Re: git gc and worktrees

[Junio C Hamano <gitster@pobox.com>]

Michael Haggerty <mhagger@alum.mit.edu> writes:

> On 06/01/2016 09:39 PM, Junio C Hamano wrote:
>> ...
> I think I would represent the logical store of a worktree repo as
> follows. First, ...
> ...
>> Up to this point, I am all for your "separate physical stores are
>> composited to give a logical view".  I can see how multi-worktree
>> world view fits within that framework.
>> 
>>  * With pluggable ref backend, we may gain yet another "physical
>>    reference store" possibility, e.g. one backed by lmdb.  If it
>>    supports symrefs, a repoitory may use lmdb backed reference store
>>    without the traditional two.
>> 
>>    But it is unclear how it would interact with the multi-worktree
>>    world order.
>
> Since you could plug-and-play different ref_stores in the above scheme,
> I don't see any problem here.
>
>     def get_logical_ref_store() {
>         local_ref_store = get_local_ref_store(git_dir)
>         if (is_linked_repo) {
>             common_ref_store = get_ref_store(common_dir)
>             return worktree_ref_store(local_ref_store,
>                                       common_ref_store)
>         } else {
>             return local_ref_store;
>         }
>     }
>
> get_ref_store() would read the git config to decide what the ref store
> to use for the specified repository, which itself might be an
> lmdb_ref_store or an overlay_ref_store(loose_ref_store, packed_ref_store).

Sounds all sensible.  Thanks.