From a4c9f62c6b0512eaaa4fc0137b95e83568f74e13 Mon Sep 17 00:00:00 2001
From: Conner Fromknecht <conner@lightning.engineering>
Date: Sun, 26 Aug 2018 21:36:17 -0700
Subject: [PATCH] chainntnfs/bitcoind: use HistoricalConfDispatch in ntfn
 registry

---
 chainntnfs/bitcoindnotify/bitcoind.go | 34 +++++++++++++++------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/chainntnfs/bitcoindnotify/bitcoind.go b/chainntnfs/bitcoindnotify/bitcoind.go
index c592c3c8..32756903 100644
--- a/chainntnfs/bitcoindnotify/bitcoind.go
+++ b/chainntnfs/bitcoindnotify/bitcoind.go
@@ -254,13 +254,7 @@ out:
 				}
 				b.spendNotifications[op][msg.spendID] = msg
 
-			case *chainntnfs.ConfNtfn:
-				chainntnfs.Log.Infof("New confirmation "+
-					"subscription: txid=%v, numconfs=%v",
-					msg.TxID, msg.NumConfirmations)
-
-				currentHeight := uint32(b.bestBlock.Height)
-
+			case *chainntnfs.HistoricalConfDispatch:
 				// Look up whether the transaction is already
 				// included in the active chain. We'll do this
 				// in a goroutine to prevent blocking
@@ -270,8 +264,7 @@ out:
 					defer b.wg.Done()
 
 					confDetails, _, err := b.historicalConfDetails(
-						msg.TxID, msg.HeightHint,
-						currentHeight,
+						msg.TxID, msg.StartHeight, msg.EndHeight,
 					)
 					if err != nil {
 						chainntnfs.Log.Error(err)
@@ -286,8 +279,7 @@ out:
 					// cache at tip, since any pending
 					// rescans have now completed.
 					err = b.txConfNotifier.UpdateConfDetails(
-						*msg.TxID, msg.ConfID,
-						confDetails,
+						*msg.TxID, confDetails,
 					)
 					if err != nil {
 						chainntnfs.Log.Error(err)
@@ -453,7 +445,7 @@ func (b *BitcoindNotifier) handleRelevantTx(tx chain.RelevantTx, bestHeight int3
 // historicalConfDetails looks up whether a transaction is already included in a
 // block in the active chain and, if so, returns details about the confirmation.
 func (b *BitcoindNotifier) historicalConfDetails(txid *chainhash.Hash,
-	heightHint, currentHeight uint32) (*chainntnfs.TxConfirmation,
+	startHeight, endHeight uint32) (*chainntnfs.TxConfirmation,
 	chainntnfs.TxConfStatus, error) {
 
 	// We'll first attempt to retrieve the transaction using the node's
@@ -469,7 +461,7 @@ func (b *BitcoindNotifier) historicalConfDetails(txid *chainhash.Hash,
 	case err != nil:
 		chainntnfs.Log.Debugf("Failed getting conf details from "+
 			"index (%v), scanning manually", err)
-		return b.confDetailsManually(txid, heightHint, currentHeight)
+		return b.confDetailsManually(txid, startHeight, endHeight)
 
 	// The transaction was found within the node's mempool.
 	case txStatus == chainntnfs.TxFoundMempool:
@@ -964,12 +956,24 @@ func (b *BitcoindNotifier) RegisterConfirmationsNtfn(txid *chainhash.Hash,
 		HeightHint:       heightHint,
 	}
 
-	if err := b.txConfNotifier.Register(ntfn); err != nil {
+	chainntnfs.Log.Infof("New confirmation subscription: "+
+		"txid=%v, numconfs=%v", txid, numConfs)
+
+	// Register the conf notification with txconfnotifier. A non-nil value
+	// for `dispatch` will be returned if we are required to perform a
+	// manual scan for the confirmation. Otherwise the notifier will begin
+	// watching at tip for the transaction to confirm.
+	dispatch, err := b.txConfNotifier.Register(ntfn)
+	if err != nil {
 		return nil, err
 	}
 
+	if dispatch == nil {
+		return ntfn.Event, nil
+	}
+
 	select {
-	case b.notificationRegistry <- ntfn:
+	case b.notificationRegistry <- dispatch:
 		return ntfn.Event, nil
 	case <-b.quit:
 		return nil, ErrChainNotifierShuttingDown