24 from __future__
import absolute_import
26 from future
import standard_library
28 from .
import NoRepositroyAtRoot
29 standard_library.install_aliases()
33 """Base class for storages"""
42 """Register derived classes for lookup by URI scheme.
44 A scheme is a name that describes the form a resource at the beginning of a URI
45 e.g. 'http' indicates HTML and related code, such as is found in http://www.lsst.org
47 The only currently supported schemes are:
48 * 'file' where the portion of the URI after the // indicates an absolute locaiton on disk.
49 for example: file:/my_repository_folder/
50 * '' (no scheme) where the entire string is a relative path on the local system
51 for example "my_repository_folder" will indicate a folder in the current working directory with the
54 See documentation for the urlparse python library for more information.
58 Storage is 'wet paint' and very likely to change during factorization of Butler back end and
59 storage formats (DM-6225). Use of it in production code other than via the 'old butler' API is
65 Name of the `scheme` the class is being registered for, which appears at the beginning of a URI.
67 A class object that should be used for a given scheme.
69 if scheme
in Storage.storages:
70 raise RuntimeError(
"Scheme '%s' already registered:%s" % (scheme, Storage.storages[scheme]))
71 Storage.storages[scheme] = cls
74 """Get a RepositoryCfg from a location specified by uri.
76 If a cfg is found then it is cached by the uri, so that multiple lookups
77 are not performed on storages that might be remote.
79 RepositoryCfgs are not supposed to change once they are created so this
80 should not lead to stale data.
82 cfg = self.repositoryCfgs.get(uri,
None)
85 parseRes = urllib.parse.urlparse(uri)
86 if parseRes.scheme
in Storage.storages:
91 raise RuntimeError(
"No storage registered for scheme %s" % parseRes.scheme)
96 """Write a RepositoryCfg object to a location described by uri"""
98 parseRes = urllib.parse.urlparse(uri)
99 if parseRes.scheme
in Storage.storages:
102 raise RuntimeError(
"No storage registered for scheme %s" % parseRes.scheme)
107 """Get a mapper class cfg value from location described by uri.
109 Note that in legacy repositories the mapper may be specified by a file called _mapper at the uri
110 location, and in newer repositories the mapper would be specified by a RepositoryCfg stored at the uri
115 Storage is 'wet paint' and very likely to change during factorization of Butler back end and
116 storage formats (DM-6225). Use of it in production code other than via the 'old butler' API is
117 strongly discouraged.
121 parseRes = urllib.parse.urlparse(uri)
122 if parseRes.scheme
in Storage.storages:
125 raise RuntimeError(
"No storage registered for scheme %s" % parseRes.scheme)
130 '''Instantiate a StorageInterface sublcass from a URI.
134 Storage is 'wet paint' and very likely to change during factorization of Butler back end and
135 storage formats (DM-6225). Use of it in production code other than via the 'old butler' API is
136 strongly discouraged.
141 The uri to the root location of a repository.
142 create : bool, optional
143 If True The StorageInterface subclass should create a new
144 repository at the root location. If False then a new repository
149 A Storage subclass instance, or if create is False and a repository
150 does not exist at the root location then returns None.
155 When a StorageInterface subclass does not exist for the scheme
156 indicated by the uri.
159 parseRes = urllib.parse.urlparse(uri)
160 if parseRes.scheme
in Storage.storages:
161 theClass = Storage.storages[parseRes.scheme]
163 ret = theClass(uri=uri, create=create)
164 except NoRepositroyAtRoot:
167 raise RuntimeError(
"No storage registered for scheme %s" % parseRes.scheme)
172 """Test if a URI is for a local filesystem storage.
174 This is mostly for backward compatibility; Butler V1 repositories were only ever on the local
175 filesystem. They may exist but not have a RepositoryCfg class. This enables conditional checking for a
178 This function treats 'file' and '' (no scheme) as posix storages, see
179 the class docstring for more details.
184 URI to the root of a Repository.
189 True if the URI is associated with a posix storage, else false.
191 parseRes = urllib.parse.urlparse(uri)
192 if parseRes.scheme
in (
'file',
''):
198 """Get a relative path from a location to a location, if a relative path for these 2 locations exists.
203 A URI that describes a location at which to start.
205 A URI that describes a target location.
210 A relative path that describes the path from fromUri to toUri, provided one exists. If a relative
211 path between the two URIs does not exist then the entire toUri path is returned.
213 fromUriParseRes = urllib.parse.urlparse(fromUri)
214 toUriParseRes = urllib.parse.urlparse(toUri)
215 if fromUriParseRes.scheme != toUriParseRes.scheme:
217 storage = Storage.storages.get(fromUriParseRes.scheme,
None)
220 return storage.relativePath(fromUri, toUri)
224 """Get an absolute path for the path from fromUri to toUri
228 fromUri : the starting location
230 toUri : the location relative to fromUri
236 URI that is absolutepath fromUri + toUri, if one exists. If toUri is absolute or if fromUri is not
237 related to toUri (e.g. are of different storage types) then toUri will be returned.
239 fromUriParseRes = urllib.parse.urlparse(fromUri)
240 toUriParseRes = urllib.parse.urlparse(toUri)
241 if fromUriParseRes.scheme != toUriParseRes.scheme:
243 storage = Storage.storages.get(fromUriParseRes.scheme,
None)
246 return storage.absolutePath(fromUri, toUri)
250 """Look for the given path in a storage root at URI; return None if it can't be found.
252 If the path contains an HDU indicator (a number in brackets before the
253 dot, e.g. 'foo.fits[1]', this will be stripped when searching and so
254 will match filenames without the HDU indicator, e.g. 'foo.fits'. The
255 path returned WILL contain the indicator though, e.g. ['foo.fits[1]'].
261 URI to the the root location to search
263 A filename (and optionally prefix path) to search for within root.
268 The location that was found, or None if no location was found.
270 parseRes = urllib.parse.urlparse(uri)
271 storage = Storage.storages.get(parseRes.scheme,
None)
273 return storage.search(uri, path)
278 """Ask if a storage at the location described by uri exists
283 URI to the the root location of the storage
288 True if the storage exists, false if not
290 parseRes = urllib.parse.urlparse(uri)
291 storage = Storage.storages.get(parseRes.scheme,
None)
293 return storage.storageExists(uri)