Excerpts from Stanislau Hlebik's message of 2017-02-16 19:39:07 +0000:
> Excerpts from Stanislau Hlebik's message of 2017-02-14 09:29:25 +0000:
> > Excerpts from Sean Farley's message of 2017-02-13 18:30:25 -0800:
> > > Jun Wu <qu...@fb.com> writes:
> > >
> > > > Excerpts from Sean Farley's message of 2017-02-13 17:04:35 -0800:
> > > >> I was thinking about a more high-level approach (please feel free to
> > > >> pick apart):
> > > >>
> > > >> r = repo.filtered("bitmap1")
> > > >> r2 = r.filtered("bitmap2")
> > > >>
> > > >> So that r2 would be an intersection of bitmap1 and bitmap2 (haven't
> > > >> thought about a union nor the inverse).
> > > >
> > > > That does not conflict with my comments. It could be implemented as
> > > > nested
> > > > filters, or flatten the bitmap by doing an "or" operation.
> > >
> > > Righto. Just wanted to bring it up early before things are set in stone.
> >
> > Current `repoview.filtered()` implementation can apply only one filter. I
> > think it will be error-prone to change it, won't it?
>
> It seems that it's better to use sorted lists instead of bitmaps. In a
> couple of places it is expected that repo.filteredrevs supports
> iteration. But iteration over a bitmap is very slow. Instead we can
> store list of non-public revs and list of precursor revs and load them
> in a set.
>
> It will be slow for the case where repo has lots of draft commits.
> In this case it's probably better to disable this feature completely.
I think it's fine to have slow iteration, as long as the iteration operation
is uncommon. The point is, the most common operation should be fast - that
is, ishidden(rev) should be fast. Stateful chg will help the read-only case,
the bitmap + mmap would ideally make write (like rebase) cases fast.
Some code can be changed - "scmutil.filteredhash" seems to be one user that
iterates "filteredrevs". But what it needs is only a hash - it could hash
something else, like the mtime, size etc.
Bitmaps could also be smarter - like maintaining the min and max revisions
so it does not need to be exactly len(repo).
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