Be able to report the current size of the LoadBalancer's message store

sparta/src/load_balancer.rs

@@ -355,4 +355,10 @@ impl LoadBalancer {
 
         responses.drain(0..num_requests).map(|r| r.0).collect()
     }
+
+    pub fn size(&self) -> usize {
+        self.submaps
+            .iter()
+            .fold(0usize, |acc, submap| acc + submap.size())
+    }
 }

sparta/src/omap.rs

@@ -130,4 +130,8 @@ impl ObliviousMap {
         self.message_store.truncate(final_size);
         response
     }
+
+    pub fn size(&self) -> usize {
+        self.message_store.len()
+    }
 }