Bzr development stopped

Stephen J. Turnbull stephen at xemacs.org
Tue Nov 27 02:56:22 UTC 2012


Talden writes:

 > In which-case I see what you mean, using git as the back-end might
 > have very little impact on storage and it's only the meta-data that
 > we'd miss.

The point of using the git storage system surely isn't storage
volume.  If git ever performed better than other VCSes on storage
volume it was purely an accident of using compressed files to store
versions.  It's performance and robustness in maintenance because of
the very simple data model used by the VCS itself.  No weaves or
whatever attempting to optimize VCS operations.

As far as tracking renames goes, there's a very simple strategy for
guaranteeing 100% accuracy for git's inference algorithm: always
rename (or copy, for that matter) in a separate commit, ensuring that
git can do the matching at the "tree object" level by object hash.  Of
course then you're not happy as a Java developer, because the rename
happens in a different commit.

With bit of fussing, either in the VCS itself or in the IDE you could
ensure that such commits happen on a branch, which is automatically
merged with the desired parent.  It will be a WTF for people who
haven't seen it before looking at the history DAG.  Except for that
glitch, though, this strategy should pretty much satisfy the needs of
Java developers, since it's not the rename tracking per se that they
care about at commit time, it's that renames be bound to the content
changes.

The git storage system possibly could also be adapted to handle empty
directories trivially, simply by allowing empty tree objects to
exist.  I don't know about the ramifications of this in detail though.

I don't claim this is actually satisfactory to people who worry about
git's technology, only that it should be possible to achieve the
expressed goals.  Of course it's not at all pretty, and that matters.
But I think worries that use of the git storage backend will cost all
the nice features that Bazaar has achieved are misplaced.





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