routing: stop tracking totalAmount in paymentLifecycle

This commit removes the field `totalAmount` from `paymentLifecycle` and
only reads it from the channeldb payment.

routing/mock_test.go

@@ -758,6 +758,7 @@ func (m *mockControlTower) FetchPayment(phash lntypes.Hash) (
 	// Make a copy of the payment here to avoid data race.
 	p := args.Get(0).(*channeldb.MPPayment)
 	payment := &channeldb.MPPayment{
+		Info:          p.Info,
 		FailureReason: p.FailureReason,
 	}
 	payment.HTLCs = make([]channeldb.HTLCAttempt, len(p.HTLCs))

routing/payment_lifecycle.go

@@ -23,7 +23,6 @@ var errShardHandlerExiting = fmt.Errorf("shard handler exiting")
 // needed to resume if from any point.
 type paymentLifecycle struct {
 	router        *ChannelRouter
-	totalAmount   lnwire.MilliSatoshi
 	feeLimit      lnwire.MilliSatoshi
 	identifier    lntypes.Hash
 	paySession    PaymentSession
@@ -83,9 +82,10 @@ func (p *paymentLifecycle) fetchPaymentState() (*channeldb.MPPayment,
 	sentAmt, fees := payment.SentAmt()
 
 	// Sanity check we haven't sent a value larger than the payment amount.
-	if sentAmt > p.totalAmount {
+	totalAmt := payment.Info.Value
+	if sentAmt > totalAmt {
 		return nil, nil, fmt.Errorf("amount sent %v exceeds "+
-			"total amount %v", sentAmt, p.totalAmount)
+			"total amount %v", sentAmt, totalAmt)
 	}
 
 	// We'll subtract the used fee from our fee budget, but allow the fees
@@ -109,7 +109,7 @@ func (p *paymentLifecycle) fetchPaymentState() (*channeldb.MPPayment,
 	// Update the payment state.
 	state := &paymentState{
 		numShardsInFlight: len(payment.InFlightHTLCs()),
-		remainingAmt:      p.totalAmount - sentAmt,
+		remainingAmt:      totalAmt - sentAmt,
 		remainingFees:     feeBudget,
 		terminate:         terminate,
 	}

routing/payment_lifecycle_test.go

@@ -1052,10 +1052,9 @@ func TestUpdatePaymentState(t *testing.T) {
 			ct := &mockControlTower{}
 			rt := &ChannelRouter{cfg: &Config{Control: ct}}
 			pl := &paymentLifecycle{
-				router:      rt,
-				identifier:  paymentHash,
-				totalAmount: lnwire.MilliSatoshi(tc.totalAmt),
-				feeLimit:    lnwire.MilliSatoshi(tc.feeLimit),
+				router:     rt,
+				identifier: paymentHash,
+				feeLimit:   lnwire.MilliSatoshi(tc.feeLimit),
 			}
 
 			if tc.payment == nil {
@@ -1066,6 +1065,12 @@ func TestUpdatePaymentState(t *testing.T) {
 					nil, dummyErr,
 				)
 			} else {
+				// Attach the payment info.
+				info := &channeldb.PaymentCreationInfo{
+					Value: lnwire.MilliSatoshi(tc.totalAmt),
+				}
+				tc.payment.Info = info
+
 				// Otherwise we will return the payment.
 				ct.On("FetchPayment", paymentHash).Return(
 					tc.payment, nil,

routing/router.go

@@ -667,9 +667,8 @@ func (r *ChannelRouter) Start() error {
 			// also set a zero fee limit, as no more routes should
 			// be tried.
 			_, _, err := r.sendPayment(
-				payment.Info.Value, 0,
-				payment.Info.PaymentIdentifier, 0, paySession,
-				shardTracker,
+				0, payment.Info.PaymentIdentifier, 0,
+				paySession, shardTracker,
 			)
 			if err != nil {
 				log.Errorf("Resuming payment %v failed: %v.",
@@ -2048,7 +2047,7 @@ func (r *ChannelRouter) SendPayment(payment *LightningPayment) ([32]byte,
 	// Since this is the first time this payment is being made, we pass nil
 	// for the existing attempt.
 	return r.sendPayment(
-		payment.Amount, payment.FeeLimit, payment.Identifier(),
+		payment.FeeLimit, payment.Identifier(),
 		payment.PayAttemptTimeout, paySession, shardTracker,
 	)
 }
@@ -2071,7 +2070,7 @@ func (r *ChannelRouter) SendPaymentAsync(payment *LightningPayment) error {
 			spewPayment(payment))
 
 		_, _, err := r.sendPayment(
-			payment.Amount, payment.FeeLimit, payment.Identifier(),
+			payment.FeeLimit, payment.Identifier(),
 			payment.PayAttemptTimeout, paySession, shardTracker,
 		)
 		if err != nil {
@@ -2335,9 +2334,9 @@ func (r *ChannelRouter) sendToRoute(htlcHash lntypes.Hash, rt *route.Route,
 // carry out its execution. After restarts it is safe, and assumed, that the
 // router will call this method for every payment still in-flight according to
 // the ControlTower.
-func (r *ChannelRouter) sendPayment(
-	totalAmt, feeLimit lnwire.MilliSatoshi, identifier lntypes.Hash,
-	timeout time.Duration, paySession PaymentSession,
+func (r *ChannelRouter) sendPayment(feeLimit lnwire.MilliSatoshi,
+	identifier lntypes.Hash, timeout time.Duration,
+	paySession PaymentSession,
 	shardTracker shards.ShardTracker) ([32]byte, *route.Route, error) {
 
 	// We'll also fetch the current block height so we can properly
@@ -2351,7 +2350,6 @@ func (r *ChannelRouter) sendPayment(
 	// can resume the payment from the current state.
 	p := &paymentLifecycle{
 		router:        r,
-		totalAmount:   totalAmt,
 		feeLimit:      feeLimit,
 		identifier:    identifier,
 		paySession:    paySession,

routing/router_test.go

@@ -3421,7 +3421,9 @@ func TestSendMPPaymentSucceed(t *testing.T) {
 	// The following mocked methods are called inside resumePayment. Note
 	// that the payment object below will determine the state of the
 	// paymentLifecycle.
-	payment := &channeldb.MPPayment{}
+	payment := &channeldb.MPPayment{
+		Info: &channeldb.PaymentCreationInfo{Value: paymentAmt},
+	}
 	controlTower.On("FetchPayment", identifier).Return(payment, nil)
 
 	// Create a route that can send 1/4 of the total amount. This value
@@ -3588,7 +3590,9 @@ func TestSendMPPaymentSucceedOnExtraShards(t *testing.T) {
 	// The following mocked methods are called inside resumePayment. Note
 	// that the payment object below will determine the state of the
 	// paymentLifecycle.
-	payment := &channeldb.MPPayment{}
+	payment := &channeldb.MPPayment{
+		Info: &channeldb.PaymentCreationInfo{Value: paymentAmt},
+	}
 	controlTower.On("FetchPayment", identifier).Return(payment, nil)
 
 	// Create a route that can send 1/4 of the total amount. This value
@@ -3800,7 +3804,9 @@ func TestSendMPPaymentFailed(t *testing.T) {
 	// The following mocked methods are called inside resumePayment. Note
 	// that the payment object below will determine the state of the
 	// paymentLifecycle.
-	payment := &channeldb.MPPayment{}
+	payment := &channeldb.MPPayment{
+		Info: &channeldb.PaymentCreationInfo{Value: paymentAmt},
+	}
 	controlTower.On("FetchPayment", identifier).Return(payment, nil)
 
 	// Create a route that can send 1/4 of the total amount. This value
@@ -4004,7 +4010,9 @@ func TestSendMPPaymentFailedWithShardsInFlight(t *testing.T) {
 	// The following mocked methods are called inside resumePayment. Note
 	// that the payment object below will determine the state of the
 	// paymentLifecycle.
-	payment := &channeldb.MPPayment{}
+	payment := &channeldb.MPPayment{
+		Info: &channeldb.PaymentCreationInfo{Value: paymentAmt},
+	}
 	controlTower.On("FetchPayment", identifier).Return(payment, nil)
 
 	// Create a route that can send 1/4 of the total amount. This value