chainfee: create new chainfee package extracting fees from lnwallet

In this commit, we create a new chainfee package, that houses all fee
related functionality used within the codebase. The creation of this new
package furthers our long-term goal of extracting functionality from the
bloated `lnwallet` package into new distinct packages. Additionally,
this new packages resolves a class of import cycle that could arise if a
new package that was imported by something in `lnwallet` wanted to use
the existing fee related functions in the prior `lnwallet` package.

breacharbiter.go

@@ -21,6 +21,7 @@ import (
 	"github.com/lightningnetwork/lnd/htlcswitch"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 )
 
 var (
@@ -78,7 +79,7 @@ type BreachConfig struct {
 	// Estimator is used by the breach arbiter to determine an appropriate
 	// fee level when generating, signing, and broadcasting sweep
 	// transactions.
-	Estimator lnwallet.FeeEstimator
+	Estimator chainfee.Estimator
 
 	// GenSweepScript generates the receiving scripts for swept outputs.
 	GenSweepScript func() ([]byte, error)

breacharbiter_test.go

@@ -31,6 +31,7 @@ import (
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/lntest/wait"
 	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/shachain"
 )
@@ -1675,7 +1676,7 @@ func createTestArbiter(t *testing.T, contractBreaches chan *ContractBreachEvent,
 	ba := newBreachArbiter(&BreachConfig{
 		CloseLink:          func(_ *wire.OutPoint, _ htlcswitch.ChannelCloseType) {},
 		DB:                 db,
-		Estimator:          lnwallet.NewStaticFeeEstimator(12500, 0),
+		Estimator:          chainfee.NewStaticEstimator(12500, 0),
 		GenSweepScript:     func() ([]byte, error) { return nil, nil },
 		ContractBreaches:   contractBreaches,
 		Signer:             signer,
@@ -1824,7 +1825,7 @@ func createInitChannels(revocationWindow int) (*lnwallet.LightningChannel, *lnwa
 		return nil, nil, nil, err
 	}
 
-	estimator := lnwallet.NewStaticFeeEstimator(12500, 0)
+	estimator := chainfee.NewStaticEstimator(12500, 0)
 	feePerKw, err := estimator.EstimateFeePerKW(1)
 	if err != nil {
 		return nil, nil, nil, err

chainregistry.go

@@ -30,6 +30,7 @@ import (
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwallet/btcwallet"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/routing/chainview"
 )
@@ -55,11 +56,11 @@ const (
 
 	// defaultBitcoinStaticFeePerKW is the fee rate of 50 sat/vbyte
 	// expressed in sat/kw.
-	defaultBitcoinStaticFeePerKW = lnwallet.SatPerKWeight(12500)
+	defaultBitcoinStaticFeePerKW = chainfee.SatPerKWeight(12500)
 
 	// defaultLitecoinStaticFeePerKW is the fee rate of 200 sat/vbyte
 	// expressed in sat/kw.
-	defaultLitecoinStaticFeePerKW = lnwallet.SatPerKWeight(50000)
+	defaultLitecoinStaticFeePerKW = chainfee.SatPerKWeight(50000)
 
 	// btcToLtcConversionRate is a fixed ratio used in order to scale up
 	// payments when running on the Litecoin chain.
@@ -112,7 +113,7 @@ func (c chainCode) String() string {
 type chainControl struct {
 	chainIO lnwallet.BlockChainIO
 
-	feeEstimator lnwallet.FeeEstimator
+	feeEstimator chainfee.Estimator
 
 	signer input.Signer
 
@@ -161,7 +162,7 @@ func newChainControlFromConfig(cfg *config, chanDB *channeldb.DB,
 			FeeRate:       cfg.Bitcoin.FeeRate,
 			TimeLockDelta: cfg.Bitcoin.TimeLockDelta,
 		}
-		cc.feeEstimator = lnwallet.NewStaticFeeEstimator(
+		cc.feeEstimator = chainfee.NewStaticEstimator(
 			defaultBitcoinStaticFeePerKW, 0,
 		)
 	case litecoinChain:
@@ -171,7 +172,7 @@ func newChainControlFromConfig(cfg *config, chanDB *channeldb.DB,
 			FeeRate:       cfg.Litecoin.FeeRate,
 			TimeLockDelta: cfg.Litecoin.TimeLockDelta,
 		}
-		cc.feeEstimator = lnwallet.NewStaticFeeEstimator(
+		cc.feeEstimator = chainfee.NewStaticEstimator(
 			defaultLitecoinStaticFeePerKW, 0,
 		)
 	default:
@@ -219,8 +220,8 @@ func newChainControlFromConfig(cfg *config, chanDB *channeldb.DB,
 		if cfg.NeutrinoMode.FeeURL != "" {
 			ltndLog.Infof("Using API fee estimator!")
 
-			estimator := lnwallet.NewWebAPIFeeEstimator(
-				lnwallet.SparseConfFeeSource{
+			estimator := chainfee.NewWebAPIEstimator(
+				chainfee.SparseConfFeeSource{
 					URL: cfg.NeutrinoMode.FeeURL,
 				},
 				defaultBitcoinStaticFeePerKW,
@@ -323,8 +324,8 @@ func newChainControlFromConfig(cfg *config, chanDB *channeldb.DB,
 			// if we're using bitcoind as a backend, then we can
 			// use live fee estimates, rather than a statically
 			// coded value.
-			fallBackFeeRate := lnwallet.SatPerKVByte(25 * 1000)
-			cc.feeEstimator, err = lnwallet.NewBitcoindFeeEstimator(
+			fallBackFeeRate := chainfee.SatPerKVByte(25 * 1000)
+			cc.feeEstimator, err = chainfee.NewBitcoindEstimator(
 				*rpcConfig, fallBackFeeRate.FeePerKWeight(),
 			)
 			if err != nil {
@@ -340,8 +341,8 @@ func newChainControlFromConfig(cfg *config, chanDB *channeldb.DB,
 			// if we're using litecoind as a backend, then we can
 			// use live fee estimates, rather than a statically
 			// coded value.
-			fallBackFeeRate := lnwallet.SatPerKVByte(25 * 1000)
-			cc.feeEstimator, err = lnwallet.NewBitcoindFeeEstimator(
+			fallBackFeeRate := chainfee.SatPerKVByte(25 * 1000)
+			cc.feeEstimator, err = chainfee.NewBitcoindEstimator(
 				*rpcConfig, fallBackFeeRate.FeePerKWeight(),
 			)
 			if err != nil {
@@ -445,8 +446,8 @@ func newChainControlFromConfig(cfg *config, chanDB *channeldb.DB,
 			// if we're using btcd as a backend, then we can use
 			// live fee estimates, rather than a statically coded
 			// value.
-			fallBackFeeRate := lnwallet.SatPerKVByte(25 * 1000)
-			cc.feeEstimator, err = lnwallet.NewBtcdFeeEstimator(
+			fallBackFeeRate := chainfee.SatPerKVByte(25 * 1000)
+			cc.feeEstimator, err = chainfee.NewBtcdEstimator(
 				*rpcConfig, fallBackFeeRate.FeePerKWeight(),
 			)
 			if err != nil {

chancloser.go

@@ -9,6 +9,7 @@ import (
 	"github.com/davecgh/go-spew/spew"
 	"github.com/lightningnetwork/lnd/htlcswitch"
 	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 )
 
@@ -150,7 +151,7 @@ type channelCloser struct {
 // passed configuration, and delivery+fee preference. The final argument should
 // only be populated iff, we're the initiator of this closing request.
 func newChannelCloser(cfg chanCloseCfg, deliveryScript []byte,
-	idealFeePerKw lnwallet.SatPerKWeight, negotiationHeight uint32,
+	idealFeePerKw chainfee.SatPerKWeight, negotiationHeight uint32,
 	closeReq *htlcswitch.ChanClose) *channelCloser {
 
 	// Given the target fee-per-kw, we'll compute what our ideal _total_

contractcourt/chain_arbitrator.go

@@ -13,6 +13,7 @@ import (
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/sweep"
 )
@@ -131,7 +132,7 @@ type ChainArbitratorConfig struct {
 	Signer input.Signer
 
 	// FeeEstimator will be used to return fee estimates.
-	FeeEstimator lnwallet.FeeEstimator
+	FeeEstimator chainfee.Estimator
 
 	// ChainIO allows us to query the state of the current main chain.
 	ChainIO lnwallet.BlockChainIO

fundingmanager.go

@@ -24,6 +24,7 @@ import (
 	"github.com/lightningnetwork/lnd/lnpeer"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/routing"
 	"golang.org/x/crypto/salsa20"
@@ -230,7 +231,7 @@ type fundingConfig struct {
 
 	// FeeEstimator calculates appropriate fee rates based on historical
 	// transaction information.
-	FeeEstimator lnwallet.FeeEstimator
+	FeeEstimator chainfee.Estimator
 
 	// Notifier is used by the FundingManager to determine when the
 	// channel's funding transaction has been confirmed on the blockchain
@@ -1218,7 +1219,7 @@ func (f *fundingManager) handleFundingOpen(fmsg *fundingOpenMsg) {
 		NodeAddr:         fmsg.peer.Address(),
 		LocalFundingAmt:  0,
 		RemoteFundingAmt: amt,
-		CommitFeePerKw:   lnwallet.SatPerKWeight(msg.FeePerKiloWeight),
+		CommitFeePerKw:   chainfee.SatPerKWeight(msg.FeePerKiloWeight),
 		FundingFeePerKw:  0,
 		PushMSat:         msg.PushAmount,
 		Flags:            msg.ChannelFlags,

fundingmanager_test.go

@@ -32,6 +32,7 @@ import (
 	"github.com/lightningnetwork/lnd/lnpeer"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 )
 
@@ -218,7 +219,7 @@ func createTestWallet(cdb *channeldb.DB, netParams *chaincfg.Params,
 	notifier chainntnfs.ChainNotifier, wc lnwallet.WalletController,
 	signer input.Signer, keyRing keychain.SecretKeyRing,
 	bio lnwallet.BlockChainIO,
-	estimator lnwallet.FeeEstimator) (*lnwallet.LightningWallet, error) {
+	estimator chainfee.Estimator) (*lnwallet.LightningWallet, error) {
 
 	wallet, err := lnwallet.NewLightningWallet(lnwallet.Config{
 		Database:           cdb,
@@ -247,7 +248,7 @@ func createTestFundingManager(t *testing.T, privKey *btcec.PrivateKey,
 	options ...cfgOption) (*testNode, error) {
 
 	netParams := activeNetParams.Params
-	estimator := lnwallet.NewStaticFeeEstimator(62500, 0)
+	estimator := chainfee.NewStaticEstimator(62500, 0)
 
 	chainNotifier := &mockNotifier{
 		oneConfChannel: make(chan *chainntnfs.TxConfirmation, 1),

htlcswitch/link.go

@@ -24,6 +24,7 @@ import (
 	"github.com/lightningnetwork/lnd/lnpeer"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/queue"
 	"github.com/lightningnetwork/lnd/ticker"
@@ -199,7 +200,7 @@ type ChannelLinkConfig struct {
 	// FeeEstimator is an instance of a live fee estimator which will be
 	// used to dynamically regulate the current fee of the commitment
 	// transaction to ensure timely confirmation.
-	FeeEstimator lnwallet.FeeEstimator
+	FeeEstimator chainfee.Estimator
 
 	// hodl.Mask is a bitvector composed of hodl.Flags, specifying breakpoints
 	// for HTLC forwarding internal to the switch.
@@ -570,7 +571,7 @@ func (l *channelLink) markReestablished() {
 // chain in a timely manner. The returned value is expressed in fee-per-kw, as
 // this is the native rate used when computing the fee for commitment
 // transactions, and the second-level HTLC transactions.
-func (l *channelLink) sampleNetworkFee() (lnwallet.SatPerKWeight, error) {
+func (l *channelLink) sampleNetworkFee() (chainfee.SatPerKWeight, error) {
 	// We'll first query for the sat/kw recommended to be confirmed within 3
 	// blocks.
 	feePerKw, err := l.cfg.FeeEstimator.EstimateFeePerKW(3)
@@ -587,7 +588,7 @@ func (l *channelLink) sampleNetworkFee() (lnwallet.SatPerKWeight, error) {
 // shouldAdjustCommitFee returns true if we should update our commitment fee to
 // match that of the network fee. We'll only update our commitment fee if the
 // network fee is +/- 10% to our network fee.
-func shouldAdjustCommitFee(netFee, chanFee lnwallet.SatPerKWeight) bool {
+func shouldAdjustCommitFee(netFee, chanFee chainfee.SatPerKWeight) bool {
 	switch {
 	// If the network fee is greater than the commitment fee, then we'll
 	// switch to it if it's at least 10% greater than the commit fee.
@@ -1061,7 +1062,7 @@ out:
 			// fee rate to our max fee allocation.
 			commitFee := l.channel.CommitFeeRate()
 			maxFee := l.channel.MaxFeeRate(l.cfg.MaxFeeAllocation)
-			newCommitFee := lnwallet.SatPerKWeight(
+			newCommitFee := chainfee.SatPerKWeight(
 				math.Min(float64(netFee), float64(maxFee)),
 			)
 			if !shouldAdjustCommitFee(newCommitFee, commitFee) {
@@ -1894,7 +1895,7 @@ func (l *channelLink) handleUpstreamMsg(msg lnwire.Message) {
 	case *lnwire.UpdateFee:
 		// We received fee update from peer. If we are the initiator we
 		// will fail the channel, if not we will apply the update.
-		fee := lnwallet.SatPerKWeight(msg.FeePerKw)
+		fee := chainfee.SatPerKWeight(msg.FeePerKw)
 		if err := l.channel.ReceiveUpdateFee(fee); err != nil {
 			l.fail(LinkFailureError{code: ErrInvalidUpdate},
 				"error receiving fee update: %v", err)
@@ -2394,7 +2395,7 @@ func (l *channelLink) HandleChannelUpdate(message lnwire.Message) {
 
 // updateChannelFee updates the commitment fee-per-kw on this channel by
 // committing to an update_fee message.
-func (l *channelLink) updateChannelFee(feePerKw lnwallet.SatPerKWeight) error {
+func (l *channelLink) updateChannelFee(feePerKw chainfee.SatPerKWeight) error {
 
 	l.log.Infof("updating commit fee to %v sat/kw", feePerKw)
 

htlcswitch/link_test.go

@@ -31,6 +31,7 @@ import (
 	"github.com/lightningnetwork/lnd/lnpeer"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/ticker"
 )
@@ -1959,7 +1960,7 @@ func TestChannelLinkBandwidthConsistency(t *testing.T) {
 	// incoming HTLCs automatically.
 	coreLink.cfg.HodlMask = hodl.MaskFromFlags(hodl.ExitSettle)
 
-	estimator := lnwallet.NewStaticFeeEstimator(6000, 0)
+	estimator := chainfee.NewStaticEstimator(6000, 0)
 	feePerKw, err := estimator.EstimateFeePerKW(1)
 	if err != nil {
 		t.Fatalf("unable to query fee estimator: %v", err)
@@ -2379,7 +2380,7 @@ func TestChannelLinkBandwidthConsistencyOverflow(t *testing.T) {
 		aliceMsgs              = coreLink.cfg.Peer.(*mockPeer).sentMsgs
 	)
 
-	estimator := lnwallet.NewStaticFeeEstimator(6000, 0)
+	estimator := chainfee.NewStaticEstimator(6000, 0)
 	feePerKw, err := estimator.EstimateFeePerKW(1)
 	if err != nil {
 		t.Fatalf("unable to query fee estimator: %v", err)
@@ -2630,7 +2631,7 @@ func TestChannelLinkTrimCircuitsPending(t *testing.T) {
 
 	// Compute the static fees that will be used to determine the
 	// correctness of Alice's bandwidth when forwarding HTLCs.
-	estimator := lnwallet.NewStaticFeeEstimator(6000, 0)
+	estimator := chainfee.NewStaticEstimator(6000, 0)
 	feePerKw, err := estimator.EstimateFeePerKW(1)
 	if err != nil {
 		t.Fatalf("unable to query fee estimator: %v", err)
@@ -2909,7 +2910,7 @@ func TestChannelLinkTrimCircuitsNoCommit(t *testing.T) {
 
 	// Compute the static fees that will be used to determine the
 	// correctness of Alice's bandwidth when forwarding HTLCs.
-	estimator := lnwallet.NewStaticFeeEstimator(6000, 0)
+	estimator := chainfee.NewStaticEstimator(6000, 0)
 	feePerKw, err := estimator.EstimateFeePerKW(1)
 	if err != nil {
 		t.Fatalf("unable to query fee estimator: %v", err)
@@ -3167,7 +3168,7 @@ func TestChannelLinkBandwidthChanReserve(t *testing.T) {
 		aliceMsgs              = coreLink.cfg.Peer.(*mockPeer).sentMsgs
 	)
 
-	estimator := lnwallet.NewStaticFeeEstimator(6000, 0)
+	estimator := chainfee.NewStaticEstimator(6000, 0)
 	feePerKw, err := estimator.EstimateFeePerKW(1)
 	if err != nil {
 		t.Fatalf("unable to query fee estimator: %v", err)
@@ -3554,8 +3555,8 @@ func TestChannelRetransmission(t *testing.T) {
 // deviates from our current fee by more 10% or more.
 func TestShouldAdjustCommitFee(t *testing.T) {
 	tests := []struct {
-		netFee       lnwallet.SatPerKWeight
-		chanFee      lnwallet.SatPerKWeight
+		netFee       chainfee.SatPerKWeight
+		chanFee      chainfee.SatPerKWeight
 		shouldAdjust bool
 	}{
 
@@ -3837,7 +3838,7 @@ func TestChannelLinkUpdateCommitFee(t *testing.T) {
 
 	// triggerFeeUpdate is a helper closure to determine whether a fee
 	// update was triggered and completed properly.
-	triggerFeeUpdate := func(feeEstimate, newFeeRate lnwallet.SatPerKWeight,
+	triggerFeeUpdate := func(feeEstimate, newFeeRate chainfee.SatPerKWeight,
 		shouldUpdate bool) {
 
 		t.Helper()
@@ -3898,7 +3899,7 @@ func TestChannelLinkUpdateCommitFee(t *testing.T) {
 	// Triggering the link to update the fee of the channel with a fee rate
 	// that exceeds its maximum fee allocation should result in a fee rate
 	// corresponding to the maximum fee allocation.
-	const maxFeeRate lnwallet.SatPerKWeight = 207182320
+	const maxFeeRate chainfee.SatPerKWeight = 207182320
 	triggerFeeUpdate(maxFeeRate+1, maxFeeRate, true)
 }