The "files" backend has implemented special logic when committing
the first transactions in an otherwise empty ref store: instead of
writing all refs as separate loose files, it instead knows to write them
all into a "packed-refs" file directly. This is significantly more
efficient than having to write each of the refs as separate "loose" ref.
The only user of this optimization is git-clone(1), which only uses this
mechanism to write regular refs. Consequently, the implementation does
not know how to handle both symbolic and root refs. While fine in the
context of git-clone(1), this keeps us from using the mechanism in more
cases.
Adapt the logic to also support symbolic and root refs by using a second
transaction that we use for all of the refs that need to be written as
loose refs.
Signed-off-by: Patrick Steinhardt <ps@xxxxxx>
---
refs/files-backend.c | 44 ++++++++++++++++++++++++++++++++++----------
1 file changed, 34 insertions(+), 10 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 3ed18475a72aa4798d15b2912c37b4caabd47aac..116d4259697b20583cb2db34ed47025e8781cd42 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2995,6 +2995,7 @@ static int files_transaction_finish_initial(struct files_ref_store *refs,
int ret = 0;
struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
struct ref_transaction *packed_transaction = NULL;
+ struct ref_transaction *loose_transaction = NULL;
assert(err);
@@ -3040,6 +3041,7 @@ static int files_transaction_finish_initial(struct files_ref_store *refs,
if ((update->flags & REF_HAVE_OLD) &&
!is_null_oid(&update->old_oid))
BUG("initial ref transaction with old_sha1 set");
+
if (refs_verify_refname_available(&refs->base, update->refname,
&affected_refnames, NULL,
err)) {
@@ -3048,26 +3050,48 @@ static int files_transaction_finish_initial(struct files_ref_store *refs,
}
/*
- * Add a reference creation for this reference to the
- * packed-refs transaction:
+ * packed-refs don't support symbolic refs and root refs, so we
+ * have to queue these references via the loose transaction.
*/
- ref_transaction_add_update(packed_transaction, update->refname,
- update->flags & ~REF_HAVE_OLD,
- &update->new_oid, &update->old_oid,
- NULL, NULL, NULL);
+ if (update->new_target || is_root_ref(update->refname)) {
+ if (!loose_transaction) {
+ loose_transaction = ref_store_transaction_begin(&refs->base, 0, err);
+ if (!loose_transaction) {
+ ret = TRANSACTION_GENERIC_ERROR;
+ goto cleanup;
+ }
+ }
+
+ ref_transaction_add_update(loose_transaction, update->refname,
+ update->flags & ~REF_HAVE_OLD,
+ update->new_target ? NULL : &update->new_oid, NULL,
+ update->new_target, NULL, NULL);
+ } else {
+ ref_transaction_add_update(packed_transaction, update->refname,
+ update->flags & ~REF_HAVE_OLD,
+ &update->new_oid, &update->old_oid,
+ NULL, NULL, NULL);
+ }
}
- if (packed_refs_lock(refs->packed_ref_store, 0, err)) {
+ if (packed_refs_lock(refs->packed_ref_store, 0, err) ||
+ ref_transaction_commit(packed_transaction, err)) {
ret = TRANSACTION_GENERIC_ERROR;
goto cleanup;
}
+ packed_refs_unlock(refs->packed_ref_store);
- if (ref_transaction_commit(packed_transaction, err)) {
- ret = TRANSACTION_GENERIC_ERROR;
+ if (loose_transaction) {
+ if (ref_transaction_prepare(loose_transaction, err) ||
+ ref_transaction_commit(loose_transaction, err)) {
+ ret = TRANSACTION_GENERIC_ERROR;
+ goto cleanup;
+ }
}
- packed_refs_unlock(refs->packed_ref_store);
cleanup:
+ if (loose_transaction)
+ ref_transaction_free(loose_transaction);
if (packed_transaction)
ref_transaction_free(packed_transaction);
transaction->state = REF_TRANSACTION_CLOSED;
--
2.47.0.274.g962d0b743d.dirty
