lnwallet: pack htlcView.{OurUpdates|TheirUpdates} into Dual.

This commit moves the collection of updates behind a Dual structure.
This allows us in a later commit to index into it via a ChannelParty
parameter which will simplify the loops in evaluateHTLCView.

lnwallet/channel.go

@@ -2675,11 +2675,8 @@ type HtlcView struct {
 	// created using this view.
 	NextHeight uint64
 
-	// OurUpdates are our outgoing HTLCs.
+	// Updates is a Dual of the Local and Remote HTLCs.
-	OurUpdates []*paymentDescriptor
+	Updates lntypes.Dual[[]*paymentDescriptor]
-
-	// TheirUpdates are their incoming HTLCs.
-	TheirUpdates []*paymentDescriptor
 
 	// FeePerKw is the fee rate in sat/kw of the commitment transaction.
 	FeePerKw chainfee.SatPerKWeight
@@ -2688,13 +2685,13 @@ type HtlcView struct {
 // AuxOurUpdates returns the outgoing HTLCs as a read-only copy of
 // AuxHtlcDescriptors.
 func (v *HtlcView) AuxOurUpdates() []AuxHtlcDescriptor {
-	return fn.Map(newAuxHtlcDescriptor, v.OurUpdates)
+	return fn.Map(newAuxHtlcDescriptor, v.Updates.Local)
 }
 
 // AuxTheirUpdates returns the incoming HTLCs as a read-only copy of
 // AuxHtlcDescriptors.
 func (v *HtlcView) AuxTheirUpdates() []AuxHtlcDescriptor {
-	return fn.Map(newAuxHtlcDescriptor, v.TheirUpdates)
+	return fn.Map(newAuxHtlcDescriptor, v.Updates.Remote)
 }
 
 // fetchHTLCView returns all the candidate HTLC updates which should be
@@ -2728,8 +2725,10 @@ func (lc *LightningChannel) fetchHTLCView(theirLogIndex,
 	}
 
 	return &HtlcView{
-		OurUpdates:   ourHTLCs,
+		Updates: lntypes.Dual[[]*paymentDescriptor]{
-		TheirUpdates: theirHTLCs,
+			Local:  ourHTLCs,
+			Remote: theirHTLCs,
+		},
 	}
 }
 
@@ -2853,15 +2852,15 @@ func (lc *LightningChannel) fetchCommitmentView(
 	// commitment are mutated, we'll manually copy over each HTLC to its
 	// respective slice.
 	c.outgoingHTLCs = make(
-		[]paymentDescriptor, len(filteredHTLCView.OurUpdates),
+		[]paymentDescriptor, len(filteredHTLCView.Updates.Local),
 	)
-	for i, htlc := range filteredHTLCView.OurUpdates {
+	for i, htlc := range filteredHTLCView.Updates.Local {
 		c.outgoingHTLCs[i] = *htlc
 	}
 	c.incomingHTLCs = make(
-		[]paymentDescriptor, len(filteredHTLCView.TheirUpdates),
+		[]paymentDescriptor, len(filteredHTLCView.Updates.Remote),
 	)
-	for i, htlc := range filteredHTLCView.TheirUpdates {
+	for i, htlc := range filteredHTLCView.Updates.Remote {
 		c.incomingHTLCs[i] = *htlc
 	}
 
@@ -2916,7 +2915,7 @@ func (lc *LightningChannel) evaluateHTLCView(view *HtlcView, ourBalance,
 
 	// First we run through non-add entries in both logs, populating the
 	// skip sets.
-	for _, entry := range view.OurUpdates {
+	for _, entry := range view.Updates.Local {
 		switch entry.EntryType {
 		// Skip adds for now. They will be processed below.
 		case Add:
@@ -2961,7 +2960,7 @@ func (lc *LightningChannel) evaluateHTLCView(view *HtlcView, ourBalance,
 	}
 
 	// Do the same for our peer's updates.
-	for _, entry := range view.TheirUpdates {
+	for _, entry := range view.Updates.Remote {
 		switch entry.EntryType {
 		// Skip adds for now. They will be processed below.
 		case Add:
@@ -3007,7 +3006,7 @@ func (lc *LightningChannel) evaluateHTLCView(view *HtlcView, ourBalance,
 	// Next we take a second pass through all the log entries, skipping any
 	// settled HTLCs, and debiting the chain state balance due to any newly
 	// added HTLCs.
-	for _, entry := range view.OurUpdates {
+	for _, entry := range view.Updates.Local {
 		isAdd := entry.EntryType == Add
 		if skipUs.Contains(entry.HtlcIndex) || !isAdd {
 			continue
@@ -3024,11 +3023,11 @@ func (lc *LightningChannel) evaluateHTLCView(view *HtlcView, ourBalance,
 			)
 		}
 
-		newView.OurUpdates = append(newView.OurUpdates, entry)
+		newView.Updates.Local = append(newView.Updates.Local, entry)
 	}
 
 	// Again, we do the same for our peer's updates.
-	for _, entry := range view.TheirUpdates {
+	for _, entry := range view.Updates.Remote {
 		isAdd := entry.EntryType == Add
 		if skipThem.Contains(entry.HtlcIndex) || !isAdd {
 			continue
@@ -3045,7 +3044,7 @@ func (lc *LightningChannel) evaluateHTLCView(view *HtlcView, ourBalance,
 			)
 		}
 
-		newView.TheirUpdates = append(newView.TheirUpdates, entry)
+		newView.Updates.Remote = append(newView.Updates.Remote, entry)
 	}
 
 	// Create a function that is capable of identifying whether or not the
@@ -3075,10 +3074,12 @@ func (lc *LightningChannel) evaluateHTLCView(view *HtlcView, ourBalance,
 
 	// Collect all of the updates that haven't had their commit heights set
 	// for the commitment chain corresponding to whoseCommitmentChain.
-	uncommittedUpdates := lntypes.Dual[[]*paymentDescriptor]{
+	uncommittedUpdates := lntypes.MapDual(
-		Local:  fn.Filter(isUncommitted, view.OurUpdates),
+		view.Updates,
-		Remote: fn.Filter(isUncommitted, view.TheirUpdates),
+		func(us []*paymentDescriptor) []*paymentDescriptor {
-	}
+			return fn.Filter(isUncommitted, us)
+		},
+	)
 
 	return newView, uncommittedUpdates, nil
 }
@@ -3746,10 +3747,12 @@ func (lc *LightningChannel) validateCommitmentSanity(theirLogCounter,
 	// appropriate update log, in order to validate the sanity of the
 	// commitment resulting from _actually adding_ this HTLC to the state.
 	if predictOurAdd != nil {
-		view.OurUpdates = append(view.OurUpdates, predictOurAdd)
+		view.Updates.Local = append(view.Updates.Local, predictOurAdd)
 	}
 	if predictTheirAdd != nil {
-		view.TheirUpdates = append(view.TheirUpdates, predictTheirAdd)
+		view.Updates.Remote = append(
+			view.Updates.Remote, predictTheirAdd,
+		)
 	}
 
 	ourBalance, theirBalance, commitWeight, filteredView, err := lc.computeView(
@@ -3904,7 +3907,7 @@ func (lc *LightningChannel) validateCommitmentSanity(theirLogCounter,
 	// First check that the remote updates won't violate it's channel
 	// constraints.
 	err = validateUpdates(
-		filteredView.TheirUpdates, &lc.channelState.RemoteChanCfg,
+		filteredView.Updates.Remote, &lc.channelState.RemoteChanCfg,
 	)
 	if err != nil {
 		return err
@@ -3913,7 +3916,7 @@ func (lc *LightningChannel) validateCommitmentSanity(theirLogCounter,
 	// Secondly check that our updates won't violate our channel
 	// constraints.
 	err = validateUpdates(
-		filteredView.OurUpdates, &lc.channelState.LocalChanCfg,
+		filteredView.Updates.Local, &lc.channelState.LocalChanCfg,
 	)
 	if err != nil {
 		return err
@@ -4700,7 +4703,7 @@ func (lc *LightningChannel) computeView(view *HtlcView,
 	// Now go through all HTLCs at this stage, to calculate the total
 	// weight, needed to calculate the transaction fee.
 	var totalHtlcWeight lntypes.WeightUnit
-	for _, htlc := range filteredHTLCView.OurUpdates {
+	for _, htlc := range filteredHTLCView.Updates.Local {
 		if HtlcIsDust(
 			lc.channelState.ChanType, false, whoseCommitChain,
 			feePerKw, htlc.Amount.ToSatoshis(), dustLimit,
@@ -4711,7 +4714,7 @@ func (lc *LightningChannel) computeView(view *HtlcView,
 
 		totalHtlcWeight += input.HTLCWeight
 	}
-	for _, htlc := range filteredHTLCView.TheirUpdates {
+	for _, htlc := range filteredHTLCView.Updates.Remote {
 		if HtlcIsDust(
 			lc.channelState.ChanType, true, whoseCommitChain,
 			feePerKw, htlc.Amount.ToSatoshis(), dustLimit,

lnwallet/channel_test.go

@@ -8941,9 +8941,11 @@ func TestEvaluateView(t *testing.T) {
 			}
 
 			view := &HtlcView{
-				OurUpdates:   test.ourHtlcs,
+				Updates: lntypes.Dual[[]*paymentDescriptor]{
-				TheirUpdates: test.theirHtlcs,
+					Local:  test.ourHtlcs,
-				FeePerKw:     feePerKw,
+					Remote: test.theirHtlcs,
+				},
+				FeePerKw: feePerKw,
 			}
 
 			var (
@@ -8996,11 +8998,12 @@ func TestEvaluateView(t *testing.T) {
 			}
 
 			checkExpectedHtlcs(
-				t, result.OurUpdates, test.ourExpectedHtlcs,
+				t, result.Updates.Local, test.ourExpectedHtlcs,
 			)
 
 			checkExpectedHtlcs(
-				t, result.TheirUpdates, test.theirExpectedHtlcs,
+				t, result.Updates.Remote,
+				test.theirExpectedHtlcs,
 			)
 
 			if lc.channelState.TotalMSatSent != test.expectSent {

lnwallet/commitment.go

@@ -702,7 +702,7 @@ func (cb *CommitmentBuilder) createUnsignedCommitmentTx(ourBalance,
 	}
 
 	numHTLCs := int64(0)
-	for _, htlc := range filteredHTLCView.OurUpdates {
+	for _, htlc := range filteredHTLCView.Updates.Local {
 		if HtlcIsDust(
 			cb.chanState.ChanType, false, whoseCommit, feePerKw,
 			htlc.Amount.ToSatoshis(), dustLimit,
@@ -713,7 +713,7 @@ func (cb *CommitmentBuilder) createUnsignedCommitmentTx(ourBalance,
 
 		numHTLCs++
 	}
-	for _, htlc := range filteredHTLCView.TheirUpdates {
+	for _, htlc := range filteredHTLCView.Updates.Remote {
 		if HtlcIsDust(
 			cb.chanState.ChanType, true, whoseCommit, feePerKw,
 			htlc.Amount.ToSatoshis(), dustLimit,
@@ -827,7 +827,7 @@ func (cb *CommitmentBuilder) createUnsignedCommitmentTx(ourBalance,
 	// purposes of sorting.
 	cltvs := make([]uint32, len(commitTx.TxOut))
 	htlcIndexes := make([]input.HtlcIndex, len(commitTx.TxOut))
-	for _, htlc := range filteredHTLCView.OurUpdates {
+	for _, htlc := range filteredHTLCView.Updates.Local {
 		if HtlcIsDust(
 			cb.chanState.ChanType, false, whoseCommit, feePerKw,
 			htlc.Amount.ToSatoshis(), dustLimit,
@@ -855,7 +855,7 @@ func (cb *CommitmentBuilder) createUnsignedCommitmentTx(ourBalance,
 		cltvs = append(cltvs, htlc.Timeout)               //nolint
 		htlcIndexes = append(htlcIndexes, htlc.HtlcIndex) //nolint
 	}
-	for _, htlc := range filteredHTLCView.TheirUpdates {
+	for _, htlc := range filteredHTLCView.Updates.Remote {
 		if HtlcIsDust(
 			cb.chanState.ChanType, true, whoseCommit, feePerKw,
 			htlc.Amount.ToSatoshis(), dustLimit,