Refactor SerializeBucketName to be read-only for struct fields

plugins/outputs/librato/librato.go

@@ -153,8 +153,7 @@ func (l *Librato) Description() string {
 
 func (l *Librato) buildGauges(m telegraf.Metric) ([]*Gauge, error) {
 	gauges := []*Gauge{}
-	serializer := graphite.GraphiteSerializer{Template: l.Template}
-	bucket := serializer.SerializeBucketName(m.Name(), m.Tags())
+	bucket := graphite.SerializeBucketName(m.Name(), m.Tags(), l.Template, "")
 	for fieldName, value := range m.Fields() {
 		gauge := &Gauge{
 			Name:        graphite.InsertField(bucket, fieldName),

plugins/serializers/graphite/graphite.go

@@ -10,22 +10,23 @@ import (
 
 const DEFAULT_TEMPLATE = "host.tags.measurement.field"
 
-var fieldDeleter = strings.NewReplacer(".FIELDNAME", "", "FIELDNAME.", "")
+var (
+	fieldDeleter   = strings.NewReplacer(".FIELDNAME", "", "FIELDNAME.", "")
+	sanitizedChars = strings.NewReplacer("/", "-", "@", "-", "*", "-", " ", "_", "..", ".")
+)
 
 type GraphiteSerializer struct {
 	Prefix   string
 	Template string
 }
 
-var sanitizedChars = strings.NewReplacer("/", "-", "@", "-", "*", "-", " ", "_", "..", ".")
-
-func (s *GraphiteSerializer) Serialize(metric telegraf.Metric) ([]string, error) {
+func (s GraphiteSerializer) Serialize(metric telegraf.Metric) ([]string, error) {
 	out := []string{}
 
 	// Convert UnixNano to Unix timestamps
 	timestamp := metric.UnixNano() / 1000000000
 
-	bucket := s.SerializeBucketName(metric.Name(), metric.Tags())
+	bucket := SerializeBucketName(metric.Name(), metric.Tags(), s.Template, s.Prefix)
 	if bucket == "" {
 		return out, nil
 	}
@@ -51,11 +52,12 @@ func (s *GraphiteSerializer) Serialize(metric telegraf.Metric) ([]string, error)
 // FIELDNAME. It is up to the user to replace this. This is so that
 // SerializeBucketName can be called just once per measurement, rather than
 // once per field. See GraphiteSerializer.InsertField() function.
-func (s *GraphiteSerializer) SerializeBucketName(
+func SerializeBucketName(
 	measurement string,
 	tags map[string]string,
+	template string,
+	prefix string,
 ) string {
-	template := s.Template
 	if template == "" {
 		template = DEFAULT_TEMPLATE
 	}
@@ -97,10 +99,10 @@ func (s *GraphiteSerializer) SerializeBucketName(
 		return ""
 	}
 
-	if s.Prefix == "" {
+	if prefix == "" {
 		return sanitizedChars.Replace(strings.Join(out, "."))
 	}
-	return sanitizedChars.Replace(s.Prefix + "." + strings.Join(out, "."))
+	return sanitizedChars.Replace(prefix + "." + strings.Join(out, "."))
 }
 
 // InsertField takes the bucket string from SerializeBucketName and replaces the

plugins/serializers/graphite/graphite_test.go

@@ -225,8 +225,7 @@ func TestSerializeBucketNameNoHost(t *testing.T) {
 	m, err := telegraf.NewMetric("cpu", tags, fields, now)
 	assert.NoError(t, err)
 
-	s := GraphiteSerializer{}
-	mS := s.SerializeBucketName(m.Name(), m.Tags())
+	mS := SerializeBucketName(m.Name(), m.Tags(), "", "")
 
 	expS := "cpu0.us-west-2.cpu.FIELDNAME"
 	assert.Equal(t, expS, mS)
@@ -240,8 +239,7 @@ func TestSerializeBucketNameHost(t *testing.T) {
 	m, err := telegraf.NewMetric("cpu", defaultTags, fields, now)
 	assert.NoError(t, err)
 
-	s := GraphiteSerializer{}
-	mS := s.SerializeBucketName(m.Name(), m.Tags())
+	mS := SerializeBucketName(m.Name(), m.Tags(), "", "")
 
 	expS := "localhost.cpu0.us-west-2.cpu.FIELDNAME"
 	assert.Equal(t, expS, mS)
@@ -255,8 +253,7 @@ func TestSerializeBucketNamePrefix(t *testing.T) {
 	m, err := telegraf.NewMetric("cpu", defaultTags, fields, now)
 	assert.NoError(t, err)
 
-	s := GraphiteSerializer{Prefix: "prefix"}
-	mS := s.SerializeBucketName(m.Name(), m.Tags())
+	mS := SerializeBucketName(m.Name(), m.Tags(), "", "prefix")
 
 	expS := "prefix.localhost.cpu0.us-west-2.cpu.FIELDNAME"
 	assert.Equal(t, expS, mS)
@@ -270,8 +267,7 @@ func TestTemplate1(t *testing.T) {
 	m, err := telegraf.NewMetric("cpu", defaultTags, fields, now)
 	assert.NoError(t, err)
 
-	s := GraphiteSerializer{Template: template1}
-	mS := s.SerializeBucketName(m.Name(), m.Tags())
+	mS := SerializeBucketName(m.Name(), m.Tags(), template1, "")
 
 	expS := "cpu0.us-west-2.localhost.cpu.FIELDNAME"
 	assert.Equal(t, expS, mS)
@@ -285,8 +281,7 @@ func TestTemplate2(t *testing.T) {
 	m, err := telegraf.NewMetric("cpu", defaultTags, fields, now)
 	assert.NoError(t, err)
 
-	s := GraphiteSerializer{Template: template2}
-	mS := s.SerializeBucketName(m.Name(), m.Tags())
+	mS := SerializeBucketName(m.Name(), m.Tags(), template2, "")
 
 	expS := "localhost.cpu.FIELDNAME"
 	assert.Equal(t, expS, mS)
@@ -300,8 +295,7 @@ func TestTemplate3(t *testing.T) {
 	m, err := telegraf.NewMetric("cpu", defaultTags, fields, now)
 	assert.NoError(t, err)
 
-	s := GraphiteSerializer{Template: template3}
-	mS := s.SerializeBucketName(m.Name(), m.Tags())
+	mS := SerializeBucketName(m.Name(), m.Tags(), template3, "")
 
 	expS := "localhost.cpu0.us-west-2.FIELDNAME"
 	assert.Equal(t, expS, mS)
@@ -315,8 +309,7 @@ func TestTemplate4(t *testing.T) {
 	m, err := telegraf.NewMetric("cpu", defaultTags, fields, now)
 	assert.NoError(t, err)
 
-	s := GraphiteSerializer{Template: template4}
-	mS := s.SerializeBucketName(m.Name(), m.Tags())
+	mS := SerializeBucketName(m.Name(), m.Tags(), template4, "")
 
 	expS := "localhost.cpu0.us-west-2.cpu"
 	assert.Equal(t, expS, mS)
@@ -330,8 +323,7 @@ func TestTemplate5(t *testing.T) {
 	m, err := telegraf.NewMetric("cpu", defaultTags, fields, now)
 	assert.NoError(t, err)
 
-	s := GraphiteSerializer{Template: template5}
-	mS := s.SerializeBucketName(m.Name(), m.Tags())
+	mS := SerializeBucketName(m.Name(), m.Tags(), template5, "")
 
 	expS := "localhost.us-west-2.cpu0.cpu.FIELDNAME"
 	assert.Equal(t, expS, mS)
@@ -345,8 +337,7 @@ func TestTemplate6(t *testing.T) {
 	m, err := telegraf.NewMetric("cpu", defaultTags, fields, now)
 	assert.NoError(t, err)
 
-	s := GraphiteSerializer{Template: template6}
-	mS := s.SerializeBucketName(m.Name(), m.Tags())
+	mS := SerializeBucketName(m.Name(), m.Tags(), template6, "")
 
 	expS := "localhost.cpu0.us-west-2.cpu.FIELDNAME"
 	assert.Equal(t, expS, mS)