refs: move to using the '.optimize' functions

The `struct ref_store` variable exposes two ways to optimize a reftable
backend:

  1. pack_refs
  2. optimize

The former was specific to the 'files' + 'packed' refs backend. The
latter is more generic and covers all backends. While the naming is
different, both of these functions perform the same functionality.

Consolidate this code to only maintain the 'optimize' functions. Do this
by modifying the backends so that they exclusively implement the
`optimize` callback, only. All users of the refs subsystem already use
the 'optimize' function so there is no changes needed on the callee
side. Finally, cleanup all references to the 'pack_refs' field of the
structure and code around it.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refs.c

@@ -2313,12 +2313,6 @@ void base_ref_store_init(struct ref_store *refs, struct repository *repo,
 	refs->gitdir = xstrdup(path);
 }
 
-/* backend functions */
-int refs_pack_refs(struct ref_store *refs, struct pack_refs_opts *opts)
-{
-	return refs->be->pack_refs(refs, opts);
-}
-
 int refs_optimize(struct ref_store *refs, struct pack_refs_opts *opts)
 {
 	return refs->be->optimize(refs, opts);

refs.h

@@ -514,12 +514,6 @@ struct pack_refs_opts {
 	struct string_list *includes;
 };
 
-/*
- * Write a packed-refs file for the current repository.
- * flags: Combination of the above PACK_REFS_* flags.
- */
-int refs_pack_refs(struct ref_store *refs, struct pack_refs_opts *opts);
-
 /*
  * Optimize the ref store. The exact behavior is up to the backend.
  * For the files backend, this is equivalent to packing refs.

refs/debug.c

@@ -116,11 +116,11 @@ static int debug_transaction_abort(struct ref_store *refs,
 	return res;
 }
 
-static int debug_pack_refs(struct ref_store *ref_store, struct pack_refs_opts *opts)
+static int debug_optimize(struct ref_store *ref_store, struct pack_refs_opts *opts)
 {
 	struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
-	int res = drefs->refs->be->pack_refs(drefs->refs, opts);
-	trace_printf_key(&trace_refs, "pack_refs: %d\n", res);
+	int res = drefs->refs->be->optimize(drefs->refs, opts);
+	trace_printf_key(&trace_refs, "optimize: %d\n", res);
 	return res;
 }
 
@@ -430,7 +430,7 @@ struct ref_storage_be refs_be_debug = {
 	.transaction_finish = debug_transaction_finish,
 	.transaction_abort = debug_transaction_abort,
 
-	.pack_refs = debug_pack_refs,
+	.optimize = debug_optimize,
 	.rename_ref = debug_rename_ref,
 	.copy_ref = debug_copy_ref,
 

refs/files-backend.c

@@ -1444,7 +1444,7 @@ static int should_pack_refs(struct files_ref_store *refs,
 	return 0;
 }
 
-static int files_pack_refs(struct ref_store *ref_store,
+static int files_optimize(struct ref_store *ref_store,
 			  struct pack_refs_opts *opts)
 {
 	struct files_ref_store *refs =
@@ -1512,15 +1512,6 @@ static int files_pack_refs(struct ref_store *ref_store,
 	return 0;
 }
 
-static int files_optimize(struct ref_store *ref_store, struct pack_refs_opts *opts)
-{
-	/*
-	 * For the "files" backend, "optimizing" is the same as "packing".
-	 * So, we just call the existing worker function for packing.
-	 */
-	return files_pack_refs(ref_store, opts);
-}
-
 /*
  * People using contrib's git-new-workdir have .git/logs/refs ->
  * /some/other/path/.git/logs/refs, and that may live on another device.
@@ -3975,7 +3966,6 @@ struct ref_storage_be refs_be_files = {
 	.transaction_finish = files_transaction_finish,
 	.transaction_abort = files_transaction_abort,
 
-	.pack_refs = files_pack_refs,
 	.optimize = files_optimize,
 	.rename_ref = files_rename_ref,
 	.copy_ref = files_copy_ref,

refs/packed-backend.c

@@ -1773,7 +1773,7 @@ cleanup:
 	return ret;
 }
 
-static int packed_pack_refs(struct ref_store *ref_store UNUSED,
+static int packed_optimize(struct ref_store *ref_store UNUSED,
 			   struct pack_refs_opts *pack_opts UNUSED)
 {
 	/*
@@ -2129,7 +2129,7 @@ struct ref_storage_be refs_be_packed = {
 	.transaction_finish = packed_transaction_finish,
 	.transaction_abort = packed_transaction_abort,
 
-	.pack_refs = packed_pack_refs,
+	.optimize = packed_optimize,
 	.rename_ref = NULL,
 	.copy_ref = NULL,
 

refs/refs-internal.h

@@ -422,8 +422,6 @@ typedef int ref_transaction_commit_fn(struct ref_store *refs,
 				      struct ref_transaction *transaction,
 				      struct strbuf *err);
 
-typedef int pack_refs_fn(struct ref_store *ref_store,
-			 struct pack_refs_opts *opts);
 typedef int optimize_fn(struct ref_store *ref_store,
 			struct pack_refs_opts *opts);
 typedef int rename_ref_fn(struct ref_store *ref_store,
@@ -550,7 +548,6 @@ struct ref_storage_be {
 	ref_transaction_finish_fn *transaction_finish;
 	ref_transaction_abort_fn *transaction_abort;
 
-	pack_refs_fn *pack_refs;
 	optimize_fn *optimize;
 	rename_ref_fn *rename_ref;
 	copy_ref_fn *copy_ref;

refs/reftable-backend.c

@@ -1700,11 +1700,11 @@ done:
 	return ret;
 }
 
-static int reftable_be_pack_refs(struct ref_store *ref_store,
+static int reftable_be_optimize(struct ref_store *ref_store,
 				struct pack_refs_opts *opts)
 {
 	struct reftable_ref_store *refs =
-		reftable_be_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB, "pack_refs");
+		reftable_be_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB, "optimize_refs");
 	struct reftable_stack *stack;
 	int ret;
 
@@ -1733,12 +1733,6 @@ out:
 	return ret;
 }
 
-static int reftable_be_optimize(struct ref_store *ref_store,
-				struct pack_refs_opts *opts)
-{
-	return reftable_be_pack_refs(ref_store, opts);
-}
-
 struct write_create_symref_arg {
 	struct reftable_ref_store *refs;
 	struct reftable_stack *stack;
@@ -2761,7 +2755,6 @@ struct ref_storage_be refs_be_reftable = {
 	.transaction_finish = reftable_be_transaction_finish,
 	.transaction_abort = reftable_be_transaction_abort,
 
-	.pack_refs = reftable_be_pack_refs,
 	.optimize = reftable_be_optimize,
 	.rename_ref = reftable_be_rename_ref,
 	.copy_ref = reftable_be_copy_ref,