routing: persist mission control data

lnrpc/routerrpc/config.go

@@ -24,4 +24,8 @@ type RoutingConfig struct {
 	// executing a payment attempt that fails. It is used to trade off
 	// potentially better routes against their probability of succeeding.
 	AttemptCost btcutil.Amount `long:"attemptcost" description:"The (virtual) cost in sats of a failed payment attempt"`
+
+	// MaxMcHistory defines the maximum number of payment results that
+	// are held on disk by mission control.
+	MaxMcHistory int `long:"maxmchistory" description:"the maximum number of payment results that are held on disk by mission control"`
 }

lnrpc/routerrpc/config_active.go

@@ -49,6 +49,7 @@ func DefaultConfig() *Config {
 		PenaltyHalfLife:       routing.DefaultPenaltyHalfLife,
 		AttemptCost: routing.DefaultPaymentAttemptPenalty.
 			ToSatoshis(),
+		MaxMcHistory: routing.DefaultMaxMcHistory,
 	}
 
 	return &Config{
@@ -63,5 +64,6 @@ func GetRoutingConfig(cfg *Config) *RoutingConfig {
 		MinRouteProbability:   cfg.MinRouteProbability,
 		AttemptCost:           cfg.AttemptCost,
 		PenaltyHalfLife:       cfg.PenaltyHalfLife,
+		MaxMcHistory:          cfg.MaxMcHistory,
 	}
 }

lnrpc/routerrpc/config_default.go

@@ -22,5 +22,6 @@ func GetRoutingConfig(cfg *Config) *RoutingConfig {
 		AttemptCost: routing.DefaultPaymentAttemptPenalty.
 			ToSatoshis(),
 		PenaltyHalfLife: routing.DefaultPenaltyHalfLife,
+		MaxMcHistory:    routing.DefaultMaxMcHistory,
 	}
 }

lnrpc/routerrpc/router_backend.go

@@ -64,7 +64,7 @@ type MissionControl interface {
 
 	// ResetHistory resets the history of MissionControl returning it to a state as
 	// if no payment attempts have been made.
-	ResetHistory()
+	ResetHistory() error
 
 	// GetHistorySnapshot takes a snapshot from the current mission control state
 	// and actual probability estimates.

lnrpc/routerrpc/router_backend_test.go

@@ -147,7 +147,9 @@ func (m *mockMissionControl) GetEdgeProbability(fromNode route.Vertex,
 	return testMissionControlProb
 }
 
-func (m *mockMissionControl) ResetHistory() {}
+func (m *mockMissionControl) ResetHistory() error {
+	return nil
+}
 
 func (m *mockMissionControl) GetHistorySnapshot() *routing.MissionControlSnapshot {
 	return nil

lnrpc/routerrpc/router_server.go

@@ -436,7 +436,10 @@ func marshallChannelUpdate(update *lnwire.ChannelUpdate) *ChannelUpdate {
 func (s *Server) ResetMissionControl(ctx context.Context,
 	req *ResetMissionControlRequest) (*ResetMissionControlResponse, error) {
 
-	s.cfg.RouterBackend.MissionControl.ResetHistory()
+	err := s.cfg.RouterBackend.MissionControl.ResetHistory()
+	if err != nil {
+		return nil, err
+	}
 
 	return &ResetMissionControlResponse{}, nil
 }