From 9f7625d6992e56fdd76dc0c88797964988bc68d2 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 6 Nov 2019 16:10:37 +0300
Subject: [PATCH] core: don't do useless DB reads if nothing was persisted

---
 pkg/core/blockchain.go | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index d33ee264a..ac8ca3365 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -492,18 +492,18 @@ func (bc *Blockchain) persist() error {
 	if err != nil {
 		return err
 	}
-	bHeight, err := storage.CurrentBlockHeight(bc.store)
-	if err != nil {
-		return err
-	}
-	oldHeight := atomic.SwapUint32(&bc.persistedHeight, bHeight)
-	diff := bHeight - oldHeight
-
-	storedHeaderHeight, _, err := storage.CurrentHeaderHeight(bc.store)
-	if err != nil {
-		return err
-	}
 	if persisted > 0 {
+		bHeight, err := storage.CurrentBlockHeight(bc.store)
+		if err != nil {
+			return err
+		}
+		oldHeight := atomic.SwapUint32(&bc.persistedHeight, bHeight)
+		diff := bHeight - oldHeight
+
+		storedHeaderHeight, _, err := storage.CurrentHeaderHeight(bc.store)
+		if err != nil {
+			return err
+		}
 		log.WithFields(log.Fields{
 			"persistedBlocks": diff,
 			"persistedKeys":   persisted,