Re: Borrowing objects from nearby repositories

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 25, 2014, 17:02 UTC
Message-ID: <xmqqtxammctc.fsf@gitster.dls.corp.google.com>
In-Reply-To: <CACBZZX5teZuqtNkPT4PdXJn=g34cOhRH2oNehROT8kJ_M2cgfg@mail.gmail.com>

Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

Show 16 quoted lines

>> 1) Introduce '--borrow' to `git-fetch`.  This would behave similarly
> to '--reference', except that it operates on a temporary basis, and
> does not assume that the reference repository will exist after the
> operation completes, so any used objects are copied into the local
> objects database.  In theory, this mechanism would be distinct from
> --reference', so if both are used, some objects would be copied, and
> some objects would be accessible via a reference repository referenced
> by the alternates file.
>
> Isn't this the same as git clone --reference <path> --no-hardlinks
> <url> ?
>
> Also without --no-hardlinks we're not assuming that the other repo
> doesn't go away (you could rm-rf it), just that the files won't be
> *modified*, which Git won't do, but you could manually do with other
> tools, so the default is to hardlink.

I think that the standard practice with the existing toolset is to clone with reference and then repack. That is:

    $ git clone --reference <borrowee> git://over/there mine
    $ cd mine
    $ git repack -a -d

And then you can try this:

    $ mv .git/objects/info/alternates .git/objects/info/alternates.disabled
    $ git fsck

to make sure that you are no longer borrowing anything from the borrowee. Once you are satisfied, you can remove the saved-away alternates.disabled file.