Split out validator index gRPC call

validator_client/src/duties/grpc.rs

@@ -1,6 +1,8 @@
 use super::traits::{BeaconNode, BeaconNodeError};
 use super::EpochDuties;
-use protos::services::ValidatorAssignmentRequest;
+use protos::services::{
+    IndexResponse, ProposeBlockSlotRequest, ProposeBlockSlotResponse, PublicKey as IndexRequest,
+};
 use protos::services_grpc::ValidatorServiceClient;
 use ssz::ssz_encode;
 use types::PublicKey;
@@ -11,30 +13,33 @@ impl BeaconNode for ValidatorServiceClient {
         epoch: u64,
         public_key: &PublicKey,
     ) -> Result<Option<EpochDuties>, BeaconNodeError> {
-        let mut req = ValidatorAssignmentRequest::new();
+        // Lookup the validator index for the supplied public key.
+        let validator_index = {
+            let mut req = IndexRequest::new();
+            req.set_public_key(ssz_encode(public_key).to_vec());
+            let resp = self
+                .validator_index(&req)
+                .map_err(|err| BeaconNodeError::RemoteFailure(format!("{:?}", err)))?;
+            resp.get_index()
+        };
+
+        let mut req = ProposeBlockSlotRequest::new();
+        req.set_validator_index(validator_index);
         req.set_epoch(epoch);
-        req.set_public_key(ssz_encode(public_key).to_vec());
 
         let reply = self
-            .validator_assignment(&req)
+            .propose_block_slot(&req)
             .map_err(|err| BeaconNodeError::RemoteFailure(format!("{:?}", err)))?;
 
-        if reply.has_validator_assignment() {
-            let assignment = reply.get_validator_assignment();
-
-            let block_production_slot = if assignment.has_block_production_slot() {
-                Some(assignment.get_block_production_slot())
-            } else {
-                None
-            };
-
-            let duties = EpochDuties {
-                block_production_slot,
-            };
-
-            Ok(Some(duties))
+        let block_production_slot = if reply.has_slot() {
+            Some(reply.get_slot())
         } else {
-            Ok(None)
-        }
+            None
+        };
+
+        Ok(Some(EpochDuties {
+            validator_index,
+            block_production_slot,
+        }))
     }
 }