D7118: rust-dirstatemap: remove additional lookups in traverse

[Alphare (Raphaël Gomès)]

Alphare added a comment.


  In D7118#104834 <https://phab.mercurial-scm.org/D7118#104834>, @yuja wrote:
  
  >> +++ b/mercurial/dirstate.py
  >> @@ -919,6 +919,9 @@
  >>
  >>   matchalways = match.always()
  >>   matchtdir = match.traversedir
  >>   dmap = self._map
  >>
  >> +        if rustmod is not None:
  >> +            dmap = self._map._rustmap
  >
  > If it's the same trick, can't it be abstracted away? `if rustmod` seems weird.
  
  The main issue I faced is that Python classes built from `rust-cpython` cannot be subclassed, so we have to resort to an additional level of indirection. IIRC, the main reason was that there was no way of enforcing a subclass to call `super()` which would result in the Rust class not being initialized properly. Or maybe I'm missing the point?

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D7118/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D7118

To: Alphare, #hg-reviewers
Cc: yuja, mercurial-devel