Instantiated OTEL Metrics

Signed-off-by: Wise-Wizard <saransh.shankar@gmail.com>

pkg/metrics/factory.go

@@ -16,7 +16,11 @@
 package metrics
 
 import (
+	"context"
 	"time"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/metric"
 )
 
 // NSOptions defines the name and tags map associated with a factory namespace
@@ -48,6 +52,47 @@ type HistogramOptions struct {
 	Buckets []float64
 }
 
+type otelFactory struct {
+	meter metric.Meter
+}
+
+func NewOTelFactory() Factory {
+	return &otelFactory{
+		meter: otel.Meter("jaeger-V2"),
+	}
+}
+
+func (f *otelFactory) Counter(options Options) Counter {
+	counter, _ := f.meter.Int64Counter(options.Name)
+	attrs := getAttributes(options.Tags)
+	return &otelCounter{
+		counter: counter,
+		ctx:     context.Background(),
+		attrs:   attrs,
+	}
+}
+
+func (f *otelFactory) Timer(options TimerOptions) Timer {
+	// Implement the OTEL Timer
+	return NullTimer
+}
+
+func (f *otelFactory) Gauge(options Options) Gauge {
+	// Implement the OTEL Gauge
+	return NullGauge
+}
+
+func (f *otelFactory) Histogram(options HistogramOptions) Histogram {
+	// Implement the OTEL Histogram
+	return NullHistogram
+}
+
+func (f *otelFactory) Namespace(scope NSOptions) Factory {
+	return &otelFactory{
+		meter: otel.Meter(scope.Name),
+	}
+}
+
 // Factory creates new metrics
 type Factory interface {
 	Counter(metric Options) Counter

pkg/metrics/otelCounter.go

@@ -0,0 +1,28 @@
+package metrics
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+)
+
+// otelCounter is a wrapper around otel.Counter
+
+type otelCounter struct {
+	counter   metric.Int64Counter
+	ctx       context.Context
+	attrs     []metric.AddOption
+}
+
+func (c *otelCounter) Inc(value int64) {
+	c.counter.Add(c.ctx, value, c.attrs...)
+}
+
+func getAttributes(tags map[string]string) []metric.AddOption {
+	var options []metric.AddOption
+	for k, v := range tags {
+		options = append(options, metric.WithAttributes(attribute.String(k, v)))
+	}
+	return options
+}