[Add] Structure

src/util/mod.rs

@@ -1,2 +1,16 @@
 pub mod file_util;
 pub mod logger;
+
+use mtp::codec::{DataType, DataTypeId, TypeMap};
+
+/*
+ * Omikron serializes fields using the latest TypeMap, whose built-in fields
+ * are required by the protocol. Keep the invariant in one place while using
+ * the non-deprecated conversion API.
+ */
+pub fn data_type_id(data_type: DataType, type_map: &TypeMap) -> DataTypeId {
+    let Some(id) = data_type.try_to_id(type_map) else {
+        panic!("required data type is missing from the TypeMap: {data_type:?}");
+    };
+    id
+}