use metadata.Metadata (#8)

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

metrics/noop.go

@@ -2,6 +2,8 @@ package metrics
 
 import (
 	"time"
+
+	"github.com/unistack-org/micro/v3/metadata"
 )
 
 // NoopReporter is an noop implementation of Reporter:
@@ -25,17 +27,17 @@ func (r *noopReporter) Init(opts ...Option) error {
 }
 
 // Count implements the Reporter interface Count method:
-func (r *noopReporter) Count(metricName string, value int64, tags Tags) error {
+func (r *noopReporter) Count(metricName string, value int64, md metadata.Metadata) error {
 	return nil
 }
 
 // Gauge implements the Reporter interface Gauge method:
-func (r *noopReporter) Gauge(metricName string, value float64, tags Tags) error {
+func (r *noopReporter) Gauge(metricName string, value float64, md metadata.Metadata) error {
 	return nil
 }
 
 // Timing implements the Reporter interface Timing method:
-func (r *noopReporter) Timing(metricName string, value time.Duration, tags Tags) error {
+func (r *noopReporter) Timing(metricName string, value time.Duration, md metadata.Metadata) error {
 	return nil
 }
 

metrics/options.go

@@ -1,6 +1,9 @@
 package metrics
 
-import "github.com/unistack-org/micro/v3/logger"
+import (
+	"github.com/unistack-org/micro/v3/logger"
+	"github.com/unistack-org/micro/v3/metadata"
+)
 
 var (
 	// The Prometheus metrics will be made available on this port:
@@ -18,7 +21,7 @@ type Option func(*Options)
 type Options struct {
 	Address          string
 	Path             string
-	DefaultTags      Tags
+	DefaultTags      metadata.Metadata
 	TimingObjectives map[float64]float64
 	Logger           logger.Logger
 }
@@ -27,7 +30,7 @@ type Options struct {
 func NewOptions(opt ...Option) Options {
 	opts := Options{
 		Address:          defaultPrometheusListenAddress,
-		DefaultTags:      make(Tags),
+		DefaultTags:      metadata.New(2),
 		Path:             defaultPath,
 		TimingObjectives: defaultTimingObjectives,
 	}
@@ -54,9 +57,9 @@ func Address(value string) Option {
 }
 
 // DefaultTags will be added to every metric:
-func DefaultTags(value Tags) Option {
+func DefaultTags(md metadata.Metadata) Option {
 	return func(o *Options) {
-		o.DefaultTags = value
+		o.DefaultTags = metadata.Copy(md)
 	}
 }
 

metrics/reporter.go

@@ -1,10 +1,11 @@
 // Package metrics is for instrumentation and debugging
 package metrics
 
-import "time"
+import (
+	"time"
 
-// Tags is a map of fields to add to a metric:
-type Tags map[string]string
+	"github.com/unistack-org/micro/v3/metadata"
+)
 
 var (
 	DefaultReporter Reporter = NewReporter()
@@ -13,8 +14,8 @@ var (
 // Reporter is an interface for collecting and instrumenting metrics
 type Reporter interface {
 	Init(...Option) error
-	Count(id string, value int64, tags Tags) error
-	Gauge(id string, value float64, tags Tags) error
-	Timing(id string, value time.Duration, tags Tags) error
+	Count(id string, value int64, md metadata.Metadata) error
+	Gauge(id string, value float64, md metadata.Metadata) error
+	Timing(id string, value time.Duration, md metadata.Metadata) error
 	Options() Options
 }

metrics/wrapper/metrics_wrapper.go

@@ -1,10 +1,10 @@
 package wrapper
 
 import (
+	"context"
 	"time"
 
-	"context"
-
+	"github.com/unistack-org/micro/v3/metadata"
 	"github.com/unistack-org/micro/v3/metrics"
 	"github.com/unistack-org/micro/v3/server"
 )
@@ -26,9 +26,8 @@ func (w *Wrapper) HandlerFunc(handlerFunction server.HandlerFunc) server.Handler
 	return func(ctx context.Context, req server.Request, rsp interface{}) error {
 
 		// Build some tags to describe the call:
-		tags := metrics.Tags{
-			"method": req.Method(),
-		}
+		tags := metadata.New(2)
+		tags.Set("method", req.Method())
 
 		// Start the clock:
 		callTime := time.Now()