[Tarantool-patches] [PATCH v3 2/3] sql: specify field types in ephemeral space format

[imeevma@tarantool.org]

This patch specifies field types in ephemeral space format in SQL.
Prior to this patch, all fields had a SCALAR field type.

This patch allows us to not use the primary index to obtain field
types, since now the ephemeral space has field types in the
format. This allows us to change the structure of the primary
index, which helps to solve the issue #4256. In addition, since we
can now set the field types of the ephemeral space, we can use
this feature to set the field types according to the left value of
the IN operator. This will fix issue #4692.

Needed for #4256
Needed for #4692
Closes #3841
---
 src/box/sql.c | 53 +++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 39 insertions(+), 14 deletions(-)

diff --git a/src/box/sql.c b/src/box/sql.c
index f6afb86..6436f64 100644
--- a/src/box/sql.c
+++ b/src/box/sql.c
@@ -324,13 +324,44 @@ sql_ephemeral_space_create(uint32_t field_count, struct sql_key_info *key_info)
 			return NULL;
 	}
 
-	struct key_part_def *ephemer_key_parts = region_alloc(&fiber()->gc,
-				sizeof(*ephemer_key_parts) * field_count);
-	if (ephemer_key_parts == NULL) {
-		diag_set(OutOfMemory, sizeof(*ephemer_key_parts) * field_count,
-			 "region", "key parts");
+	struct region *region = &fiber()->gc;
+	/*
+	 * Name of the fields will be "_COLUMN_1", "_COLUMN_2"
+	 * and so on. Due to this, length of each name is no more
+	 * than strlen("_COLUMN_") plus length of UINT32_MAX
+	 * turned to string, which is 10 and plus 1 for \0.
+	 */
+	uint32_t name_len = strlen("_COLUMN_") + 11;
+	uint32_t size = field_count * (sizeof(struct field_def) + name_len +
+				       sizeof(struct key_part_def));
+	struct field_def *fields = region_alloc(region, size);
+	if (fields == NULL) {
+		diag_set(OutOfMemory, size, "region_alloc", "fields");
 		return NULL;
 	}
+	struct key_part_def *ephemer_key_parts =
+		(void *)fields + field_count * sizeof(struct field_def);
+	char *names = (char *)ephemer_key_parts +
+		      field_count * sizeof(struct key_part_def);
+	for (uint32_t i = 0; i < field_count; ++i) {
+		struct field_def *field = &fields[i];
+		field->name = names;
+		names += name_len;
+		sprintf(field->name, "_COLUMN_%d", i);
+		field->is_nullable = true;
+		field->nullable_action = ON_CONFLICT_ACTION_NONE;
+		field->default_value = NULL;
+		field->default_value_expr = NULL;
+		if (def != NULL && i < def->part_count) {
+			assert(def->parts[i].type < field_type_MAX);
+			field->type = def->parts[i].type;
+			field->coll_id = def->parts[i].coll_id;
+		} else {
+			field->coll_id = COLL_NONE;
+			field->type = FIELD_TYPE_SCALAR;
+		}
+	}
+
 	for (uint32_t i = 0; i < field_count; ++i) {
 		struct key_part_def *part = &ephemer_key_parts[i];
 		part->fieldno = i;
@@ -338,14 +369,8 @@ sql_ephemeral_space_create(uint32_t field_count, struct sql_key_info *key_info)
 		part->is_nullable = true;
 		part->sort_order = SORT_ORDER_ASC;
 		part->path = NULL;
-		if (def != NULL && i < def->part_count) {
-			assert(def->parts[i].type < field_type_MAX);
-			part->type = def->parts[i].type;
-			part->coll_id = def->parts[i].coll_id;
-		} else {
-			part->coll_id = COLL_NONE;
-			part->type = FIELD_TYPE_SCALAR;
-		}
+		part->type = fields[i].type;
+		part->coll_id = fields[i].coll_id;
 	}
 	struct key_def *ephemer_key_def = key_def_new(ephemer_key_parts,
 						      field_count, false);
@@ -364,7 +389,7 @@ sql_ephemeral_space_create(uint32_t field_count, struct sql_key_info *key_info)
 	rlist_add_entry(&key_list, ephemer_index_def, link);
 
 	struct space_def *ephemer_space_def =
-		space_def_new_ephemeral(field_count, NULL);
+		space_def_new_ephemeral(field_count, fields);
 	if (ephemer_space_def == NULL) {
 		index_def_delete(ephemer_index_def);
 		return NULL;
-- 
2.7.4