RE: [OJB-developers] ObjectCache and IdentityFactory]

[Mahler T. <tho...@it...>]

Hi Florian,

> Hi!
> 
> I'm currently investigating how to improve the object cache and how to
> create a "factory" for Identity objects.
> 
> The object cache already stores identities and objects in a 
> HashMap, but
> unfortunately you cannot retrieve the key of a value from a HashMap
> reasonably. The idea is now to create a "DoubleHashMap" that 
> maps keys to
> values and values to keys in an efficient way using SoftReferences.

If I get you right, you want to use the already existing ObjectCache to
serve also a Identity cache.
That's a cool idea !

<snip>
> 
> Now the questions:
> 
> - Do you think this approach is valid and is it worth to pursue it
> 

Yes !!!

> - Does anybody know of an implementation of this concept (I known the
> jakarta project has a somewhat related class, but it is a 
> DoubleTreeMap and
> we do not need the overhead of sorting the objects).
>

in class ObjectEnvelopeTable we have somewhat similar problem that requires
to maintain a HashMap and a List to have two independend views on the Table
of ObjectEnvelopes registered to a transaction.

Maybe you find some inspiration there.

My general suggestion: Keep it simple. Better to waste some memory by
maintaining two hashtables than building a too difficult solution.
 
Thomas