Coverage for python/lsst/daf/butler/core/location.py : 26%

Hot-keys on this page
r m x p toggle line displays
j k next/prev highlighted chunk
0 (zero) top of page
1 (one) first highlighted chunk
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__all__ = ("Location", "LocationFactory")
26import os
27import os.path
28import posixpath
29import types
31from typing import (
32 Optional,
33 Union,
34)
36from ._butlerUri import ButlerURI
39class Location:
40 """Identifies a location within the `Datastore`.
42 Parameters
43 ----------
44 datastoreRootUri : `ButlerURI` or `str`
45 Base URI for this datastore, must include an absolute path.
46 path : `str`
47 Relative path within datastore. Assumed to be using the local
48 path separator if a ``file`` scheme is being used for the URI,
49 else a POSIX separator.
50 """
52 __slots__ = ("_datastoreRootUri", "_path", "_uri")
54 def __init__(self, datastoreRootUri: Union[ButlerURI, str], path: str):
55 if isinstance(datastoreRootUri, str):
56 datastoreRootUri = ButlerURI(datastoreRootUri, forceDirectory=True)
57 elif not isinstance(datastoreRootUri, ButlerURI):
58 raise ValueError("Datastore root must be a ButlerURI instance")
60 if not posixpath.isabs(datastoreRootUri.path):
61 raise ValueError(f"Supplied URI must be an absolute path (given {datastoreRootUri}).")
63 self._datastoreRootUri = datastoreRootUri
65 pathModule: types.ModuleType
66 if not self._datastoreRootUri.scheme:
67 pathModule = os.path
68 else:
69 pathModule = posixpath
71 # mypy can not work out that these modules support isabs
72 if pathModule.isabs(path): # type: ignore
73 raise ValueError("Path within datastore must be relative not absolute")
75 self._path = path
77 # Internal cache of the full location as a ButlerURI
78 self._uri: Optional[ButlerURI] = None
80 # Check that the resulting URI is inside the datastore
81 # This can go wrong if we were given ../dir as path
82 pathInStore = self.uri.relative_to(self._datastoreRootUri)
83 if pathInStore is None:
84 raise ValueError(f"Unexpectedly {path} jumps out of {self._datastoreRootUri}")
86 def __str__(self) -> str:
87 return str(self.uri)
89 def __repr__(self) -> str:
90 uri = self._datastoreRootUri.geturl()
91 path = self._path
92 return f"{self.__class__.__name__}({uri!r}, {path!r})"
94 @property
95 def uri(self) -> ButlerURI:
96 """URI corresponding to fully-specified location in datastore.
97 """
98 if self._uri is None:
99 self._uri = self._datastoreRootUri.join(self._path)
100 return self._uri
102 @property
103 def path(self) -> str:
104 """Path corresponding to location.
106 This path includes the root of the `Datastore`, but does not include
107 non-path components of the root URI. Paths will not include URI
108 quoting. If a file URI scheme is being used the path will be returned
109 with the local OS path separator.
110 """
111 full = self.uri
112 try:
113 return full.ospath
114 except AttributeError:
115 return full.unquoted_path
117 @property
118 def pathInStore(self) -> str:
119 """Path corresponding to location relative to `Datastore` root.
121 Uses the same path separator as supplied to the object constructor.
122 """
123 return self._path
125 @property
126 def netloc(self) -> str:
127 """The URI network location."""
128 return self._datastoreRootUri.netloc
130 @property
131 def relativeToPathRoot(self) -> str:
132 """Returns the path component of the URI relative to the network
133 location.
135 Effectively, this is the path property with POSIX separator stripped
136 from the left hand side of the path. Will be unquoted.
137 """
138 return self.uri.relativeToPathRoot
140 def updateExtension(self, ext: Optional[str]) -> None:
141 """Update the file extension associated with this `Location`.
143 All file extensions are replaced.
145 Parameters
146 ----------
147 ext : `str`
148 New extension. If an empty string is given any extension will
149 be removed. If `None` is given there will be no change.
150 """
151 if ext is None:
152 return
154 # Get the extension and remove it from the path if one is found
155 # .fits.gz counts as one extension do not use os.path.splitext
156 current = self.getExtension()
157 path = self.pathInStore
158 if current:
159 path = path[:-len(current)]
161 # Ensure that we have a leading "." on file extension (and we do not
162 # try to modify the empty string)
163 if ext and not ext.startswith("."):
164 ext = "." + ext
166 self._path = path + ext
168 # Clear the URI cache so it can be recreated with the new path
169 self._uri = None
171 def getExtension(self) -> str:
172 """Return the file extension(s) associated with this location.
174 Returns
175 -------
176 ext : `str`
177 The file extension (including the ``.``). Can be empty string
178 if there is no file extension. Will return all file extensions
179 as a single extension such that ``file.fits.gz`` will return
180 a value of ``.fits.gz``.
181 """
182 return self.uri.getExtension()
185class LocationFactory:
186 """Factory for `Location` instances.
188 The factory is constructed from the root location of the datastore.
189 This location can be a path on the file system (absolute or relative)
190 or as a URI.
192 Parameters
193 ----------
194 datastoreRoot : `str`
195 Root location of the `Datastore` either as a path in the local
196 filesystem or as a URI. File scheme URIs can be used. If a local
197 filesystem path is used without URI scheme, it will be converted
198 to an absolute path and any home directory indicators expanded.
199 If a file scheme is used with a relative path, the path will
200 be treated as a posixpath but then converted to an absolute path.
201 """
203 def __init__(self, datastoreRoot: Union[ButlerURI, str]):
204 self._datastoreRootUri = ButlerURI(datastoreRoot, forceAbsolute=True,
205 forceDirectory=True)
207 def __str__(self) -> str:
208 return f"{self.__class__.__name__}@{self._datastoreRootUri}"
210 @property
211 def netloc(self) -> str:
212 """Returns the network location of root location of the `Datastore`."""
213 return self._datastoreRootUri.netloc
215 def fromPath(self, path: str) -> Location:
216 """Factory function to create a `Location` from a POSIX path.
218 Parameters
219 ----------
220 path : `str`
221 A standard POSIX path, relative to the `Datastore` root.
223 Returns
224 -------
225 location : `Location`
226 The equivalent `Location`.
227 """
228 if os.path.isabs(path):
229 raise ValueError("LocationFactory path must be relative to datastore, not absolute.")
230 return Location(self._datastoreRootUri, path)