[infinispan-dev] keySet(), values() and entrySet() impl progress and some questions

[Manik Surtani]

On 9 Jun 2009, at 16:08, Galder Zamarreno wrote:

> Hi all,
>
> I'm making good progress with https://jira.jboss.org/jira/browse/ISPN-94 
> . I'm currently testing that with DIST mode, only local contents are  
> returned.
>
> We had agreed that these operations should not be participating in  
> transactions and I assume that this is so that locks are not  
> acquired. From what I understand, to achieve this, CacheDelegate  
> method implementation would need to pass a  
> icc.createNonTxInvocationContext(), correct?

Something for Mircea to confirm.

> We also agreed that we needed to document the limitations in javadoc  
> but in which javadoc? Obviously, Map javadoc cannot be touched, so I  
> suppose we should redefine the ops in the Cache interface and  
> document them there, correct?

Yes, plus also have a paragraph on the class-level Javadoc on Cache.

> Finally, one note about the MVI. As per an IRC conversation with  
> Manik, the collections returned by these methods need to be modified  
> so that marshalled values are swapped by real values. The  
> collections returned by these methods are not currently ready to be  
> mutable so instead I've gone for the copying option changing the  
> marshalled values to the real objects.
>
> I've taken this decision because:
> - The implementation was simpler by just copying.
> - Not sure there's much point in implementing mutable collections  
> for the return of these methods if we're only gonna need to mutate  
> them for the marshalled value edge case. The one advantage of  
> mutable collections would be the ability to swap the marshalled  
> values directly without copying, hence memory consumption would less.
> - Remember that these collection returning methods should primarily  
> used for debugging and not for production, hence the extra memory  
> consumption for these type of methods doesn't sound like such a bad  
> thing.

Yes, I agree.  In general this sentiment should be reflected in the  
Javadocs as well: that these methods are not recommended for anything  
important, and they only exist to meet the Map contract.

Cheers
Manik

> Thoughts?
> -- 
> Galder Zamarreño
> Sr. Software Maintenance Engineer
> JBoss, a division of Red Hat
> _______________________________________________
> infinispan-dev mailing list
> infinispan-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/infinispan-dev

--
Manik Surtani
manik at jboss.org
Lead, Infinispan
Lead, JBoss Cache
http://www.infinispan.org
http://www.jbosscache.org