Re: [PATCH 1/8] odb: store locality in object database sources

> Object database sources are classified either as:
>
>   - Local, which means that the source is the repository's primary
>     source. This is typically ".git/objects".
>
>   - Non-local, which is everything else. Most importantly this includes
>     alternates and quarantine directories.
>
> This locality is often computed ad-hoc by checking whether a given
> object source is the first one. This works, but it is quite roundabout.
>
> Refactor the code so that we store locality when creating the sources in
> the first place. This makes it both more accessible and robust.
>
> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---
>  midx.c       | 5 +++--
>  midx.h       | 2 +-
>  odb.c        | 1 +
>  odb.h        | 8 ++++++++
>  packfile.c   | 9 ++++-----
>  repository.c | 1 +
>  6 files changed, 18 insertions(+), 8 deletions(-)
>
> diff --git a/midx.c b/midx.c
> index 7d407682e6..b9ca0915a6 100644
> --- a/midx.c
> +++ b/midx.c
> @@ -723,7 +723,7 @@ int midx_preferred_pack(struct multi_pack_index *m, uint32_t *pack_int_id)
>  	return 0;
>  }
>
> -int prepare_multi_pack_index_one(struct odb_source *source, int local)
> +int prepare_multi_pack_index_one(struct odb_source *source)
>  {
>  	struct repository *r = source->odb->repo;
>
> @@ -734,7 +734,8 @@ int prepare_multi_pack_index_one(struct odb_source *source, int local)
>  	if (source->midx)
>  		return 1;
>
> -	source->midx = load_multi_pack_index(r, source->path, local);
> +	source->midx = load_multi_pack_index(r, source->path,
> +					     source->local);
>
>  	return !!source->midx;
>  }
> diff --git a/midx.h b/midx.h
> index 076382de8a..28c426a823 100644
> --- a/midx.h
> +++ b/midx.h
> @@ -122,7 +122,7 @@ int fill_midx_entry(struct repository *r, const struct object_id *oid, struct pa
>  int midx_contains_pack(struct multi_pack_index *m,
>  		       const char *idx_or_pack_name);
>  int midx_preferred_pack(struct multi_pack_index *m, uint32_t *pack_int_id);
> -int prepare_multi_pack_index_one(struct odb_source *source, int local);
> +int prepare_multi_pack_index_one(struct odb_source *source);
>
>  /*
>   * Variant of write_midx_file which writes a MIDX containing only the packs
> diff --git a/odb.c b/odb.c
> index 1f48a0448e..1761a50840 100644
> --- a/odb.c
> +++ b/odb.c
> @@ -176,6 +176,7 @@ static int link_alt_odb_entry(struct object_database *odb,
>
>  	CALLOC_ARRAY(alternate, 1);
>  	alternate->odb = odb;
> +	alternate->local = false;
>  	/* pathbuf.buf is already in r->objects->source_by_path */
>  	alternate->path = strbuf_detach(&pathbuf, NULL);
>
> diff --git a/odb.h b/odb.h
> index 09177bf430..d9f4dcf79f 100644
> --- a/odb.h
> +++ b/odb.h
> @@ -63,6 +63,14 @@ struct odb_source {
>  	 */
>  	struct multi_pack_index *midx;
>
> +	/*
> +	 * Figure out whether this is the local alternate of the owning
> +	 * repository, which would typically be its ".git/objects" directory.
> +	 * This local object directory is usually where objects would be
> +	 * written to.
> +	 */
> +	bool local;
> +

>  	/*
>  	 * This is a temporary object store created by the tmp_objdir
>  	 * facility. Disable ref updates since the objects in the store
> diff --git a/packfile.c b/packfile.c
> index 5d73932f50..a38544b87b 100644
> --- a/packfile.c
> +++ b/packfile.c
> @@ -935,14 +935,14 @@ static void prepare_pack(const char *full_name, size_t full_name_len,
>  		report_garbage(PACKDIR_FILE_GARBAGE, full_name);
>  }
>
> -static void prepare_packed_git_one(struct odb_source *source, int local)
> +static void prepare_packed_git_one(struct odb_source *source)
>  {
>  	struct string_list garbage = STRING_LIST_INIT_DUP;
>  	struct prepare_pack_data data = {
>  		.m = source->midx,
>  		.r = source->odb->repo,
>  		.garbage = &garbage,
> -		.local = local,
> +		.local = source->local,
>

>  	};
>
>  	for_each_file_in_pack_dir(source->path, prepare_pack, &data);
> @@ -1037,9 +1037,8 @@ static void prepare_packed_git(struct repository *r)
>
>  	odb_prepare_alternates(r->objects);
>  	for (source = r->objects->sources; source; source = source->next) {
> -		int local = (source == r->objects->sources);
> -		prepare_multi_pack_index_one(source, local);
> -		prepare_packed_git_one(source, local);
> +		prepare_multi_pack_index_one(source);
> +		prepare_packed_git_one(source);
>  	}
>  	rearrange_packed_git(r);
>
> diff --git a/repository.c b/repository.c
> index ecd691181f..97f0578381 100644
> --- a/repository.c
> +++ b/repository.c
> @@ -168,6 +168,7 @@ void repo_set_gitdir(struct repository *repo,
>  	if (!repo->objects->sources) {
>  		CALLOC_ARRAY(repo->objects->sources, 1);
>  		repo->objects->sources->odb = repo->objects;
> +		repo->objects->sources->local = true;
>  		repo->objects->sources_tail = &repo->objects->sources->next;
>  	}
>  	expand_base_dir(&repo->objects->sources->path, o->object_dir,
>