discovery: using the new basesheads()
Our ultimate goal is to switch eventually to a Rust implementation, but
this move actually seems to increase the performance in a pure Python
build.
What follows is a quick measurement done on PyPy on repos prepared with
`contrib/discovery-helper.sh 50 100`.
Before:
! wall 0.894384 comb 0.890000 user 0.890000 sys 0.000000 (best of 11)
! wall 0.971199 comb 0.970000 user 0.950000 sys 0.020000 (max of 11)
! wall 0.927993 comb 0.925455 user 0.919091 sys 0.006364 (avg of 11)
! wall 0.921619 comb 0.920000 user 0.910000 sys 0.010000 (median of 11)
After:
! wall 0.614278 comb 0.610000 user 0.610000 sys 0.000000 (best of 14)
! wall 0.789459 comb 0.790000 user 0.770000 sys 0.020000 (max of 14)
! wall 0.722765 comb 0.720000 user 0.715714 sys 0.004286 (avg of 14)
! wall 0.734448 comb 0.720000 user 0.720000 sys 0.000000 (median of 14)
Differential Revision: https://phab.mercurial-scm.org/D5583
--- a/mercurial/setdiscovery.py Mon Jan 14 18:36:09 2019 +0100
+++ b/mercurial/setdiscovery.py Mon Jan 14 18:52:01 2019 +0100
@@ -229,9 +229,7 @@
"""the heads of the known common set"""
# heads(common) == heads(common.bases) since common represents
# common.bases and all its ancestors
- # The presence of nullrev will confuse heads(). So filter it out.
- return set(self._repo.revs('heads(%ld)',
- self._common.bases - {nullrev}))
+ return self._common.basesheads()
def findcommonheads(ui, local, remote,
initialsamplesize=100,