Coverage for python/lsst/daf/butler/core/location.py : 18%

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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/>.
22__all__ = ("Location", "LocationFactory", "ButlerURI")
24import os
25import os.path
26import urllib
27import posixpath
28from pathlib import Path, PurePath, PurePosixPath
29import copy
31# Determine if the path separator for the OS looks like POSIX
32IS_POSIX = os.sep == posixpath.sep
34# Root path for this operating system
35OS_ROOT_PATH = Path().resolve().root
38def os2posix(ospath):
39 """Convert a local path description to a POSIX path description.
41 Parameters
42 ----------
43 path : `str`
44 Path using the local path separator.
46 Returns
47 -------
48 posix : `str`
49 Path using POSIX path separator
50 """
51 if IS_POSIX:
52 return ospath
54 posix = PurePath(ospath).as_posix()
56 # PurePath strips trailing "/" from paths such that you can no
57 # longer tell if a path is meant to be referring to a directory
58 # Try to fix this.
59 if ospath.endswith(os.sep) and not posix.endswith(posixpath.sep):
60 posix += posixpath.sep
62 return posix
65def posix2os(posix):
66 """Convert a POSIX path description to a local path description.
68 Parameters
69 ----------
70 posix : `str`
71 Path using the POSIX path separator.
73 Returns
74 -------
75 ospath : `str`
76 Path using OS path separator
77 """
78 if IS_POSIX:
79 return posix
81 posixPath = PurePosixPath(posix)
82 paths = list(posixPath.parts)
84 # Have to convert the root directory after splitting
85 if paths[0] == posixPath.root:
86 paths[0] = OS_ROOT_PATH
88 # Trailing "/" is stripped so we need to add back an empty path
89 # for consistency
90 if posix.endswith(posixpath.sep):
91 paths.append("")
93 return os.path.join(*paths)
96class ButlerURI:
97 """Convenience wrapper around URI parsers.
99 Provides access to URI components and can convert file
100 paths into absolute path URIs. Scheme-less URIs are treated as if
101 they are local file system paths and are converted to absolute URIs.
103 Parameters
104 ----------
105 uri : `str` or `urllib.parse.ParseResult`
106 URI in string form. Can be scheme-less if referring to a local
107 filesystem path.
108 root : `str`, optional
109 When fixing up a relative path in a ``file`` scheme or if scheme-less,
110 use this as the root. Must be absolute. If `None` the current
111 working directory will be used.
112 forceAbsolute : `bool`, optional
113 If `True`, scheme-less relative URI will be converted to an absolute
114 path using a ``file`` scheme. If `False` scheme-less URI will remain
115 scheme-less and will not be updated to ``file`` or absolute path.
116 forceDirectory: `bool`, optional
117 If `True` forces the URI to end with a separator, otherwise given URI
118 is interpreted as is.
119 """
121 def __init__(self, uri, root=None, forceAbsolute=True, forceDirectory=False):
122 if isinstance(uri, str):
123 parsed = urllib.parse.urlparse(uri)
124 elif isinstance(uri, urllib.parse.ParseResult):
125 parsed = copy.copy(uri)
126 else:
127 raise ValueError("Supplied URI must be either string or ParseResult")
129 parsed, dirLike = self._fixupPathUri(parsed, root=root,
130 forceAbsolute=forceAbsolute,
131 forceDirectory=forceDirectory)
133 self.dirLike = dirLike
134 self._uri = parsed
136 @property
137 def scheme(self):
138 """The URI scheme (``://`` is not part of the scheme)."""
139 return self._uri.scheme
141 @property
142 def netloc(self):
143 """The URI network location."""
144 return self._uri.netloc
146 @property
147 def path(self):
148 """The path component of the URI."""
149 return self._uri.path
151 @property
152 def ospath(self):
153 """Path component of the URI localized to current OS."""
154 if self.scheme == 's3':
155 raise AttributeError('S3 URIs have no OS path.')
156 return posix2os(self._uri.path)
158 @property
159 def relativeToPathRoot(self):
160 """Returns path relative to network location.
162 Effectively, this is the path property with posix separator stripped
163 from the left hand side of the path.
164 """
165 if not self.scheme:
166 p = PurePath(self.path)
167 else:
168 p = PurePosixPath(self.path)
169 relToRoot = str(p.relative_to(p.root))
170 if self.dirLike and not relToRoot.endswith("/"):
171 relToRoot += "/"
172 return relToRoot
174 @property
175 def fragment(self):
176 """The fragment component of the URI."""
177 return self._uri.fragment
179 @property
180 def params(self):
181 """Any parameters included in the URI."""
182 return self._uri.params
184 @property
185 def query(self):
186 """Any query strings included in the URI."""
187 return self._uri.query
189 def geturl(self):
190 """Return the URI in string form.
192 Returns
193 -------
194 url : `str`
195 String form of URI.
196 """
197 return self._uri.geturl()
199 def split(self):
200 """Splits URI into head and tail. Equivalent to os.path.split where
201 head preserves the URI components.
203 Returns
204 -------
205 head: `ButlerURI`
206 Everything leading up to tail, expanded and normalized as per
207 ButlerURI rules.
208 tail : `str`
209 Last `self.path` component. Tail will be empty if path ends on a
210 separator. Tail will never contain separators.
211 """
212 if self.scheme:
213 head, tail = posixpath.split(self.path)
214 else:
215 head, tail = os.path.split(self.path)
216 headuri = self._uri._replace(path=head)
217 return self.__class__(headuri, forceDirectory=True), tail
219 def basename(self):
220 """Returns the base name, last element of path, of the URI. If URI ends
221 on a slash returns an empty string. This is the second element returned
222 by split().
224 Equivalent of os.path.basename().
226 Returns
227 -------
228 tail : `str`
229 Last part of the path attribute. Trail will be empty if path ends
230 on a separator.
231 """
232 return self.split()[1]
234 def dirname(self):
235 """Returns a ButlerURI containing all the directories of the path
236 attribute.
238 Equivalent of os.path.dirname()
240 Returns
241 -------
242 head : `ButlerURI`
243 Everything except the tail of path attribute, expanded and
244 normalized as per ButlerURI rules.
245 """
246 return self.split()[0]
248 def replace(self, **kwargs):
249 """Replace components in a URI with new values and return a new
250 instance.
252 Returns
253 -------
254 new : `ButlerURI`
255 New `ButlerURI` object with updated values.
256 """
257 return self.__class__(self._uri._replace(**kwargs))
259 def updateFile(self, newfile):
260 """Update in place the final component of the path with the supplied
261 file name.
263 Parameters
264 ----------
265 newfile : `str`
266 File name with no path component.
268 Notes
269 -----
270 Updates the URI in place.
271 Updates the ButlerURI.dirLike attribute.
272 """
273 if self.scheme:
274 # POSIX
275 pathclass = posixpath
276 else:
277 pathclass = os.path
279 dir, _ = pathclass.split(self.path)
280 newpath = pathclass.join(dir, newfile)
282 self.dirLike = False
283 self._uri = self._uri._replace(path=newpath)
285 def __str__(self):
286 return self.geturl()
288 def __repr__(self) -> str:
289 return f'ButlerURI("{self.geturl()}")'
291 def __eq__(self, other) -> bool:
292 if not isinstance(other, ButlerURI):
293 return False
294 return self.geturl() == other.geturl()
296 @staticmethod
297 def _fixupPathUri(parsed, root=None, forceAbsolute=False, forceDirectory=False):
298 """Fix up relative paths in URI instances.
300 Parameters
301 ----------
302 parsed : `~urllib.parse.ParseResult`
303 The result from parsing a URI using `urllib.parse`.
304 root : `str`, optional
305 Path to use as root when converting relative to absolute.
306 If `None`, it will be the current working directory. This
307 is a local file system path, not a URI.
308 forceAbsolute : `bool`, optional
309 If `True`, scheme-less relative URI will be converted to an
310 absolute path using a ``file`` scheme. If `False` scheme-less URI
311 will remain scheme-less and will not be updated to ``file`` or
312 absolute path. URIs with a defined scheme will not be affected
313 by this parameter.
314 forceDirectory : `bool`, optional
315 If `True` forces the URI to end with a separator, otherwise given
316 URI is interpreted as is.
318 Returns
319 -------
320 modified : `~urllib.parse.ParseResult`
321 Update result if a URI is being handled.
322 dirLike : `bool`
323 `True` if given parsed URI has a trailing separator or
324 forceDirectory is True. Otherwise `False`.
326 Notes
327 -----
328 Relative paths are explicitly not supported by RFC8089 but `urllib`
329 does accept URIs of the form ``file:relative/path.ext``. They need
330 to be turned into absolute paths before they can be used. This is
331 always done regardless of the ``forceAbsolute`` parameter.
333 AWS S3 differentiates between keys with trailing POSIX separators (i.e
334 `/dir` and `/dir/`) whereas POSIX does not neccessarily.
336 Scheme-less paths are normalized.
337 """
338 # assume we are not dealing with a directory like URI
339 dirLike = False
340 if not parsed.scheme or parsed.scheme == "file":
342 # Replacement values for the URI
343 replacements = {}
345 if root is None:
346 root = os.path.abspath(os.path.curdir)
348 if not parsed.scheme:
349 # if there was no scheme this is a local OS file path
350 # which can support tilde expansion.
351 expandedPath = os.path.expanduser(parsed.path)
353 # Ensure that this is a file URI if it is already absolute
354 if os.path.isabs(expandedPath):
355 replacements["scheme"] = "file"
356 replacements["path"] = os2posix(os.path.normpath(expandedPath))
357 elif forceAbsolute:
358 # This can stay in OS path form, do not change to file
359 # scheme.
360 replacements["path"] = os.path.normpath(os.path.join(root, expandedPath))
361 else:
362 # No change needed for relative local path staying relative
363 # except normalization
364 replacements["path"] = os.path.normpath(expandedPath)
365 # normalization of empty path returns "." so we are dirLike
366 if expandedPath == "":
367 dirLike = True
369 # normpath strips trailing "/" which makes it hard to keep
370 # track of directory vs file when calling replaceFile
371 # find the appropriate separator
372 if "scheme" in replacements:
373 sep = posixpath.sep
374 else:
375 sep = os.sep
377 # add the trailing separator only if explicitly required or
378 # if it was stripped by normpath. Acknowledge that trailing
379 # separator exists.
380 endsOnSep = expandedPath.endswith(os.sep) and not replacements["path"].endswith(sep)
381 if (forceDirectory or endsOnSep or dirLike):
382 dirLike = True
383 replacements["path"] += sep
385 elif parsed.scheme == "file":
386 # file URI implies POSIX path separators so split as POSIX,
387 # then join as os, and convert to abspath. Do not handle
388 # home directories since "file" scheme is explicitly documented
389 # to not do tilde expansion.
390 sep = posixpath.sep
391 if posixpath.isabs(parsed.path):
392 if forceDirectory:
393 parsed = parsed._replace(path=parsed.path+sep)
394 dirLike = True
395 return copy.copy(parsed), dirLike
397 replacements["path"] = posixpath.normpath(posixpath.join(os2posix(root), parsed.path))
399 # normpath strips trailing "/" so put it back if necessary
400 # Acknowledge that trailing separator exists.
401 if forceDirectory or (parsed.path.endswith(sep) and not replacements["path"].endswith(sep)):
402 replacements["path"] += sep
403 dirLike = True
404 else:
405 raise RuntimeError("Unexpectedly got confused by URI scheme")
407 # ParseResult is a NamedTuple so _replace is standard API
408 parsed = parsed._replace(**replacements)
410 # URI is dir-like if explicitly stated or if it ends on a separator
411 endsOnSep = parsed.path.endswith(posixpath.sep)
412 if forceDirectory or endsOnSep:
413 dirLike = True
414 # only add the separator if it's not already there
415 if not endsOnSep:
416 parsed = parsed._replace(path=parsed.path+posixpath.sep)
418 if dirLike is None:
419 raise RuntimeError("ButlerURI.dirLike attribute not set successfully.")
421 return parsed, dirLike
424class Location:
425 """Identifies a location within the `Datastore`.
427 Parameters
428 ----------
429 datastoreRootUri : `ButlerURI` or `str`
430 Base URI for this datastore, must include an absolute path.
431 path : `str`
432 Relative path within datastore. Assumed to be using the local
433 path separator if a ``file`` scheme is being used for the URI,
434 else a POSIX separator.
435 """
437 __slots__ = ("_datastoreRootUri", "_path")
439 def __init__(self, datastoreRootUri, path):
440 if isinstance(datastoreRootUri, str):
441 datastoreRootUri = ButlerURI(datastoreRootUri, forceDirectory=True)
442 elif not isinstance(datastoreRootUri, ButlerURI):
443 raise ValueError("Datastore root must be a ButlerURI instance")
445 if not posixpath.isabs(datastoreRootUri.path):
446 raise ValueError(f"Supplied URI must be an absolute path (given {datastoreRootUri}).")
448 self._datastoreRootUri = datastoreRootUri
450 if self._datastoreRootUri.scheme == "file":
451 pathModule = os.path
452 else:
453 pathModule = posixpath
455 if pathModule.isabs(path):
456 raise ValueError("Path within datastore must be relative not absolute")
458 self._path = path
460 def __str__(self):
461 return self.uri
463 def __repr__(self):
464 uri = self._datastoreRootUri.geturl()
465 path = self._path
466 return f"{self.__class__.__name__}({uri!r}, {path!r})"
468 @property
469 def uri(self):
470 """URI string corresponding to fully-specified location in datastore.
471 """
472 uriPath = os2posix(self.path)
473 return self._datastoreRootUri.replace(path=uriPath).geturl()
475 @property
476 def path(self):
477 """Path corresponding to location.
479 This path includes the root of the `Datastore`, but does not include
480 non-path components of the root URI. If a file URI scheme is being
481 used the path will be returned with the local OS path separator.
482 """
483 if not self._datastoreRootUri.scheme:
484 # Entirely local file system
485 return os.path.normpath(os.path.join(self._datastoreRootUri.path, self.pathInStore))
486 elif self._datastoreRootUri.scheme == "file":
487 return os.path.normpath(os.path.join(posix2os(self._datastoreRootUri.path), self.pathInStore))
488 else:
489 return posixpath.join(self._datastoreRootUri.path, self.pathInStore)
491 @property
492 def pathInStore(self):
493 """Path corresponding to location relative to `Datastore` root.
495 Uses the same path separator as supplied to the object constructor.
496 """
497 return self._path
499 @property
500 def netloc(self):
501 """The URI network location."""
502 return self._datastoreRootUri.netloc
504 @property
505 def relativeToPathRoot(self):
506 """Returns the path component of the URI relative to the network
507 location.
509 Effectively, this is the path property with POSIX separator stripped
510 from the left hand side of the path.
511 """
512 if self._datastoreRootUri.scheme == 'file' or not self._datastoreRootUri.scheme:
513 p = PurePath(os2posix(self.path))
514 else:
515 p = PurePosixPath(self.path)
516 stripped = p.relative_to(p.root)
517 return str(posix2os(stripped))
519 def updateExtension(self, ext):
520 """Update the file extension associated with this `Location`.
522 Parameters
523 ----------
524 ext : `str`
525 New extension. If an empty string is given any extension will
526 be removed. If `None` is given there will be no change.
527 """
528 if ext is None:
529 return
531 path, _ = os.path.splitext(self.pathInStore)
533 # Ensure that we have a leading "." on file extension (and we do not
534 # try to modify the empty string)
535 if ext and not ext.startswith("."):
536 ext = "." + ext
538 self._path = path + ext
541class LocationFactory:
542 """Factory for `Location` instances.
544 The factory is constructed from the root location of the datastore.
545 This location can be a path on the file system (absolute or relative)
546 or as a URI.
548 Parameters
549 ----------
550 datastoreRoot : `str`
551 Root location of the `Datastore` either as a path in the local
552 filesystem or as a URI. File scheme URIs can be used. If a local
553 filesystem path is used without URI scheme, it will be converted
554 to an absolute path and any home directory indicators expanded.
555 If a file scheme is used with a relative path, the path will
556 be treated as a posixpath but then converted to an absolute path.
557 """
559 def __init__(self, datastoreRoot):
560 self._datastoreRootUri = ButlerURI(datastoreRoot, forceAbsolute=True,
561 forceDirectory=True)
563 def __str__(self):
564 return f"{self.__class__.__name__}@{self._datastoreRootUri}"
566 @property
567 def netloc(self):
568 """Returns the network location of root location of the `Datastore`."""
569 return self._datastoreRootUri.netloc
571 def fromPath(self, path):
572 """Factory function to create a `Location` from a POSIX path.
574 Parameters
575 ----------
576 path : `str`
577 A standard POSIX path, relative to the `Datastore` root.
579 Returns
580 -------
581 location : `Location`
582 The equivalent `Location`.
583 """
584 if os.path.isabs(path):
585 raise ValueError("LocationFactory path must be relative to datastore, not absolute.")
586 return Location(self._datastoreRootUri, path)