On 12/4/06, Peter Leonard <[EMAIL PROTECTED]> wrote: > A second RDBO question - Does RDBO play nicely with Storable? Can I > freeze/thaw RDBO objects among various processes and get clean results? > (In a serial fashion, of course - I would not try to make updates to > the same object in several different places at once.)
Freeze/thawing an unmodified RDBO-derived object will probably not do what you want because each object has a back-pointer to the metadata object for that class (which, in turn, has code references inside it). When you thaw it, you may have already loaded that class, and will therefore end up with two metadata objects for the same class, one of which is "dangling" (i.e., not connected to the metadata "registry" that knows how to look up the metadata object for each class). I've tried to implement Storable hooks for "db" (Rose::DB) objects, mostly just to discard the DBI $dbh (which won't survive freeze/thaw anyway), and that experience has shown me that Storable's hooks are pretty limited. (Or maybe I'm just doing it wrong...) If anyone wants to take a crack at making Storable hooks for RDBO that enable safe, coherent freeze/thaw, by all means, take a crack at it :) In the meantime, I suggest looking at the various serialization-related Helper methods like, column_values_as_json() and column_values_as_yaml(), and their reverse methods, init_with_json() and init_with_yaml() http://search.cpan.org/dist/Rose-DB-Object/lib/Rose/DB/Object/Helpers.pm Even if you don't use them, you can look at the implementation and then make your own, similar methods that use Storable for serialization instead. It should be quite simple. The basic idea is not to serialize the entire object, but instead just serialize the column values. Deserialization then becomes simple instantiation and init()ialization with the thawed column values (+/- the futzing with column/method name mapping--again, check the code for examples). (Serializing a "tree" of nested RDBO-derived objects could be done using a similar approach for each object in the tree, plus a bit of extra info detailing how to hook things back up later, but it'd be considerably more complex than doing single objects. It's on my long-term list...) -John ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Rose-db-object mailing list Rose-db-object@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rose-db-object
