Cheaper branching under consideration?

[John A Meinel]

Magnus Therning wrote:
> This might very well have been discussed already. Just thought I'd ask
> anyway.
>
> Is cheaper branching, regarding space, being considered?
>
> When I've used CVS I always create a branch tag when making a release
> X.Y. If there's a bug in a release I check out the particular version,
> make a change, check it in on the branch, tag it as X.Y+1 and then make a
> merge between the branch and the main line.
>
> AFAICS this would still be the way to do it in bzr. But there is no
> central repo, so I need to keep a directory around with history up to
> the revision that is X.Y. However, I don't need all the history in this
> dir so why keep it in there?
>
> I've been playing around a bit in a branch of a project removing files.
> It all works quite fine, removing files in inventory-store and
> text-store. You loose some history (every revision that's removed) so
> 'bzr log' is "destroyed". Also, since entries in revision-history have
> to be removed 'bzr revno' will be "destroyed".
>
> There might be less destructive way of pruning files in a branch, but is
> this something that people feel anything for?
>
> /M
>

I'm sure you received lots of other replies (like stuff about
centralized storage, weavefiles, revfiles, etc).

But also, the files in the "revision-store" are actually pretty small,
the inventory-store also aren't very large, but they are O(number of
files in the tree).
The big portion is the text-store, which are just compressed versions of
the actual texts at each revision. Which is overly expensive, and means
you have much more to copy than you have to. The are also only required
when you actually want to compare against them.

So if you only deleted stuff from text-store, I think 90% of the bzr
commands would still work. You could delete all of the text store, and
if there were no changes, "bzr status" should still work, since the
inventory keeps track of the file hashes. (This may not be a perfectly
accurate statement, but theoretically it is true).

John
=:->
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 253 bytes
Desc: OpenPGP digital signature
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20050823/4ba7f6e8/attachment.pgp