Subject: [GSoC][PATCH 1/5] builtin/pack-refs: factor out core logic into a helper

From: Meet Soni <[email-masked]>
Date: Tue, 26 Aug 2025 13:06:41 +0530

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.

Introduce a new `pack-refs.h` header to define the public interface
for this shared logic. It contains the declaration for a new helper
function, `pack_refs_core()`, and a macro for the common usage
options.

Move the option parsing and packing logic from `cmd_pack_refs()` into a
new helper function named `pack_refs_core()`. This helper is made
generic by accepting the command's usage string as a parameter.

The original `cmd_pack_refs()` is simplified to a thin wrapper that
is only responsible for defining its specific usage array and calling
the shared helper.

Mentored-by: Patrick Steinhardt <[email-masked]>
Mentored-by: shejialuo <[email-masked]>
Signed-off-by: Meet Soni <[email-masked]>
---
 builtin/pack-refs.c | 31 ++++++++++++++++++++-----------
 pack-refs.h         | 22 ++++++++++++++++++++++
 2 files changed, 42 insertions(+), 11 deletions(-)
 create mode 100644 pack-refs.h

diff --git a/builtin/pack-refs.c b/builtin/pack-refs.c
index 5e28d0f9e8..7c4d7854c8 100644
--- a/builtin/pack-refs.c
+++ b/builtin/pack-refs.c
@@ -2,19 +2,16 @@
 #include "config.h"
 #include "environment.h"
 #include "gettext.h"
+#include "pack-refs.h"
 #include "parse-options.h"
 #include "refs.h"
 #include "revision.h"
 
-static char const * const pack_refs_usage[] = {
-	N_("git pack-refs [--all] [--no-prune] [--auto] [--include <pattern>] [--exclude <pattern>]"),
-	NULL
-};
-
-int cmd_pack_refs(int argc,
-		  const char **argv,
-		  const char *prefix,
-		  struct repository *repo)
+int pack_refs_core(int argc,
+		   const char **argv,
+		   const char *prefix,
+		   struct repository *repo,
+		   const char * const *usage_opts)
 {
 	struct ref_exclusions excludes = REF_EXCLUSIONS_INIT;
 	struct string_list included_refs = STRING_LIST_INIT_NODUP;
@@ -39,8 +36,8 @@ int cmd_pack_refs(int argc,
 		OPT_END(),
 	};
 	repo_config(repo, git_default_config, NULL);
-	if (parse_options(argc, argv, prefix, opts, pack_refs_usage, 0))
-		usage_with_options(pack_refs_usage, opts);
+	if (parse_options(argc, argv, prefix, opts, usage_opts, 0))
+		usage_with_options(usage_opts, opts);
 
 	for_each_string_list_item(item, &option_excluded_refs)
 		add_ref_exclusion(pack_refs_opts.exclusions, item->string);
@@ -58,3 +55,15 @@ int cmd_pack_refs(int argc,
 	string_list_clear(&option_excluded_refs, 0);
 	return ret;
 }
+
+int cmd_pack_refs(int argc,
+		  const char **argv,
+		  const char *prefix,
+		  struct repository *repo)
+{
+	static char const * const pack_refs_usage[] = {
+		N_("git pack-refs " PACK_REFS_OPTS),
+		NULL
+	};
+	return pack_refs_core(argc, argv, prefix, repo, pack_refs_usage);
+}
diff --git a/pack-refs.h b/pack-refs.h
new file mode 100644
index 0000000000..ba51d154e3
--- /dev/null
+++ b/pack-refs.h
@@ -0,0 +1,22 @@
+#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 \
+	"[--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 */
-- 
2.34.1