code review changes and cleanup

Author: Angith

collector.go

@@ -4,6 +4,7 @@ package instana
 
 import (
 	"context"
+	"fmt"
 	"sync"
 
 	ot "github.com/opentracing/opentracing-go"
@@ -27,8 +28,8 @@ type Collector struct {
 var _ TracerLogger = (*Collector)(nil)
 
 var (
-	once        sync.Once
-	muCollector sync.Mutex
+	once sync.Once
+	muc  sync.Mutex
 )
 
 // InitCollector creates a new [Collector]
@@ -51,8 +52,8 @@ func InitCollector(opts *Options) TracerLogger {
 			recorder: opts.Recorder,
 		}
 
-		muCollector.Lock()
-		defer muCollector.Unlock()
+		muc.Lock()
+		defer muc.Unlock()
 
 		c = &Collector{
 			t:             tracer,
@@ -65,11 +66,16 @@ func InitCollector(opts *Options) TracerLogger {
 	return c
 }
 
-// GetC return the instance of instana Collector
-func GetC() TracerLogger {
-	muCollector.Lock()
-	defer muCollector.Unlock()
-	return c
+// GetCollector return the instance of instana Collector
+func GetCollector() (TracerLogger, error) {
+	muc.Lock()
+	defer muc.Unlock()
+
+	if _, ok := c.(*Collector); !ok {
+		return c, fmt.Errorf("collector is not initialized")
+	}
+
+	return c, nil
 }
 
 // Extract() returns a SpanContext instance given `format` and `carrier`. It matches [opentracing.Tracer.Extract].

collector_test.go

@@ -15,14 +15,19 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func getInstanaCollector() instana.TracerLogger {
+	c, _ := instana.GetCollector()
+	return c
+}
+
 func Test_Collector_Noop(t *testing.T) {
-	assert.NotNil(t, instana.GetC(), "instana collector should never be nil and be initialized as noop")
+	assert.NotNil(t, getInstanaCollector(), "instana collector should never be nil and be initialized as noop")
 
-	sc, err := instana.GetC().Extract(nil, nil)
+	sc, err := getInstanaCollector().Extract(nil, nil)
 	assert.Nil(t, sc)
 	assert.Error(t, err)
-	assert.Nil(t, instana.GetC().StartSpan(""))
-	assert.Nil(t, instana.GetC().LegacySensor())
+	assert.Nil(t, getInstanaCollector().StartSpan(""))
+	assert.Nil(t, getInstanaCollector().LegacySensor())
 }
 
 func Test_Collector_LegacySensor(t *testing.T) {
@@ -31,7 +36,7 @@ func Test_Collector_LegacySensor(t *testing.T) {
 	s := c.LegacySensor()
 	defer instana.ShutdownCollector()
 
-	assert.NotNil(t, instana.GetC().LegacySensor())
+	assert.NotNil(t, getInstanaCollector().LegacySensor())
 
 	h := instana.TracingHandlerFunc(s, "/{action}", func(w http.ResponseWriter, req *http.Request) {
 		fmt.Fprintln(w, "Ok")
@@ -41,7 +46,7 @@ func Test_Collector_LegacySensor(t *testing.T) {
 
 	h.ServeHTTP(httptest.NewRecorder(), req)
 
-	assert.Len(t, recorder.GetQueuedSpans(), 1, "Instrumentations should still work fine with instana.GetC().LegacySensor()")
+	assert.Len(t, recorder.GetQueuedSpans(), 1, "Instrumentations should still work fine with getInstanaCollector().LegacySensor()")
 }
 
 func Test_Collector_Singleton(t *testing.T) {
@@ -50,17 +55,17 @@ func Test_Collector_Singleton(t *testing.T) {
 
 	defer instana.ShutdownCollector()
 
-	_, ok = instana.GetC().(*instana.Collector)
+	_, ok = getInstanaCollector().(*instana.Collector)
 	assert.False(t, ok, "instana collector is noop before InitCollector is called")
 
 	instana.InitCollector(instana.DefaultOptions())
 
-	instance, ok = instana.GetC().(*instana.Collector)
+	instance, ok = getInstanaCollector().(*instana.Collector)
 	assert.True(t, ok, "instana collector is of type instana.Collector after InitCollector is called")
 
 	instana.InitCollector(instana.DefaultOptions())
 
-	assert.Equal(t, instana.GetC(), instance, "instana collector is singleton and should not be reassigned if InitCollector is called again")
+	assert.Equal(t, getInstanaCollector(), instance, "instana collector is singleton and should not be reassigned if InitCollector is called again")
 }
 
 func Test_Collector_EmbeddedTracer(t *testing.T) {
@@ -98,13 +103,15 @@ func Test_Collector_Logger(t *testing.T) {
 
 	l := &mylogger{}
 
-	instana.GetC().SetLogger(l)
+	c := getInstanaCollector()
+
+	c.SetLogger(l)
 
-	instana.GetC().Debug()
-	instana.GetC().Info()
-	instana.GetC().Warn()
-	instana.GetC().Error()
-	instana.GetC().Error()
+	c.Debug()
+	c.Info()
+	c.Warn()
+	c.Error()
+	c.Error()
 
 	assert.Equal(t, 1, l.counter["debug"])
 	assert.Equal(t, 1, l.counter["info"])

sensor.go

@@ -290,8 +290,8 @@ func ShutdownSensor() {
 // It will also reset the singleton as the next time that instana.InitCollector API is called,
 // collector and sensor will be reinitialized.
 func ShutdownCollector() {
-	muCollector.Lock()
-	defer muCollector.Unlock()
+	muc.Lock()
+	defer muc.Unlock()
 	if sensor != nil {
 		sensor = nil
 	}