graph/db: refactor CachedEdgePolicy to use explicit boolean fields

Replace MessageFlags and ChannelFlags bitfields in CachedEdgePolicy
with explicit boolean fields to improve clarity and support both v1
and v2 channel updates:

- Replace MessageFlags with HasMaxHTLC boolean.
- Replace ChannelFlags with IsNode1 and IsDisabled booleans.
- Update NewCachedPolicy to extract these fields version-appropriately:
  - For v1: derive from MessageFlags and ChannelFlags bits.
  - For v2: derive from policy.SecondPeer and policy.DisableFlags.

Update all call sites that used method calls IsNode1() and IsDisabled()
to instead access the fields directly. This includes:
- graph_cache.go: policy direction and disable checks
- unified_edges.go: HasMaxHTLC and IsDisabled checks
- Tests: policy construction and assertions

This refactoring improves readability by making the cached policy's
state explicit rather than encoded in bitfields, and enables seamless
support for both gossip protocol versions.

graph/db/graph_cache.go

@@ -142,8 +142,8 @@ func (c *GraphCache) AddChannel(info *models.CachedEdgeInfo,
 	// Skip adding policies if both are disabled, as the channel is
 	// currently unusable for routing. However, we still add the channel
 	// structure above so that policy updates can later enable it.
-	if policy1 != nil && policy1.IsDisabled() &&
-		policy2 != nil && policy2.IsDisabled() {
+	if policy1 != nil && policy1.IsDisabled &&
+		policy2 != nil && policy2.IsDisabled {
 
 		log.Debugf("Skipping policies for channel %v: both "+
 			"policies are disabled (channel structure still "+
@@ -156,14 +156,14 @@ func (c *GraphCache) AddChannel(info *models.CachedEdgeInfo,
 	// of node 2 then we have the policy 1 as seen from node 1.
 	if policy1 != nil {
 		fromNode, toNode := info.NodeKey1Bytes, info.NodeKey2Bytes
-		if !policy1.IsNode1() {
+		if !policy1.IsNode1 {
 			fromNode, toNode = toNode, fromNode
 		}
 		c.UpdatePolicy(policy1, fromNode, toNode)
 	}
 	if policy2 != nil {
 		fromNode, toNode := info.NodeKey2Bytes, info.NodeKey1Bytes
-		if policy2.IsNode1() {
+		if policy2.IsNode1 {
 			fromNode, toNode = toNode, fromNode
 		}
 		c.UpdatePolicy(policy2, fromNode, toNode)
@@ -210,7 +210,7 @@ func (c *GraphCache) UpdatePolicy(policy *models.CachedEdgePolicy, fromNode,
 		switch {
 		// This is node 1, and it is edge 1, so this is the outgoing
 		// policy for node 1.
-		case channel.IsNode1 && policy.IsNode1():
+		case channel.IsNode1 && policy.IsNode1:
 			channel.OutPolicySet = true
 			policy.InboundFee.WhenSome(func(fee lnwire.Fee) {
 				channel.InboundFee = fee
@@ -218,7 +218,7 @@ func (c *GraphCache) UpdatePolicy(policy *models.CachedEdgePolicy, fromNode,
 
 		// This is node 2, and it is edge 2, so this is the outgoing
 		// policy for node 2.
-		case !channel.IsNode1 && !policy.IsNode1():
+		case !channel.IsNode1 && !policy.IsNode1:
 			channel.OutPolicySet = true
 			policy.InboundFee.WhenSome(func(fee lnwire.Fee) {
 				channel.InboundFee = fee

graph/db/graph_cache_test.go

@@ -33,9 +33,9 @@ func TestGraphCacheAddNode(t *testing.T) {
 	runTest := func(nodeA, nodeB route.Vertex) {
 		t.Helper()
 
-		channelFlagA, channelFlagB := 0, 1
+		isNode1A, isNode1B := true, false
 		if nodeA == pubKey2 {
-			channelFlagA, channelFlagB = 1, 0
+			isNode1A, isNode1B = false, true
 		}
 
 		inboundFee := lnwire.Fee{
@@ -44,8 +44,9 @@ func TestGraphCacheAddNode(t *testing.T) {
 		}
 
 		outPolicy1 := &models.CachedEdgePolicy{
-			ChannelID:    1000,
-			ChannelFlags: lnwire.ChanUpdateChanFlags(channelFlagA),
+			ChannelID:  1000,
+			IsNode1:    isNode1A,
+			IsDisabled: false,
 			ToNodePubKey: func() route.Vertex {
 				return nodeB
 			},
@@ -53,8 +54,9 @@ func TestGraphCacheAddNode(t *testing.T) {
 			InboundFee: fn.Some(inboundFee),
 		}
 		inPolicy1 := &models.CachedEdgePolicy{
-			ChannelID:    1000,
-			ChannelFlags: lnwire.ChanUpdateChanFlags(channelFlagB),
+			ChannelID:  1000,
+			IsNode1:    isNode1B,
+			IsDisabled: false,
 			ToNodePubKey: func() route.Vertex {
 				return nodeA
 			},
@@ -125,8 +127,9 @@ func assertCachedPolicyEqual(t *testing.T, original,
 	cached *models.CachedEdgePolicy) {
 
 	require.Equal(t, original.ChannelID, cached.ChannelID)
-	require.Equal(t, original.MessageFlags, cached.MessageFlags)
-	require.Equal(t, original.ChannelFlags, cached.ChannelFlags)
+	require.Equal(t, original.HasMaxHTLC, cached.HasMaxHTLC)
+	require.Equal(t, original.IsNode1, cached.IsNode1)
+	require.Equal(t, original.IsDisabled, cached.IsDisabled)
 	require.Equal(t, original.TimeLockDelta, cached.TimeLockDelta)
 	require.Equal(t, original.MinHTLC, cached.MinHTLC)
 	require.Equal(t, original.MaxHTLC, cached.MaxHTLC)
@@ -171,13 +174,14 @@ func TestGraphCacheDisabledPoliciesRegression(t *testing.T) {
 
 	// Create two disabled policies.
 	disabledPolicy1 := &models.CachedEdgePolicy{
-		ChannelID:    chanID,
-		ChannelFlags: lnwire.ChanUpdateDisabled,
+		ChannelID:  chanID,
+		IsNode1:    true,
+		IsDisabled: true,
 	}
 	disabledPolicy2 := &models.CachedEdgePolicy{
-		ChannelID: chanID,
-		ChannelFlags: lnwire.ChanUpdateDisabled |
-			lnwire.ChanUpdateDirection,
+		ChannelID:  chanID,
+		IsNode1:    false,
+		IsDisabled: true,
 	}
 
 	// Add the channel with both policies disabled (simulating
@@ -207,7 +211,8 @@ func TestGraphCacheDisabledPoliciesRegression(t *testing.T) {
 	// Now simulate receiving a fresh update enabling one direction.
 	enabledPolicy1 := &models.CachedEdgePolicy{
 		ChannelID:     chanID,
-		ChannelFlags:  0, // NOT disabled anymore
+		IsNode1:       true,
+		IsDisabled:    false,
 		TimeLockDelta: 40,
 		MinHTLC:       lnwire.MilliSatoshi(1000),
 	}

graph/db/models/cached_edge_policy.go

@@ -20,13 +20,15 @@ type CachedEdgePolicy struct {
 	// and the last 2 bytes are the output index for the channel.
 	ChannelID uint64
 
-	// MessageFlags is a bitfield which indicates the presence of optional
-	// fields (like max_htlc) in the policy.
-	MessageFlags lnwire.ChanUpdateMsgFlags
+	// HasMaxHTLC indicates whether the policy has a max HTLC value.
+	HasMaxHTLC bool
 
-	// ChannelFlags is a bitfield which signals the capabilities of the
-	// channel as well as the directed edge this update applies to.
-	ChannelFlags lnwire.ChanUpdateChanFlags
+	// IsNode1 indicates whether this policy was announced by the channel's
+	// node_1.
+	IsNode1 bool
+
+	// IsDisabled indicates whether the policy disables forwarding.
+	IsDisabled bool
 
 	// TimeLockDelta is the number of blocks this node will subtract from
 	// the expiry of an incoming HTLC. This value expresses the time buffer
@@ -75,24 +77,31 @@ func (c *CachedEdgePolicy) ComputeFee(
 	return c.FeeBaseMSat + (amt*c.FeeProportionalMillionths)/feeRateParts
 }
 
-// IsDisabled returns true if the channel is disabled in the direction from  the
-// advertising node.
-func (c *CachedEdgePolicy) IsDisabled() bool {
-	return c.ChannelFlags&lnwire.ChanUpdateDisabled != 0
-}
-
-// IsNode1 returns true if this policy was announced by the channel's node_1
-// node.
-func (c *CachedEdgePolicy) IsNode1() bool {
-	return c.ChannelFlags&lnwire.ChanUpdateDirection == 0
-}
-
 // NewCachedPolicy turns a full policy into a minimal one that can be cached.
 func NewCachedPolicy(policy *ChannelEdgePolicy) *CachedEdgePolicy {
+	if policy.Version != lnwire.GossipVersion2 {
+		return &CachedEdgePolicy{
+			ChannelID:  policy.ChannelID,
+			HasMaxHTLC: policy.MessageFlags.HasMaxHtlc(),
+			IsDisabled: policy.ChannelFlags&
+				lnwire.ChanUpdateDisabled != 0,
+			IsNode1: policy.ChannelFlags&
+				lnwire.ChanUpdateDirection == 0,
+			TimeLockDelta: policy.TimeLockDelta,
+			MinHTLC:       policy.MinHTLC,
+			MaxHTLC:       policy.MaxHTLC,
+			FeeBaseMSat:   policy.FeeBaseMSat,
+			FeeProportionalMillionths: policy.
+				FeeProportionalMillionths,
+			InboundFee: policy.InboundFee,
+		}
+	}
+
 	return &CachedEdgePolicy{
 		ChannelID:                 policy.ChannelID,
-		MessageFlags:              policy.MessageFlags,
-		ChannelFlags:              policy.ChannelFlags,
+		HasMaxHTLC:                true,
+		IsNode1:                   !policy.SecondPeer,
+		IsDisabled:                !policy.DisableFlags.IsEnabled(),
 		TimeLockDelta:             policy.TimeLockDelta,
 		MinHTLC:                   policy.MinHTLC,
 		MaxHTLC:                   policy.MaxHTLC,

routing/unified_edges.go

@@ -188,7 +188,7 @@ func (u *unifiedEdge) amtInRange(amt lnwire.MilliSatoshi) bool {
 	}
 
 	// Skip channels for which this htlc is too large.
-	if u.policy.MessageFlags.HasMaxHtlc() &&
+	if u.policy.HasMaxHTLC &&
 		amt > u.policy.MaxHTLC {
 
 		log.Tracef("Exceeds policy's MaxHTLC: amt=%v, MaxHTLC=%v",
@@ -376,7 +376,7 @@ func (u *edgeUnifier) getEdgeNetwork(netAmtReceived lnwire.MilliSatoshi,
 		}
 
 		// For network channels, skip the disabled ones.
-		if edge.policy.IsDisabled() {
+		if edge.policy.IsDisabled {
 			log.Debugf("Skipped edge %v due to it being disabled",
 				edge.policy.ChannelID)
 			continue
@@ -385,7 +385,7 @@ func (u *edgeUnifier) getEdgeNetwork(netAmtReceived lnwire.MilliSatoshi,
 		// Track the maximal capacity for usable channels. If we don't
 		// know the capacity, we fall back to MaxHTLC.
 		capMsat := lnwire.NewMSatFromSatoshis(edge.capacity)
-		if capMsat == 0 && edge.policy.MessageFlags.HasMaxHtlc() {
+		if capMsat == 0 && edge.policy.HasMaxHTLC {
 			log.Tracef("No capacity available for channel %v, "+
 				"using MaxHtlcMsat (%v) as a fallback.",
 				edge.policy.ChannelID, edge.policy.MaxHTLC)

routing/unified_edges_test.go

@@ -30,7 +30,7 @@ func TestNodeEdgeUnifier(t *testing.T) {
 		FeeProportionalMillionths: 100000,
 		FeeBaseMSat:               30,
 		TimeLockDelta:             60,
-		MessageFlags:              lnwire.ChanUpdateRequiredMaxHtlc,
+		HasMaxHTLC:                true,
 		MaxHTLC:                   5000,
 		MinHTLC:                   100,
 	}
@@ -39,7 +39,7 @@ func TestNodeEdgeUnifier(t *testing.T) {
 		FeeProportionalMillionths: 190000,
 		FeeBaseMSat:               10,
 		TimeLockDelta:             40,
-		MessageFlags:              lnwire.ChanUpdateRequiredMaxHtlc,
+		HasMaxHTLC:                true,
 		MaxHTLC:                   4000,
 		MinHTLC:                   100,
 	}