Merge pull request #3154 from halseth/chainntfs-neutrino-async-getutxo

neutrinonotify: async call GetUtxo from RegisterSpendNtfn

chainntnfs/neutrinonotify/neutrino.go

@@ -740,10 +740,14 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	}
 
 	// With the filter updated, we'll dispatch our historical rescan to
-	// ensure we detect the spend if it happened in the past. We'll ensure
+	// ensure we detect the spend if it happened in the past.
-	// that neutrino is caught up to the starting height before we attempt
+	n.wg.Add(1)
-	// to fetch the UTXO from the chain. If we're behind, then we may miss a
+	go func() {
-	// notification dispatch.
+		defer n.wg.Done()
+
+		// We'll ensure that neutrino is caught up to the starting
+		// height before we attempt to fetch the UTXO from the chain.
+		// If we're behind, then we may miss a notification dispatch.
 		for {
 			n.bestBlockMtx.RLock()
 			currentHeight := uint32(n.bestBlock.Height)
@@ -753,7 +757,11 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 				break
 			}
 
-		time.Sleep(time.Millisecond * 200)
+			select {
+			case <-time.After(time.Millisecond * 200):
+			case <-n.quit:
+				return
+			}
 		}
 
 		spendReport, err := n.p2pNode.GetUtxo(
@@ -767,7 +775,8 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 			neutrino.QuitChan(n.quit),
 		)
 		if err != nil && !strings.Contains(err.Error(), "not found") {
-		return nil, err
+			chainntnfs.Log.Errorf("Failed getting UTXO: %v", err)
+			return
 		}
 
 		// If a spend report was returned, and the transaction is present, then
@@ -790,8 +799,10 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 		// blocks.
 		err = n.txNotifier.UpdateSpendDetails(spendRequest, spendDetails)
 		if err != nil {
-		return nil, err
+			chainntnfs.Log.Errorf("Failed to update spend details: %v", err)
+			return
 		}
+	}()
 
 	return ntfn.Event, nil
 }