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lnwallet: use distinct fee rate for funding transaction coin selection

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This commit modifies the coin selection logic around selecting inputs
for a funding transaction to query the fee estimator directly (and use
fee-per-byte), rather than use the fee estimate which was passed into
the context.

We also use the value passed into the InitChannelReservation method
directly rather than make a call to the fee estimator. With this
change, the responder to a funding workflow will now properly adopt the
fee-per-kw suggested by the funder of the channel.
This commit is contained in:
Olaoluwa Osuntokun 2017-05-16 19:00:19 -07:00
parent 222385bf73
commit c324b11b95
No known key found for this signature in database
GPG Key ID: 9CC5B105D03521A2
1 changed files with 45 additions and 34 deletions
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79
lnwallet/wallet.go
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@ -74,31 +74,31 @@ func (e *ErrInsufficientFunds) Error() string {
//
// TODO(roasbeef): zombie reservation sweeper goroutine.
type initFundingReserveMsg struct {
// The ID of the remote node we would like to open a channel with.
// nodeId is the ID of the remote node we would like to open a channel
// with.
nodeID *btcec.PublicKey
// The IP address plus port that we used to either establish or accept
// the connection which led to the negotiation of this funding
// workflow.
// nodeAddr is the IP address plus port that we used to either
// establish or accept the connection which led to the negotiation of
// this funding workflow.
nodeAddr *net.TCPAddr
// The number of confirmations required before the channel is considered
// open.
// numConfs is the number of confirmations required before the channel
// is considered open.
numConfs uint16
// The amount of funds requested for this channel.
// fundingAmount is the amount of funds requested for this channel.
fundingAmount btcutil.Amount
// The total capacity of the channel which includes the amount of funds
// the remote party contributes (if any).
// capacity is the total capacity of the channel which includes the
// amount of funds the remote party contributes (if any).
capacity btcutil.Amount
// The minimum accepted satoshis/KB fee for the funding transaction. In
// order to ensure timely confirmation, it is recomened that this fee
// should be generous, paying some multiple of the accepted base fee
// rate of the network.
// TODO(roasbeef): integrate fee estimation project...
minFeeRate btcutil.Amount
// feePerKw is the accepted satoshis/Kw fee for the funding
// transaction. In order to ensure timely confirmation, it is
// recommended that this fee should be generous, paying some multiple
// of the accepted base fee rate of the network.
feePerKw btcutil.Amount
// ourDustLimit is the threshold below which no HTLC output should be
// generated for our commitment transaction; ie. HTLCs below
@ -109,17 +109,21 @@ type initFundingReserveMsg struct {
// responder as part of the initial channel creation.
pushSat btcutil.Amount
// The delay on the "pay-to-self" output(s) of the commitment transaction.
// csvDelay is the delay on the "pay-to-self" output(s) of the
// commitment transaction.
csvDelay uint32
// A channel in which all errors will be sent accross. Will be nil if
// this initial set is succesful.
// err is a channel in which all errors will be sent across. Will be
// nil if this initial set is successful.
//
// NOTE: In order to avoid deadlocks, this channel MUST be buffered.
err chan error
// A ChannelReservation with our contributions filled in will be sent
// accross this channel in the case of a succesfully reservation
// initiation. In the case of an error, this will read a nil pointer.
// resp is channel in which a ChannelReservation with our contributions
// filled in will be sent across this channel in the case of a
// successfully reservation initiation. In the case of an error, this
// will read a nil pointer.
//
// NOTE: In order to avoid deadlocks, this channel MUST be buffered.
resp chan *ChannelReservation
}
@ -487,16 +491,15 @@ out:
// commitment transaction is valid.
func (l *LightningWallet) InitChannelReservation(capacity,
ourFundAmt btcutil.Amount, theirID *btcec.PublicKey,
theirAddr *net.TCPAddr, numConfs uint16,
csvDelay uint32, ourDustLimit btcutil.Amount,
pushSat btcutil.Amount) (*ChannelReservation, error) {
theirAddr *net.TCPAddr, numConfs uint16, csvDelay uint32,
ourDustLimit btcutil.Amount, pushSat btcutil.Amount,
feePerKw btcutil.Amount) (*ChannelReservation, error) {
// TODO(roasbeef): make the above into an initial config as part of the
// refactor to implement spec compliant funding flow
errChan := make(chan error, 1)
respChan := make(chan *ChannelReservation, 1)
minFeeRate := btcutil.Amount(l.FeeEstimator.EstimateFeePerWeight(1))
l.msgChan <- &initFundingReserveMsg{
capacity: capacity,
@ -504,7 +507,7 @@ func (l *LightningWallet) InitChannelReservation(capacity,
fundingAmount: ourFundAmt,
csvDelay: csvDelay,
ourDustLimit: ourDustLimit,
minFeeRate: minFeeRate,
feePerKw: feePerKw,
pushSat: pushSat,
nodeID: theirID,
nodeAddr: theirAddr,
@ -528,7 +531,7 @@ func (l *LightningWallet) handleFundingReserveRequest(req *initFundingReserveMsg
id := atomic.AddUint64(&l.nextFundingID, 1)
reservation := NewChannelReservation(req.capacity, req.fundingAmount,
req.minFeeRate, l, id, req.numConfs, req.pushSat)
req.feePerKw, l, id, req.numConfs, req.pushSat)
// Grab the mutex on the ChannelReservation to ensure thread-safety
reservation.Lock()
@ -549,10 +552,14 @@ func (l *LightningWallet) handleFundingReserveRequest(req *initFundingReserveMsg
// don't need to perform any coin selection. Otherwise, attempt to
// obtain enough coins to meet the required funding amount.
if req.fundingAmount != 0 {
// TODO(roasbeef): consult model for proper fee rate on funding
// tx
err := l.selectCoinsAndChange(uint64(req.minFeeRate),
req.fundingAmount, ourContribution)
// Coin selection is done on the basis of sat-per-byte, so
// we'll query the fee estimator for a fee to use to ensure the
// funding transaction gets into the _next_ block.
//
// TODO(roasbeef): shouldn't be targeting next block
satPerByte := l.FeeEstimator.EstimateFeePerByte(1)
err := l.selectCoinsAndChange(satPerByte, req.fundingAmount,
ourContribution)
if err != nil {
req.err <- err
req.resp <- nil
@ -1212,7 +1219,8 @@ func (l *LightningWallet) handleSingleFunderSigs(req *addSingleFunderSigsMsg) {
// Add the complete funding transaction to the DB, in it's open bucket
// which will be used for the lifetime of this channel.
if err := pendingReservation.partialState.SyncPending(pendingReservation.nodeAddr); err != nil {
err = pendingReservation.partialState.SyncPending(pendingReservation.nodeAddr)
if err != nil {
req.err <- err
req.completeChan <- nil
return
@ -1241,9 +1249,12 @@ func (l *LightningWallet) selectCoinsAndChange(feeRate uint64, amt btcutil.Amoun
l.coinSelectMtx.Lock()
defer l.coinSelectMtx.Unlock()
walletLog.Infof("Performing coin selection using %v sat/byte as fee "+
"rate", feeRate)
// Find all unlocked unspent witness outputs with greater than 1
// confirmation.
// TODO(roasbeef): make num confs a configuration paramter
// TODO(roasbeef): make num confs a configuration parameter
coins, err := l.ListUnspentWitness(1)
if err != nil {
return err
@ -1442,7 +1453,7 @@ func coinSelect(feeRate uint64, amt btcutil.Amount,
}
// StaticFeeEstimator will return a static value for all fee calculation
// requests. It is designed to be replaced by a proper fee calcuation
// requests. It is designed to be replaced by a proper fee calculation
// implementation.
type StaticFeeEstimator struct {
FeeRate uint64