[PATCH 1/2] xrow: allow to store tuple metadata in request

[Vladimir Davydov <vdavydov.dev@gmail.com>]

This patch set allows to store msgpack map with arbitrary keys inside
a request. In particular, this is needed to store vinyl statement flags
in run files.

Needed for #2129
---
 src/box/iproto_constants.c |  3 ++-
 src/box/iproto_constants.h |  3 ++-
 src/box/xrow.c             | 13 ++++++++++++-
 src/box/xrow.h             |  3 +++
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/box/iproto_constants.c b/src/box/iproto_constants.c
index e35738b4..a8d15cb1 100644
--- a/src/box/iproto_constants.c
+++ b/src/box/iproto_constants.c
@@ -87,6 +87,7 @@ const unsigned char iproto_key_type[IPROTO_KEY_MAX] =
 	/* 0x27 */	MP_STR, /* IPROTO_EXPR */
 	/* 0x28 */	MP_ARRAY, /* IPROTO_OPS */
 	/* 0x29 */	MP_MAP, /* IPROTO_BALLOT */
+	/* 0x2a */	MP_MAP, /* IPROTO_TUPLE_META */
 	/* }}} */
 };
 
@@ -168,7 +169,7 @@ const char *iproto_key_strs[IPROTO_KEY_MAX] = {
 	"expression",       /* 0x27 */
 	"operations",       /* 0x28 */
 	"ballot",           /* 0x29 */
-	NULL,               /* 0x2a */
+	"tuple meta",       /* 0x2a */
 	NULL,               /* 0x2b */
 	NULL,               /* 0x2c */
 	NULL,               /* 0x2d */
diff --git a/src/box/iproto_constants.h b/src/box/iproto_constants.h
index f282a0b2..404f97a2 100644
--- a/src/box/iproto_constants.h
+++ b/src/box/iproto_constants.h
@@ -78,6 +78,7 @@ enum iproto_key {
 	IPROTO_EXPR = 0x27, /* EVAL */
 	IPROTO_OPS = 0x28, /* UPSERT but not UPDATE ops, because of legacy */
 	IPROTO_BALLOT = 0x29,
+	IPROTO_TUPLE_META = 0x2a,
 	/* Leave a gap between request keys and response keys */
 	IPROTO_DATA = 0x30,
 	IPROTO_ERROR = 0x31,
@@ -96,7 +97,7 @@ enum iproto_ballot_key {
 			  bit(LSN) | bit(SCHEMA_VERSION))
 #define IPROTO_DML_BODY_BMAP (bit(SPACE_ID) | bit(INDEX_ID) | bit(LIMIT) |\
 			      bit(OFFSET) | bit(ITERATOR) | bit(INDEX_BASE) |\
-			      bit(KEY) | bit(TUPLE) | bit(OPS))
+			      bit(KEY) | bit(TUPLE) | bit(OPS) | bit(TUPLE_META))
 
 static inline bool
 xrow_header_has_key(const char *pos, const char *end)
diff --git a/src/box/xrow.c b/src/box/xrow.c
index 269a6e68..7a35d0db 100644
--- a/src/box/xrow.c
+++ b/src/box/xrow.c
@@ -532,6 +532,10 @@ error:
 			request->ops = value;
 			request->ops_end = data;
 			break;
+		case IPROTO_TUPLE_META:
+			request->tuple_meta = value;
+			request->tuple_meta_end = data;
+			break;
 		default:
 			break;
 		}
@@ -585,7 +589,8 @@ xrow_encode_dml(const struct request *request, struct iovec *iov)
 	const int MAP_LEN_MAX = 40;
 	uint32_t key_len = request->key_end - request->key;
 	uint32_t ops_len = request->ops_end - request->ops;
-	uint32_t len = MAP_LEN_MAX + key_len + ops_len;
+	uint32_t tuple_meta_len = request->tuple_meta_end - request->tuple_meta;
+	uint32_t len = MAP_LEN_MAX + key_len + ops_len + tuple_meta_len;
 	char *begin = (char *) region_alloc(&fiber()->gc, len);
 	if (begin == NULL) {
 		diag_set(OutOfMemory, len, "region_alloc", "begin");
@@ -620,6 +625,12 @@ xrow_encode_dml(const struct request *request, struct iovec *iov)
 		pos += ops_len;
 		map_size++;
 	}
+	if (request->tuple_meta) {
+		pos = mp_encode_uint(pos, IPROTO_TUPLE_META);
+		memcpy(pos, request->tuple_meta, tuple_meta_len);
+		pos += tuple_meta_len;
+		map_size++;
+	}
 	if (request->tuple) {
 		pos = mp_encode_uint(pos, IPROTO_TUPLE);
 		iov[iovcnt].iov_base = (void *) request->tuple;
diff --git a/src/box/xrow.h b/src/box/xrow.h
index 9887382c..47216705 100644
--- a/src/box/xrow.h
+++ b/src/box/xrow.h
@@ -127,6 +127,9 @@ struct request {
 	/** Upsert operations. */
 	const char *ops;
 	const char *ops_end;
+	/** Tuple metadata. */
+	const char *tuple_meta;
+	const char *tuple_meta_end;
 	/** Base field offset for UPDATE/UPSERT, e.g. 0 for C and 1 for Lua. */
 	int index_base;
 };
-- 
2.11.0