D392: util: add base class for transactional context managers

[indygreg (Gregory Szorc)]

indygreg requested changes to this revision.
indygreg added inline comments.
This revision now requires changes to proceed.

INLINE COMMENTS

> util.py:597-601
> +    def close(self):
> +        raise NotImplementedError
> +
> +    def release(self):
> +        raise NotImplementedError

How do you feel about changing this to use `abc.ABCMeta` so the interface is enforced as type creation time? I'm doing this in https://phab.mercurial-scm.org/D332 and people seem to be on board.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D392

To: martinvonz, #hg-reviewers, indygreg
Cc: indygreg, mercurial-devel