private Transaction BuildHtlcTransaction(Htlc htlc)
{
bool incoming = htlc.Direction == Direction.Incoming;
var fee = TransactionFee.CalculateFee(FeeratePerKw, incoming ? TransactionFee.HtlcSuccessWeight : TransactionFee.HtlcTimeoutWeight);
var witnessScript = CreateHtlcWitnessScript(htlc);
var outputScript = OutputScripts.ToLocal(CommitmentTxParams.RevocationPublicKey.ToPubKey(), CommitmentTxParams.DelayedPaymentPublicKey.ToPubKey(), ChannelParameters.ToSelfDelay);
var outputIndex = _htlcOutputIndexMap[htlc];
var amount = htlc.AmountMsat.MSatToSatoshi() - fee;
if (amount < ChannelParameters.DustLimitSatoshis)
{
throw new InvalidOperationException("HTLC amount below dust limit");
}
Transaction tx = Transaction.Create(Network);
TxIn txIn = new TxIn(new OutPoint(_commitmentTransaction, outputIndex));
txIn.Sequence = 0;
txIn.ScriptSig = witnessScript.WitHash.ScriptPubKey;
tx.Inputs.Add(txIn);
TxOut txOut = new TxOut(Money.Satoshis(amount), outputScript.WitHash.ScriptPubKey);
tx.Outputs.Add(txOut);
tx.Version = 2;
tx.LockTime = incoming ? 0 : htlc.Expiry;
return(tx);
}
private List <Htlc> GetTrimmedOfferedHtlcs()
{
var htlcTimeoutFee = TransactionFee.CalculateFee(FeeratePerKw, TransactionFee.HtlcTimeoutWeight);
return(Htlcs.Where(h => h.Direction == Direction.Outgoing &&
h.AmountMsat >= (ChannelParameters.DustLimitSatoshis + htlcTimeoutFee) * 1000).ToList());
}
private List <Htlc> GetTrimmedReceivedHtlcs()
{
var htlcSuccessFee = TransactionFee.CalculateFee(FeeratePerKw, TransactionFee.HtlcSuccessWeight);
return(Htlcs.Where(h => h.Direction == Direction.Incoming &&
h.AmountMsat >= (ChannelParameters.DustLimitSatoshis + htlcSuccessFee) * 1000).ToList());
}
private ulong CalculateFee(List <Htlc> trimmedOfferedHtlcs, List <Htlc> trimmedReceivedHtlcs)
{
var weight = TransactionFee.CommitWeight + 172 * ((ulong)trimmedOfferedHtlcs.Count + (ulong)trimmedReceivedHtlcs.Count);
return(TransactionFee.CalculateFee(FeeratePerKw, weight));
}