Mercurial > hg
changeset 18063:34a1a639d835
revset.children: ignore rev numbers that are too low
This replaces unnecessary parentrevs() calls with calculating min(parentset).
Even though the min operation is O(size of parentset), since parentrevs is
relatively expensive, this tradeoff almost always works in our favour. In a
repository with over 400,000 changesets, hg perfrevset "children(X)" takes:
Set X Before After
-1 0.51s 0.06s
-1000: 0.55s 0.08s
-10000: 0.56s 0.10s
-100000: 0.60s 0.25s
-100000:-99000 0.55s 0.19s
0:100000 0.60s 0.61s
all() 0.72s 0.74s
The relative performance is similar for Mercurial's own repository -- several
times faster in most cases, slightly slower for revisions close to 0 and
all().
| author | Siddharth Agarwal <sid0@fb.com> |
|---|---|
| date | Fri, 07 Dec 2012 10:37:43 -0800 |
| parents | 1471f5e83686 |
| children | 2acd9c14b0d7 |
| files | mercurial/revset.py |
| diffstat | 1 files changed, 5 insertions(+), 0 deletions(-) [+] |
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--- a/mercurial/revset.py Thu Dec 06 11:21:11 2012 -0800 +++ b/mercurial/revset.py Fri Dec 07 10:37:43 2012 -0800 @@ -488,8 +488,13 @@ def _children(repo, narrow, parentset): cs = set() + if not parentset: + return cs pr = repo.changelog.parentrevs + minrev = min(parentset) for r in narrow: + if r <= minrev: + continue for p in pr(r): if p in parentset: cs.add(r)