box: introduce box_space_id_by_name

Part of #3273.

src/box/box.cc

@@ -877,7 +877,7 @@ box_return_tuple(box_function_ctx_t *ctx, box_tuple_t *tuple)
 
 /* schema_find_id()-like method using only public API */
 uint32_t
-box_space_id_by_name(const char *name, uint32_t len)
+space_id_by_name(uint32_t system_space_id, const char *name, uint32_t len)
 {
 	if (len > BOX_NAME_MAX)
 		return BOX_ID_NIL;
@@ -892,7 +892,7 @@ box_space_id_by_name(const char *name, uint32_t len)
 
 	/* NOTE: error and missing key cases are indistinguishable */
 	box_tuple_t *tuple;
-	if (box_index_get(BOX_VSPACE_ID, 2, begin, end, &tuple) != 0)
+	if (box_index_get(system_space_id, 2, begin, end, &tuple) != 0)
 		return BOX_ID_NIL;
 	if (tuple == NULL)
 		return BOX_ID_NIL;
@@ -901,6 +901,12 @@ box_space_id_by_name(const char *name, uint32_t len)
 	return result;
 }
 
+uint32_t
+box_space_id_by_name(const char *name, uint32_t len)
+{
+	return space_id_by_name(BOX_VSPACE_ID, name, len);
+}
+
 uint32_t
 box_index_id_by_name(uint32_t space_id, const char *name, uint32_t len)
 {

src/box/box.h

@@ -219,6 +219,20 @@ typedef struct box_function_ctx box_function_ctx_t;
 API_EXPORT int
 box_return_tuple(box_function_ctx_t *ctx, box_tuple_t *tuple);
 
+/**
+ * Find space id by name in specified system space.
+ *
+ * This function performs SELECT request to _vspace system space.
+ * \param system_space_id space to lookup name.
+ * \param name space name
+ * \param len length of \a name
+ * \retval BOX_ID_NIL on error or if not found (check box_error_last())
+ * \retval space_id otherwise
+ * \sa box_index_id_by_name
+ */
+uint32_t
+space_id_by_name(uint32_t system_space_id, const char *name, uint32_t len);
+
 /**
  * Find space id by name.
  *