Add get_latest_commited_state method to Process

src/process.rs

@@ -283,6 +283,37 @@ impl Process {
         self.states.split_off(pos)
     }
 
+    pub fn get_latest_commited_state(&self) -> Option<&ProcessState> {
+        if self.states.is_empty() {
+            return None;
+        }
+
+        let latest_state = self.get_latest_state().unwrap();
+
+        // a commited outpoint with an index of u32::MAX is a pending state
+        if latest_state.commited_in.vout != u32::MAX {
+            // This state is commited, there's no pending state
+            return Some(latest_state);
+        }
+
+        // We look for the last state before all the pending states
+        let latest_outpoint = latest_state.commited_in;
+
+        let pos = self
+            .states
+            .iter()
+            .position(|s| s.commited_in == latest_outpoint)
+            .unwrap();
+
+        if pos == 0 {
+            // There's no commited states, we just return None
+            return None;
+        } else {
+            // The state just before is last commited state
+            return self.get_state_at(pos-1);
+        }
+    }
+
     pub fn insert_impending_request(&mut self, request: Prd) {
         self.impending_requests.push(request);
     }