From 4b3dba42184fd87186b63cb6c509f5ce17f34024 Mon Sep 17 00:00:00 2001
From: Maksym Pavlenko <pavlenko.maksym@gmail.com>
Date: Sat, 6 Apr 2019 12:54:09 -0700
Subject: [PATCH] Write feed only if updated

---
 pkg/feeds/feeds.go | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/pkg/feeds/feeds.go b/pkg/feeds/feeds.go
index 54aa9fe..db2e9fe 100644
--- a/pkg/feeds/feeds.go
+++ b/pkg/feeds/feeds.go
@@ -157,14 +157,18 @@ func (s *Service) BuildFeed(hashID string) ([]byte, error) {
 
 	log.Infof("building new feed %q", hashID)
 
+	oldLastID := feed.LastID
+
 	if err := builder.Build(feed); err != nil {
 		log.WithError(err).WithField("feed_id", hashID).Error("failed to build feed")
 		return nil, err
 	}
 
-	if err := s.storage.UpdateFeed(feed); err != nil {
-		log.WithError(err).WithField("feed_id", hashID).Error("failed to save feed")
-		return nil, err
+	if oldLastID != feed.LastID {
+		if err := s.storage.UpdateFeed(feed); err != nil {
+			log.WithError(err).WithField("feed_id", hashID).Error("failed to save feed")
+			return nil, err
+		}
 	}
 
 	podcast, err := s.buildPodcast(feed)