pli/persistance/sql/shelve.py

   1 #=======================================================================
   2
   3 __version__ = '''0.0.01'''
   4 __sub_version__ = '''20051010153516'''
   5 __copyright__ = '''(c) Alex A. Naanou 2003'''
   6
   7
   8 #-----------------------------------------------------------------------
   9
  10 import pli.pattern.mixin.mapping as mapping
  11
  12
  13 #-----------------------------------------------------------SQLShelve---
  14 ##!!!
  15 # XXX should this be live???
  16 class SQLShelve(mapping.Mapping):
  17         '''
  18         '''
  19         # TODO make this create a new dict for the id if one is not
  20         #      present.... (might be a good idea to use some other id
  21         #      method...)
  22         #      one alternative id method is to create a root dict that will
  23         #      contain names of all the dicts used and their coresponding
  24         #      id's...
  25         def __init__(self, interface, name):
  26                 '''
  27                 '''
  28                 self._interface = interface
  29                 self._name = name
  30                 # if such a name does not exist...
  31                 try:
  32                         self._data = interface.get(name)
  33                 except KeyError:
  34                         d = self._data = {}
  35                         interface.write(name, d)
  36                 ##!!! sanity check: if the name refereneces a non-dict or non-dict-like...
  37                 ##!!!
  38         def __getitem__(self, name):
  39                 '''
  40                 '''
  41                 if name in self._data:
  42                         return self._interface.get(self._data[name])
  43                 raise KeyError, name
  44         ##!!! make this safe...
  45         def __setitem__(self, name, value):
  46                 '''
  47                 '''
  48                 data = self._data
  49                 # insert the object...
  50                 oid = self._interface.write(value)
  51                 # update the keys dict...
  52                 data[name] = oid
  53                 self._interface.write(data)
  54         def __delitem__(self, name):
  55                 '''
  56                 '''
  57                 return self._interface.delete(self._data.pop(name))
  58         def __iter__(self):
  59                 '''
  60                 '''
  61                 for name in self._data:
  62                         yield name
  63
  64
  65
  66 #=======================================================================
  67 #                                            vim:set ts=4 sw=4 nowrap :