reftable/stack: open-code reading refs

To read a reference for the reftable stack, we first create a generic
`reftable_table` from the merged table and then read the reference via a
convenience function. We are about to remove these generic interfaces,
so let's instead open-code the logic to prepare for this removal.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/reftable/stack.c b/reftable/stack.c
index 7f4e267ea9890af3ce8945893f176df1617b07e3..d08ec009590266a492fd50145475168d7d58512e 100644 (file)
--- a/reftable/stack.c
+++ b/reftable/stack.c
@@ -1468,9 +1468,28 @@ reftable_stack_compaction_stats(struct reftable_stack *st)
 int reftable_stack_read_ref(struct reftable_stack *st, const char *refname,
                            struct reftable_ref_record *ref)
 {
-       struct reftable_table tab = { NULL };
-       reftable_table_from_merged_table(&tab, reftable_stack_merged_table(st));
-       return reftable_table_read_ref(&tab, refname, ref);
+       struct reftable_iterator it = { 0 };
+       int ret;
+
+       reftable_merged_table_init_ref_iterator(st->merged, &it);
+       ret = reftable_iterator_seek_ref(&it, refname);
+       if (ret)
+               goto out;
+
+       ret = reftable_iterator_next_ref(&it, ref);
+       if (ret)
+               goto out;
+
+       if (strcmp(ref->refname, refname) ||
+           reftable_ref_record_is_deletion(ref)) {
+               reftable_ref_record_release(ref);
+               ret = 1;
+               goto out;
+       }
+
+out:
+       reftable_iterator_destroy(&it);
+       return ret;
 }
 
 int reftable_stack_read_log(struct reftable_stack *st, const char *refname,