chainntnfs/txnotifier: support reorg detection for scripts

chainntnfs/txnotifier.go

@@ -1371,11 +1371,11 @@ func (n *TxNotifier) NotifyHeight(height uint32) error {
 }
 
 // DisconnectTip handles the tip of the current chain being disconnected during
-// a chain reorganization. If any watched transactions or spending transactions
+// a chain reorganization. If any watched requests were included in this block,
-// for registered outpoints were included in this block, internal structures are
+// internal structures are updated to ensure confirmation/spend notifications
-// updated to ensure confirmation/spend notifications are consumed (if not
+// are consumed (if not already), and reorg notifications are dispatched
-// already), and reorg notifications are dispatched instead. Confirmation/spend
+// instead. Confirmation/spend notifications will be dispatched again upon block
-// notifications will be dispatched again upon block inclusion.
+// inclusion.
 func (n *TxNotifier) DisconnectTip(blockHeight uint32) error {
 	select {
 	case <-n.quit:
@@ -1395,19 +1395,19 @@ func (n *TxNotifier) DisconnectTip(blockHeight uint32) error {
 	n.reorgDepth++
 
 	// With the block disconnected, we'll update the confirm and spend hints
-	// for our transactions and outpoints to reflect the new height, except
+	// for our notification requests to reflect the new height, except for
-	// for those that have confirmed/spent at previous heights.
+	// those that have confirmed/spent at previous heights.
 	n.updateHints(blockHeight)
 
-	// We'll go through all of our watched transactions and attempt to drain
+	// We'll go through all of our watched confirmation requests and attempt
-	// their notification channels to ensure sending notifications to the
+	// to drain their notification channels to ensure sending notifications
-	// clients is always non-blocking.
+	// to the clients is always non-blocking.
-	for initialHeight, txHashes := range n.txsByInitialHeight {
+	for initialHeight, txHashes := range n.confsByInitialHeight {
 		for txHash := range txHashes {
-			// If the transaction has been reorged out of the chain,
+			// If the transaction/output script has been reorged out
-			// we'll make sure to remove the cached confirmation
+			// of the chain, we'll make sure to remove the cached
-			// details to prevent notifying clients with old
+			// confirmation details to prevent notifying clients
-			// information.
+			// with old information.
 			confSet := n.confNotifications[txHash]
 			if initialHeight == blockHeight {
 				confSet.details = nil
@@ -1424,10 +1424,11 @@ func (n *TxNotifier) DisconnectTip(blockHeight uint32) error {
 				default:
 				}
 
-				// Then, we'll check if the current transaction
+				// Then, we'll check if the current
-				// was included in the block currently being
+				// transaction/output script was included in the
-				// disconnected. If it was, we'll need to
+				// block currently being disconnected. If it
-				// dispatch a reorg notification to the client.
+				// was, we'll need to dispatch a reorg
+				// notification to the client.
 				if initialHeight == blockHeight {
 					err := n.dispatchConfReorg(
 						ntfn, blockHeight,
@@ -1440,15 +1441,15 @@ func (n *TxNotifier) DisconnectTip(blockHeight uint32) error {
 		}
 	}
 
-	// We'll also go through our watched outpoints and attempt to drain
+	// We'll also go through our watched spend requests and attempt to drain
 	// their dispatched notifications to ensure dispatching notifications to
-	// clients later on is always non-blocking.  We're only interested in
+	// clients later on is always non-blocking. We're only interested in
-	// outpoints whose spending transaction was included at the height being
+	// requests whose spending transaction was included at the height being
 	// disconnected.
-	for op := range n.opsBySpendHeight[blockHeight] {
+	for op := range n.spendsByHeight[blockHeight] {
 		// Since the spending transaction is being reorged out of the
 		// chain, we'll need to clear out the spending details of the
-		// outpoint.
+		// request.
 		spendSet := n.spendNotifications[op]
 		spendSet.details = nil
 
@@ -1462,12 +1463,12 @@ func (n *TxNotifier) DisconnectTip(blockHeight uint32) error {
 		}
 	}
 
-	// Finally, we can remove the transactions that were confirmed and the
+	// Finally, we can remove the requests that were confirmed and/or spent
-	// outpoints that were spent at the height being disconnected. We'll
+	// at the height being disconnected. We'll still continue to track them
-	// still continue to track them until they have been confirmed/spent and
+	// until they have been confirmed/spent and are no longer under the risk
-	// are no longer under the risk of being reorged out of the chain again.
+	// of being reorged out of the chain again.
-	delete(n.txsByInitialHeight, blockHeight)
+	delete(n.confsByInitialHeight, blockHeight)
-	delete(n.opsBySpendHeight, blockHeight)
+	delete(n.spendsByHeight, blockHeight)
 
 	return nil
 }
@@ -1568,10 +1569,10 @@ func (n *TxNotifier) unspentOutPoints() []wire.OutPoint {
 func (n *TxNotifier) dispatchConfReorg(ntfn *ConfNtfn,
 	heightDisconnected uint32) error {
 
-	// If the transaction's confirmation notification has yet to be
+	// If the request's confirmation notification has yet to be dispatched,
-	// dispatched, we'll need to clear its entry within the
+	// we'll need to clear its entry within the ntfnsByConfirmHeight index
-	// ntfnsByConfirmHeight index to prevent from notifying the client once
+	// to prevent from notifying the client once the notifier reaches the
-	// the notifier reaches the confirmation height.
+	// confirmation height.
 	if !ntfn.dispatched {
 		confHeight := heightDisconnected + ntfn.NumConfirmations - 1
 		ntfnSet, exists := n.ntfnsByConfirmHeight[confHeight]