Re: Detachment contract

[Craig Russell]

Hi Geoff, Thanks for the feedback. On Jul 13, 2005, at 12:56 PM, Geoff hendrey wrote: <AMEN> The jdoDetachedState is an Object[ ] that consists of: { Object objectId, Object version, BitSet loadedFields, BitSet modifiedFields } </AMEN> I also think it would be a nice improvement to make loadedFields and modifiedFields accessible and useable for non-detached classes. It's in good keeping with Law of Demeter to keep this information as close to the source as possible, instead of forcing the StateManager  to track it. We'd need to add jdoGetLoadedFields() and jdoGetModifiedFields().  Or is there some reason this wouldn't work or doesn't make sense? I'm not sold on the idea that we should make a user api out of these. We have survived the past 5 years without making this internal state visible, and I personally never heard anyone asking for it. I don't believe that requiring the State Manager to track loaded and modified fields violates the Law of Demeter (of which I am a huge fan, by the way). It is specifically *not* the responsibility or the concern of the Persistence Capable instance to know whether a field is loaded or modified. It *is* the responsibility of the State Manager to know this and to enforce the policy of the JDO implementation. In fact, the way the PC/SM contract is written, the PC doesn't know which fields are loaded.  However, there is a valid reason for making the information standard when it is being externalized for detachment. The PC must be responsible for this information while detached. But it's arguably not the most efficient  way to have the State Manager handle it, and it's not even required for the State Manager to keep the information in this form until externalization. So I would be against the requirement to have the State Manager track loaded and modified fields using this technique. And against the requirement to expose this state to user code. Others? Craig -geoff          ____________________________________________________ Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs Craig Russell Architect, Sun Java Enterprise System http://java.sun.com/products/jdo 408 276-5638 mailto:[EMAIL PROTECTED] P.S. A good JDO? O, Gasp!

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