[Spambayes] locking pickle/dbm against concurrent access?

[Skip Montanaro]

    >>>> Skip Montanaro wrote
    >> Depending how your training works you might wind up copying a 20+MB
    >> file for each message.

    Anthony> Copying? When? You'd write out the new pickles, sure, but you
    Anthony> have to do that, anyway.

How do you get the temp file from the real file without copying it?  If I
understand the way things work, you'd do something like

    * copy real to temp
    * train on new messages
    * update temp
    * move temp back to real (the atomic part we all want)

Skip