watchtower: start using the new channel max heights

This commit also adds tests for the DB changes made in the previous
commit since we can now read the new field with the FetchChanInfos
method.

The commit following this one does the backfill migration.

watchtower/wtclient/client.go

@@ -17,6 +17,7 @@ import (
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/channelnotifier"
+	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/lnwallet"
@@ -295,9 +296,8 @@ type TowerClient struct {
 
 	closableSessionQueue *sessionCloseMinHeap
 
-	backupMu          sync.Mutex
-	summaries         wtdb.ChannelSummaries
-	chanCommitHeights map[lnwire.ChannelID]uint64
+	backupMu  sync.Mutex
+	chanInfos wtdb.ChannelInfos
 
 	statTicker *time.Ticker
 	stats      *ClientStats
@@ -339,9 +339,7 @@ func New(config *Config) (*TowerClient, error) {
 
 	plog := build.NewPrefixLog(prefix, log)
 
-	// Load the sweep pkscripts that have been generated for all previously
-	// registered channels.
-	chanSummaries, err := cfg.DB.FetchChanSummaries()
+	chanInfos, err := cfg.DB.FetchChanInfos()
 	if err != nil {
 		return nil, err
 	}
@@ -358,9 +356,8 @@ func New(config *Config) (*TowerClient, error) {
 		cfg:                  cfg,
 		log:                  plog,
 		pipeline:             queue,
-		chanCommitHeights:    make(map[lnwire.ChannelID]uint64),
 		activeSessions:       newSessionQueueSet(),
-		summaries:            chanSummaries,
+		chanInfos:            chanInfos,
 		closableSessionQueue: newSessionCloseMinHeap(),
 		statTicker:           time.NewTicker(DefaultStatInterval),
 		stats:                new(ClientStats),
@@ -369,44 +366,6 @@ func New(config *Config) (*TowerClient, error) {
 		quit:                 make(chan struct{}),
 	}
 
-	// perUpdate is a callback function that will be used to inspect the
-	// full set of candidate client sessions loaded from disk, and to
-	// determine the highest known commit height for each channel. This
-	// allows the client to reject backups that it has already processed for
-	// its active policy.
-	perUpdate := func(policy wtpolicy.Policy, chanID lnwire.ChannelID,
-		commitHeight uint64) {
-
-		// We only want to consider accepted updates that have been
-		// accepted under an identical policy to the client's current
-		// policy.
-		if policy != c.cfg.Policy {
-			return
-		}
-
-		c.backupMu.Lock()
-		defer c.backupMu.Unlock()
-
-		// Take the highest commit height found in the session's acked
-		// updates.
-		height, ok := c.chanCommitHeights[chanID]
-		if !ok || commitHeight > height {
-			c.chanCommitHeights[chanID] = commitHeight
-		}
-	}
-
-	perMaxHeight := func(s *wtdb.ClientSession, chanID lnwire.ChannelID,
-		height uint64) {
-
-		perUpdate(s.Policy, chanID, height)
-	}
-
-	perCommittedUpdate := func(s *wtdb.ClientSession,
-		u *wtdb.CommittedUpdate) {
-
-		perUpdate(s.Policy, u.BackupID.ChanID, u.BackupID.CommitHeight)
-	}
-
 	candidateTowers := newTowerListIterator()
 	perActiveTower := func(tower *Tower) {
 		// If the tower has already been marked as active, then there is
@@ -429,8 +388,6 @@ func New(config *Config) (*TowerClient, error) {
 	candidateSessions, err := getTowerAndSessionCandidates(
 		cfg.DB, cfg.SecretKeyRing, perActiveTower,
 		wtdb.WithPreEvalFilterFn(c.genSessionFilter(true)),
-		wtdb.WithPerMaxHeight(perMaxHeight),
-		wtdb.WithPerCommittedUpdate(perCommittedUpdate),
 		wtdb.WithPostEvalFilterFn(ExhaustedSessionFilter()),
 	)
 	if err != nil {
@@ -594,7 +551,7 @@ func (c *TowerClient) Start() error {
 
 		// Iterate over the list of registered channels and check if
 		// any of them can be marked as closed.
-		for id := range c.summaries {
+		for id := range c.chanInfos {
 			isClosed, closedHeight, err := c.isChannelClosed(id)
 			if err != nil {
 				returnErr = err
@@ -615,7 +572,7 @@ func (c *TowerClient) Start() error {
 
 			// Since the channel has been marked as closed, we can
 			// also remove it from the channel summaries map.
-			delete(c.summaries, id)
+			delete(c.chanInfos, id)
 		}
 
 		// Load all closable sessions.
@@ -732,7 +689,7 @@ func (c *TowerClient) RegisterChannel(chanID lnwire.ChannelID) error {
 
 	// If a pkscript for this channel already exists, the channel has been
 	// previously registered.
-	if _, ok := c.summaries[chanID]; ok {
+	if _, ok := c.chanInfos[chanID]; ok {
 		return nil
 	}
 
@@ -752,8 +709,10 @@ func (c *TowerClient) RegisterChannel(chanID lnwire.ChannelID) error {
 
 	// Finally, cache the pkscript in our in-memory cache to avoid db
 	// lookups for the remainder of the daemon's execution.
-	c.summaries[chanID] = wtdb.ClientChanSummary{
-		SweepPkScript: pkScript,
+	c.chanInfos[chanID] = &wtdb.ChannelInfo{
+		ClientChanSummary: wtdb.ClientChanSummary{
+			SweepPkScript: pkScript,
+		},
 	}
 
 	return nil
@@ -770,16 +729,23 @@ func (c *TowerClient) BackupState(chanID *lnwire.ChannelID,
 
 	// Make sure that this channel is registered with the tower client.
 	c.backupMu.Lock()
-	if _, ok := c.summaries[*chanID]; !ok {
+	info, ok := c.chanInfos[*chanID]
+	if !ok {
 		c.backupMu.Unlock()
 
 		return ErrUnregisteredChannel
 	}
 
 	// Ignore backups that have already been presented to the client.
-	height, ok := c.chanCommitHeights[*chanID]
-	if ok && stateNum <= height {
+	var duplicate bool
+	info.MaxHeight.WhenSome(func(maxHeight uint64) {
+		if stateNum <= maxHeight {
+			duplicate = true
+		}
+	})
+	if duplicate {
 		c.backupMu.Unlock()
+
 		c.log.Debugf("Ignoring duplicate backup for chanid=%v at "+
 			"height=%d", chanID, stateNum)
 
@@ -789,7 +755,7 @@ func (c *TowerClient) BackupState(chanID *lnwire.ChannelID,
 	// This backup has a higher commit height than any known backup for this
 	// channel. We'll update our tip so that we won't accept it again if the
 	// link flaps.
-	c.chanCommitHeights[*chanID] = stateNum
+	c.chanInfos[*chanID].MaxHeight = fn.Some(stateNum)
 	c.backupMu.Unlock()
 
 	id := &wtdb.BackupID{
@@ -899,7 +865,7 @@ func (c *TowerClient) handleClosedChannel(chanID lnwire.ChannelID,
 	defer c.backupMu.Unlock()
 
 	// We only care about channels registered with the tower client.
-	if _, ok := c.summaries[chanID]; !ok {
+	if _, ok := c.chanInfos[chanID]; !ok {
 		return nil
 	}
 
@@ -924,8 +890,7 @@ func (c *TowerClient) handleClosedChannel(chanID lnwire.ChannelID,
 		return fmt.Errorf("could not track closable sessions: %w", err)
 	}
 
-	delete(c.summaries, chanID)
-	delete(c.chanCommitHeights, chanID)
+	delete(c.chanInfos, chanID)
 
 	return nil
 }
@@ -1332,7 +1297,7 @@ func (c *TowerClient) backupDispatcher() {
 // the prevTask, and should be reprocessed after obtaining a new sessionQueue.
 func (c *TowerClient) processTask(task *wtdb.BackupID) {
 	c.backupMu.Lock()
-	summary, ok := c.summaries[task.ChanID]
+	summary, ok := c.chanInfos[task.ChanID]
 	if !ok {
 		c.backupMu.Unlock()
 

watchtower/wtclient/interface.go

@@ -81,10 +81,10 @@ type DB interface {
 	// successfully backed up using the given session.
 	NumAckedUpdates(id *wtdb.SessionID) (uint64, error)
 
-	// FetchChanSummaries loads a mapping from all registered channels to
-	// their channel summaries. Only the channels that have not yet been
+	// FetchChanInfos loads a mapping from all registered channels to
+	// their wtdb.ChannelInfo. Only the channels that have not yet been
 	// marked as closed will be loaded.
-	FetchChanSummaries() (wtdb.ChannelSummaries, error)
+	FetchChanInfos() (wtdb.ChannelInfos, error)
 
 	// MarkChannelClosed will mark a registered channel as closed by setting
 	// its closed-height as the given block height. It returns a list of