The draft() & ::x type query could be common for selecting one or more
draft feature branches being worked on.
Before this patch, ::x may travel through the changelog DAG for a long
distance until it gets a smaller revision number than min(draft()). It
could be very slow on long changelog with distant (in terms of revision
numbers) drafts.
This patch adds a fast path for this situation, and will stop traveling the
changelog DAG once ::x hits a non-draft revision.
The fast path also works for secret() and not public().
To measure the performance difference, I used drawdag to create a repo that
emulates distant drafts:
DRAFT4 | DRAFT3 # draft / PUBLIC9999 # public | PUBLIC9998 | . DRAFT2 . | . DRAFT1 # draft | / PUBLIC0001 # public
And measured the performance using the repo:
(BEFORE) $ hg perfrevset 'draft() & ::(DRAFT2+DRAFT4)' ! wall 0.017132 comb 0.010000 user 0.010000 sys 0.000000 (best of 156) $ hg perfrevset 'draft() & ::(all())' ! wall 0.024221 comb 0.030000 user 0.030000 sys 0.000000 (best of 113) (AFTER) $ hg perfrevset 'draft() & ::(DRAFT2+DRAFT4)' ! wall 0.000243 comb 0.000000 user 0.000000 sys 0.000000 (best of 9303) $ hg perfrevset 'draft() & ::(all())' ! wall 0.004319 comb 0.000000 user 0.000000 sys 0.000000 (best of 655)
Could use revs.filter instead.