channeldb+migration: export commonly used methods

This commit exports several commonly used methods that can be used by
later migrations. It also adds a channel commit deserializer.

channeldb/migration24/migration.go

@@ -70,7 +70,7 @@ func MigrateFwdPkgCleanup(tx kvdb.RwTx) error {
 
 	// Iterate over all close channels and remove their forwarding packages.
 	for _, summery := range chanSummaries {
-		sourceBytes := makeLogKey(summery.ShortChanID.ToUint64())
+		sourceBytes := MakeLogKey(summery.ShortChanID.ToUint64())
 
 		// First, we will try to find the corresponding bucket. If there
 		// is not a nested bucket matching the ShortChanID, we will skip
@@ -112,7 +112,7 @@ func deserializeCloseChannelSummary(
 }
 
 // makeLogKey converts a uint64 into an 8 byte array.
-func makeLogKey(updateNum uint64) [8]byte {
+func MakeLogKey(updateNum uint64) [8]byte {
 	var key [8]byte
 	binary.BigEndian.PutUint64(key[:], updateNum)
 	return key

channeldb/migration24/migration_test.go

@@ -187,7 +187,7 @@ func genAfterMigration(deleted, untouched []int) func(kvdb.RwTx) error {
 		// Reading deleted buckets should return nil
 		for _, id := range deleted {
 			chanID := lnwire.NewShortChanIDFromInt(uint64(id))
-			sourceKey := makeLogKey(chanID.ToUint64())
+			sourceKey := MakeLogKey(chanID.ToUint64())
 			sourceBkt := fwdPkgBkt.NestedReadBucket(sourceKey[:])
 			if sourceBkt != nil {
 				return fmt.Errorf(
@@ -200,7 +200,7 @@ func genAfterMigration(deleted, untouched []int) func(kvdb.RwTx) error {
 		// Reading untouched buckets should return not nil
 		for _, id := range untouched {
 			chanID := lnwire.NewShortChanIDFromInt(uint64(id))
-			sourceKey := makeLogKey(chanID.ToUint64())
+			sourceKey := MakeLogKey(chanID.ToUint64())
 			sourceBkt := fwdPkgBkt.NestedReadBucket(sourceKey[:])
 			if sourceBkt == nil {
 				return fmt.Errorf(
@@ -259,7 +259,7 @@ func createTestFwdPkgBucket(tx kvdb.RwTx, chanID lnwire.ShortChannelID) error {
 		return err
 	}
 
-	source := makeLogKey(chanID.ToUint64())
+	source := MakeLogKey(chanID.ToUint64())
 	if _, err := fwdPkgBkt.CreateBucketIfNotExists(source[:]); err != nil {
 		return err
 	}

channeldb/migration_01_to_11/channel.go

@@ -616,7 +616,7 @@ func serializeChannelCloseSummary(w io.Writer, cs *ChannelCloseSummary) error {
 		return err
 	}
 
-	if err := writeChanConfig(w, &cs.LocalChanConfig); err != nil {
+	if err := WriteChanConfig(w, &cs.LocalChanConfig); err != nil {
 		return err
 	}
 
@@ -680,7 +680,7 @@ func deserializeCloseChannelSummary(r io.Reader) (*ChannelCloseSummary, error) {
 		return nil, err
 	}
 
-	if err := readChanConfig(r, &c.LocalChanConfig); err != nil {
+	if err := ReadChanConfig(r, &c.LocalChanConfig); err != nil {
 		return nil, err
 	}
 
@@ -731,7 +731,7 @@ func deserializeCloseChannelSummary(r io.Reader) (*ChannelCloseSummary, error) {
 	return c, nil
 }
 
-func writeChanConfig(b io.Writer, c *ChannelConfig) error {
+func WriteChanConfig(b io.Writer, c *ChannelConfig) error {
 	return WriteElements(b,
 		c.DustLimit, c.MaxPendingAmount, c.ChanReserve, c.MinHTLC,
 		c.MaxAcceptedHtlcs, c.CsvDelay, c.MultiSigKey,
@@ -740,7 +740,7 @@ func writeChanConfig(b io.Writer, c *ChannelConfig) error {
 	)
 }
 
-func readChanConfig(b io.Reader, c *ChannelConfig) error {
+func ReadChanConfig(b io.Reader, c *ChannelConfig) error {
 	return ReadElements(b,
 		&c.DustLimit, &c.MaxPendingAmount, &c.ChanReserve,
 		&c.MinHTLC, &c.MaxAcceptedHtlcs, &c.CsvDelay,
@@ -749,3 +749,92 @@ func readChanConfig(b io.Reader, c *ChannelConfig) error {
 		&c.HtlcBasePoint,
 	)
 }
+
+func DeserializeChanCommit(r io.Reader) (ChannelCommitment, error) {
+	var c ChannelCommitment
+
+	err := ReadElements(r,
+		&c.CommitHeight, &c.LocalLogIndex, &c.LocalHtlcIndex, &c.RemoteLogIndex,
+		&c.RemoteHtlcIndex, &c.LocalBalance, &c.RemoteBalance,
+		&c.CommitFee, &c.FeePerKw, &c.CommitTx, &c.CommitSig,
+	)
+	if err != nil {
+		return c, err
+	}
+
+	c.Htlcs, err = DeserializeHtlcs(r)
+	if err != nil {
+		return c, err
+	}
+
+	return c, nil
+}
+
+// DeserializeHtlcs attempts to read out a slice of HTLC's from the passed
+// io.Reader. The bytes within the passed reader MUST have been previously
+// written to using the SerializeHtlcs function.
+//
+// NOTE: This API is NOT stable, the on-disk format will likely change in the
+// future.
+func DeserializeHtlcs(r io.Reader) ([]HTLC, error) {
+	var numHtlcs uint16
+	if err := ReadElement(r, &numHtlcs); err != nil {
+		return nil, err
+	}
+
+	var htlcs []HTLC
+	if numHtlcs == 0 {
+		return htlcs, nil
+	}
+
+	htlcs = make([]HTLC, numHtlcs)
+	for i := uint16(0); i < numHtlcs; i++ {
+		if err := ReadElements(r,
+			&htlcs[i].Signature, &htlcs[i].RHash, &htlcs[i].Amt,
+			&htlcs[i].RefundTimeout, &htlcs[i].OutputIndex,
+			&htlcs[i].Incoming, &htlcs[i].OnionBlob,
+			&htlcs[i].HtlcIndex, &htlcs[i].LogIndex,
+		); err != nil {
+			return htlcs, err
+		}
+	}
+
+	return htlcs, nil
+}
+
+func SerializeChanCommit(w io.Writer, c *ChannelCommitment) error {
+	if err := WriteElements(w,
+		c.CommitHeight, c.LocalLogIndex, c.LocalHtlcIndex,
+		c.RemoteLogIndex, c.RemoteHtlcIndex, c.LocalBalance,
+		c.RemoteBalance, c.CommitFee, c.FeePerKw, c.CommitTx,
+		c.CommitSig,
+	); err != nil {
+		return err
+	}
+
+	return SerializeHtlcs(w, c.Htlcs...)
+}
+
+// SerializeHtlcs writes out the passed set of HTLC's into the passed writer
+// using the current default on-disk serialization format.
+//
+// NOTE: This API is NOT stable, the on-disk format will likely change in the
+// future.
+func SerializeHtlcs(b io.Writer, htlcs ...HTLC) error {
+	numHtlcs := uint16(len(htlcs))
+	if err := WriteElement(b, numHtlcs); err != nil {
+		return err
+	}
+
+	for _, htlc := range htlcs {
+		if err := WriteElements(b,
+			htlc.Signature, htlc.RHash, htlc.Amt, htlc.RefundTimeout,
+			htlc.OutputIndex, htlc.Incoming, htlc.OnionBlob[:],
+			htlc.HtlcIndex, htlc.LogIndex,
+		); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

channeldb/migration_01_to_11/codec.go

@@ -15,9 +15,9 @@ import (
 	"github.com/lightningnetwork/lnd/shachain"
 )
 
-// writeOutpoint writes an outpoint to the passed writer using the minimal
+// WriteOutpoint writes an outpoint to the passed writer using the minimal
 // amount of bytes possible.
-func writeOutpoint(w io.Writer, o *wire.OutPoint) error {
+func WriteOutpoint(w io.Writer, o *wire.OutPoint) error {
 	if _, err := w.Write(o.Hash[:]); err != nil {
 		return err
 	}
@@ -28,9 +28,9 @@ func writeOutpoint(w io.Writer, o *wire.OutPoint) error {
 	return nil
 }
 
-// readOutpoint reads an outpoint from the passed reader that was previously
+// ReadOutpoint reads an outpoint from the passed reader that was previously
 // written using the writeOutpoint struct.
-func readOutpoint(r io.Reader, o *wire.OutPoint) error {
+func ReadOutpoint(r io.Reader, o *wire.OutPoint) error {
 	if _, err := io.ReadFull(r, o.Hash[:]); err != nil {
 		return err
 	}
@@ -88,7 +88,7 @@ func WriteElement(w io.Writer, element interface{}) error {
 		}
 
 	case wire.OutPoint:
-		return writeOutpoint(w, &e)
+		return WriteOutpoint(w, &e)
 
 	case lnwire.ShortChannelID:
 		if err := binary.Write(w, byteOrder, e.ToUint64()); err != nil {
@@ -258,7 +258,7 @@ func ReadElement(r io.Reader, element interface{}) error {
 		}
 
 	case *wire.OutPoint:
-		return readOutpoint(r, e)
+		return ReadOutpoint(r, e)
 
 	case *lnwire.ShortChannelID:
 		var a uint64

channeldb/migration_01_to_11/graph.go

@@ -836,7 +836,7 @@ func deserializeChanEdgeInfo(r io.Reader) (ChannelEdgeInfo, error) {
 	}
 
 	edgeInfo.ChannelPoint = wire.OutPoint{}
-	if err := readOutpoint(r, &edgeInfo.ChannelPoint); err != nil {
+	if err := ReadOutpoint(r, &edgeInfo.ChannelPoint); err != nil {
 		return ChannelEdgeInfo{}, err
 	}
 	if err := binary.Read(r, byteOrder, &edgeInfo.Capacity); err != nil {

channeldb/migration_01_to_11/legacy_serialization.go

@@ -34,7 +34,7 @@ func deserializeCloseChannelSummaryV6(r io.Reader) (*ChannelCloseSummary, error)
 		return nil, err
 	}
 
-	if err := readChanConfig(r, &c.LocalChanConfig); err != nil {
+	if err := ReadChanConfig(r, &c.LocalChanConfig); err != nil {
 		return nil, err
 	}
 

channeldb/migration_01_to_11/migrations_test.go

@@ -203,7 +203,7 @@ func TestMigrateOptionalChannelCloseSummaryFields(t *testing.T) {
 	}
 
 	var chanPointBuf bytes.Buffer
-	err = writeOutpoint(&chanPointBuf, &chanState.FundingOutpoint)
+	err = WriteOutpoint(&chanPointBuf, &chanState.FundingOutpoint)
 	if err != nil {
 		t.Fatalf("unable to write outpoint: %v", err)
 	}
@@ -303,7 +303,7 @@ func TestMigrateOptionalChannelCloseSummaryFields(t *testing.T) {
 					t.Fatal(err)
 				}
 
-				err = writeChanConfig(&buf, &cs.LocalChanConfig)
+				err = WriteChanConfig(&buf, &cs.LocalChanConfig)
 				if err != nil {
 					t.Fatal(err)
 				}
@@ -354,7 +354,7 @@ func TestMigrateOptionalChannelCloseSummaryFields(t *testing.T) {
 					t.Fatal(err)
 				}
 
-				err = writeChanConfig(&buf, &cs.LocalChanConfig)
+				err = WriteChanConfig(&buf, &cs.LocalChanConfig)
 				if err != nil {
 					t.Fatal(err)
 				}