multi: add NewLogClosure in lnutils to avoid repetition

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

lnrpc/devrpc/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 // nolint:unused
-
-// 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 { // nolint:unused
-	return logClosure(c)
-}

lnrpc/invoicesrpc/addinvoice.go

@@ -20,6 +20,7 @@ import (
 	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/invoices"
 	"github.com/lightningnetwork/lnd/lntypes"
+	"github.com/lightningnetwork/lnd/lnutils"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/netann"
 	"github.com/lightningnetwork/lnd/routing"
@@ -473,7 +474,7 @@ func AddInvoice(ctx context.Context, cfg *AddInvoiceConfig,
 	}
 
 	log.Tracef("[addinvoice] adding new invoice %v",
-		newLogClosure(func() string {
+		lnutils.NewLogClosure(func() string {
 			return spew.Sdump(newInvoice)
 		}),
 	)

lnrpc/invoicesrpc/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)
-}