mutli: rename HodlEvent to HtlcResolution

This commit renames HodlEvent to HtlcResolution
to better reflect the fact that the struct is
only used for htlc settles and cancels, and that
it is not specifically used for hodl invoices.

contractcourt/htlc_incoming_contest_resolver.go

@@ -167,9 +167,9 @@ func (h *htlcIncomingContestResolver) Resolve() (ContractResolver, error) {
 	preimageSubscription := h.PreimageDB.SubscribeUpdates()
 	defer preimageSubscription.CancelSubscription()
 
-	// Define closure to process hodl events either direct or triggered by
-	// later notifcation.
-	processHodlEvent := func(e invoices.HodlEvent) (ContractResolver,
+	// Define closure to process htlc resolutions either direct or triggered by
+	// later notification.
+	processHodlEvent := func(e invoices.HtlcResolution) (ContractResolver,
 		error) {
 
 		if e.Preimage == nil {
@@ -252,9 +252,9 @@ func (h *htlcIncomingContestResolver) Resolve() (ContractResolver, error) {
 			return &h.htlcSuccessResolver, nil
 
 		case hodlItem := <-hodlChan:
-			hodlEvent := hodlItem.(invoices.HodlEvent)
+			htlcResolution := hodlItem.(invoices.HtlcResolution)
 
-			return processHodlEvent(hodlEvent)
+			return processHodlEvent(htlcResolution)
 
 		case newBlock, ok := <-blockEpochs.Epochs:
 			if !ok {

contractcourt/htlc_incoming_resolver_test.go

@@ -96,7 +96,7 @@ func TestHtlcIncomingResolverExitSettle(t *testing.T) {
 	defer timeout(t)()
 
 	ctx := newIncomingResolverTestContext(t)
-	ctx.registry.notifyEvent = &invoices.HodlEvent{
+	ctx.registry.notifyEvent = &invoices.HtlcResolution{
 		CircuitKey: testResCircuitKey,
 		Preimage:   &testResPreimage,
 	}
@@ -126,7 +126,7 @@ func TestHtlcIncomingResolverExitCancel(t *testing.T) {
 	defer timeout(t)()
 
 	ctx := newIncomingResolverTestContext(t)
-	ctx.registry.notifyEvent = &invoices.HodlEvent{
+	ctx.registry.notifyEvent = &invoices.HtlcResolution{
 		CircuitKey: testResCircuitKey,
 	}
 	ctx.resolve()
@@ -143,7 +143,7 @@ func TestHtlcIncomingResolverExitSettleHodl(t *testing.T) {
 	ctx.resolve()
 
 	notifyData := <-ctx.registry.notifyChan
-	notifyData.hodlChan <- invoices.HodlEvent{
+	notifyData.hodlChan <- invoices.HtlcResolution{
 		CircuitKey: testResCircuitKey,
 		Preimage:   &testResPreimage,
 	}
@@ -172,7 +172,7 @@ func TestHtlcIncomingResolverExitCancelHodl(t *testing.T) {
 	ctx := newIncomingResolverTestContext(t)
 	ctx.resolve()
 	notifyData := <-ctx.registry.notifyChan
-	notifyData.hodlChan <- invoices.HodlEvent{
+	notifyData.hodlChan <- invoices.HtlcResolution{
 		CircuitKey: testResCircuitKey,
 	}
 	ctx.waitForResult(false)

contractcourt/interfaces.go

@@ -27,9 +27,9 @@ type Registry interface {
 	NotifyExitHopHtlc(payHash lntypes.Hash, paidAmount lnwire.MilliSatoshi,
 		expiry uint32, currentHeight int32,
 		circuitKey channeldb.CircuitKey, hodlChan chan<- interface{},
-		payload invoices.Payload) (*invoices.HodlEvent, error)
+		payload invoices.Payload) (*invoices.HtlcResolution, error)
 
-	// HodlUnsubscribeAll unsubscribes from all hodl events.
+	// HodlUnsubscribeAll unsubscribes from all htlc resolutions.
 	HodlUnsubscribeAll(subscriber chan<- interface{})
 }
 

contractcourt/mock_registry_test.go

@@ -18,13 +18,13 @@ type notifyExitHopData struct {
 type mockRegistry struct {
 	notifyChan  chan notifyExitHopData
 	notifyErr   error
-	notifyEvent *invoices.HodlEvent
+	notifyEvent *invoices.HtlcResolution
 }
 
 func (r *mockRegistry) NotifyExitHopHtlc(payHash lntypes.Hash,
 	paidAmount lnwire.MilliSatoshi, expiry uint32, currentHeight int32,
 	circuitKey channeldb.CircuitKey, hodlChan chan<- interface{},
-	payload invoices.Payload) (*invoices.HodlEvent, error) {
+	payload invoices.Payload) (*invoices.HtlcResolution, error) {
 
 	r.notifyChan <- notifyExitHopData{
 		hodlChan:      hodlChan,

htlcswitch/interfaces.go

@@ -27,7 +27,7 @@ type InvoiceDatabase interface {
 	NotifyExitHopHtlc(payHash lntypes.Hash, paidAmount lnwire.MilliSatoshi,
 		expiry uint32, currentHeight int32,
 		circuitKey channeldb.CircuitKey, hodlChan chan<- interface{},
-		payload invoices.Payload) (*invoices.HodlEvent, error)
+		payload invoices.Payload) (*invoices.HtlcResolution, error)
 
 	// CancelInvoice attempts to cancel the invoice corresponding to the
 	// passed payment hash.
@@ -36,7 +36,7 @@ type InvoiceDatabase interface {
 	// SettleHodlInvoice settles a hold invoice.
 	SettleHodlInvoice(preimage lntypes.Preimage) error
 
-	// HodlUnsubscribeAll unsubscribes from all hodl events.
+	// HodlUnsubscribeAll unsubscribes from all htlc resolutions.
 	HodlUnsubscribeAll(subscriber chan<- interface{})
 }
 

htlcswitch/link.go

@@ -489,8 +489,8 @@ func (l *channelLink) Stop() {
 
 	l.log.Info("stopping")
 
-	// As the link is stopping, we are no longer interested in hodl events
-	// coming from the invoice registry.
+	// As the link is stopping, we are no longer interested in htlc
+	// resolutions coming from the invoice registry.
 	l.cfg.Registry.HodlUnsubscribeAll(l.hodlQueue.ChanIn())
 
 	if l.cfg.ChainEvents.Cancel != nil {
@@ -1126,11 +1126,11 @@ out:
 		case msg := <-l.upstream:
 			l.handleUpstreamMsg(msg)
 
-		// A hodl event is received. This means that we now have a
+		// A htlc resolution is received. This means that we now have a
 		// resolution for a previously accepted htlc.
 		case hodlItem := <-l.hodlQueue.ChanOut():
-			hodlEvent := hodlItem.(invoices.HodlEvent)
-			err := l.processHodlQueue(hodlEvent)
+			htlcResolution := hodlItem.(invoices.HtlcResolution)
+			err := l.processHodlQueue(htlcResolution)
 			if err != nil {
 				l.fail(LinkFailureError{code: ErrInternalError},
 					fmt.Sprintf("process hodl queue: %v",
@@ -1145,24 +1145,26 @@ out:
 	}
 }
 
-// processHodlQueue processes a received hodl event and continues reading from
-// the hodl queue until no more events remain. When this function returns
-// without an error, the commit tx should be updated.
-func (l *channelLink) processHodlQueue(firstHodlEvent invoices.HodlEvent) error {
+// processHodlQueue processes a received htlc resolution and continues reading
+// from the hodl queue until no more resolutions remain. When this function
+// returns without an error, the commit tx should be updated.
+func (l *channelLink) processHodlQueue(
+	firstResolution invoices.HtlcResolution) error {
+
 	// Try to read all waiting resolution messages, so that they can all be
 	// processed in a single commitment tx update.
-	hodlEvent := firstHodlEvent
+	htlcResolution := firstResolution
 loop:
 	for {
 		// Lookup all hodl htlcs that can be failed or settled with this event.
 		// The hodl htlc must be present in the map.
-		circuitKey := hodlEvent.CircuitKey
+		circuitKey := htlcResolution.CircuitKey
 		hodlHtlc, ok := l.hodlMap[circuitKey]
 		if !ok {
 			return fmt.Errorf("hodl htlc not found: %v", circuitKey)
 		}
 
-		if err := l.processHodlEvent(hodlEvent, hodlHtlc); err != nil {
+		if err := l.processHodlEvent(htlcResolution, hodlHtlc); err != nil {
 			return err
 		}
 
@@ -1171,7 +1173,7 @@ loop:
 
 		select {
 		case item := <-l.hodlQueue.ChanOut():
-			hodlEvent = item.(invoices.HodlEvent)
+			htlcResolution = item.(invoices.HtlcResolution)
 		default:
 			break loop
 		}
@@ -1185,29 +1187,29 @@ loop:
 	return nil
 }
 
-// processHodlEvent applies a received hodl event to the provided htlc. When
-// this function returns without an error, the commit tx should be updated.
-func (l *channelLink) processHodlEvent(hodlEvent invoices.HodlEvent,
+// processHodlEvent applies a received htlc resolution to the provided htlc.
+// When this function returns without an error, the commit tx should be updated.
+func (l *channelLink) processHodlEvent(resolution invoices.HtlcResolution,
 	htlc hodlHtlc) error {
 
-	circuitKey := hodlEvent.CircuitKey
+	circuitKey := resolution.CircuitKey
 
 	// Determine required action for the resolution.
-	if hodlEvent.Preimage != nil {
-		l.log.Debugf("received hodl settle event for %v", circuitKey)
+	if resolution.Preimage != nil {
+		l.log.Debugf("received settle resolution for %v", circuitKey)
 
 		return l.settleHTLC(
-			*hodlEvent.Preimage, htlc.pd.HtlcIndex,
+			*resolution.Preimage, htlc.pd.HtlcIndex,
 			htlc.pd.SourceRef,
 		)
 	}
 
-	l.log.Debugf("received hodl cancel event for %v", circuitKey)
+	l.log.Debugf("received cancel resolution for %v", circuitKey)
 
 	// In case of a cancel, always return
 	// incorrect_or_unknown_payment_details in order to avoid leaking info.
 	failure := lnwire.NewFailIncorrectDetails(
-		htlc.pd.Amount, uint32(hodlEvent.AcceptHeight),
+		htlc.pd.Amount, uint32(resolution.AcceptHeight),
 	)
 
 	l.sendHTLCError(

htlcswitch/mock.go

@@ -819,7 +819,7 @@ func (i *mockInvoiceRegistry) SettleHodlInvoice(preimage lntypes.Preimage) error
 func (i *mockInvoiceRegistry) NotifyExitHopHtlc(rhash lntypes.Hash,
 	amt lnwire.MilliSatoshi, expiry uint32, currentHeight int32,
 	circuitKey channeldb.CircuitKey, hodlChan chan<- interface{},
-	payload invoices.Payload) (*invoices.HodlEvent, error) {
+	payload invoices.Payload) (*invoices.HtlcResolution, error) {
 
 	event, err := i.registry.NotifyExitHopHtlc(
 		rhash, amt, expiry, currentHeight, circuitKey, hodlChan,

invoices/invoiceregistry.go

@@ -35,10 +35,10 @@ const (
 	DefaultHtlcHoldDuration = 120 * time.Second
 )
 
-// HodlEvent describes how an htlc should be resolved. If HodlEvent.Preimage is
-// set, the event indicates a settle event. If Preimage is nil, it is a cancel
-// event.
-type HodlEvent struct {
+// HtlcResolution describes how an htlc should be resolved. If the preimage
+// field is set, the event indicates a settle event. If Preimage is nil, it is
+// a cancel event.
+type HtlcResolution struct {
 	// Preimage is the htlc preimage. Its value is nil in case of a cancel.
 	Preimage *lntypes.Preimage
 
@@ -652,7 +652,7 @@ func (i *InvoiceRegistry) cancelSingleHtlc(hash lntypes.Hash,
 		return fmt.Errorf("htlc %v not found", key)
 	}
 	if htlc.State == channeldb.HtlcStateCanceled {
-		i.notifyHodlSubscribers(HodlEvent{
+		i.notifyHodlSubscribers(HtlcResolution{
 			CircuitKey:   key,
 			AcceptHeight: int32(htlc.AcceptHeight),
 			Preimage:     nil,
@@ -679,7 +679,7 @@ func (i *InvoiceRegistry) cancelSingleHtlc(hash lntypes.Hash,
 func (i *InvoiceRegistry) NotifyExitHopHtlc(rHash lntypes.Hash,
 	amtPaid lnwire.MilliSatoshi, expiry uint32, currentHeight int32,
 	circuitKey channeldb.CircuitKey, hodlChan chan<- interface{},
-	payload Payload) (*HodlEvent, error) {
+	payload Payload) (*HtlcResolution, error) {
 
 	i.Lock()
 	defer i.Unlock()
@@ -745,7 +745,7 @@ func (i *InvoiceRegistry) NotifyExitHopHtlc(rHash lntypes.Hash,
 
 	// If it isn't recorded, cancel htlc.
 	if !ok {
-		return &HodlEvent{
+		return &HtlcResolution{
 			CircuitKey:   circuitKey,
 			AcceptHeight: currentHeight,
 		}, nil
@@ -759,7 +759,7 @@ func (i *InvoiceRegistry) NotifyExitHopHtlc(rHash lntypes.Hash,
 
 	switch invoiceHtlc.State {
 	case channeldb.HtlcStateCanceled:
-		return &HodlEvent{
+		return &HtlcResolution{
 			CircuitKey:   circuitKey,
 			AcceptHeight: acceptHeight,
 		}, nil
@@ -773,14 +773,14 @@ func (i *InvoiceRegistry) NotifyExitHopHtlc(rHash lntypes.Hash,
 				continue
 			}
 
-			i.notifyHodlSubscribers(HodlEvent{
+			i.notifyHodlSubscribers(HtlcResolution{
 				CircuitKey:   key,
 				Preimage:     &invoice.Terms.PaymentPreimage,
 				AcceptHeight: int32(htlc.AcceptHeight),
 			})
 		}
 
-		return &HodlEvent{
+		return &HtlcResolution{
 			CircuitKey:   circuitKey,
 			Preimage:     &invoice.Terms.PaymentPreimage,
 			AcceptHeight: acceptHeight,
@@ -854,7 +854,7 @@ func (i *InvoiceRegistry) SettleHodlInvoice(preimage lntypes.Preimage) error {
 			continue
 		}
 
-		i.notifyHodlSubscribers(HodlEvent{
+		i.notifyHodlSubscribers(HtlcResolution{
 			CircuitKey:   key,
 			Preimage:     &preimage,
 			AcceptHeight: int32(htlc.AcceptHeight),
@@ -932,7 +932,7 @@ func (i *InvoiceRegistry) cancelInvoiceImpl(payHash lntypes.Hash,
 			continue
 		}
 
-		i.notifyHodlSubscribers(HodlEvent{
+		i.notifyHodlSubscribers(HtlcResolution{
 			CircuitKey:   key,
 			AcceptHeight: int32(htlc.AcceptHeight),
 		})
@@ -1201,9 +1201,10 @@ func (i *InvoiceRegistry) SubscribeSingleInvoice(
 	return client, nil
 }
 
-// notifyHodlSubscribers sends out the hodl event to all current subscribers.
-func (i *InvoiceRegistry) notifyHodlSubscribers(hodlEvent HodlEvent) {
-	subscribers, ok := i.hodlSubscriptions[hodlEvent.CircuitKey]
+// notifyHodlSubscribers sends out the htlc resolution to all current
+// subscribers.
+func (i *InvoiceRegistry) notifyHodlSubscribers(htlcResolution HtlcResolution) {
+	subscribers, ok := i.hodlSubscriptions[htlcResolution.CircuitKey]
 	if !ok {
 		return
 	}
@@ -1213,18 +1214,18 @@ func (i *InvoiceRegistry) notifyHodlSubscribers(hodlEvent HodlEvent) {
 	// single resolution for each hash.
 	for subscriber := range subscribers {
 		select {
-		case subscriber <- hodlEvent:
+		case subscriber <- htlcResolution:
 		case <-i.quit:
 			return
 		}
 
 		delete(
 			i.hodlReverseSubscriptions[subscriber],
-			hodlEvent.CircuitKey,
+			htlcResolution.CircuitKey,
 		)
 	}
 
-	delete(i.hodlSubscriptions, hodlEvent.CircuitKey)
+	delete(i.hodlSubscriptions, htlcResolution.CircuitKey)
 }
 
 // hodlSubscribe adds a new invoice subscription.

invoices/invoiceregistry_test.go

@@ -281,7 +281,7 @@ func TestCancelInvoice(t *testing.T) {
 	}
 
 	if event.Preimage != nil {
-		t.Fatal("expected cancel hodl event")
+		t.Fatal("expected cancel htlc resolution")
 	}
 	if event.AcceptHeight != testCurrentHeight {
 		t.Fatalf("expected acceptHeight %v, but got %v",
@@ -421,11 +421,11 @@ func TestSettleHoldInvoice(t *testing.T) {
 		t.Fatal("expected set preimage to succeed")
 	}
 
-	hodlEvent := (<-hodlChan).(HodlEvent)
-	if *hodlEvent.Preimage != testInvoicePreimage {
-		t.Fatal("unexpected preimage in hodl event")
+	htlcResolution := (<-hodlChan).(HtlcResolution)
+	if *htlcResolution.Preimage != testInvoicePreimage {
+		t.Fatal("unexpected preimage in hodl resolution")
 	}
-	if hodlEvent.AcceptHeight != testCurrentHeight {
+	if htlcResolution.AcceptHeight != testCurrentHeight {
 		t.Fatalf("expected acceptHeight %v, but got %v",
 			testCurrentHeight, event.AcceptHeight)
 	}
@@ -513,9 +513,9 @@ func TestCancelHoldInvoice(t *testing.T) {
 		t.Fatal("cancel invoice failed")
 	}
 
-	hodlEvent := (<-hodlChan).(HodlEvent)
-	if hodlEvent.Preimage != nil {
-		t.Fatal("expected cancel hodl event")
+	htlcResolution := (<-hodlChan).(HtlcResolution)
+	if htlcResolution.Preimage != nil {
+		t.Fatal("expected cancel htlc resolution")
 	}
 
 	// Offering the same htlc again at a higher height should still result
@@ -538,10 +538,10 @@ func TestCancelHoldInvoice(t *testing.T) {
 }
 
 // TestUnknownInvoice tests that invoice registry returns an error when the
-// invoice is unknown. This is to guard against returning a cancel hodl event
-// for forwarded htlcs. In the link, NotifyExitHopHtlc is only called if we are
-// the exit hop, but in htlcIncomingContestResolver it is called with forwarded
-// htlc hashes as well.
+// invoice is unknown. This is to guard against returning a cancel htlc
+// resolution for forwarded htlcs. In the link, NotifyExitHopHtlc is only called
+// if we are the exit hop, but in htlcIncomingContestResolver it is called with
+// forwarded htlc hashes as well.
 func TestUnknownInvoice(t *testing.T) {
 	ctx := newTestContext(t)
 	defer ctx.cleanup()
@@ -593,8 +593,8 @@ func TestSettleMpp(t *testing.T) {
 	// Simulate mpp timeout releasing htlc 1.
 	ctx.clock.SetTime(testTime.Add(30 * time.Second))
 
-	hodlEvent := (<-hodlChan1).(HodlEvent)
-	if hodlEvent.Preimage != nil {
+	htlcResolution := (<-hodlChan1).(HtlcResolution)
+	if htlcResolution.Preimage != nil {
 		t.Fatal("expected cancel event")
 	}