Feature: non-blocking tracer, changed license (#57)

* refactor tracer, introduce worker to avoid un-blocker trace strategy

* fixed unit test and refactor dockerFile

* buffered events chan

* refactor yaml API core, initial web hook tracing implementations

* added banner

* changed license from GPL 3 to MIT

* Edit readme

tracer/tracer.go

@@ -5,8 +5,11 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
+	log "github.com/sirupsen/logrus"
 )
 
+const Workers = 5
+
 type Event struct {
 	DateTime        string
 	RemoteAddr      string
@@ -32,7 +35,7 @@ type Event struct {
 
 type (
 	Protocol int
-	Status int
+	Status   int
 )
 
 const (
@@ -63,7 +66,8 @@ type Tracer interface {
 }
 
 type tracer struct {
-	strategy Strategy
+	strategy   Strategy
+	eventsChan chan Event
 }
 
 var (
@@ -90,17 +94,32 @@ var (
 )
 
 func Init(strategy Strategy) *tracer {
-	return &tracer{
-		strategy: strategy,
+	tracer := &tracer{
+		strategy:   strategy,
+		eventsChan: make(chan Event, Workers),
 	}
+
+	for i := 0; i < Workers; i++ {
+		go func(i int) {
+			log.Debug("Init trace worker: ", i)
+			for event := range tracer.eventsChan {
+				tracer.strategy(event)
+			}
+		}(i)
+	}
+
+	return tracer
+}
+
+func (tracer *tracer) setStrategy(strategy Strategy) {
+	tracer.strategy = strategy
 }
 
 func (tracer *tracer) TraceEvent(event Event) {
 	event.DateTime = time.Now().UTC().Format(time.RFC3339)
 
-	tracer.strategy(event)
+	tracer.eventsChan <- event
 
-	//Openmetrics
 	eventsTotal.Inc()
 
 	switch event.Protocol {

tracer/tracer_test.go

@@ -1,8 +1,10 @@
 package tracer
 
 import (
-	"github.com/stretchr/testify/assert"
+	"sync"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestInit(t *testing.T) {
@@ -15,23 +17,56 @@ func TestInit(t *testing.T) {
 
 func TestTraceEvent(t *testing.T) {
 	eventCalled := Event{}
+	var wg sync.WaitGroup
 
 	mockStrategy := func(event Event) {
+		defer wg.Done()
+
 		eventCalled = event
 	}
 
 	tracer := Init(mockStrategy)
 
+	wg.Add(1)
 	tracer.TraceEvent(Event{
 		ID:       "mockID",
 		Protocol: HTTP.String(),
 		Status:   Stateless.String(),
 	})
+	wg.Wait()
 
 	assert.NotNil(t, eventCalled.ID)
-	assert.Equal(t, eventCalled.ID, "mockID")
-	assert.Equal(t, eventCalled.Protocol, HTTP.String())
-	assert.Equal(t, eventCalled.Status, Stateless.String())
+	assert.Equal(t, "mockID", eventCalled.ID)
+	assert.Equal(t, HTTP.String(), eventCalled.Protocol)
+	assert.Equal(t, Stateless.String(), eventCalled.Status)
+}
+
+func TestSetStrategy(t *testing.T) {
+	eventCalled := Event{}
+	var wg sync.WaitGroup
+
+	mockStrategy := func(event Event) {
+		defer wg.Done()
+
+		eventCalled = event
+	}
+
+	tracer := Init(mockStrategy)
+
+	tracer.setStrategy(mockStrategy)
+
+	wg.Add(1)
+	tracer.TraceEvent(Event{
+		ID:       "mockID",
+		Protocol: HTTP.String(),
+		Status:   Stateless.String(),
+	})
+	wg.Wait()
+
+	assert.NotNil(t, eventCalled.ID)
+	assert.Equal(t, "mockID", eventCalled.ID)
+	assert.Equal(t, HTTP.String(), eventCalled.Protocol)
+	assert.Equal(t, Stateless.String(), eventCalled.Status)
 }
 
 func TestStringStatus(t *testing.T) {