Re: [GSoC][PATCH v4 5/9] builtin/pack-refs: factor out core logic into a shared library

[Patrick Steinhardt <ps@pks.im>]

On Fri, Sep 19, 2025 at 01:56:43PM +0530, Meet Soni wrote:
> The implementation of `git pack-refs` is monolithic within
> `cmd_pack_refs()`, making it impossible to share its logic with other
> commands. To enable code reuse for the upcoming `git refs optimize`
> subcommand, refactor the core logic into a shared helper function.
> 
> Split the original `builtin/pack-refs.c` file into two parts:
> 
> - A new shared library file, `pack-refs.c`, which contains the
>   core option parsing and packing logic in a new `pack_refs_core()`
>   helper function.

Should we maybe host that file in "refs/pack.c"? This ensures that all
ref-related infra continues to sit in one place. We could also build on
your previous steps and call it "refs/optimize.c" right away.

> diff --git a/pack-refs.c b/pack-refs.c
> new file mode 100644
> index 0000000000..1a5e07d8b8
> --- /dev/null
> +++ b/pack-refs.c
> @@ -0,0 +1,56 @@
> +#include "builtin.h"
> +#include "config.h"
> +#include "environment.h"
> +#include "pack-refs.h"
> +#include "parse-options.h"
> +#include "refs.h"
> +#include "revision.h"
> +
> +int pack_refs_core(int argc,

If we want to go with "refs/optimize.c" I'd call this
`refs_optimize_core()`.

> diff --git a/pack-refs.h b/pack-refs.h
> new file mode 100644
> index 0000000000..5de27e7da8
> --- /dev/null
> +++ b/pack-refs.h
> @@ -0,0 +1,23 @@
> +#ifndef PACK_REFS_H
> +#define PACK_REFS_H
> +
> +struct repository;
> +
> +/*
> + * Shared usage string for options common to git-pack-refs(1)
> + * and git-refs-optimize(1). The command-specific part (e.g., "git refs optimize ")
> + * must be prepended by the caller.
> + */
> +#define PACK_REFS_OPTS \

This would become `REFS_OPTIMIZE_OPTS`.

> +	"[--all] [--no-prune] [--auto] [--include <pattern>] [--exclude <pattern>]"
> +
> +/*
> + * The core logic for pack-refs and its clones.
> + */
> +int pack_refs_core(int argc,
> +		   const char **argv,
> +		   const char *prefix,
> +		   struct repository *repo,
> +		   const char * const *usage_opts);
> +
> +#endif /* PACK_REFS_H */

Patrick