From 51626a137161bb0dc7d01908013c6797fb82e1cb Mon Sep 17 00:00:00 2001
From: "Sascha L. Teichmann" <sascha.teichmann@intevation.de>
Date: Wed, 17 Sep 2014 17:34:03 +0200
Subject: [PATCH] Do nort send notifications if nothing changed.

---
 cmd/mtredisalize/changetracker.go | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/cmd/mtredisalize/changetracker.go b/cmd/mtredisalize/changetracker.go
index 3b0af4d..9f90d86 100644
--- a/cmd/mtredisalize/changetracker.go
+++ b/cmd/mtredisalize/changetracker.go
@@ -31,7 +31,6 @@ func (ct *ChangeTracker) BlockChanged(key []byte) {
 		log.Printf("decoding key failed: %s", err)
 		return
 	}
-	log.Printf("changed block: %v", coord)
 	ct.mutex.Lock()
 	ct.changes[quantizedXZ{X: coord.X / 16, Z: coord.Z / 16}] = true
 	ct.mutex.Unlock()
@@ -40,10 +39,17 @@ func (ct *ChangeTracker) BlockChanged(key []byte) {
 func (ct *ChangeTracker) FlushChanges(url string) (err error) {
 	log.Println("change flush triggered")
 	var oldChanges map[quantizedXZ]bool
+	var sendNotification bool
 	ct.mutex.Lock()
 	oldChanges = ct.changes
-	ct.changes = make(map[quantizedXZ]bool)
+	if len(oldChanges) > 0 {
+		sendNotification = true
+		ct.changes = make(map[quantizedXZ]bool)
+	}
 	ct.mutex.Unlock()
+	if !sendNotification {
+		return
+	}
 	go func() {
 		changes := make([]quantizedXZ, len(oldChanges))
 		i := 0