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...)
Mercurial git BK (*)
storage revlog delta compressed revisions SCCS weave
storage naming by filename by revision hash by filename
merge file DAGs changeset DAG file DAGs?
consistency SHA1 SHA1 CRC
signable? yes yes no
retrieve file tip O(1) O(1) O(revs)
add rev O(1) O(1) O(revs)
find prev file rev O(1) O(changesets) O(revs)
annotate file O(revs) O(changesets) O(revs)
find file changeset O(1) O(changesets) ?
checkout O(files) O(files) O(revs)?
commit O(changes) O(changes) ?
6 patches/s 6 patches/s slow
diff working dir O(changes) O(changes) ?
< 1s < 1s ?
tree diff revs O(changes) O(changes) ?
< 1s < 1s ?
hardlink clone O(files) O(revisions) O(files)
find remote csets O(log new) rsync: O(revisions) ?
git-http: O(changesets)
pull remote csets O(patch) O(modified files) O(patch)
repo growth O(patch) O(revisions) O(patch)
kernel history 300M 3.5G? 250M?
lines of code 2500 6500 (+ cogito) ??
* I've never used BK so this is just guesses