utxonursery: connect to time-based sweeper

Previously, nursery generated and published its own sweep txes. It
stored the sweep tx in nursery_store to prevent a new tx with a new
sweep address from being generated on restart.

In this commit, sweep generation and publication is removed from nursery
and delegated to the sweeper. Also the confirmation notification is
received from the sweeper.

server.go

@@ -17,8 +17,6 @@ import (
 	"sync/atomic"
 	"time"
 
-	"github.com/lightningnetwork/lnd/sweep"
-
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/connmgr"
@@ -40,6 +38,7 @@ import (
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/nat"
 	"github.com/lightningnetwork/lnd/routing"
+	"github.com/lightningnetwork/lnd/sweep"
 	"github.com/lightningnetwork/lnd/ticker"
 	"github.com/lightningnetwork/lnd/tor"
 )
@@ -156,6 +155,8 @@ type server struct {
 
 	utxoNursery *utxoNursery
 
+	sweeper *sweep.UtxoSweeper
+
 	chainArb *contractcourt.ChainArbitrator
 
 	sphinx *htlcswitch.OnionProcessor
@@ -597,24 +598,45 @@ func newServer(listenAddrs []net.Addr, chanDB *channeldb.DB, cc *chainControl,
 		return nil, err
 	}
 
-	sweeper := sweep.New(&sweep.UtxoSweeperConfig{
+	srvrLog.Tracef("Sweeper batch window duration: %v",
+		sweep.DefaultBatchWindowDuration)
+
+	sweeperStore, err := sweep.NewSweeperStore(
+		chanDB, activeNetParams.GenesisHash,
+	)
+	if err != nil {
+		srvrLog.Errorf("unable to create sweeper store: %v", err)
+		return nil, err
+	}
+
+	s.sweeper = sweep.New(&sweep.UtxoSweeperConfig{
 		Estimator: cc.feeEstimator,
 		GenSweepScript: func() ([]byte, error) {
 			return newSweepPkScript(cc.wallet)
 		},
-		Signer: cc.wallet.Cfg.Signer,
+		Signer:             cc.wallet.Cfg.Signer,
+		PublishTransaction: cc.wallet.PublishTransaction,
+		NewBatchTimer: func() <-chan time.Time {
+			return time.NewTimer(sweep.DefaultBatchWindowDuration).C
+		},
+		SweepTxConfTarget:    6,
+		Notifier:             cc.chainNotifier,
+		ChainIO:              cc.chainIO,
+		Store:                sweeperStore,
+		MaxInputsPerTx:       sweep.DefaultMaxInputsPerTx,
+		MaxSweepAttempts:     sweep.DefaultMaxSweepAttempts,
+		NextAttemptDeltaFunc: sweep.DefaultNextAttemptDeltaFunc,
 	})
 
 	s.utxoNursery = newUtxoNursery(&NurseryConfig{
 		ChainIO:             cc.chainIO,
 		ConfDepth:           1,
-		SweepTxConfTarget:   6,
 		FetchClosedChannels: chanDB.FetchClosedChannels,
 		FetchClosedChannel:  chanDB.FetchClosedChannel,
 		Notifier:            cc.chainNotifier,
 		PublishTransaction:  cc.wallet.PublishTransaction,
 		Store:               utxnStore,
-		Sweeper:             sweeper,
+		Sweeper:             s.sweeper,
 	})
 
 	// Construct a closure that wraps the htlcswitch's CloseLink method.
@@ -706,7 +728,7 @@ func newServer(listenAddrs []net.Addr, chanDB *channeldb.DB, cc *chainControl,
 		DisableChannel: func(op wire.OutPoint) error {
 			return s.announceChanStatus(op, true)
 		},
-		Sweeper: sweeper,
+		Sweeper: s.sweeper,
 	}, chanDB)
 
 	s.breachArbiter = newBreachArbiter(&BreachConfig{
@@ -963,6 +985,9 @@ func (s *server) Start() error {
 	if err := s.htlcSwitch.Start(); err != nil {
 		return err
 	}
+	if err := s.sweeper.Start(); err != nil {
+		return err
+	}
 	if err := s.utxoNursery.Start(); err != nil {
 		return err
 	}
@@ -1050,6 +1075,7 @@ func (s *server) Stop() error {
 	s.breachArbiter.Stop()
 	s.authGossiper.Stop()
 	s.chainArb.Stop()
+	s.sweeper.Stop()
 	s.cc.wallet.Shutdown()
 	s.cc.chainView.Stop()
 	s.connMgr.Stop()