Optimize manifest.add Testing shows that manifest.add is spending a significant percentage of its time running calcoffsets and doing text = "".join(addlist). This patch removes the need for both of these by storying the manifest in a character array, and using a modified bisect search to find lines without the help of a separate index of line offsets. manifest.add was also reworked to push delta construction/combination into the main loop. Time to apply 2751 patches (without psyco, ext3 noatime,data=writeback): Stock hg: 4m45s real 3m32s user 55s sys patched: 2m48s real 1m53s user 43s sys quilt: 2m30s real 45s user 50s sys (quilt does much more io...)

#!/usr/bin/env python
import sys, os
from mercurial import hg

f = sys.argv[1]

r1 = hg.revlog(open, f + ".i", f + ".d")
r2 = hg.revlog(open, f + ".i2", f + ".d2")

tr = hg.transaction(open, "journal")

for i in xrange(r1.count()):
    n = r1.node(i)
    p1, p2 = r1.parents(n)
    l = r1.linkrev(n)
    t = r1.revision(n)
    n2 = r2.addrevision(t, tr, l, p1, p2)
tr.close()

os.rename(f + ".i", f + ".i.old")
os.rename(f + ".d", f + ".d.old")
os.rename(f + ".i2", f + ".i")
os.rename(f + ".d2", f + ".d")