revset: changed limit revset implementation to work with lazy revsets
Performance benchmarking:
$ time hg log -qr "first(branch(default))"
0:9117c6561b0b
real 0m3.130s
user 0m3.025s
sys 0m0.074s
$ time ./hg log -qr "first(branch(default))"
0:9117c6561b0b
real 0m0.300s
user 0m0.198s
sys 0m0.069s
--- a/mercurial/revset.py Wed Feb 05 16:12:03 2014 -0800
+++ b/mercurial/revset.py Tue Jan 28 16:19:30 2014 -0800
@@ -944,8 +944,17 @@
# i18n: "limit" is a keyword
raise error.ParseError(_("limit expects a number"))
ss = subset.set()
- os = getset(repo, baseset(repo), l[0])[:lim]
- return baseset([r for r in os if r in ss])
+ os = getset(repo, baseset(repo), l[0])
+ bs = baseset([])
+ it = iter(os)
+ for x in xrange(lim):
+ try:
+ y = it.next()
+ if y in ss:
+ bs.append(y)
+ except (StopIteration):
+ break
+ return bs
def last(repo, subset, x):
"""``last(set, [n])``