Re: efficient cloning

[Junio C Hamano <junkio@cox.net>]

Josef Weidendorfer <Josef.Weidendorfer@gmx.de> writes:

> On Monday 20 March 2006 09:54, you wrote:
>>  * A new flag --use-separate-remote stops contaminating local
>>    branch namespace by upstream branch names.  The upstream
>>    branch heads are copied in .git/refs/remotes/ instead of
>
> Shouldn't this be .git/refs/remotes/origin/?
> Ie. different namespaces for different remotes?
>
> Linus wanted to still be able to say "origin" which automatically
> would map to "remotes/origin/master", where the name of the remote

I do not remember that, but even if he said something similar to
that, I suspect it would not be "map remotes/origin/master to
origin", but "origin could mean remotes/origin when origin is
the unique tail-name anywhere under refs/".

I think what is reasonable is something like this:

 - If you start from a repository cloned in the traditional
   way, the upstream "master" is kept track of with your
   "origin", so "diff origin master" would be "my changes on top
   of the upstream".

 - If your repository was cloned with --use-separate-remote, the
   upstream "master" is refs/remotes/master, so the same diff
   can be had with "diff remotes/master master".

 - Regardless of how you started your cloned repository, with an
   $GIT_DIR/{remotes,refs/heads,refs/remotes} editor I hinted in
   a separate message, you can rearrange things to organize the
   refs/ hierarchy any way you want.

   - You could for example arrange to track my "master" as
     refs/heads/origin and all the other branch heads under
     refs/remotes/junkio/ (or not even track my other branches
     if you are not interested).  Then the same diff can be had
     with "diff origin master".

   - You could for example arrange to track all my branches in
     refs/remotes/junkio/, and if git-pasky were still alive,
     Pasky's branches in refs/remotes/pasky.  If we had a "take
     the unique tail-name anywhere under refs/" logic, the same
     diff can be had with "diff junkio/master master".

So I think two things that would be nice to have on top of what
we have are (1) the said "remotes-and-refs editor" [*1*], and
(2) a change to sha1_name.c to look for places other than
built-in tags/ and heads/ under refs/ to find a unique
tail-match.

Since I do not do Porcelain, (2) would obviously be the next
thing for me to work on on this topic.  I should also address
"Ouch I did not realize I have given the same name to a tag and
a branch" warning issue while doing so.


[Footnote]

*1* ... which currently I do not plan to do myself unless I have
absolutely nothing else to do and really bored.  A sound of huge
hint dropping ;-).