Re: GSOC Proposal draft: git-remote-svn

[Stephen Bash <bash@genarts.com>]

----- Original Message -----
> From: "Andrew Sayers" <andrew-git@pileofstuff.org>
> Sent: Saturday, April 14, 2012 5:35:59 PM
> Subject: Re: GSOC Proposal draft: git-remote-svn
>
> ... snip ...
> 
> One solution you could look at would be storing dead branches in a
> JSON file somewhere.  If you go down that route, remember that `git
> gc` will try to garbage collect the commits once the branches have
> been dead for long enough.

I don't remember if this has already been discussed, but as I see it there are basically three approaches to closed/deleted SVN branches in the Git world:

  1) Just delete the branch, allow git gc to later cleanup the objects
  2) Just leave them be for the user to deal with at a later date
  3) Move them to another namespace

I think (3) is the only semi-tricky one.  If you read the git-gc manpage, it turns out gc will consider any object reachable from any ref under refs/ as safe.  When cloning/pushing/pulling/etc. git only looks at refs/heads and refs/tags (unless told otherwise).  So for our conversion I created refs/hidden/heads and refs/hidden/tags (other choices could be refs/svn or refs/junk, but you get the idea).  Just as a fun stat, the hidden namespace in our central repo has 280 refs in it vs 502 in the visible/normal namespace (surprisingly the hidden ones are almost perfectly split with 138 dead Subversion branches and 142 SVN tags that were later retagged/committed to).

Thanks,
Stephen