[Spambayes-checkins] spambayes/spambayes storage.py,1.18,1.19

[Tony Meyer]

Update of /cvsroot/spambayes/spambayes/spambayes
In directory sc8-pr-cvs1:/tmp/cvs-serv1266/spambayes

Modified Files:
	storage.py 
Log Message:
Add a function that will return the appropriate storage object given the data source
name.  This means that pop3proxy, imapfilter, hammie et al can all use the same
code to open up the storage object.

Also add a bit to this function to hopefully preempt lots of people complaining because
dumbdbm no longer works and explain to them what to do.

Index: storage.py
===================================================================
RCS file: /cvsroot/spambayes/spambayes/spambayes/storage.py,v
retrieving revision 1.18
retrieving revision 1.19
diff -C2 -d -r1.18 -r1.19
*** storage.py	7 Aug 2003 05:04:09 -0000	1.18
--- storage.py	25 Aug 2003 08:48:56 -0000	1.19
***************
*** 572,575 ****
--- 572,621 ----
          Trainer.__init__(self, bayes, False, updateprobs)
  
+ class NoSuchClassifierError(Exception):
+     def __init__(self, invalid_name):
+         self.invalid_name = invalid_name
+     def __str__(self):
+         return repr(self.invalid_name)
+ 
+ _storage_types = {"dbm" : DBDictClassifier,
+                   "pickle" : PickledClassifier,
+                   "pgsql" : PGClassifier,
+                   "mysql" : mySQLClassifier,
+                   }
+ 
+ def open_storage(data_source_name, useDB=True):
+     '''Return a storage object appropriate to the given parameters.
+ 
+     By centralizing this code here, all the applications will behave
+     the same given the same options.
+ 
+     If useDB is false, a pickle will be used, otherwise if the data
+     source name includes "::", whatever is before that determines
+     the type of database.  If the source name doesn't include "::",
+     then a DBDictClassifier is used.'''
+     if useDB:
+         if '::' in data_source_name:
+             db_type, rest = data_source_name.split('::', 1)
+             if _storage_types.has_key(db_type.lower()):
+                 klass = _storage_types[db_type.lower()]
+                 data_source_name = rest
+             else:
+                 raise NoSuchClassifierError(db_type)
+         else:
+             klass = DBDictClassifier
+     else:
+         klass = PickledClassifier
+     try:
+         return klass(data_source_name)
+     except dbmstorage.error, e:
+         if str(e) == "No dbm modules available!":
+             # We expect this to hit a fair few people, so warn them nicely,
+             # rather than just printing the trackback.
+             print """You do not have a dbm module available to use.  You
+ need to either use a pickle (see the FAQ), use Python 2.3 (or above), or
+ install a dbm module such as bsddb (see http://sf.net/projects/pybsddb)."""
+             import sys
+             sys.exit()
+ 
  
  if __name__ == '__main__':