add shard lookup convenience

client/history/redirector.go

@@ -74,6 +74,14 @@ func (t operationTarget) validate() error {
 	return nil
 }
 
+func shardLookup(resolver membership.ServiceResolver, shardID int32) (rpcAddress, error) {
+	hostInfo, err := resolver.Lookup(convert.Int32ToString(shardID))
+	if err != nil {
+		return "", err
+	}
+	return rpcAddress(hostInfo.GetAddress()), nil
+}
+
 func newBasicRedirector(
 	connections *clientConnections,
 	historyServiceResolver membership.ServiceResolver,
@@ -92,11 +100,11 @@ func (r *basicRedirector) clientForTarget(target operationTarget) (historyservic
 		connection := r.connections.getOrCreateClientConn(target.address)
 		return connection.historyClient, nil
 	}
-	hostInfo, err := r.historyServiceResolver.Lookup(convert.Int32ToString(target.shardID))
+	address, err := shardLookup(r.historyServiceResolver, target.shardID)
 	if err != nil {
 		return nil, err
 	}
-	clientConn := r.connections.getOrCreateClientConn(rpcAddress(hostInfo.GetAddress()))
+	clientConn := r.connections.getOrCreateClientConn(address)
 	return clientConn.historyClient, nil
 }
 
@@ -108,11 +116,10 @@ func (r *basicRedirector) execute(ctx context.Context, target operationTarget, o
 		connection := r.connections.getOrCreateClientConn(target.address)
 		return op(ctx, connection.historyClient)
 	}
-	hostInfo, err := r.historyServiceResolver.Lookup(convert.Int32ToString(target.shardID))
+	address, err := shardLookup(r.historyServiceResolver, target.shardID)
 	if err != nil {
 		return err
 	}
-	address := rpcAddress(hostInfo.GetAddress())
 	return r.redirectLoop(ctx, address, op)
 }