From 948bfb291fec06497718a770998f422c6662f64e Mon Sep 17 00:00:00 2001
From: Julian Kornberger <jk+github@digineo.de>
Date: Mon, 28 Mar 2016 15:46:22 +0200
Subject: [PATCH] Optimize bulk insertion to InfluxDB

---
 stats_db.go | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/stats_db.go b/stats_db.go
index 70a4144..ab889b4 100644
--- a/stats_db.go
+++ b/stats_db.go
@@ -10,7 +10,7 @@ import (
 )
 
 const (
-	batchWaiting = time.Second * 5
+	batchDuration = time.Second * 5
 )
 
 type StatsDb struct {
@@ -106,44 +106,46 @@ func (c *StatsDb) worker() {
 
 	var bp client.BatchPoints
 	var err error
-	var dirty, closed bool
-	var batchStarted time.Time
+	var writeNow, closed bool
+	timer := time.NewTimer(batchDuration)
 
 	for !closed {
-		// create new batch points?
-		if bp == nil {
-			if bp, err = client.NewBatchPoints(bpConfig); err != nil {
-				panic(err)
-			}
-		}
 
 		// wait for new points
 		select {
 		case point, ok := <-c.points:
 			if ok {
-				bp.AddPoint(point)
-				if !dirty {
-					batchStarted = time.Now()
-					dirty = true
+				if bp == nil {
+					// create new batch
+					timer.Reset(batchDuration)
+					if bp, err = client.NewBatchPoints(bpConfig); err != nil {
+						panic(err)
+					}
 				}
+				bp.AddPoint(point)
 			} else {
 				closed = true
 			}
-		case <-time.After(time.Second):
-			// nothing
+		case <-timer.C:
+			if bp == nil {
+				timer.Reset(batchDuration)
+			} else {
+				writeNow = true
+			}
 		}
 
 		// write batch now?
-		if (dirty && batchStarted.Add(batchWaiting).Before(time.Now())) || closed {
+		if bp != nil && (writeNow || closed) {
 			log.Println("saving", len(bp.Points()), "points")
 
 			if err = c.client.Write(bp); err != nil {
 				panic(err)
 			}
-			dirty = false
+			writeNow = false
 			bp = nil
 		}
 	}
 
+	timer.Stop()
 	c.wg.Done()
 }