Coverage for python/lsst/daf/butler/core/location.py: 33%

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1# This file is part of daf_butler. 

2# 

3# Developed for the LSST Data Management System. 

4# This product includes software developed by the LSST Project 

5# (http://www.lsst.org). 

6# See the COPYRIGHT file at the top-level directory of this distribution 

7# for details of code ownership. 

8# 

9# This program is free software: you can redistribute it and/or modify 

10# it under the terms of the GNU General Public License as published by 

11# the Free Software Foundation, either version 3 of the License, or 

12# (at your option) any later version. 

13# 

14# This program is distributed in the hope that it will be useful, 

15# but WITHOUT ANY WARRANTY; without even the implied warranty of 

16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

17# GNU General Public License for more details. 

18# 

19# You should have received a copy of the GNU General Public License 

20# along with this program. If not, see <http://www.gnu.org/licenses/>. 

21 

22from __future__ import annotations 

23 

24__all__ = ("Location", "LocationFactory") 

25 

26from lsst.resources import ResourcePath, ResourcePathExpression 

27 

28 

29class Location: 

30 """Identifies a location within the `Datastore`. 

31 

32 Parameters 

33 ---------- 

34 datastoreRootUri : `lsst.resources.ResourcePathExpression` or `None` 

35 Base URI for this datastore, must include an absolute path. 

36 If `None` the `path` must correspond to an absolute URI. 

37 path : `lsst.resources.ResourcePathExpression` 

38 Relative path within datastore. Assumed to be using the local 

39 path separator if a ``file`` scheme is being used for the URI, 

40 else a POSIX separator. Can be a full URI if the root URI is `None`. 

41 Can also be a schemeless URI if it refers to a relative path. 

42 """ 

43 

44 __slots__ = ("_datastoreRootUri", "_path", "_uri") 

45 

46 def __init__(self, datastoreRootUri: None | ResourcePathExpression, path: ResourcePathExpression): 

47 # Be careful not to force a relative local path to absolute path 

48 path_uri = ResourcePath(path, forceAbsolute=False) 

49 

50 if isinstance(datastoreRootUri, str): 

51 datastoreRootUri = ResourcePath(datastoreRootUri, forceDirectory=True) 

52 elif datastoreRootUri is None: 

53 if not path_uri.isabs(): 

54 raise ValueError(f"No datastore root URI given but path '{path}' was not absolute URI.") 

55 elif not isinstance(datastoreRootUri, ResourcePath): 

56 raise ValueError("Datastore root must be a ResourcePath instance") 

57 

58 if datastoreRootUri is not None and not datastoreRootUri.isabs(): 

59 raise ValueError(f"Supplied root URI must be an absolute path (given {datastoreRootUri}).") 

60 

61 self._datastoreRootUri = datastoreRootUri 

62 

63 # if the root URI is not None the path must not be absolute since 

64 # it is required to be within the root. 

65 if datastoreRootUri is not None and path_uri.isabs(): 

66 raise ValueError(f"Path within datastore must be relative not absolute, got {path_uri}") 

67 

68 self._path = path_uri 

69 

70 # Internal cache of the full location as a ResourcePath 

71 self._uri: ResourcePath | None = None 

72 

73 # Check that the resulting URI is inside the datastore 

74 # This can go wrong if we were given ../dir as path 

75 if self._datastoreRootUri is not None: 

76 pathInStore = self.uri.relative_to(self._datastoreRootUri) 

77 if pathInStore is None: 

78 raise ValueError(f"Unexpectedly {path} jumps out of {self._datastoreRootUri}") 

79 

80 def __str__(self) -> str: 

81 return str(self.uri) 

82 

83 def __repr__(self) -> str: 

84 uri = self._datastoreRootUri 

85 path = self._path 

86 return f"{self.__class__.__name__}({uri!r}, {path.path!r})" 

87 

88 def __eq__(self, other: object) -> bool: 

89 if not isinstance(other, Location): 

90 return NotImplemented 

91 # Compare the combined URI rather than how it is apportioned 

92 return self.uri == other.uri 

93 

94 @property 

95 def uri(self) -> ResourcePath: 

96 """Return URI corresponding to fully-specified datastore location.""" 

97 if self._uri is None: 

98 root = self._datastoreRootUri 

99 if root is None: 

100 uri = self._path 

101 else: 

102 uri = root.join(self._path) 

103 self._uri = uri 

104 return self._uri 

105 

106 @property 

107 def path(self) -> str: 

108 """Return path corresponding to location. 

109 

110 This path includes the root of the `Datastore`, but does not include 

111 non-path components of the root URI. Paths will not include URI 

112 quoting. If a file URI scheme is being used the path will be returned 

113 with the local OS path separator. 

114 """ 

115 full = self.uri 

116 try: 

117 return full.ospath 

118 except AttributeError: 

119 return full.unquoted_path 

120 

121 @property 

122 def pathInStore(self) -> ResourcePath: 

123 """Return path corresponding to location relative to `Datastore` root. 

124 

125 Uses the same path separator as supplied to the object constructor. 

126 Can be an absolute URI if that is how the location was configured. 

127 """ 

128 return self._path 

129 

130 @property 

131 def netloc(self) -> str: 

132 """Return the URI network location.""" 

133 return self.uri.netloc 

134 

135 @property 

136 def relativeToPathRoot(self) -> str: 

137 """Return the path component relative to the network location. 

138 

139 Effectively, this is the path property with POSIX separator stripped 

140 from the left hand side of the path. Will be unquoted. 

141 """ 

142 return self.uri.relativeToPathRoot 

143 

144 def updateExtension(self, ext: str | None) -> None: 

145 """Update the file extension associated with this `Location`. 

146 

147 All file extensions are replaced. 

148 

149 Parameters 

150 ---------- 

151 ext : `str` 

152 New extension. If an empty string is given any extension will 

153 be removed. If `None` is given there will be no change. 

154 """ 

155 if ext is None: 

156 return 

157 

158 self._path = self._path.updatedExtension(ext) 

159 

160 # Clear the URI cache so it can be recreated with the new path 

161 self._uri = None 

162 

163 def getExtension(self) -> str: 

164 """Return the file extension(s) associated with this location. 

165 

166 Returns 

167 ------- 

168 ext : `str` 

169 The file extension (including the ``.``). Can be empty string 

170 if there is no file extension. Will return all file extensions 

171 as a single extension such that ``file.fits.gz`` will return 

172 a value of ``.fits.gz``. 

173 """ 

174 return self.uri.getExtension() 

175 

176 

177class LocationFactory: 

178 """Factory for `Location` instances. 

179 

180 The factory is constructed from the root location of the datastore. 

181 This location can be a path on the file system (absolute or relative) 

182 or as a URI. 

183 

184 Parameters 

185 ---------- 

186 datastoreRoot : `str` 

187 Root location of the `Datastore` either as a path in the local 

188 filesystem or as a URI. File scheme URIs can be used. If a local 

189 filesystem path is used without URI scheme, it will be converted 

190 to an absolute path and any home directory indicators expanded. 

191 If a file scheme is used with a relative path, the path will 

192 be treated as a posixpath but then converted to an absolute path. 

193 """ 

194 

195 def __init__(self, datastoreRoot: ResourcePathExpression): 

196 self._datastoreRootUri = ResourcePath(datastoreRoot, forceAbsolute=True, forceDirectory=True) 

197 

198 def __str__(self) -> str: 

199 return f"{self.__class__.__name__}@{self._datastoreRootUri}" 

200 

201 @property 

202 def netloc(self) -> str: 

203 """Return the network location of root location of the `Datastore`.""" 

204 return self._datastoreRootUri.netloc 

205 

206 def fromPath(self, path: ResourcePathExpression) -> Location: 

207 """Create a `Location` from a POSIX path. 

208 

209 Parameters 

210 ---------- 

211 path : `str` or `lsst.resources.ResourcePath` 

212 A standard POSIX path, relative to the `Datastore` root. 

213 If it is a `lsst.resources.ResourcePath` it must not be absolute. 

214 

215 Returns 

216 ------- 

217 location : `Location` 

218 The equivalent `Location`. 

219 """ 

220 path = ResourcePath(path, forceAbsolute=False) 

221 if path.isabs(): 

222 raise ValueError("LocationFactory path must be relative to datastore, not absolute.") 

223 return Location(self._datastoreRootUri, path)