annotate: add a new experimental --skip option to skip revs This option is most useful for mechanical code modifications, especially ones that retain the same number of lines.

annotate: add core algorithm to skip a rev The core algorithm is inspired by git hyper-blame, implemented at https://chromium.googlesource.com/chromium/tools/depot_tools.git/+/master/git_hyper_blame.py. The heuristic is as documented in the comments.

annotate: make pair take all parents to pair against In upcoming patches we'll need to be aware of all parents at the same time. This also exposes a potential bug: if a line can be annotated with both parents of a merge commit, it'll always be annotated with p2, not p1. I'm not sure if that's what we want, but at least the code makes it clear now.

annotate: move pair function to top level We'll want to make this more complicated and have unit tests for it in upcoming patches.

bookmarks: fix check of hash-like name to not abort by ambiguous identifier 'mark in repo' may raise LookupError. I set it to not be warned since bookmark names shorter than 4 chars aren't checked and short names are likely to be ambiguous.

localrepo: document that __contains__() may raise LookupError

hidden: drop outdated comment about "dynamic" performance This comment is now irrelevant since we have a faster algorithm and no cache.

hidden: unify the static and dynamic blocker logic We no longer have cache and they both work the same way. Unifying the logic simplify the code and reduce the amount of set copies.

hidden: drop the hidden cache logic The improvement in time complexitty and the speed-up in computation is large enough that the has little use now. Its update time can even gets in the way. So we drop it. This will allow us to unify the static/dynamic blockers logic in the next changeset.

hidden: simplify the computation of consistency blocker For a couple of years, we now have precomputed set for all mutable phases. We can use this set restrict our search and quickly detect non-hideable children of hideable changesets. This speeds up the hidden computation. See docstring of the new function for details. This new version reuses the '_domainancestors' function to keep the computation of revealed changeset in O(len(visible)) Below are perfvolatilesets timing from two Mozilla repositories with different contents. hidden cache is disabled while obtaining them. 1) Mozilla repository with: * 400667 changesets * 35 hidden changesets (first rev-268334) * 288 visible drafts * 1 unstable changeset Before: ! visible ! wall 0.001744 comb 0.000000 user 0.000000 sys 0.000000 (best of 1563) After: ! visible ! wall 0.000742 comb 0.000000 user 0.000000 sys 0.000000 (best of 3755) The timing above include the computation of obsolete changeset: ! obsolete ! wall 0.000396 comb 0.000000 user 0.000000 sys 0.000000 (best of 6816) So adjusted time give 1.3ms before versus 0.3ms after. A 4x speedup. 2) Mozilla repository with: * 405645 changesets * 4312 hidden changesets (first rev-326004) * 264 visible drafts * 1 unstable changeset Before: ! visible ! wall 0.025476 comb 0.030000 user 0.030000 sys 0.000000 (best of 111) After ! visible ! wall 0.007703 comb 0.010000 user 0.010000 sys 0.000000 (best of 358) The timing above include the computation of obsolete changeset: ! obsolete ! wall 0.006408 comb 0.010000 user 0.010000 sys 0.000000 (best of 404) So adjusted time give 19ms before versus 1.3ms after. A 17x speedup.

hidden: use _domainancestors to compute revs revealed by dynamic blocker The complexity of computing the revealed changesets is now 'O(revealed)'. This massively speeds up the computation on large repository. Moving it to the millisecond range. Below are timing from two Mozilla repositories with different contents: 1) mozilla repository with: * 400667 changesets * 35 hidden changesets (first rev-268334) * 288 visible drafts * obsolete working copy (dynamicblockers), Before: ! visible ! wall 0.030247 comb 0.030000 user 0.030000 sys 0.000000 (best of 100) After: ! visible ! wall 0.000585 comb 0.000000 user 0.000000 sys 0.000000 (best of 4221) The timing above include the computation of obsolete changeset: ! obsolete ! wall 0.000396 comb 0.000000 user 0.000000 sys 0.000000 (best of 6816) So adjusted time give 30ms before versus 0.2ms after. A 150x speedup. 2) mozilla repository with: * 405645 changesets * 4312 hidden changesets (first rev-326004) * 264 visible drafts * obsolete working copy (dynamicblockers), Before: ! visible ! wall 0.168658 comb 0.170000 user 0.170000 sys 0.000000 (best of 48) After ! visible ! wall 0.008612 comb 0.010000 user 0.010000 sys 0.000000 (best of 325) The timing above include the computation of obsolete changeset: ! obsolete ! wall 0.006408 comb 0.010000 user 0.010000 sys 0.000000 (best of 404) So adjusted time give 160ms before versus 2ms after. A 75x speedup.

hidden: add a function returning ancestors of revs within a domain See documentation for details. This will be used to improve the hidden computation algorithm. See new changesets for usage.