revlog: optimize ancestors() to not check filtered revisions for each
While reviewing the Rust implementation, I noticed iter(ancestors) doesn't
need to check filtering state for each parent revision. And doing that appears
to have some measurable perf win.
$ hg perfancestors -R mercurial
(orig) wall 0.038093 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)
(this) wall 0.024795 comb 0.020000 user 0.020000 sys 0.000000 (best of 117)
Our full contribution guidelines are in our wiki, please see:
https://www.mercurial-scm.org/wiki/ContributingChanges
If you just want a checklist to follow, you can go straight to
https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist
If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).