channeldb: add total time locked balance to CloseChannelSummary

This commit adds the total time locked balance of a closed channel at
closure time to the CloseChannelSummary struct. With this information,
we now provide sub-systems within the daemon further knowledge which
can aide them in properly handling querying for the state of pending
close transactions, or if they should watch a channel for closure or
not.

channeldb/channel.go

@@ -699,9 +699,18 @@ type ChannelCloseSummary struct {
 	// Capacity was the total capacity of the channel.
 	Capacity btcutil.Amount
 
-	// OurBalance is our total balance settled balance at the time of
+	// SettledBalance is our total balance settled balance at the time of
-	// channel closure.
+	// channel closure. This _does not_ include the sum of any outputs that
-	OurBalance btcutil.Amount
+	// have been time-locked as a result of the unilateral channel closure.
+	SettledBalance btcutil.Amount
+
+	// TimeLockedBalance is the sum of all the time-locked outputs at the
+	// time of channel closure. If we triggered the force closure of this
+	// channel, then this value will be non-zero if our settled output is
+	// above the dust limit. If we were on the receiving side of a channel
+	// force closure, then this value will be non-zero if we had any
+	// outstanding outgoing HTLC's at the time of channel closure.
+	TimeLockedBalance btcutil.Amount
 
 	// CloseType details exactly _how_ the channel was closed. Three
 	// closure types are possible: cooperative, force, and breach.
@@ -865,7 +874,10 @@ func serializeChannelCloseSummary(w io.Writer, cs *ChannelCloseSummary) error {
 		return err
 	}
 
-	if err := binary.Write(w, byteOrder, cs.OurBalance); err != nil {
+	if err := binary.Write(w, byteOrder, cs.SettledBalance); err != nil {
+		return err
+	}
+	if err := binary.Write(w, byteOrder, cs.TimeLockedBalance); err != nil {
 		return err
 	}
 	if err := binary.Write(w, byteOrder, cs.Capacity); err != nil {
@@ -917,7 +929,10 @@ func deserializeCloseChannelSummary(r io.Reader) (*ChannelCloseSummary, error) {
 		return nil, err
 	}
 
-	if err := binary.Read(r, byteOrder, &c.OurBalance); err != nil {
+	if err := binary.Read(r, byteOrder, &c.SettledBalance); err != nil {
+		return nil, err
+	}
+	if err := binary.Read(r, byteOrder, &c.TimeLockedBalance); err != nil {
 		return nil, err
 	}
 	if err := binary.Read(r, byteOrder, &c.Capacity); err != nil {

channeldb/channel_test.go

@@ -375,7 +375,8 @@ func TestOpenChannelPutGetDelete(t *testing.T) {
 	closeSummary := &ChannelCloseSummary{
 		ChanPoint:         *state.ChanID,
 		RemotePub:         state.IdentityPub,
-		OurBalance: btcutil.Amount(500),
+		SettledBalance:    btcutil.Amount(500),
+		TimeLockedBalance: btcutil.Amount(10000),
 		IsPending:         false,
 		CloseType:         CooperativeClose,
 	}
@@ -607,7 +608,8 @@ func TestChannelStateTransition(t *testing.T) {
 	closeSummary := &ChannelCloseSummary{
 		ChanPoint:         *channel.ChanID,
 		RemotePub:         channel.IdentityPub,
-		OurBalance: btcutil.Amount(500),
+		SettledBalance:    btcutil.Amount(500),
+		TimeLockedBalance: btcutil.Amount(10000),
 		IsPending:         false,
 		CloseType:         ForceClose,
 	}
@@ -732,7 +734,8 @@ func TestFetchClosedChannels(t *testing.T) {
 		ClosingTXID:       rev,
 		RemotePub:         state.IdentityPub,
 		Capacity:          state.Capacity,
-		OurBalance:  state.OurBalance,
+		SettledBalance:    state.OurBalance,
+		TimeLockedBalance: state.OurBalance + 10000,
 		CloseType:         ForceClose,
 		IsPending:         true,
 	}