Mercurial > hg
changeset 22450:95af98616aa7
revset: make parents() O(number of parents)
Strip executes a revset like this:
max(parents(_intlist('1234\x001235')) - _intlist('1234\x001235'))
Previously the parents() revset would do 'subset & parents' which iterates over
each item in the subset and checks if it's in parents. subset is usually the
entire repo (a spanset) so this takes a while.
Reversing the parameters to be 'parents & subset' means the operation becomes
O(number of parents) instead of O(size of repo). It also means the result gets
evaluated immediately (since parents isn't a lazy set), but I think this is a
win in most scenarios.
This shaves 0.3 seconds off strip (amend/histedit/rebase/etc) for large repositories.
revset #0: parents(20000)
0) obsolete feature not enabled but 54243 markers found!
! wall 0.006256 comb 0.010000 user 0.010000 sys 0.000000 (best of 289)
1) obsolete feature not enabled but 54243 markers found!
! wall 0.000391 comb 0.000000 user 0.000000 sys 0.000000 (best of 4323)
| author | Durham Goode <durham@fb.com> |
|---|---|
| date | Fri, 12 Sep 2014 15:00:51 -0700 |
| parents | da05fe01170b |
| children | 186fd06283b4 |
| files | contrib/revsetbenchmarks.txt mercurial/revset.py tests/test-revset.t |
| diffstat | 3 files changed, 3 insertions(+), 2 deletions(-) [+] |
line wrap: on
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--- a/contrib/revsetbenchmarks.txt Fri Sep 12 16:21:13 2014 -0700 +++ b/contrib/revsetbenchmarks.txt Fri Sep 12 15:00:51 2014 -0700 @@ -23,4 +23,5 @@ max(::(tip~20) - obsolete()) roots((0:tip)::) (not public() - obsolete()) +parents(20000) (20000::) - (20000)
--- a/mercurial/revset.py Fri Sep 12 16:21:13 2014 -0700 +++ b/mercurial/revset.py Fri Sep 12 15:00:51 2014 -0700 @@ -1236,7 +1236,7 @@ cl = repo.changelog for r in getset(repo, spanset(repo), x): ps.update(cl.parentrevs(r)) - return subset & ps + return baseset(ps) & subset def parentspec(repo, subset, x, n): """``set^0``