refs: add a `optimize_required` field to `struct ref_storage_be`

To allow users of the refs namespace to check if the reference backend requires optimization, add a new field `optimize_required` field to `struct ref_storage_be`. This field is of type `optimize_required_fn` which is also introduced in this commit. Modify the debug, files, packed and reftable backend to implement this field. A following commit will expose this via 'git pack-refs' and 'git refs optimize'. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Acked-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Karthik Nayak committed Nov 8, 2025 at 22:51 UTC f6c5ca387a7693b16158826d157178be0ba439dc
7 files changed +82
refs.c
+7
@@ -2318,6 +2318,13 @@ int refs_optimize(struct ref_store *refs, struct refs_optimize_opts *opts)
2318 return refs->be->optimize(refs, opts);
2319 }
2320
2321 +int refs_optimize_required(struct ref_store *refs,
2322 + struct refs_optimize_opts *opts,
2323 + bool *required)
2324 +{
2325 + return refs->be->optimize_required(refs, opts, required);
2326 +}
2327 +
2328 int reference_get_peeled_oid(struct repository *repo,
2329 const struct reference *ref,
2330 struct object_id *peeled_oid)
refs.h
+7
@@ -520,6 +520,13 @@ struct refs_optimize_opts {
520 */
521 int refs_optimize(struct ref_store *refs, struct refs_optimize_opts *opts);
522
523 +/*
524 + * Check if refs backend can be optimized by calling 'refs_optimize'.
525 + */
526 +int refs_optimize_required(struct ref_store *ref_store,
527 + struct refs_optimize_opts *opts,
528 + bool *required);
529 +
530 /*
531 * Setup reflog before using. Fill in err and return -1 on failure.
532 */
refs/debug.c
+13
@@ -124,6 +124,17 @@ static int debug_optimize(struct ref_store *ref_store, struct refs_optimize_opts
124 return res;
125 }
126
127 +static int debug_optimize_required(struct ref_store *ref_store,
128 + struct refs_optimize_opts *opts,
129 + bool *required)
130 +{
131 + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
132 + int res = drefs->refs->be->optimize_required(drefs->refs, opts, required);
133 + trace_printf_key(&trace_refs, "optimize_required: %s, res: %d\n",
134 + required ? "yes" : "no", res);
135 + return res;
136 +}
137 +
138 static int debug_rename_ref(struct ref_store *ref_store, const char *oldref,
139 const char *newref, const char *logmsg)
140 {
@@ -431,6 +442,8 @@ struct ref_storage_be refs_be_debug = {
442 .transaction_abort = debug_transaction_abort,
443
444 .optimize = debug_optimize,
445 + .optimize_required = debug_optimize_required,
446 +
447 .rename_ref = debug_rename_ref,
448 .copy_ref = debug_copy_ref,
449
refs/files-backend.c
+11
@@ -1512,6 +1512,16 @@ static int files_optimize(struct ref_store *ref_store,
1512 return 0;
1513 }
1514
1515 +static int files_optimize_required(struct ref_store *ref_store,
1516 + struct refs_optimize_opts *opts,
1517 + bool *required)
1518 +{
1519 + struct files_ref_store *refs = files_downcast(ref_store, REF_STORE_READ,
1520 + "optimize_required");
1521 + *required = should_pack_refs(refs, opts);
1522 + return 0;
1523 +}
1524 +
1525 /*
1526 * People using contrib's git-new-workdir have .git/logs/refs ->
1527 * /some/other/path/.git/logs/refs, and that may live on another device.
@@ -3982,6 +3992,7 @@ struct ref_storage_be refs_be_files = {
3992 .transaction_abort = files_transaction_abort,
3993
3994 .optimize = files_optimize,
3995 + .optimize_required = files_optimize_required,
3996 .rename_ref = files_rename_ref,
3997 .copy_ref = files_copy_ref,
3998
refs/packed-backend.c
+13
@@ -1784,6 +1784,17 @@ static int packed_optimize(struct ref_store *ref_store UNUSED,
1784 return 0;
1785 }
1786
1787 +static int packed_optimize_required(struct ref_store *ref_store UNUSED,
1788 + struct refs_optimize_opts *opts UNUSED,
1789 + bool *required)
1790 +{
1791 + /*
1792 + * Packed refs are already optimized.
1793 + */
1794 + *required = false;
1795 + return 0;
1796 +}
1797 +
1798 static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_store UNUSED)
1799 {
1800 return empty_ref_iterator_begin();
@@ -2130,6 +2141,8 @@ struct ref_storage_be refs_be_packed = {
2141 .transaction_abort = packed_transaction_abort,
2142
2143 .optimize = packed_optimize,
2144 + .optimize_required = packed_optimize_required,
2145 +
2146 .rename_ref = NULL,
2147 .copy_ref = NULL,
2148
refs/refs-internal.h
+6
@@ -424,6 +424,11 @@ typedef int ref_transaction_commit_fn(struct ref_store *refs,
424
425 typedef int optimize_fn(struct ref_store *ref_store,
426 struct refs_optimize_opts *opts);
427 +
428 +typedef int optimize_required_fn(struct ref_store *ref_store,
429 + struct refs_optimize_opts *opts,
430 + bool *required);
431 +
432 typedef int rename_ref_fn(struct ref_store *ref_store,
433 const char *oldref, const char *newref,
434 const char *logmsg);
@@ -549,6 +554,7 @@ struct ref_storage_be {
554 ref_transaction_abort_fn *transaction_abort;
555
556 optimize_fn *optimize;
557 + optimize_required_fn *optimize_required;
558 rename_ref_fn *rename_ref;
559 copy_ref_fn *copy_ref;
560
refs/reftable-backend.c
+25
@@ -1733,6 +1733,29 @@ out:
1733 return ret;
1734 }
1735
1736 +static int reftable_be_optimize_required(struct ref_store *ref_store,
1737 + struct refs_optimize_opts *opts,
1738 + bool *required)
1739 +{
1740 + struct reftable_ref_store *refs = reftable_be_downcast(ref_store, REF_STORE_READ,
1741 + "optimize_refs_required");
1742 + struct reftable_stack *stack;
1743 + bool use_heuristics = false;
1744 +
1745 + if (refs->err)
1746 + return refs->err;
1747 +
1748 + stack = refs->worktree_backend.stack;
1749 + if (!stack)
1750 + stack = refs->main_backend.stack;
1751 +
1752 + if (opts->flags & REFS_OPTIMIZE_AUTO)
1753 + use_heuristics = true;
1754 +
1755 + return reftable_stack_compaction_required(stack, use_heuristics,
1756 + required);
1757 +}
1758 +
1759 struct write_create_symref_arg {
1760 struct reftable_ref_store *refs;
1761 struct reftable_stack *stack;
@@ -2756,6 +2779,8 @@ struct ref_storage_be refs_be_reftable = {
2779 .transaction_abort = reftable_be_transaction_abort,
2780
2781 .optimize = reftable_be_optimize,
2782 + .optimize_required = reftable_be_optimize_required,
2783 +
2784 .rename_ref = reftable_be_rename_ref,
2785 .copy_ref = reftable_be_copy_ref,
2786