Re: [PATCH v3 2/4] refs: introduce get_worktree_ref_store()

> files-backend at this point is still aware of the per-repo/worktree
> separation in refs, so it can handle a linked worktree.
> 
> Some refs operations are known not working when current files-backend is
> used in a linked worktree (e.g. reflog). Tests will be written when
> refs_* functions start to be called with worktree backend to verify that
> they work as expected.
> 
> Note: accessing a worktree of a submodule remains unaddressed. Perhaps
> after get_worktrees() can access submodule (or rather a new function
> get_submodule_worktrees(), that lists worktrees of a submodule), we can
> update this function to work with submodules as well.
> ---
>  refs.c | 32 ++++++++++++++++++++++++++++++++
>  refs.h |  2 ++
>  2 files changed, 34 insertions(+)
> 
> diff --git a/refs.c b/refs.c
> index 77a39f8b17..6695140cfe 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -10,6 +10,7 @@
>  #include "object.h"
>  #include "tag.h"
>  #include "submodule.h"
> +#include "worktree.h"
>  
>  /*
>   * List of all available backends
> @@ -1593,6 +1594,37 @@ struct ref_store *get_submodule_ref_store(const char *submodule)
>  	return refs;
>  }
>  
> +struct ref_store *get_worktree_ref_store(const struct worktree *wt)
> +{
> +	struct ref_store *refs;
> +	unsigned int refs_all_capabilities =
> +		REF_STORE_READ | REF_STORE_WRITE |
> +		REF_STORE_ODB | REF_STORE_MAIN;
> +
> +	if (wt->is_current)
> +		return get_main_ref_store();
> +
> +	/*
> +	 * We share the same hash map with submodules for
> +	 * now. submodule paths are always relative (to topdir) while
> +	 * worktree paths are always absolute. No chance of conflict.
> +	 */
> +	refs = lookup_submodule_ref_store(wt->path);
> +	if (refs)
> +		return refs;
> +
> +	if (wt->id)
> +		refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
> +				      refs_all_capabilities);
> +	else
> +		refs = ref_store_init(get_git_common_dir(),
> +				      refs_all_capabilities);
> +
> +	if (refs)
> +		register_submodule_ref_store(refs, wt->path);
> +	return refs;
> +}
> +