refs debug: add a wrapper for "read_symbolic_ref"

In cd475b3b03 (refs: add ability for backends to special-case reading
of symbolic refs, 2022-03-01) when the "read_symbolic_ref" callback
was added we'd fall back on "refs_read_raw_ref" if there wasn't any
backend implementation of "read_symbolic_ref".

As discussed in the preceding commit this would only happen if we were
running the "debug" backend, e.g. in the "setup for ref completion"
test in with:

    GIT_TRACE_REFS=1 git fetch --no-tags other

Let's improve the trace output, but and also eliminate the
now-redundant refs_read_raw_ref() fallback case. As noted in the
preceding commit the "packed" backend will never call
refs_read_symbolic_ref() (nor is it ever going to). For any future
backend such as reftable it's OK to ask that they either implement
this (or a wrapper) themselves.

Signed-off-by: Ævar Arnfjörð Bjarmason <>
Signed-off-by: Junio C Hamano <>
Ævar Arnfjörð Bjarmason 6 months ago committed by Junio C Hamano
parent ca40893a41
commit 5b8754043c
  1. 13
  2. 27

@ -1676,18 +1676,7 @@ int refs_read_raw_ref(struct ref_store *ref_store, const char *refname,
int refs_read_symbolic_ref(struct ref_store *ref_store, const char *refname,
struct strbuf *referent)
struct object_id oid;
int ret, failure_errno = 0;
unsigned int type = 0;
if (ref_store->be->read_symbolic_ref)
return ref_store->be->read_symbolic_ref(ref_store, refname, referent);
ret = refs_read_raw_ref(ref_store, refname, &oid, referent, &type, &failure_errno);
if (ret || !(type & REF_ISSYMREF))
return -1;
return 0;
return ref_store->be->read_symbolic_ref(ref_store, refname, referent);
const char *refs_resolve_ref_unsafe(struct ref_store *refs,

@ -262,6 +262,24 @@ static int debug_read_raw_ref(struct ref_store *ref_store, const char *refname,
return res;
static int debug_read_symbolic_ref(struct ref_store *ref_store, const char *refname,
struct strbuf *referent)
struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
struct ref_store *refs = drefs->refs;
int res;
res = refs->be->read_symbolic_ref(refs, refname, referent);
if (!res)
trace_printf_key(&trace_refs, "read_symbolic_ref: %s: (%s)\n",
refname, referent->buf);
"read_symbolic_ref: %s: %d\n", refname, res);
return res;
static struct ref_iterator *
debug_reflog_iterator_begin(struct ref_store *ref_store)
@ -423,6 +441,13 @@ struct ref_storage_be refs_be_debug = {
.name = "debug",
.init = NULL,
.init_db = debug_init_db,
* None of these should be NULL. If the "files" backend (in
* "struct ref_storage_be refs_be_files" in files-backend.c)
* has a function we should also have a wrapper for it here.
* Test the output with "GIT_TRACE_REFS=1".
.transaction_prepare = debug_transaction_prepare,
.transaction_finish = debug_transaction_finish,
.transaction_abort = debug_transaction_abort,
@ -436,7 +461,7 @@ struct ref_storage_be refs_be_debug = {
.iterator_begin = debug_ref_iterator_begin,
.read_raw_ref = debug_read_raw_ref,
.read_symbolic_ref = NULL,
.read_symbolic_ref = debug_read_symbolic_ref,
.reflog_iterator_begin = debug_reflog_iterator_begin,
.for_each_reflog_ent = debug_for_each_reflog_ent,