[Nepomuk] Refactoring for Soprano 3

[Evgeny Egorochkin]

В сообщении от Вторник 13 октября 2009 17:57:58 автор Sebastian Trüg написал:
> Soprano 2 IMHO has a nice design. Backend, Model, and FilterModel suited my
> needs very well and were nice to use. But now it slowly reaches its limits.
> 
> With Virtuoso the introduction of transactions become very important. I
>  tried to stack them on top of Model as you can see in the experimental
>  branch[1] but the resulting design is flawed and cannot be any different
>  since we need to stay binary compatible for KDE.
> 
> Thus, it is time for a redesign and also time for you to state your needs
>  and ideas.
> 
> Attached you find a preliminary design in the form of a crude UML diagram.
>  It is based on the sesame2 idea of Respository vs. RespositoryConnection.
> 
> A few words of explanation:
> - Model is split into two classes Repository and RepositoryConnection.
>   Each RespositoryConnection represents its own transaction object, i.e.
>   can perform multiple transactions.
> - A Repository can create an arbitrary number of RespositoryConnection
>   objects.
> - Backend is now RepositoryFactoy (better name welcome). It is used to
>   create StorageRepositories which replace StorageModel and have settings
>   like storage dir and the like.

Backend does sound a lot better than RepositoryFactory :)
Thesaurus says that repository is synonymous to all other storage-related 
words so you aren't likely to find a better and meaningful name than this:
cache, depot, repository, stash, stockpile, vault, warehouse.

Or can get creative and say come up with MetaRepository, SuperRepository, or 
Storage?

> - FilterRepository and FilterRepositoryConnection replace the current
>   FilterModel.
>   A FilterRepository would need to create its own connections which carry
>   as a member a parent connection created by the parent Repository.
> 
> This is the basis I would like to start the discussion from.

This sounds ok. Hope it won't add too much overhead though.

> Another issue is inference which I would like to integrate deeper into
> Soprano. The straight forward design would be to add a flags parameter to
> method like query() and listStatements() which can for example be
> EnableInference.

If you want it to be black and white, this is the way to go. We need to make 
sure this is enough...

-- Evgeny