wip: FailoverTopology implementation for PostgreSQL on the way!

harmony_types/src/lib.rs

@@ -1,3 +1,4 @@
 pub mod id;
 pub mod net;
 pub mod switch;
+pub mod storage;

harmony_types/src/storage.rs

@@ -0,0 +1,6 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, PartialOrd, Ord, Debug)]
+pub struct StorageSize {
+    size_bytes: u64,
+}