[Tarantool-patches] [PATCH v2 4/7] qsync: provide a binary form of CONFIRM/ROLLBACK entries

[Cyrill Gorcunov <gorcunov@gmail.com>]

These msgpack entries will be needed to write them
down to a journal without involving txn engine.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 src/box/iproto_constants.h | 27 +++++++++++++++++++++++++++
 src/box/xrow.c             | 23 ++++++++---------------
 2 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/src/box/iproto_constants.h b/src/box/iproto_constants.h
index 6b850f101..1e6566e0f 100644
--- a/src/box/iproto_constants.h
+++ b/src/box/iproto_constants.h
@@ -328,6 +328,33 @@ iproto_type_is_synchro_request(uint32_t type)
 	return type == IPROTO_CONFIRM || type == IPROTO_ROLLBACK;
 }
 
+/** CONFIRM/ROLLBACK entries encoded in MsgPack. */
+struct PACKED request_synchro_body {
+	uint8_t m_body;
+	uint8_t k_replica_id;
+	uint8_t m_replica_id;
+	uint32_t v_replica_id;
+	uint8_t k_lsn;
+	uint8_t m_lsn;
+	uint64_t v_lsn;
+};
+
+/**
+ * Creates CONFIRM/ROLLBACK entry.
+ */
+static inline void
+request_synchro_body_create(struct request_synchro_body *body,
+			    uint32_t replica_id, int64_t lsn)
+{
+	body->m_body = 0x80 | 2;
+	body->k_replica_id = IPROTO_REPLICA_ID;
+	body->m_replica_id = 0xce;
+	body->v_replica_id = mp_bswap_u32(replica_id);
+	body->k_lsn = IPROTO_LSN;
+	body->m_lsn = 0xcf;
+	body->v_lsn = mp_bswap_u64(lsn);
+}
+
 /** This is an error. */
 static inline bool
 iproto_type_is_error(uint32_t type)
diff --git a/src/box/xrow.c b/src/box/xrow.c
index 0c797a9d5..c2f4ba40a 100644
--- a/src/box/xrow.c
+++ b/src/box/xrow.c
@@ -897,26 +897,19 @@ static int
 xrow_encode_confirm_rollback(struct xrow_header *row, struct region *region,
 			     uint32_t replica_id, int64_t lsn, int type)
 {
-	size_t len = mp_sizeof_map(2) + mp_sizeof_uint(IPROTO_REPLICA_ID) +
-		     mp_sizeof_uint(replica_id) + mp_sizeof_uint(IPROTO_LSN) +
-		     mp_sizeof_uint(lsn);
-	char *buf = (char *)region_alloc(region, len);
-	if (buf == NULL) {
-		diag_set(OutOfMemory, len, "region_alloc", "buf");
+	struct request_synchro_body *body;
+
+	body = region_alloc(region, sizeof(*body));
+	if (body == NULL) {
+		diag_set(OutOfMemory, sizeof(*body), "region_alloc", "body");
 		return -1;
 	}
-	char *pos = buf;
-
-	pos = mp_encode_map(pos, 2);
-	pos = mp_encode_uint(pos, IPROTO_REPLICA_ID);
-	pos = mp_encode_uint(pos, replica_id);
-	pos = mp_encode_uint(pos, IPROTO_LSN);
-	pos = mp_encode_uint(pos, lsn);
+	request_synchro_body_create(body, replica_id, lsn);
 
 	memset(row, 0, sizeof(*row));
 
-	row->body[0].iov_base = buf;
-	row->body[0].iov_len = len;
+	row->body[0].iov_base = (void *)body;
+	row->body[0].iov_len = sizeof(*body);
 	row->bodycnt = 1;
 
 	row->type = type;
-- 
2.26.2