meter: rework labels

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

meter/meter.go

@@ -3,6 +3,7 @@ package meter
 
 import (
 	"io"
+	"reflect"
 	"sort"
 	"time"
 )
@@ -76,66 +77,36 @@ type Summary interface {
 	UpdateDuration(time.Time)
 }
 
-// Labels holds the metrics labels with k, v
-type Labels struct {
-	keys []string
-	vals []string
+type byKey []string
+
+func (k byKey) Len() int           { return len(k) / 2 }
+func (k byKey) Less(i, j int) bool { return k[i*2] < k[j*2] }
+func (k byKey) Swap(i, j int) {
+	k[i*2], k[i*2+1], k[j*2], k[j*2+1] = k[j*2], k[j*2+1], k[i*2], k[i*2+1]
 }
 
-// Append adds labels to label set
-func (ls Labels) Append(nls Labels) Labels {
-	for n := range nls.keys {
-		ls.keys = append(ls.keys, nls.keys[n])
-		ls.vals = append(ls.vals, nls.vals[n])
+func Sort(slice *[]string) {
+	bk := byKey(*slice)
+	if bk.Len() <= 1 {
+		return
 	}
-	return ls
-}
-
-// Len returns number of labels
-func (ls Labels) Len() int {
-	return len(ls.keys)
-}
-
-type labels Labels
-
-func (ls labels) Len() int {
-	return len(ls.keys)
-}
-
-func (ls labels) Sort() {
-	sort.Sort(ls)
-}
-
-func (ls labels) Swap(i, j int) {
-	ls.keys[i], ls.keys[j] = ls.keys[j], ls.keys[i]
-	ls.vals[i], ls.vals[j] = ls.vals[j], ls.vals[i]
-}
-
-func (ls labels) Less(i, j int) bool {
-	return ls.keys[i] < ls.keys[j]
-}
-
-// LabelIter holds the
-type LabelIter struct {
-	labels Labels
-	cnt    int
-	cur    int
-}
-
-// Iter returns labels iterator
-func (ls Labels) Iter() *LabelIter {
-	labels(ls).Sort()
-	return &LabelIter{labels: ls, cnt: len(ls.keys)}
-}
-
-// Next advance itarator to new pos
-func (iter *LabelIter) Next(k, v *string) bool {
-	if iter.cur+1 > iter.cnt {
-		return false
+	sort.Sort(bk)
+	v := reflect.ValueOf(slice).Elem()
+	cnt := 0
+	key := 0
+	val := 1
+	for key < v.Len() {
+		if len(bk) > key+2 && bk[key] == bk[key+2] {
+			key += 2
+			val += 2
+			continue
+		}
+		v.Index(cnt).Set(v.Index(key))
+		cnt++
+		v.Index(cnt).Set(v.Index(val))
+		cnt++
+		key += 2
+		val += 2
 	}
-
-	*k = iter.labels.keys[iter.cur]
-	*v = iter.labels.vals[iter.cur]
-	iter.cur++
-	return true
+	v.SetLen(cnt)
 }

meter/meter_test.go

@@ -10,46 +10,15 @@ func TestNoopMeter(t *testing.T) {
 		t.Fatalf("invalid options parsing: %v", m.Options())
 	}
 
-	cnt := m.Counter("counter", Label("server", "noop"))
+	cnt := m.Counter("counter", Labels("server", "noop"))
 	cnt.Inc()
 }
 
-func TestLabelsAppend(t *testing.T) {
-	var ls Labels
-	ls.keys = []string{"type", "server"}
-	ls.vals = []string{"noop", "http"}
+func TestLabelsSort(t *testing.T) {
+	ls := []string{"server", "http", "register", "mdns", "broker", "broker1", "broker", "broker2", "server", "tcp"}
+	Sort(&ls)
 
-	var nls Labels
-	nls.keys = []string{"register"}
-	nls.vals = []string{"gossip"}
-	ls = ls.Append(nls)
-
-	//ls.Sort()
-
-	if ls.keys[0] != "type" || ls.vals[0] != "noop" {
-		t.Fatalf("append error: %v", ls)
-	}
-}
-
-func TestIterator(t *testing.T) {
-	options := NewOptions(
-		Label("name", "svc1"),
-		Label("version", "0.0.1"),
-		Label("id", "12345"),
-		Label("type", "noop"),
-		Label("server", "http"),
-		Label("register", "gossip"),
-		Label("aa", "kk"),
-		Label("zz", "kk"),
-	)
-
-	iter := options.Labels.Iter()
-	var k, v string
-	cnt := 0
-	for iter.Next(&k, &v) {
-		if cnt == 4 && (k != "server" || v != "http") {
-			t.Fatalf("iter error: %s != %s || %s != %s", k, "server", v, "http")
-		}
-		cnt++
+	if ls[0] != "broker" || ls[1] != "broker2" {
+		t.Fatalf("sort error: %v", ls)
 	}
 }

meter/noop.go

@@ -107,7 +107,7 @@ func (r *noopMeter) String() string {
 }
 
 type noopCounter struct {
-	labels Labels
+	labels []string
 }
 
 func (r *noopCounter) Add(int) {
@@ -131,7 +131,7 @@ func (r *noopCounter) Set(uint64) {
 }
 
 type noopFloatCounter struct {
-	labels Labels
+	labels []string
 }
 
 func (r *noopFloatCounter) Add(float64) {
@@ -151,7 +151,7 @@ func (r *noopFloatCounter) Sub(float64) {
 }
 
 type noopGauge struct {
-	labels Labels
+	labels []string
 }
 
 func (r *noopGauge) Get() float64 {
@@ -159,7 +159,7 @@ func (r *noopGauge) Get() float64 {
 }
 
 type noopSummary struct {
-	labels Labels
+	labels []string
 }
 
 func (r *noopSummary) Update(float64) {
@@ -171,7 +171,7 @@ func (r *noopSummary) UpdateDuration(time.Time) {
 }
 
 type noopHistogram struct {
-	labels Labels
+	labels []string
 }
 
 func (r *noopHistogram) Reset() {

meter/options.go

@@ -26,7 +26,7 @@ type Options struct {
 	// LabelPrefix holds the prefix for all labels
 	LabelPrefix string
 	// Labels holds the default labels
-	Labels Labels
+	Labels []string
 	// WriteProcessMetrics flag to write process metrics
 	WriteProcessMetrics bool
 	// WriteFDMetrics flag to write fd metrics
@@ -88,11 +88,9 @@ func Logger(l logger.Logger) Option {
 	}
 }
 
-// Label sets the label
-func Label(key, val string) Option {
+func Labels(ls ...string) Option {
 	return func(o *Options) {
-		o.Labels.keys = append(o.Labels.keys, key)
-		o.Labels.vals = append(o.Labels.vals, val)
+		o.Labels = ls
 	}
 }