Re: [PATCH v2 08/20] hash: require hash algorithm in `empty_tree_oid_hex()`

[Phillip Wood <phillip.wood123@gmail.com>]

On 13/06/2024 07:14, Patrick Steinhardt wrote:
> The `empty_tree_oid_hex()` function use `the_repository` to derive the
> hash function that shall be used. Require callers to pass in the hash
> algorithm to get rid of this implicit dependency.

Many of these call sites already have a repository instance available so 
don't need to use "the_repository". I haven't checked but with these 
changes it might be possible to remove some of these files from the next 
patch.

I've only really looked at this patch in this series as I was just 
checking for changes to the sequencer code. As for the series as a whole 
I think adding USE_THE_REPOSITORY_VARIABLE is a good direction.

> While at it, remove the unused `empty_blob_oid_hex()` function.
> 
> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---
>   add-interactive.c      |  2 +-
>   add-patch.c            |  2 +-
>   builtin/merge.c        |  3 ++-
>   builtin/receive-pack.c |  2 +-
>   hash-ll.h              |  3 +--
>   object-file.c          | 10 ++--------
>   sequencer.c            |  2 +-
>   submodule.c            |  6 +++---
>   wt-status.c            |  4 ++--
>   9 files changed, 14 insertions(+), 20 deletions(-)
> 
> diff --git a/add-interactive.c b/add-interactive.c
> index b5d6cd689a..a0961096cd 100644
> --- a/add-interactive.c
> +++ b/add-interactive.c
> @@ -557,7 +557,7 @@ static int get_modified_files(struct repository *r,
>   		s.skip_unseen = filter && i;
>   
>   		opt.def = is_initial ?
> -			empty_tree_oid_hex() : oid_to_hex(&head_oid);
> +			empty_tree_oid_hex(the_repository->hash_algo) : oid_to_hex(&head_oid);

The hunk fragment shows that we already have a struct repository 
instance in this function which we should use instead of "the_repository"

> diff --git a/add-patch.c b/add-patch.c
> index 814de57c4a..86181770f2 100644
> --- a/add-patch.c
> +++ b/add-patch.c
> @@ -420,7 +420,7 @@ static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
>   			    /* could be on an unborn branch */
>   			    !strcmp("HEAD", s->revision) &&
>   			    repo_get_oid(the_repository, "HEAD", &oid) ?
> -			    empty_tree_oid_hex() : s->revision);
> +			    empty_tree_oid_hex(the_repository->hash_algo) : s->revision);

It's not obvious from this hunk but there is a repository instance in 
"s->s->r" which we should use instead of "the_repository"

> diff --git a/sequencer.c b/sequencer.c
> index 68d62a12ff..823691e379 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -2263,7 +2263,7 @@ static int do_pick_commit(struct repository *r,
>   			unborn = 1;
>   		} else if (unborn)
>   			oidcpy(&head, the_hash_algo->empty_tree);
> -		if (index_differs_from(r, unborn ? empty_tree_oid_hex() : "HEAD",
> +		if (index_differs_from(r, unborn ? empty_tree_oid_hex(the_repository->hash_algo) : "HEAD",

The hunk fragment shows that we already have a struct repository 
instance in "r" which we should use instead of "the_repository" here.

> diff --git a/wt-status.c b/wt-status.c
> index ff4be071ca..5051f5e599 100644
> --- a/wt-status.c
> +++ b/wt-status.c
> @@ -641,7 +641,7 @@ static void wt_status_collect_changes_index(struct wt_status *s)
>   
>   	repo_init_revisions(s->repo, &rev, NULL);
>   	memset(&opt, 0, sizeof(opt));
> -	opt.def = s->is_initial ? empty_tree_oid_hex() : s->reference;
> +	opt.def = s->is_initial ? empty_tree_oid_hex(the_repository->hash_algo) : s->reference;

The context line above shows us that we have a repository instance 
available so we should use "s->repo" instead of "the_repository"

> @@ -1136,7 +1136,7 @@ static void wt_longstatus_print_verbose(struct wt_status *s)
>   	rev.diffopt.ita_invisible_in_index = 1;
>   
>   	memset(&opt, 0, sizeof(opt));
> -	opt.def = s->is_initial ? empty_tree_oid_hex() : s->reference;
> +	opt.def = s->is_initial ? empty_tree_oid_hex(the_repository->hash_algo) : s->reference;

We should use "s->repo" here as well

Best Wishes

Phillip