Merge pull request #7645 from shaurya947/bitcoind-minmempoolfee

sweep+lnrpc: enforce provided fee rate is no less than relay fee

lnrpc/rpc_utils.go

@@ -3,10 +3,13 @@ package lnrpc
 import (
 	"encoding/hex"
 	"errors"
+	"fmt"
 	"sort"
 
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
+	"github.com/lightningnetwork/lnd/sweep"
 	"google.golang.org/protobuf/encoding/protojson"
 )
 
@@ -193,3 +196,41 @@ func GetChanPointFundingTxid(chanPoint *ChannelPoint) (*chainhash.Hash, error) {
 
 	return chainhash.NewHash(txid)
 }
+
+// CalculateFeeRate uses either satPerByte or satPerVByte, but not both, from a
+// request to calculate the fee rate. It provides compatibility for the
+// deprecated field, satPerByte. Once the field is safe to be removed, the
+// check can then be deleted.
+func CalculateFeeRate(satPerByte, satPerVByte uint64, targetConf uint32,
+	estimator chainfee.Estimator) (chainfee.SatPerKWeight, error) {
+
+	var feeRate chainfee.SatPerKWeight
+
+	// We only allow using either the deprecated field or the new field.
+	if satPerByte != 0 && satPerVByte != 0 {
+		return feeRate, fmt.Errorf("either SatPerByte or " +
+			"SatPerVByte should be set, but not both")
+	}
+
+	// Default to satPerVByte, and overwrite it if satPerByte is set.
+	satPerKw := chainfee.SatPerKVByte(satPerVByte * 1000).FeePerKWeight()
+	if satPerByte != 0 {
+		satPerKw = chainfee.SatPerKVByte(
+			satPerByte * 1000,
+		).FeePerKWeight()
+	}
+
+	// Based on the passed fee related parameters, we'll determine an
+	// appropriate fee rate for this transaction.
+	feeRate, err := sweep.DetermineFeePerKw(
+		estimator, sweep.FeePreference{
+			ConfTarget: targetConf,
+			FeeRate:    satPerKw,
+		},
+	)
+	if err != nil {
+		return feeRate, err
+	}
+
+	return feeRate, nil
+}