[PATCH 3/5] receive-pack.c: use a single ref_transaction for atomic pushes

From

Stefan Beller <sbeller@google.com>

Date

Dec 15, 2014, 19:56 UTC

Message-ID

<1418673368-20785-4-git-send-email-sbeller@google.com>

In-Reply-To

<1418673368-20785-1-git-send-email-sbeller@google.com>

From: Ronnie Sahlberg <sahlberg@google.com>

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 builtin/receive-pack.c | 73 +++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 58 insertions(+), 15 deletions(-)

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 0c642ab..e6cf174 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -67,6 +67,8 @@ static const char *NONCE_SLOP = "SLOP";
 static const char *nonce_status;
 static long nonce_stamp_slop;
 static unsigned long nonce_stamp_slop_limit;
+struct strbuf err = STRBUF_INIT;
+struct ref_transaction *transaction;
 
 static enum deny_action parse_deny_action(const char *var, const char *value)
 {
@@ -832,34 +834,56 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 				cmd->did_not_exist = 1;
 			}
 		}
-		if (delete_ref(namespaced_name, old_sha1, 0)) {
-			rp_error("failed to delete %s", name);
-			return "failed to delete";
+		if (!use_atomic_push) {
+			if (delete_ref(namespaced_name, old_sha1, 0)) {
+				rp_error("failed to delete %s", name);
+				return "failed to delete";
+			}
+		} else {
+			if (ref_transaction_delete(transaction,
+						   namespaced_name,
+						   old_sha1,
+						   0, old_sha1 != NULL,
+						   "push", &err)) {
+				rp_error("%s", err.buf);
+				strbuf_release(&err);
+				return "failed to delete";
+			}
 		}
 		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";
 
-		transaction = ref_transaction_begin(&err);
-		if (!transaction ||
-		    ref_transaction_update(transaction, namespaced_name,
-					   new_sha1, old_sha1, 0, 1, "push",
-					   &err) ||
-		    ref_transaction_commit(transaction, &err)) {
-			ref_transaction_free(transaction);
-
+		if (!use_atomic_push) {
+			transaction = ref_transaction_begin(&err);
+			if (!transaction) {
+				rp_error("%s", err.buf);
+				strbuf_release(&err);
+				return "failed to start transaction";
+			}
+		}
+		if (ref_transaction_update(transaction,
+					   namespaced_name,
+					   new_sha1, old_sha1,
+					   0, 1, "push",
+					   &err)) {
 			rp_error("%s", err.buf);
 			strbuf_release(&err);
 			return "failed to update ref";
 		}
 
-		ref_transaction_free(transaction);
+		if (!use_atomic_push) {
+			if (ref_transaction_commit(transaction, &err)) {
+				ref_transaction_free(transaction);
+				rp_error("%s", err.buf);
+				strbuf_release(&err);
+				return "failed to update ref";
+			}
+			ref_transaction_free(transaction);
+		}
 		strbuf_release(&err);
 		return NULL; /* good */
 	}
@@ -1059,6 +1083,16 @@ static void execute_commands(struct command *commands,
 		return;
 	}
 
+	if (use_atomic_push) {
+		transaction = ref_transaction_begin(&err);
+		if (!transaction) {
+			error("%s", err.buf);
+			strbuf_release(&err);
+			for (cmd = commands; cmd; cmd = cmd->next)
+				cmd->error_string = "transaction error";
+			return;
+		}
+	}
 	data.cmds = commands;
 	data.si = si;
 	if (check_everything_connected(iterate_receive_command_list, 0, &data))
@@ -1096,6 +1130,14 @@ static void execute_commands(struct command *commands,
 		}
 	}
 
+	if (use_atomic_push) {
+		if (ref_transaction_commit(transaction, &err)) {
+			rp_error("%s", err.buf);
+			for (cmd = commands; cmd; cmd = cmd->next)
+				cmd->error_string = err.buf;
+		}
+		ref_transaction_free(transaction);
+	}
 	if (shallow_update && !checked_connectivity)
 		error("BUG: run 'git fsck' for safety.\n"
 		      "If there are errors, try to remove "
@@ -1543,5 +1585,6 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 	sha1_array_clear(&shallow);
 	sha1_array_clear(&ref);
 	free((void *)push_cert_nonce);
+	strbuf_release(&err);
 	return 0;
 }

-- 
2.2.0.33.gc2219e3.dirty