From 7fe84a1313ba670a77c7c926c2254e59e01867af Mon Sep 17 00:00:00 2001
From: Maksadbek <a.maksadbek@gmail.com>
Date: Fri, 22 Jul 2016 12:17:16 +0300
Subject: [PATCH] mean calculation, covered with tests

---
 plugins/outputs/influxdb/influxdb.go      | 33 ++++++++++++----
 plugins/outputs/influxdb/influxdb_test.go | 47 +++++++++++++++++------
 2 files changed, 61 insertions(+), 19 deletions(-)

diff --git a/plugins/outputs/influxdb/influxdb.go b/plugins/outputs/influxdb/influxdb.go
index 53ae4f4cc..7183977b7 100644
--- a/plugins/outputs/influxdb/influxdb.go
+++ b/plugins/outputs/influxdb/influxdb.go
@@ -192,7 +192,10 @@ func (i *InfluxDB) Write(metrics []telegraf.Metric) error {
 		return err
 	}
 
-	i.Downsampler.Add(metrics)
+	err = i.Downsampler.Add(metrics...)
+	if err != nil {
+		return err
+	}
 
 	for _, metric := range metrics {
 		bp.AddPoint(metric.Point())
@@ -243,7 +246,7 @@ type Downsampling struct {
 
 type Aggregation map[string]string
 
-func (d *Downsampling) Add(metrics []telegraf.Metric) error {
+func (d *Downsampling) Add(metrics ...telegraf.Metric) error {
 	d.Lock()
 	d.Metrics = append(d.Metrics, metrics...)
 	d.Unlock()
@@ -256,7 +259,6 @@ func (d *Downsampling) Run() {
 		case <-time.After(d.TimeRange):
 			aggrData := d.Aggregate()
 			fmt.Printf("%+v\n", aggrData)
-
 		}
 	}
 }
@@ -280,7 +282,11 @@ func (d *Downsampling) Mean(fields ...string) (telegraf.Metric, error) {
 
 	d.RLock()
 	for _, metric := range d.Metrics {
-		for fieldName, value := range metric.Fields() {
+		for _, fieldName := range fields {
+			value, ok := metric.Fields()[fieldName]
+			if !ok {
+				continue
+			}
 			oldVal := sums[fieldName]
 			switch value := value.(type) {
 			case int:
@@ -288,7 +294,7 @@ func (d *Downsampling) Mean(fields ...string) (telegraf.Metric, error) {
 			case int32:
 				sums[fieldName] = oldVal.(int32) + value
 			case int64:
-				sums[fieldName] = oldVal.(int64) + value
+				sums[fieldName] = oldVal.(int) + int(value)
 			case float32:
 				sums[fieldName] = oldVal.(float32) + value
 			case float64:
@@ -301,13 +307,26 @@ func (d *Downsampling) Mean(fields ...string) (telegraf.Metric, error) {
 	d.RUnlock()
 
 	for i := range sums {
-		sums[i] = sums[i] / size
+		switch value := sums[i].(type) {
+		case int:
+			sums[i] = value / int(size)
+		case int32:
+			sums[i] = value / int32(size)
+		case int64:
+			sums[i] = value / int64(size)
+		case float32:
+			sums[i] = value / float32(size)
+		case float64:
+			sums[i] = value / float64(size)
+		default:
+			continue
+		}
 	}
 
 	aggrMetric, err := telegraf.NewMetric(
 		d.Name,
 		map[string]string{},
-		fields,
+		sums,
 		time.Now(),
 	)
 	return aggrMetric, err
diff --git a/plugins/outputs/influxdb/influxdb_test.go b/plugins/outputs/influxdb/influxdb_test.go
index 8d5288ede..d1f1acb56 100644
--- a/plugins/outputs/influxdb/influxdb_test.go
+++ b/plugins/outputs/influxdb/influxdb_test.go
@@ -7,6 +7,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/testutil"
 
 	"github.com/stretchr/testify/require"
@@ -41,19 +42,41 @@ func TestHTTPInflux(t *testing.T) {
 	require.NoError(t, err)
 }
 
-/*
-func TestInfluxDS(t *testing.T) {
-	downsampler := &DS{
-		TimeRange: time.Minute,
-	}
-	i := InfluxDB{
-		URLs: []string{"udp://localhost:8089"},
-		DS:   downsampler,
-	}
+func TestDownsampling_mean(t *testing.T) {
+	ds := &Downsampling{}
+	metricA, err := telegraf.NewMetric(
+		"earthshaker",
+		map[string]string{},
+		map[string]interface{}{
+			"damage":       "high",
+			"agility":      12,
+			"strength":     120,
+			"intelligence": 60,
+		},
+		time.Now(),
+	)
 
-	err := i.Connect()
+	metricB, err := telegraf.NewMetric(
+		"sven",
+		map[string]string{},
+		map[string]interface{}{
+			"strength":     80,
+			"intelligence": 140,
+		},
+		time.Now(),
+	)
 	require.NoError(t, err)
 
-	i.DS.Add(testutil.MockMetrics())
+	err = ds.Add(metricA)
+	require.NoError(t, err)
+
+	err = ds.Add(metricB)
+	require.NoError(t, err)
+
+	aggr, err := ds.Mean("strength", "intelligence", "power")
+	require.NoError(t, err)
+
+	require.Equal(t, int64(100), aggr.Fields()["strength"])
+	require.Equal(t, int64(100), aggr.Fields()["intelligence"])
+	require.Equal(t, int64(0), aggr.Fields()["power"])
 }
-*/