Merge branch 'ps/avoid-unnecessary-hook-invocation-with-packed-refs'

Because a deletion of ref would need to remove it from both the
loose ref store and the packed ref store, a delete-ref operation
that logically removes one ref may end up invoking ref-transaction
hook twice, which has been corrected.

* ps/avoid-unnecessary-hook-invocation-with-packed-refs:
  refs: skip hooks when deleting uncovered packed refs
  refs: do not execute reference-transaction hook on packing refs
  refs: demonstrate excessive execution of the reference-transaction hook
  refs: allow skipping the reference-transaction hook
  refs: allow passing flags when beginning transactions
  refs: extract packed_refs_delete_refs() to allow control of transaction

4 files changed, 48 insertions, 14 deletions

diff --git a/refs/files-backend.c b/refs/files-backend.c
index a40267b3ae..f59589d6cc 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1114,7 +1114,8 @@ static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)
 	if (check_refname_format(r->name, 0))
 		return;
 
-	transaction = ref_store_transaction_begin(&refs->base, &err);
+	transaction = ref_store_transaction_begin(&refs->base,
+						  REF_TRANSACTION_SKIP_HOOK, &err);
 	if (!transaction)
 		goto cleanup;
 	ref_transaction_add_update(
@@ -1185,7 +1186,8 @@ static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
 	struct strbuf err = STRBUF_INIT;
 	struct ref_transaction *transaction;
 
-	transaction = ref_store_transaction_begin(refs->packed_ref_store, &err);
+	transaction = ref_store_transaction_begin(refs->packed_ref_store,
+						  REF_TRANSACTION_SKIP_HOOK, &err);
 	if (!transaction)
 		return -1;
 
@@ -1242,6 +1244,7 @@ static int files_delete_refs(struct ref_store *ref_store, const char *msg,
 {
 	struct files_ref_store *refs =
 		files_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
+	struct ref_transaction *transaction = NULL;
 	struct strbuf err = STRBUF_INIT;
 	int i, result = 0;
 
@@ -1251,10 +1254,15 @@ static int files_delete_refs(struct ref_store *ref_store, const char *msg,
 	if (packed_refs_lock(refs->packed_ref_store, 0, &err))
 		goto error;
 
-	if (refs_delete_refs(refs->packed_ref_store, msg, refnames, flags)) {
-		packed_refs_unlock(refs->packed_ref_store);
+	transaction = ref_store_transaction_begin(refs->packed_ref_store,
+						  REF_TRANSACTION_SKIP_HOOK, &err);
+	if (!transaction)
+		goto error;
+
+	result = packed_refs_delete_refs(refs->packed_ref_store,
+					 transaction, msg, refnames, flags);
+	if (result)
 		goto error;
-	}
 
 	packed_refs_unlock(refs->packed_ref_store);
 
@@ -1265,6 +1273,7 @@ static int files_delete_refs(struct ref_store *ref_store, const char *msg,
 			result |= error(_("could not remove reference %s"), refname);
 	}
 
+	ref_transaction_free(transaction);
 	strbuf_release(&err);
 	return result;
 
@@ -1281,6 +1290,7 @@ error:
 	else
 		error(_("could not delete references: %s"), err.buf);
 
+	ref_transaction_free(transaction);
 	strbuf_release(&err);
 	return -1;
 }
@@ -2751,7 +2761,8 @@ static int files_transaction_prepare(struct ref_store *ref_store,
 			 */
 			if (!packed_transaction) {
 				packed_transaction = ref_store_transaction_begin(
-						refs->packed_ref_store, err);
+						refs->packed_ref_store,
+						REF_TRANSACTION_SKIP_HOOK, err);
 				if (!packed_transaction) {
 					ret = TRANSACTION_GENERIC_ERROR;
 					goto cleanup;
@@ -3022,7 +3033,8 @@ static int files_initial_transaction_commit(struct ref_store *ref_store,
 				 &affected_refnames))
 		BUG("initial ref transaction called with existing refs");
 
-	packed_transaction = ref_store_transaction_begin(refs->packed_ref_store, err);
+	packed_transaction = ref_store_transaction_begin(refs->packed_ref_store,
+							 REF_TRANSACTION_SKIP_HOOK, err);
 	if (!packed_transaction) {
 		ret = TRANSACTION_GENERIC_ERROR;
 		goto cleanup;
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index d91a2018f6..27dd8c3922 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1521,15 +1521,10 @@ static int packed_initial_transaction_commit(struct ref_store *ref_store,
 static int packed_delete_refs(struct ref_store *ref_store, const char *msg,
 			     struct string_list *refnames, unsigned int flags)
 {
-	struct packed_ref_store *refs =
-		packed_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
 	struct strbuf err = STRBUF_INIT;
 	struct ref_transaction *transaction;
-	struct string_list_item *item;
 	int ret;
 
-	(void)refs; /* We need the check above, but don't use the variable */
-
 	if (!refnames->nr)
 		return 0;
 
@@ -1539,10 +1534,30 @@ static int packed_delete_refs(struct ref_store *ref_store, const char *msg,
 	 * updates into a single transaction.
 	 */
 
-	transaction = ref_store_transaction_begin(ref_store, &err);
+	transaction = ref_store_transaction_begin(ref_store, 0, &err);
 	if (!transaction)
 		return -1;
 
+	ret = packed_refs_delete_refs(ref_store, transaction,
+				      msg, refnames, flags);
+
+	ref_transaction_free(transaction);
+	return ret;
+}
+
+int packed_refs_delete_refs(struct ref_store *ref_store,
+			    struct ref_transaction *transaction,
+			    const char *msg,
+			    struct string_list *refnames,
+			    unsigned int flags)
+{
+	struct strbuf err = STRBUF_INIT;
+	struct string_list_item *item;
+	int ret;
+
+	/* Assert that the ref store refers to a packed backend. */
+	packed_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
+
 	for_each_string_list_item(item, refnames) {
 		if (ref_transaction_delete(transaction, item->string, NULL,
 					   flags, msg, &err)) {
@@ -1562,7 +1577,6 @@ static int packed_delete_refs(struct ref_store *ref_store, const char *msg,
 			error(_("could not delete references: %s"), err.buf);
 	}
 
-	ref_transaction_free(transaction);
 	strbuf_release(&err);
 	return ret;
 }
diff --git a/refs/packed-backend.h b/refs/packed-backend.h
index 9dd8a344c3..52e0490753 100644
--- a/refs/packed-backend.h
+++ b/refs/packed-backend.h
@@ -3,6 +3,7 @@
 
 struct repository;
 struct ref_transaction;
+struct string_list;
 
 /*
  * Support for storing references in a `packed-refs` file.
@@ -27,6 +28,12 @@ int packed_refs_lock(struct ref_store *ref_store, int flags, struct strbuf *err)
 void packed_refs_unlock(struct ref_store *ref_store);
 int packed_refs_is_locked(struct ref_store *ref_store);
 
+int packed_refs_delete_refs(struct ref_store *ref_store,
+			    struct ref_transaction *transaction,
+			    const char *msg,
+			    struct string_list *refnames,
+			    unsigned int flags);
+
 /*
  * Return true if `transaction` really needs to be carried out against
  * the specified packed_ref_store, or false if it can be skipped
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 7ff6fba4f0..6e15db3ca4 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -213,6 +213,7 @@ struct ref_transaction {
 	size_t nr;
 	enum ref_transaction_state state;
 	void *backend_data;
+	unsigned int flags;
 };
 
 /*