revset: translate node directly with changelog in 'head'
Using 'repo[X]' is much slower because it creates a 'changectx' object and goes
though multiple layers of code to do so. It is also error prone if there is
tags, bookmarks, branch or other names that could map to a node hash and take
precedence (user are wicked).
This provides a significant performance boost on repository with a lot of
heads. Benchmark result for a repo with 1181 heads.
revset: head()
plain min last reverse
0) 0.014853 0.014371 0.014350 0.015161
1) 0.001402 9% 0.000975 6% 0.000874 6% 0.001415 9%
revset: head() - public()
plain min last reverse
0) 0.015121 0.014420 0.014560 0.015028
1) 0.001674 11% 0.001109 7% 0.000980 6% 0.001693 11%
revset: draft() and head()
plain min last reverse
0) 0.015976 0.014490 0.014214 0.015892
1) 0.002335 14% 0.001018 7% 0.000887 6% 0.002340 14%
The speed up is visible even when other more costly revset are in use
revset: head() and author("mpm")
plain min last reverse
0) 0.105419 0.090046 0.017169 0.108180
1) 0.090721 86% 0.077602 86% 0.003556 20% 0.093324 86%
--- a/contrib/all-revsets.txt Wed Jun 10 19:58:27 2015 -0700
+++ b/contrib/all-revsets.txt Tue Jun 16 19:47:46 2015 -0700
@@ -118,3 +118,9 @@
# those two `roots(...)` inputs are close to what phase movement use.
roots((tip~100::) - (tip~100::tip))
roots((0::) - (0::tip))
+
+# Testing the behavior of "head()" in various situations
+head()
+head() - public()
+draft() and head()
+head() and author("mpm")
--- a/mercurial/revset.py Wed Jun 10 19:58:27 2015 -0700
+++ b/mercurial/revset.py Tue Jun 16 19:47:46 2015 -0700
@@ -1107,8 +1107,9 @@
# i18n: "head" is a keyword
getargs(x, 0, 0, _("head takes no arguments"))
hs = set()
+ cl = repo.changelog
for b, ls in repo.branchmap().iteritems():
- hs.update(repo[h].rev() for h in ls)
+ hs.update(cl.rev(h) for h in ls)
# XXX using a set to feed the baseset is wrong. Sets are not ordered.
# This does not break because of other fullreposet misbehavior.
# XXX We should not be using '.filter' here, but combines subset with '&'