diff mercurial/changegroup.py @ 19708:fd4f612f7cb6 stable

bundle: fix performance regression when bundling file changes (issue4031)

Somewhere before 2.7, a change [ec896f9e8894] was committed that
entailed a large performance regression when bundling (and therefore
remote cloning) repositories. For each file in the repository, it would
recompute the set of needed changesets even though it is the same for
all files. This computation would dominate bundle runtimes according to
profiler output (by 10x or more).

--- a/mercurial/changegroup.py	Tue Aug 06 00:52:06 2013 +0400
+++ b/mercurial/changegroup.py	Sat Sep 07 21:20:00 2013 +0200
@@ -354,11 +354,11 @@
         progress(msgbundling, None)
 
         mfs.clear()
+        needed = set(cl.rev(x) for x in clnodes)
 
         def linknodes(filerevlog, fname):
             if fastpathlinkrev:
                 ln, llr = filerevlog.node, filerevlog.linkrev
-                needed = set(cl.rev(x) for x in clnodes)
                 def genfilenodes():
                     for r in filerevlog:
                         linkrev = llr(r)