[news.eclipse.modeling.mdt.uml2] Re: Performance question:Extending the

[cristian607@xxxxxxxxx (Cristian )]

Hello Vlad,

And thank you for your answer.

Actually in our project, we use both mechanisms (medium and advanced 
according to your terminology). We needed to add some new metaclasses that 
are not related to the UML elements, so we created a metamodel extension 
(so we have the code generation loop already).

As for the Profile/Stereotypes, we use it to store some additional 
information for Packages, Classes, Properties, etc. We access this 
additional information (read/write) quite often in our algorithm (code 
generation), where every additional operation has an important impact on 
the whole execution time.

And the question is if for the above case it's worth to use the metamodel 
approach instead of the stereotype based one. So from an architectural 
point of view we are very comfortable with the current implementation, but 
I think that when running our complex code generation algorithm the 
metamodel approach would improve performance.

Best regards,
Cristi.


Vlad Varnica wrote:

> Hi Cristi,

> I would say you have three options:
> - very light option is to add directly keywords on the needed UML 
> metamodel element (e.g. I mean on the UML Superstructure)
> - medium is to use a profile and within this profile to define stereotype. 
> Don't forget that the profile is only a project mechanism and a profile 
> should be added for each modeling project/
> - advanced is to use EMF/UML codegen mechanism

> We are using the light (e.g keywords) and medium (e.g. stereotype within a 
> profile) and don't have any performance problem. I like keywords option 
> because this is really easy. If your purpose is to extend UML in order to 
> cover DSL then profile is a better option for my point of view.
> If you want to create your DSL by creating a new model which is not 
> related to the UML Superstructure then I thin this is not the right 
> approach. You can use the UML superstructure and add stereotype and there 
> is no real need to create a new model superstructure which would be 
> specific.

> Your performance problem is not related to EclipseUML2 or EMF but only to 
> the way you use it. My recommendation would be to keep your project 
> modeling extensions simple and to have as few as possible transformation 
> stages.

> Vlad 
> Omondo