[PATCH v14 24/40] receive-pack.c: use a reference transaction for updating the refs

[Ronnie Sahlberg <sahlberg@google.com>]

Wrap all the ref updates inside a transaction.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 builtin/receive-pack.c | 31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index c323081..13f4a63 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -46,6 +46,7 @@ static void *head_name_to_free;
 static int sent_capabilities;
 static int shallow_update;
 static const char *alt_shallow_file;
+static struct string_list error_strings = STRING_LIST_INIT_DUP;
 
 static enum deny_action parse_deny_action(const char *var, const char *value)
 {
@@ -475,7 +476,6 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	const char *namespaced_name;
 	unsigned char *old_sha1 = cmd->old_sha1;
 	unsigned char *new_sha1 = cmd->new_sha1;
-	struct ref_lock *lock;
 
 	/* only refs/... are allowed */
 	if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) {
@@ -576,19 +576,31 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 		return NULL; /* good */
 	}
 	else {
+		struct strbuf err = STRBUF_INIT;
+		struct ref_transaction *transaction;
+
 		if (shallow_update && si->shallow_ref[cmd->index] &&
 		    update_shallow_ref(cmd, si))
 			return "shallow error";
 
-		lock = lock_any_ref_for_update(namespaced_name, old_sha1,
-					       0, NULL);
-		if (!lock) {
-			rp_error("failed to lock %s", name);
-			return "failed to lock";
-		}
-		if (write_ref_sha1(lock, new_sha1, "push")) {
-			return "failed to write"; /* error() already called */
+		transaction = ref_transaction_begin(&err);
+		if (!transaction ||
+		    ref_transaction_update(transaction, namespaced_name,
+					   new_sha1, old_sha1, 0, 1, &err) ||
+		    ref_transaction_commit(transaction, "push", &err)) {
+
+			const char *str;
+			string_list_append(&error_strings, err.buf);
+			str = error_strings.items[error_strings.nr - 1].string;
+			strbuf_release(&err);
+
+			ref_transaction_free(transaction);
+			rp_error("%s", str);
+			return str;
 		}
+
+		ref_transaction_free(transaction);
+		strbuf_release(&err);
 		return NULL; /* good */
 	}
 }
@@ -1215,5 +1227,6 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 		packet_flush(1);
 	sha1_array_clear(&shallow);
 	sha1_array_clear(&ref);
+	string_list_clear(&error_strings, 0);
 	return 0;
 }
-- 
2.0.0.582.ge25c160