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...)

#!/bin/sh

hg init
touch a
hg add a
hg ci -m "a" -d "0 0"

echo 123 > b
hg add b
hg diff | sed -e "s/\(+++ [a-zA-Z0-9_/.-]*\).*/\1/" \
              -e "s/\(--- [a-zA-Z0-9_/.-]*\).*/\1/"

hg diff -r tip | sed -e "s/\(+++ [a-zA-Z0-9_/.-]*\).*/\1/" \
                     -e "s/\(--- [a-zA-Z0-9_/.-]*\).*/\1/"