discovery: compute newly discovered missing in a more efficient way
Calling "descendants" is expensive, instead, we bound the walk inside the know set
of undecided revision.
This help with discovery performance:
# without the revset '%ld' improvement
$ hg perfdiscovery -R pypy-left pypy-right
before: wall 0.675631 comb 0.680000 user 0.670000 sys 0.010000 (median of 15)
after: wall 0.520145 comb 0.530000 user 0.510000 sys 0.020000 (median of 19)
There is another series in flight that greatly improves performances of "%ld"
substitution in `repo.revs` call. If this changeset is applied above it, we
see a similar performance boost.
# with the revset '%ld' improvement
$ hg perfdiscovery -R pypy-left pypy-right
before: wall 0.477848 comb 0.480000 user 0.480000 sys 0.000000 (median of 22)
after: wall 0.404163 comb 0.400000 user 0.400000 sys 0.000000 (median of 24)
--- a/mercurial/setdiscovery.py Thu Jan 17 00:16:00 2019 -0500
+++ b/mercurial/setdiscovery.py Fri Jan 04 16:04:48 2019 +0100
@@ -187,14 +187,10 @@
def addmissings(self, missings):
"""registrer some nodes as missing"""
- if self.missing:
- new = self._repo.revs('descendants(%ld) - descendants(%ld)',
- missings, self.missing)
- self.missing.update(new)
- else:
- self.missing.update(self._repo.revs('descendants(%ld)', missings))
-
- self.undecided.difference_update(self.missing)
+ newmissing = self._repo.revs('%ld::%ld', missings, self.undecided)
+ if newmissing:
+ self.missing.update(newmissing)
+ self.undecided.difference_update(newmissing)
def addinfo(self, sample):
"""consume an iterable of (rev, known) tuples"""