bool = True) -> None:
713 """Write the supplied bytes to the new resource.
715 Parameters
716 ----------
717 data : `bytes`
718 The bytes to write to the resource. The entire contents of the
719 resource will be replaced.
720 overwrite : `bool`, optional
721 If `True` the resource will be overwritten if it exists. Otherwise
722 the write will fail.
723 """
724 raise NotImplementedError()
726 def mkdir(self) -> None:
727 """For a dir-like URI, create the directory resource if needed."""
728 raise NotImplementedError()
730 def isdir(self) -> bool:
731 """Return True if this URI looks like a directory, else False."""
732 return self.dirLike
734 def size(self) -> int:
735 """For non-dir-like URI, return the size of the resource.
737 Returns
738 -------
739 sz : `int`
740 The size in bytes of the resource associated with this URI.
741 Returns 0 if dir-like.
742 """
743 raise NotImplementedError()
745 def __str__(self) -> str:
746 """Convert the URI to its native string form."""
747 return self.geturl()
749 def __repr__(self) -> str:
750 """Return string representation suitable for evaluation."""
751 return f'ButlerURI("{self.geturl()}")'
753 def __eq__(self, other: Any) -> bool:
754 """Compare supplied object with this `ButlerURI`."""
755 if not isinstance(other, ButlerURI):
756 return NotImplemented
757 return self.geturl() == other.geturl()
759 def __hash__(self) -> int:
760 """Return hash of this object."""
761 return hash(str(self))
763 def __copy__(self) -> ButlerURI:
764 """Copy constructor.
766 Object is immutable so copy can return itself.
767 """
768 # Implement here because the __new__ method confuses things
769 return self
771 def __deepcopy__(self, memo: Any) -> ButlerURI:
772 """Deepcopy the object.
774 Object is immutable so copy can return itself.
775 """
776 # Implement here because the __new__ method confuses things
777 return self
779 def __getnewargs__(self) -> Tuple:
780 """Support pickling."""
781 return (str(self),)
783 @classmethod
784 def _fixDirectorySep(cls, parsed: urllib.parse.ParseResult,
785 forceDirectory: bool = False) -> Tuple[urllib.parse.ParseResult, bool]:
786 """Ensure that a path separator is present on directory paths.
788 Parameters
789 ----------
790 parsed : `~urllib.parse.ParseResult`
791 The result from parsing a URI using `urllib.parse`.
792 forceDirectory : `bool`, optional
793 If `True` forces the URI to end with a separator, otherwise given
794 URI is interpreted as is. Specifying that the URI is conceptually
795 equivalent to a directory can break some ambiguities when
796 interpreting the last element of a path.
798 Returns
799 -------
800 modified : `~urllib.parse.ParseResult`
801 Update result if a URI is being handled.
802 dirLike : `bool`
803 `True` if given parsed URI has a trailing separator or
804 forceDirectory is True. Otherwise `False`.
805 """
806 # assume we are not dealing with a directory like URI
807 dirLike = False
809 # Directory separator
810 sep = cls._pathModule.sep
812 # URI is dir-like if explicitly stated or if it ends on a separator
813 endsOnSep = parsed.path.endswith(sep)
814 if forceDirectory or endsOnSep:
815 dirLike = True
816 # only add the separator if it's not already there
817 if not endsOnSep: 817 ↛ 820line 817 didn't jump to line 820, because the condition on line 817 was never false
818 parsed = parsed._replace(path=parsed.path+sep)
820 return parsed, dirLike
822 @classmethod
823 def _fixupPathUri(cls, parsed: urllib.parse.ParseResult, root: Optional[Union[str, ButlerURI]] = None,
824 forceAbsolute: bool = False,
825 forceDirectory: bool = False) -> Tuple[urllib.parse.ParseResult, bool]:
826 """Correct any issues with the supplied URI.
828 Parameters
829 ----------
830 parsed : `~urllib.parse.ParseResult`
831 The result from parsing a URI using `urllib.parse`.
832 root : `str` or `ButlerURI`, ignored
833 Not used by the this implementation since all URIs are
834 absolute except for those representing the local file system.
835 forceAbsolute : `bool`, ignored.
836 Not used by this implementation. URIs are generally always
837 absolute.
838 forceDirectory : `bool`, optional
839 If `True` forces the URI to end with a separator, otherwise given
840 URI is interpreted as is. Specifying that the URI is conceptually
841 equivalent to a directory can break some ambiguities when
842 interpreting the last element of a path.
844 Returns
845 -------
846 modified : `~urllib.parse.ParseResult`
847 Update result if a URI is being handled.
848 dirLike : `bool`
849 `True` if given parsed URI has a trailing separator or
850 forceDirectory is True. Otherwise `False`.
852 Notes
853 -----
854 Relative paths are explicitly not supported by RFC8089 but `urllib`
855 does accept URIs of the form ``file:relative/path.ext``. They need
856 to be turned into absolute paths before they can be used. This is
857 always done regardless of the ``forceAbsolute`` parameter.
859 AWS S3 differentiates between keys with trailing POSIX separators (i.e
860 `/dir` and `/dir/`) whereas POSIX does not neccessarily.
862 Scheme-less paths are normalized.
863 """
864 return cls._fixDirectorySep(parsed, forceDirectory)
866 def transfer_from(self, src: ButlerURI, transfer: str,
867 overwrite: bool = False,
868 transaction: Optional[Union[DatastoreTransaction, NoTransaction]] = None) -> None:
869 """Transfer the current resource to a new location.
871 Parameters
872 ----------
873 src : `ButlerURI`
874 Source URI.
875 transfer : `str`
876 Mode to use for transferring the resource. Generically there are
877 many standard options: copy, link, symlink, hardlink, relsymlink.
878 Not all URIs support all modes.
879 overwrite : `bool`, optional
880 Allow an existing file to be overwritten. Defaults to `False`.
881 transaction : `DatastoreTransaction`, optional
882 A transaction object that can (depending on implementation)
883 rollback transfers on error. Not guaranteed to be implemented.
885 Notes
886 -----
887 Conceptually this is hard to scale as the number of URI schemes
888 grow. The destination URI is more important than the source URI
889 since that is where all the transfer modes are relevant (with the
890 complication that "move" deletes the source).
892 Local file to local file is the fundamental use case but every
893 other scheme has to support "copy" to local file (with implicit
894 support for "move") and copy from local file.
895 All the "link" options tend to be specific to local file systems.
897 "move" is a "copy" where the remote resource is deleted at the end.
898 Whether this works depends on the source URI rather than the
899 destination URI. Reverting a move on transaction rollback is
900 expected to be problematic if a remote resource was involved.
901 """
902 raise NotImplementedError(f"No transfer modes supported by URI scheme {self.scheme}")
904 def walk(self, file_filter: Optional[Union[str, re.Pattern]] = None) -> Iterator[Union[List,
905 Tuple[ButlerURI,
906 List[str],
907 List[str]]]]:
908 """Walk the directory tree returning matching files and directories.
910 Parameters
911 ----------
912 file_filter : `str` or `re.Pattern`, optional
913 Regex to filter out files from the list before it is returned.
915 Yields
916 ------
917 dirpath : `ButlerURI`
918 Current directory being examined.
919 dirnames : `list` of `str`
920 Names of subdirectories within dirpath.
921 filenames : `list` of `str`
922 Names of all the files within dirpath.
923 """
924 raise NotImplementedError()
926 @classmethod
927 def findFileResources(cls, candidates: Iterable[Union[str, ButlerURI]],
928 file_filter: Optional[str] = None,
929 grouped: bool = False) -> Iterator[Union[ButlerURI, Iterator[ButlerURI]]]:
930 """Get all the files from a list of values.
932 Parameters
933 ----------
934 candidates : iterable [`str` or `ButlerURI`]
935 The files to return and directories in which to look for files to
936 return.
937 file_filter : `str`, optional
938 The regex to use when searching for files within directories.
939 By default returns all the found files.
940 grouped : `bool`, optional
941 If `True` the results will be grouped by directory and each
942 yielded value will be an iterator over URIs. If `False` each
943 URI will be returned separately.
945 Yields
946 ------
947 found_file: `ButlerURI`
948 The passed-in URIs and URIs found in passed-in directories.
949 If grouping is enabled, each of the yielded values will be an
950 iterator yielding members of the group. Files given explicitly
951 will be returned as a single group at the end.
953 Notes
954 -----
955 If a value is a file it is yielded immediately. If a value is a
956 directory, all the files in the directory (recursively) that match
957 the regex will be yielded in turn.
958 """
959 fileRegex = None if file_filter is None else re.compile(file_filter)
961 singles = []
963 # Find all the files of interest
964 for location in candidates:
965 uri = ButlerURI(location)
966 if uri.isdir():
967 for found in uri.walk(fileRegex):
968 if not found:
969 # This means the uri does not exist and by
970 # convention we ignore it
971 continue
972 root, dirs, files = found
973 if not files:
974 continue
975 if grouped:
976 yield (root.join(name) for name in files)
977 else:
978 for name in files:
979 yield root.join(name)
980 else:
981 if grouped:
982 singles.append(uri)
983 else:
984 yield uri
986 # Finally, return any explicitly given files in one group
987 if grouped and singles:
988 yield iter(singles)