multi: add NewLogClosure in lnutils to avoid repetition

And replaces all usage of `logClosure` with `lnutils.LogClosure`.

sweep/fee_bumper.go

@@ -313,7 +313,7 @@ func (t *TxPublisher) isNeutrinoBackend() bool {
 //
 // NOTE: part of the Bumper interface.
 func (t *TxPublisher) Broadcast(req *BumpRequest) (<-chan *BumpResult, error) {
-	log.Tracef("Received broadcast request: %s", newLogClosure(
+	log.Tracef("Received broadcast request: %s", lnutils.NewLogClosure(
 		func() string {
 			return spew.Sdump(req)
 		})())

sweep/log.go

@@ -27,19 +27,3 @@ func DisableLog() {
 func UseLogger(logger btclog.Logger) {
 	log = logger
 }
-
-// logClosure is used to provide a closure over expensive logging operations so
-// don't have to be performed when the logging level doesn't warrant it.
-type logClosure func() string
-
-// String invokes the underlying function and returns the result.
-func (c logClosure) String() string {
-	return c()
-}
-
-// newLogClosure returns a new closure over a function that returns a string
-// which itself provides a Stringer interface so that it can be used with the
-// logging system.
-func newLogClosure(c func() string) logClosure {
-	return logClosure(c)
-}

sweep/sweeper.go

@@ -13,6 +13,7 @@ import (
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/input"
+	"github.com/lightningnetwork/lnd/lnutils"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 )
@@ -1376,7 +1377,7 @@ func (s *UtxoSweeper) handleInputSpent(spend *chainntnfs.SpendDetail) {
 
 		log.Debugf("Detected third party spend related to in flight "+
 			"inputs (is_ours=%v): %v", isOurTx,
-			newLogClosure(func() string {
+			lnutils.NewLogClosure(func() string {
 				return spew.Sdump(spend.SpendingTx)
 			}),
 		)