Move hg from storing files in data with base64 encoding to full
pathnames with .i and .d extensions. This means we naturally get good
FS layout, and cp and tar fix things up nicely rather than pessimizing
layout.
Mercurial git BK (*)
storage revlog delta compressed revisions SCCS weave
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(1)|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 ?
local clone O(files) O(revisions) O(files)
find remote csets O(log new) O(revisions) ?
pull remote csets O(patch) O(modified files) O(patch)
100 csets/s 8 csets/s ?
repo growth O(patch) O(revisions) O(patch)
kernel history 250M? 3.5G? 250M?
lines of code 2500 6500 (+ cogito) ??
* I've never used BK so this is just guesses