Source Code for Module gavo.registry.identifiers

 1  """ 
 2  Parsing identifiers, getting res tuples and resobs from them. 
 3   
 4  The DC-internal identifiers are, by default, formed as 
 5  ivo://<authority-from-config>/<sourceRD path>/<id within path>. 
 6   
 7  Thus, all renderers of a given service have the same ivo-id, which is 
 8  to say, they are all just capabilities on the same record. 
 9  """ 
10   
11  #c Copyright 2008-2019, the GAVO project 
12  #c 
13  #c This program is free software, covered by the GNU GPL.  See the 
14  #c COPYING file in the source distribution. 
15   
16   
17  import re 
18   
19  from gavo import base 
20  from gavo.registry import common 
21  from gavo.registry import nonservice 
22  from gavo.registry import servicelist 
23   
24   
25 -def computeIdentifierFromRestup(restup): 
26          """returns an identifier from a res tuple. 
27          """ 
28          return restup["ivoid"] 
29   
30   
31  _idPattern = re.compile("ivo://(\w[^!;:@%$,/]+)(/[^?#]*)?") 
32   
33 -def parseIdentifier(identifier): 
34          """returns a pair of authority, resource key for identifier. 
35   
36          Identifier has to be an ivo URI. 
37   
38          In the context of the gavo DC, the resource key either starts with 
39          static/ or consists of an RD id and a service ID. 
40          """ 
41          mat = _idPattern.match(identifier) 
42          if not mat: 
43                  raise common.IdDoesNotExist(identifier) 
44          return mat.group(1), (mat.group(2) or "")[1:] 
45   
46   
47 -def getRestupFromIdentifier(identifier): 
48          """returns the record for identifier in the services table. 
49          """ 
50          matches = servicelist.queryServicesList( 
51                  "ivoid=%(identifier)s", 
52                  locals(), tableName="resources") 
53          if len(matches)!=1: 
54                  raise common.IdDoesNotExist(identifier) 
55          return matches[0] 
56   
57   
58 -def getResobFromRestup(restup): 
59          """returns a resob for a res tuple. 
60   
61          restup at least has to contain the sourceRD and resId fields. 
62   
63          The item that is being returned is either a service or a 
64          NonServiceResource (including DeletedResource).  All of these have 
65          a getMeta method and should be able to return the standard DC 
66          metadata. 
67          """ 
68          if restup["deleted"]: 
69                  return base.makeStruct(nonservice.DeletedResource, 
70                          resTuple=restup) 
71          sourceRD, resId = restup["sourceRD"], restup["resId"] 
72          try: 
73                  return base.caches.getRD(sourceRD).getById(resId) 
74          except KeyError: 
75                  raise base.ui.logOldExc(base.NotFoundError(resId, what="service", 
76                          within="RD %s"%sourceRD, hint="This usually happens when you" 
77                          " forgot to run gavopublish %s"%sourceRD)) 
78   
79   
80 -def getResobFromIdentifier(identifier): 
81          """returns a resob for an identifier. 
82          """ 
83          return getResobFromRestup(getRestupFromIdentifier(identifier)) 
84