meter: rework meter interface

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

meter/options.go

@@ -8,12 +8,12 @@ import (
 )
 
 var (
-	// The Prometheus metrics will be made available on this port:
-	defaultPrometheusListenAddress = ":9000"
-	// This is the endpoint where the Prometheus metrics will be made available ("/metrics" is the default with Prometheus):
-	defaultPath = "/metrics"
+	// The Meter data will be made available on this port
+	DefaultAddress = ":9090"
+	// This is the endpoint where the Meter data will be made available ("/metrics" is the default)
+	DefaultPath = "/metrics"
 	// timingObjectives is the default spread of stats we maintain for timings / histograms:
-	defaultTimingObjectives = map[float64]float64{0.0: 0, 0.5: 0.05, 0.75: 0.04, 0.90: 0.03, 0.95: 0.02, 0.98: 0.001, 1: 0}
+	//defaultTimingObjectives = map[float64]float64{0.0: 0, 0.5: 0.05, 0.75: 0.04, 0.90: 0.03, 0.95: 0.02, 0.98: 0.001, 1: 0}
 )
 
 // Option powers the configuration for metrics implementations:
@@ -21,22 +21,23 @@ type Option func(*Options)
 
 // Options for metrics implementations:
 type Options struct {
-	Address          string
-	Path             string
-	DefaultTags      metadata.Metadata
-	TimingObjectives map[float64]float64
-	Logger           logger.Logger
-	Context          context.Context
+	Address  string
+	Path     string
+	Metadata metadata.Metadata
+	//TimingObjectives map[float64]float64
+	Logger  logger.Logger
+	Context context.Context
 }
 
 // NewOptions prepares a set of options:
 func NewOptions(opt ...Option) Options {
 	opts := Options{
-		Address:          defaultPrometheusListenAddress,
-		DefaultTags:      metadata.New(2),
-		Path:             defaultPath,
-		TimingObjectives: defaultTimingObjectives,
-		Context:          context.Background(),
+		Address:  DefaultAddress,
+		Metadata: metadata.New(3), // 3 elements contains service name, version and id
+		Path:     DefaultPath,
+		//	TimingObjectives: defaultTimingObjectives,
+		Context: context.Background(),
+		Logger:  logger.DefaultLogger,
 	}
 
 	for _, o := range opt {
@@ -53,33 +54,35 @@ func Context(ctx context.Context) Option {
 	}
 }
 
-// Path used to serve metrics over HTTP:
+// Path used to serve metrics over HTTP
 func Path(value string) Option {
 	return func(o *Options) {
 		o.Path = value
 	}
 }
 
-// Address is the listen address to serve metrics on:
+// Address is the listen address to serve metrics
 func Address(value string) Option {
 	return func(o *Options) {
 		o.Address = value
 	}
 }
 
-// DefaultTags will be added to every metric:
-func DefaultTags(md metadata.Metadata) Option {
+// Metadata will be added to every metric
+func Metadata(md metadata.Metadata) Option {
 	return func(o *Options) {
-		o.DefaultTags = metadata.Copy(md)
+		o.Metadata = metadata.Copy(md)
 	}
 }
 
+/*
 // TimingObjectives defines the desired spread of statistics for histogram / timing metrics:
 func TimingObjectives(value map[float64]float64) Option {
 	return func(o *Options) {
 		o.TimingObjectives = value
 	}
 }
+*/
 
 // Logger sets the logger
 func Logger(l logger.Logger) Option {