Use next epoch protocol parameters for signer registration

Author: jpraynaud

mithril-aggregator/src/http_server/routes/epoch_routes.rs

@@ -40,24 +40,31 @@ mod handlers {
         debug!("⇄ HTTP SERVER: epoch_settings");
 
         match multi_signer.read().await.get_current_beacon().await {
-            Some(beacon) => match protocol_parameters_store
-                .get_protocol_parameters(beacon.epoch)
-                .await
-            {
-                Ok(Some(protocol_parameters)) => Ok(reply::json(
-                    &EpochSettings {
-                        epoch: beacon.epoch,
-                        protocol_parameters,
-                    },
-                    StatusCode::OK,
-                )),
-                Ok(None) => {
+            Some(beacon) => match (
+                protocol_parameters_store
+                    .get_protocol_parameters(beacon.epoch)
+                    .await,
+                protocol_parameters_store
+                    .get_protocol_parameters(beacon.epoch + 1)
+                    .await,
+            ) {
+                (Ok(Some(protocol_parameters)), Ok(Some(next_protocol_parameters))) => {
+                    Ok(reply::json(
+                        &EpochSettings {
+                            epoch: beacon.epoch,
+                            protocol_parameters,
+                            next_protocol_parameters,
+                        },
+                        StatusCode::OK,
+                    ))
+                }
+                (Ok(None), Ok(Some(_))) | (Ok(Some(_)), Ok(None)) | (Ok(None), Ok(None)) => {
                     warn!("epoch_settings::could_not_retrieve_protocol_parameters");
                     Ok(reply::internal_server_error(
                         "could_not_retrieve_protocol_parameters".to_string(),
                     ))
                 }
-                Err(err) => {
+                (Err(err), _) | (_, Err(err)) => {
                     warn!("epoch_settings::error"; "error" => ?err);
                     Ok(reply::internal_server_error(err.to_string()))
                 }

mithril-common/src/entities/epoch_settings.rs

@@ -10,4 +10,8 @@ pub struct EpochSettings {
     /// Current Protocol parameters
     #[serde(rename = "protocol")]
     pub protocol_parameters: ProtocolParameters,
+
+    /// Next Protocol parameters
+    #[serde(rename = "next_protocol")]
+    pub next_protocol_parameters: ProtocolParameters,
 }

mithril-common/src/fake_data.rs

@@ -38,11 +38,13 @@ pub fn epoch_settings() -> entities::EpochSettings {
 
     // Protocol parameters
     let protocol_parameters = protocol_parameters();
+    let next_protocol_parameters = protocol_parameters.clone();
 
     // Epoch settings
     entities::EpochSettings {
         epoch: beacon.epoch,
         protocol_parameters,
+        next_protocol_parameters,
     }
 }
 

mithril-signer/src/runtime/state_machine.rs

@@ -215,7 +215,7 @@ impl StateMachine {
         let beacon = self.runner.get_current_beacon().await?;
         self.runner.update_stake_distribution(beacon.epoch).await?;
         self.runner
-            .register_signer_to_aggregator(beacon.epoch, &epoch_settings.protocol_parameters)
+            .register_signer_to_aggregator(beacon.epoch, &epoch_settings.next_protocol_parameters)
             .await?;
 
         Ok(RegisteredState { beacon })
@@ -304,6 +304,7 @@ mod tests {
         let epoch_settings = EpochSettings {
             epoch: Epoch(3),
             protocol_parameters: fake_data::protocol_parameters(),
+            next_protocol_parameters: fake_data::protocol_parameters(),
         };
         let known_epoch = Epoch(4);
         runner