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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 

26import os 

27import os.path 

28 

29from typing import ( 

30 Optional, 

31 Union, 

32) 

33 

34from ._butlerUri import ButlerURI 

35 

36 

37class Location: 

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

39 

40 Parameters 

41 ---------- 

42 datastoreRootUri : `ButlerURI` or `str` or `None` 

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

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

45 path : `ButlerURI` or `str` 

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

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

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

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

50 """ 

51 

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

53 

54 def __init__(self, datastoreRootUri: Union[None, ButlerURI, str], 

55 path: Union[ButlerURI, str]): 

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

57 path_uri = ButlerURI(path, forceAbsolute=False) 

58 

59 if isinstance(datastoreRootUri, str): 

60 datastoreRootUri = ButlerURI(datastoreRootUri, forceDirectory=True) 

61 elif datastoreRootUri is None: 

62 if not path_uri.isabs(): 

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

64 elif not isinstance(datastoreRootUri, ButlerURI): 

65 raise ValueError("Datastore root must be a ButlerURI instance") 

66 

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

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

69 

70 self._datastoreRootUri = datastoreRootUri 

71 

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

73 # it is required to be within the root. 

74 if datastoreRootUri is not None: 

75 if path_uri.isabs(): 

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

77 

78 self._path = path_uri 

79 

80 # Internal cache of the full location as a ButlerURI 

81 self._uri: Optional[ButlerURI] = None 

82 

83 # Check that the resulting URI is inside the datastore 

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

85 if self._datastoreRootUri is not None: 

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

87 if pathInStore is None: 

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

89 

90 def __str__(self) -> str: 

91 return str(self.uri) 

92 

93 def __repr__(self) -> str: 

94 uri = self._datastoreRootUri 

95 path = self._path 

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

97 

98 @property 

99 def uri(self) -> ButlerURI: 

100 """URI corresponding to fully-specified location in datastore. 

101 """ 

102 if self._uri is None: 

103 root = self._datastoreRootUri 

104 if root is None: 

105 uri = self._path 

106 else: 

107 uri = root.join(self._path) 

108 self._uri = uri 

109 return self._uri 

110 

111 @property 

112 def path(self) -> str: 

113 """Path corresponding to location. 

114 

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

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

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

118 with the local OS path separator. 

119 """ 

120 full = self.uri 

121 try: 

122 return full.ospath 

123 except AttributeError: 

124 return full.unquoted_path 

125 

126 @property 

127 def pathInStore(self) -> ButlerURI: 

128 """Path corresponding to location relative to `Datastore` root. 

129 

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

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

132 """ 

133 return self._path 

134 

135 @property 

136 def netloc(self) -> str: 

137 """The URI network location.""" 

138 return self.uri.netloc 

139 

140 @property 

141 def relativeToPathRoot(self) -> str: 

142 """Returns the path component of the URI relative to the network 

143 location. 

144 

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

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

147 """ 

148 return self.uri.relativeToPathRoot 

149 

150 def updateExtension(self, ext: Optional[str]) -> None: 

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

152 

153 All file extensions are replaced. 

154 

155 Parameters 

156 ---------- 

157 ext : `str` 

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

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

160 """ 

161 if ext is None: 

162 return 

163 

164 self._path.updateExtension(ext) 

165 

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

167 self._uri = None 

168 

169 def getExtension(self) -> str: 

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

171 

172 Returns 

173 ------- 

174 ext : `str` 

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

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

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

178 a value of ``.fits.gz``. 

179 """ 

180 return self.uri.getExtension() 

181 

182 

183class LocationFactory: 

184 """Factory for `Location` instances. 

185 

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

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

188 or as a URI. 

189 

190 Parameters 

191 ---------- 

192 datastoreRoot : `str` 

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

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

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

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

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

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

199 """ 

200 

201 def __init__(self, datastoreRoot: Union[ButlerURI, str]): 

202 self._datastoreRootUri = ButlerURI(datastoreRoot, forceAbsolute=True, 

203 forceDirectory=True) 

204 

205 def __str__(self) -> str: 

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

207 

208 @property 

209 def netloc(self) -> str: 

210 """Returns the network location of root location of the `Datastore`.""" 

211 return self._datastoreRootUri.netloc 

212 

213 def fromPath(self, path: str) -> Location: 

214 """Factory function to create a `Location` from a POSIX path. 

215 

216 Parameters 

217 ---------- 

218 path : `str` 

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

220 

221 Returns 

222 ------- 

223 location : `Location` 

224 The equivalent `Location`. 

225 """ 

226 if os.path.isabs(path): 

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

228 return Location(self._datastoreRootUri, path)