Merge pull request #3821 from halseth/pluggable-anchors-lnwallet

[anchor] pluggable anchor commitments

channeldb/channel.go

@@ -176,6 +176,12 @@ const (
 	// disk. This bit may be on if the funding transaction was crafted by a
 	// wallet external to the primary daemon.
 	NoFundingTxBit ChannelType = 1 << 2
+
+	// AnchorOutputsBit indicates that the channel makes use of anchor
+	// outputs to bump the commitment transaction's effective feerate. This
+	// channel type also uses a delayed to_remote output script. If bit is
+	// set, we'll find the size of the anchor outputs in the database.
+	AnchorOutputsBit ChannelType = 1 << 3
 )
 
 // IsSingleFunder returns true if the channel type if one of the known single
@@ -201,6 +207,12 @@ func (c ChannelType) HasFundingTx() bool {
 	return c&NoFundingTxBit == 0
 }
 
+// HasAnchors returns true if this channel type has anchor ouputs on its
+// commitment.
+func (c ChannelType) HasAnchors() bool {
+	return c&AnchorOutputsBit == AnchorOutputsBit
+}
+
 // ChannelConstraints represents a set of constraints meant to allow a node to
 // limit their exposure, enact flow control and ensure that all HTLCs are
 // economically relevant. This struct will be mirrored for both sides of the
@@ -326,13 +338,15 @@ type ChannelCommitment struct {
 	// LocalBalance is the current available settled balance within the
 	// channel directly spendable by us.
 	//
-	// NOTE: This is the balance *after* subtracting any commitment fee.
+	// NOTE: This is the balance *after* subtracting any commitment fee,
+	// AND anchor output values.
 	LocalBalance lnwire.MilliSatoshi
 
 	// RemoteBalance is the current available settled balance within the
 	// channel directly spendable by the remote node.
 	//
-	// NOTE: This is the balance *after* subtracting any commitment fee.
+	// NOTE: This is the balance *after* subtracting any commitment fee,
+	// AND anchor output values.
 	RemoteBalance lnwire.MilliSatoshi
 
 	// CommitFee is the amount calculated to be paid in fees for the