This class encapsulates all of the gdbm protocol for
saving and retrieving user records. It is a container
class for UserRecord instances; see Section 7.28, “class UserRecord”. Its interface is
dictionary-like, with user ID values as the keys.
reader.cgi
# - - - - - c l a s s U s e r D a t a b a s e
class UserDatabase:
'''Represents the file of user records.
Exports:
UserDatabase():
[ file DB_NAME can be opened read-write ->
return a UserDatabase instance representing that file ]
.__getitem__ ( self, userId ):
[ if self contains an entry for user (userId) ->
return that user's data as a UserRecord instance
else -> raise KeyError ]
.__setitem__ ( self, userId, userRecord ):
[ (userId is a string) and
(userRecord is a UserRecord instance) ->
self := self with userRecord stored under key (userId) ]
.__delitem__ ( self, userId ):
[ userId is a string ->
self := self with nothing stored under key (userId) ]
.cleanup():
[ self := self minus all entries whose expiration is
in the past ]
.close():
[ self := self closed ]
State/Invariants:
.__db: [ a gdbm.gdbm instance connected to file DB_NAME ]
'''
