diff contrib/perf.py @ 18091:f7f8159caad3

ancestor: add lazy membership testing to lazyancestors

This also makes the perfancestorset command use lazy membership testing. In a
linear repository with over 400,000 commits, without this patch, hg
perfancestorset takes 0.80 seconds no matter how far behind we're looking.
With this patch, hg perfancestorset -- X takes:

    Rev X       Time
       -1      0.00s
    -4000      0.01s
   -20000      0.04s
   -80000      0.17s
  -200000      0.43s
  -300000      0.69s
        0      0.88s

Thus, for revisions close to tip, we're up to several orders of magnitude
faster. At 0 we're around 10% slower.

--- a/contrib/perf.py	Tue Dec 18 10:14:01 2012 -0800
+++ b/contrib/perf.py	Tue Dec 18 12:47:20 2012 -0800
@@ -82,7 +82,7 @@
     revs = repo.revs(revset)
     heads = repo.changelog.headrevs()
     def d():
-        s = set(repo.changelog.ancestors(heads))
+        s = repo.changelog.ancestors(heads)
         for rev in revs:
             rev in s
     timer(d)