sweep+lnd: move ticker creation into sweeper

server.go

@@ -1059,14 +1059,12 @@ func newServer(cfg *Config, listenAddrs []net.Addr,
 	}
 
 	s.sweeper = sweep.New(&sweep.UtxoSweeperConfig{
-		FeeEstimator:      cc.FeeEstimator,
-		DetermineFeePerKw: sweep.DetermineFeePerKw,
-		GenSweepScript:    newSweepPkScriptGen(cc.Wallet),
-		Signer:            cc.Wallet.Cfg.Signer,
-		Wallet:            newSweeperWallet(cc.Wallet),
-		NewBatchTimer: func() <-chan time.Time {
-			return time.NewTimer(cfg.Sweeper.BatchWindowDuration).C
-		},
+		FeeEstimator:         cc.FeeEstimator,
+		DetermineFeePerKw:    sweep.DetermineFeePerKw,
+		GenSweepScript:       newSweepPkScriptGen(cc.Wallet),
+		Signer:               cc.Wallet.Cfg.Signer,
+		Wallet:               newSweeperWallet(cc.Wallet),
+		TickerDuration:       cfg.Sweeper.BatchWindowDuration,
 		Notifier:             cc.ChainNotifier,
 		Store:                sweeperStore,
 		MaxInputsPerTx:       sweep.DefaultMaxInputsPerTx,

sweep/sweeper.go

@@ -264,10 +264,11 @@ type UtxoSweeperConfig struct {
 	// Wallet contains the wallet functions that sweeper requires.
 	Wallet Wallet
 
-	// NewBatchTimer creates a channel that will be sent on when a certain
-	// time window has passed. During this time window, new inputs can still
-	// be added to the sweep tx that is about to be generated.
-	NewBatchTimer func() <-chan time.Time
+	// TickerDuration is used to create a channel that will be sent on when
+	// a certain time window has passed. During this time window, new
+	// inputs can still be added to the sweep tx that is about to be
+	// generated.
+	TickerDuration time.Duration
 
 	// Notifier is an instance of a chain notifier we'll use to watch for
 	// certain on-chain events.
@@ -1019,7 +1020,7 @@ func (s *UtxoSweeper) scheduleSweep(currentHeight int32) error {
 
 	// Start sweep timer to create opportunity for more inputs to be added
 	// before a tx is constructed.
-	s.timer = s.cfg.NewBatchTimer()
+	s.timer = time.NewTicker(s.cfg.TickerDuration).C
 
 	log.Debugf("Sweep timer started")
 

sweep/sweeper_test.go

@@ -127,15 +127,11 @@ func createSweeperTestContext(t *testing.T) *sweeperTestContext {
 	}
 
 	ctx.sweeper = New(&UtxoSweeperConfig{
-		Notifier: notifier,
-		Wallet:   backend,
-		NewBatchTimer: func() <-chan time.Time {
-			c := make(chan time.Time, 1)
-			ctx.timeoutChan <- c
-			return c
-		},
-		Store:  store,
-		Signer: &mock.DummySigner{},
+		Notifier:       notifier,
+		Wallet:         backend,
+		TickerDuration: 100 * time.Millisecond,
+		Store:          store,
+		Signer:         &mock.DummySigner{},
 		GenSweepScript: func() ([]byte, error) {
 			script := make([]byte, input.P2WPKHSize)
 			script[0] = 0