Mercurial: ac494b087feb

changeset 23100:ac494b087feb stable

revset: fix O(2^n) perf regression in addset hg log -r 1 ... -r 100 was never returning due to a regression in the way addset computes __nonzero__. It used 'bool(self._r1 or self._r2)' which required executing self._r1.__nonzero__ twice (once for the or, once for the bool). hg log with a lot of -r's happens to build a one sided addset tree of N length, which ends up being 2^N performance. This patch fixes it by converting to bool before or'ing. This problem can be repro'd with something as simple as: hg log `for x in $(seq 1 50) ; do echo "-r $x "; done` Adding '1 + 2 + ... + 20' to the revsetbenchmark.txt didn't seem to repro the problem, so I wasn't able to add a revset benchmark for this issue.

author Durham Goode <durham@fb.com>

date Tue, 28 Oct 2014 14:06:06 -0700

parents 6df4bc39f682

children b564330d4b1f

files mercurial/revset.py

diffstat

1 files changed, 1 insertions(+), 1 deletions(-) [+]

line wrap: on

line diff

--- a/mercurial/revset.py	Mon Oct 27 23:47:41 2014 -0500
+++ b/mercurial/revset.py	Tue Oct 28 14:06:06 2014 -0700
@@ -2500,7 +2500,7 @@
         return len(self._list)
 
     def __nonzero__(self):
-        return bool(self._r1 or self._r2)
+        return bool(self._r1) or bool(self._r2)
 
     @util.propertycache
     def _list(self):