contractcourt: move responsibility for closing coop close channel to chanArb

contractcourt/chain_watcher.go

@@ -23,6 +23,12 @@ type LocalUnilateralCloseInfo struct {
 	*lnwallet.LocalForceCloseSummary
 }
 
+// CooperativeCloseInfo encapsulates all the informnation we need to act
+// on a cooperative close that gets confirmed.
+type CooperativeCloseInfo struct {
+	*channeldb.ChannelCloseSummary
+}
+
 // ChainEventSubscription is a struct that houses a subscription to be notified
 // for any on-chain events related to a channel. There are three types of
 // possible on-chain events: a cooperative channel closure, a unilateral
@@ -42,9 +48,7 @@ type ChainEventSubscription struct {
 
 	// CooperativeClosure is a signal that will be sent upon once a
 	// cooperative channel closure has been detected confirmed.
-	//
-	// TODO(roasbeef): or something else
-	CooperativeClosure chan struct{}
+	CooperativeClosure chan *CooperativeCloseInfo
 
 	// ContractBreach is a channel that will be sent upon if we detect a
 	// contract breach. The struct sent across the channel contains all the
@@ -232,7 +236,7 @@ func (c *chainWatcher) SubscribeChannelEvents() *ChainEventSubscription {
 		ChanPoint:               c.cfg.chanState.FundingOutpoint,
 		RemoteUnilateralClosure: make(chan *lnwallet.UnilateralCloseSummary, 1),
 		LocalUnilateralClosure:  make(chan *LocalUnilateralCloseInfo, 1),
-		CooperativeClosure:      make(chan struct{}, 1),
+		CooperativeClosure:      make(chan *CooperativeCloseInfo, 1),
 		ContractBreach:          make(chan *lnwallet.BreachRetribution, 1),
 		Cancel: func() {
 			c.Lock()
@@ -511,26 +515,24 @@ func (c *chainWatcher) dispatchCooperativeClose(commitSpend *chainntnfs.SpendDet
 		SettledBalance:          localAmt,
 		CloseType:               channeldb.CooperativeClose,
 		ShortChanID:             c.cfg.chanState.ShortChanID(),
-		IsPending:               false,
+		IsPending:               true,
 		RemoteCurrentRevocation: c.cfg.chanState.RemoteCurrentRevocation,
 		RemoteNextRevocation:    c.cfg.chanState.RemoteNextRevocation,
 		LocalChanConfig:         c.cfg.chanState.LocalChanCfg,
 	}
-	err := c.cfg.chanState.CloseChannel(closeSummary)
-	if err != nil && err != channeldb.ErrNoActiveChannels &&
-		err != channeldb.ErrNoChanDBExists {
-		return fmt.Errorf("unable to close chan state: %v", err)
+
+	// Create a summary of all the information needed to handle the
+	// cooperative closure.
+	closeInfo := &CooperativeCloseInfo{
+		ChannelCloseSummary: closeSummary,
 	}
 
-	log.Infof("closeObserver: ChannelPoint(%v) is fully "+
-		"closed, at height: %v",
-		c.cfg.chanState.FundingOutpoint,
-		commitSpend.SpendingHeight)
-
+	// With the event processed, we'll now notify all subscribers of the
+	// event.
 	c.Lock()
 	for _, sub := range c.clientSubscriptions {
 		select {
-		case sub.CooperativeClosure <- struct{}{}:
+		case sub.CooperativeClosure <- closeInfo:
 		case <-c.quit:
 			c.Unlock()
 			return fmt.Errorf("exiting")