channeldb: replace opening height will short chan ID in OpenChannel

This commit modifies the OpenChannel struct to include the full short
channel ID rather than simply the opening height. This new field will
be needed by an upcoming change to uniformly switch to using short
channel ID’s when forwarding HTLC’s due to the change in per-hop
payloads.

channeldb/channel.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/boltdb/bolt"
+	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/shachain"
 	"github.com/roasbeef/btcd/btcec"
 	"github.com/roasbeef/btcd/chaincfg/chainhash"
@@ -130,9 +131,10 @@ const (
 // to an on-disk log, which can then subsequently be queried in order to
 // "time-travel" to a prior state.
 type OpenChannel struct {
-	// OpeningHeight is the height in which this channel was officially
+	// ShortChannelID encodes the exact location in the chain in which the
-	// marked open.
+	// channel was initially confirmed. This includes: the block height,
-	OpeningHeight uint32
+	// transaction index, and the output within the target transaction.
+	ShortChanID lnwire.ShortChannelID
 
 	// FundingBroadcastHeight is the height in which the funding
 	// transaction was broadcast. This value can be used by higher level
@@ -1522,9 +1524,9 @@ func putChanConfInfo(openChanBucket *bolt.Bucket, channel *OpenChannel) error {
 	copy(keyPrefix[len(confInfoPrefix):], b.Bytes())
 
 	// We store the conf info in the following format: broadcast || open.
-	var scratch [8]byte
+	var scratch [12]byte
 	byteOrder.PutUint32(scratch[:], channel.FundingBroadcastHeight)
-	byteOrder.PutUint32(scratch[4:], channel.OpeningHeight)
+	byteOrder.PutUint64(scratch[4:], channel.ShortChanID.ToUint64())
 
 	return openChanBucket.Put(keyPrefix, scratch[:])
 }
@@ -1541,7 +1543,9 @@ func fetchChanConfInfo(openChanBucket *bolt.Bucket, channel *OpenChannel) error
 
 	confInfoBytes := openChanBucket.Get(keyPrefix)
 	channel.FundingBroadcastHeight = byteOrder.Uint32(confInfoBytes[:4])
-	channel.OpeningHeight = byteOrder.Uint32(confInfoBytes[4:])
+	channel.ShortChanID = lnwire.NewShortChanIDFromInt(
+		byteOrder.Uint64(confInfoBytes[4:]),
+	)
 
 	return nil
 }

channeldb/channel_test.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/davecgh/go-spew/spew"
+	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/shachain"
 	"github.com/roasbeef/btcd/btcec"
 	"github.com/roasbeef/btcd/chaincfg"
@@ -677,8 +678,12 @@ func TestFetchPendingChannels(t *testing.T) {
 			broadcastHeight)
 	}
 
-	const openHeight = 100
+	chanOpenLoc := lnwire.ShortChannelID{
-	err = cdb.MarkChannelAsOpen(pendingChannels[0].ChanID, openHeight)
+		BlockHeight: 5,
+		TxIndex:     10,
+		TxPosition:  15,
+	}
+	err = cdb.MarkChannelAsOpen(pendingChannels[0].ChanID, chanOpenLoc)
 	if err != nil {
 		t.Fatalf("unable to mark channel as open: %v", err)
 	}
@@ -689,9 +694,10 @@ func TestFetchPendingChannels(t *testing.T) {
 	if err != nil {
 		t.Fatalf("unable to fetch channels: %v", err)
 	}
-	if openChans[0].OpeningHeight != openHeight {
+	if openChans[0].ShortChanID != chanOpenLoc {
 		t.Fatalf("channel opening heights don't match: expected %v, "+
-			"got %v", openChans[0].OpeningHeight, openHeight)
+			"got %v", spew.Sdump(openChans[0].ShortChanID),
+			chanOpenLoc)
 	}
 	if openChans[0].FundingBroadcastHeight != broadcastHeight {
 		t.Fatalf("broadcast height mismatch: expected %v, got %v",
@@ -737,8 +743,12 @@ func TestFetchClosedChannels(t *testing.T) {
 
 	// Next, simulate the confirmation of the channel by marking it as
 	// pending within the database.
-	const openHeight = 100
+	chanOpenLoc := lnwire.ShortChannelID{
-	if err := cdb.MarkChannelAsOpen(state.ChanID, openHeight); err != nil {
+		BlockHeight: 5,
+		TxIndex:     10,
+		TxPosition:  15,
+	}
+	if err := cdb.MarkChannelAsOpen(state.ChanID, chanOpenLoc); err != nil {
 		t.Fatalf("unable to mark channel as open: %v", err)
 	}
 

channeldb/db.go

@@ -9,6 +9,7 @@ import (
 	"sync"
 
 	"github.com/boltdb/bolt"
+	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/roasbeef/btcd/btcec"
 	"github.com/roasbeef/btcd/wire"
 )
@@ -364,7 +365,9 @@ func fetchChannels(d *DB, pendingOnly bool) ([]*OpenChannel, error) {
 // MarkChannelAsOpen records the finalization of the funding process and marks
 // a channel as available for use. Additionally the height in which this
 // channel as opened will also be recorded within the database.
-func (d *DB) MarkChannelAsOpen(outpoint *wire.OutPoint, openHeight uint32) error {
+func (d *DB) MarkChannelAsOpen(outpoint *wire.OutPoint,
+	openLoc lnwire.ShortChannelID) error {
+
 	return d.Update(func(tx *bolt.Tx) error {
 		openChanBucket := tx.Bucket(openChannelBucket)
 		if openChanBucket == nil {
@@ -399,7 +402,7 @@ func (d *DB) MarkChannelAsOpen(outpoint *wire.OutPoint, openHeight uint32) error
 		infoCopy := make([]byte, len(confInfoBytes))
 		copy(infoCopy[:], confInfoBytes)
 
-		byteOrder.PutUint32(infoCopy[4:], openHeight)
+		byteOrder.PutUint64(infoCopy[4:], openLoc.ToUint64())
 
 		return openChanBucket.Put(confInfoKey, infoCopy)
 	})