channeldb: final htlc resolution storage opt-in

channeldb/channel.go

@@ -1879,12 +1879,18 @@ func (c *OpenChannel) UpdateCommitment(newCommitment *ChannelCommitment,
 			return err
 		}
 
-		// Get the bucket where settled htlcs are recorded.
-		finalHtlcsBucket, err := fetchFinalHtlcsBucketRw(
-			tx, c.ShortChannelID,
-		)
-		if err != nil {
-			return err
+		// Get the bucket where settled htlcs are recorded if the user
+		// opted in to storing this information.
+		var finalHtlcsBucket kvdb.RwBucket
+		if c.Db.parent.storeFinalHtlcResolutions {
+			bucket, err := fetchFinalHtlcsBucketRw(
+				tx, c.ShortChannelID,
+			)
+			if err != nil {
+				return err
+			}
+
+			finalHtlcsBucket = bucket
 		}
 
 		var unsignedUpdates []LogUpdate
@@ -1957,15 +1963,18 @@ func processFinalHtlc(finalHtlcsBucket walletdb.ReadWriteBucket, upd LogUpdate,
 		return nil
 	}
 
-	err := putFinalHtlc(
-		finalHtlcsBucket, id,
-		FinalHtlcInfo{
-			Settled:  settled,
-			Offchain: true,
-		},
-	)
-	if err != nil {
-		return err
+	// Store the final resolution in the database if a bucket is provided.
+	if finalHtlcsBucket != nil {
+		err := putFinalHtlc(
+			finalHtlcsBucket, id,
+			FinalHtlcInfo{
+				Settled:  settled,
+				Offchain: true,
+			},
+		)
+		if err != nil {
+			return err
+		}
 	}
 
 	finalHtlcs[id] = settled

channeldb/channel_test.go

@@ -1463,7 +1463,7 @@ func TestKeyLocatorEncoding(t *testing.T) {
 func TestFinalHtlcs(t *testing.T) {
 	t.Parallel()
 
-	fullDB, err := MakeTestDB(t)
+	fullDB, err := MakeTestDB(t, OptionStoreFinalHtlcResolutions(true))
 	require.NoError(t, err, "unable to make test database")
 
 	cdb := fullDB.ChannelStateDB()

channeldb/db.go

@@ -307,6 +307,7 @@ type DB struct {
 	clock                     clock.Clock
 	dryRun                    bool
 	keepFailedPaymentAttempts bool
+	storeFinalHtlcResolutions bool
 }
 
 // Open opens or creates channeldb. Any necessary schemas migrations due
@@ -364,6 +365,7 @@ func CreateWithBackend(backend kvdb.Backend,
 		clock:                     opts.clock,
 		dryRun:                    opts.dryRun,
 		keepFailedPaymentAttempts: opts.keepFailedPaymentAttempts,
+		storeFinalHtlcResolutions: opts.storeFinalHtlcResolutions,
 	}
 
 	// Set the parent pointer (only used in tests).
@@ -1741,6 +1743,11 @@ func (c *ChannelStateDB) LookupFinalHtlc(chanID lnwire.ShortChannelID,
 func (c *ChannelStateDB) PutOnchainFinalHtlcOutcome(
 	chanID lnwire.ShortChannelID, htlcID uint64, settled bool) error {
 
+	// Skip if the user did not opt in to storing final resolutions.
+	if !c.parent.storeFinalHtlcResolutions {
+		return nil
+	}
+
 	return kvdb.Update(c.backend, func(tx kvdb.RwTx) error {
 		finalHtlcsBucket, err := fetchFinalHtlcsBucketRw(tx, chanID)
 		if err != nil {

channeldb/options.go

@@ -74,6 +74,10 @@ type Options struct {
 	// keepFailedPaymentAttempts determines whether failed htlc attempts
 	// are kept on disk or removed to save space.
 	keepFailedPaymentAttempts bool
+
+	// storeFinalHtlcResolutions determines whether to persistently store
+	// the final resolution of incoming htlcs.
+	storeFinalHtlcResolutions bool
 }
 
 // DefaultOptions returns an Options populated with default values.
@@ -187,6 +191,16 @@ func OptionKeepFailedPaymentAttempts(keepFailedPaymentAttempts bool) OptionModif
 	}
 }
 
+// OptionStoreFinalHtlcResolutions controls whether to persistently store the
+// final resolution of incoming htlcs.
+func OptionStoreFinalHtlcResolutions(
+	storeFinalHtlcResolutions bool) OptionModifier {
+
+	return func(o *Options) {
+		o.storeFinalHtlcResolutions = storeFinalHtlcResolutions
+	}
+}
+
 // OptionPruneRevocationLog specifies whether the migration for pruning
 // revocation logs needs to be applied or not.
 func OptionPruneRevocationLog(prune bool) OptionModifier {