issue-16: Create multiple copies of an event handler closes #16

README.md

@@ -1,6 +1,6 @@
 # Bell
 
-[![GoDoc](https://pkg.go.dev/badge/github.com/nuttech/bell?status.svg)](https://pkg.go.dev/github.com/nuttech/bell?tab=doc)
+[![GoDoc](https://pkg.go.dev/badge/github.com/nuttech/bell?status.svg)](https://pkg.go.dev/github.com/nuttech/bell/v2?tab=doc)
 [![Release](https://img.shields.io/github/release/nuttech/bell.svg?style=flat)](https://github.com/nuttech/bell/releases)
 [![codecov](https://codecov.io/gh/NUTtech/bell/branch/master/graph/badge.svg?token=3TMnbQkEny)](https://codecov.io/gh/NUTtech/bell)
 [![Tests](https://github.com/NUTtech/bell/actions/workflows/tests.yml/badge.svg)](https://github.com/NUTtech/bell/actions/workflows/tests.yml)
@@ -59,16 +59,22 @@ bell.Listen("event_name", func(message bell.Message) {
 })
 ```
 
+You can add a handler with multiple copies for parallel event processing.
+
+```go
+bell.ListenN("event_name", func(msg bell.Message) { fmt.Println(msg) }, 42)
+```
+
 ### Calling an event
 
 This code call event. Activating handlers, who subscribed on "event_name" event
 
 ```go
-bell.Call("event_name", "some data")
+bell.Ring("event_name", "some data")
 
-bell.Call("event_name", 1) // int
+bell.Ring("event_name", 1) // int
 
-bell.Call("event_name", false) // bool
+bell.Ring("event_name", false) // bool
 ```
 
 If you passing struct type of data:
@@ -77,7 +83,7 @@ If you passing struct type of data:
 type userStruct struct {
 	Name string
 }
-bell.Call("event_name", userStruct{Name: "Jon"})
+bell.Ring("event_name", userStruct{Name: "Jon"})
 ```
 
 Then parsing the data in the handler may look like this:

bell.go

@@ -41,31 +41,39 @@ func (e *Events) Queue(size uint) *Events {
 	return e
 }
 
-// Listen Subscribe on event where
+// ListenN Subscribe on event where
 // event - the event name,
 // handlerFunc - handler function
-func (e *Events) Listen(event string, handlerFunc func(message Message)) {
+// copiesCount - count handlers copies run
+func (e *Events) ListenN(event string, handlerFunc func(message Message), copiesCount uint) {
 	e.Lock()
 	defer e.Unlock()
 
 	channel := make(chan Message, e.queueSize)
 
-	go func(c chan Message, wg *sync.WaitGroup) {
-		for {
-			message, ok := <-c
-			if !ok {
-				break
+	for i := uint(0); i < copiesCount; i++ {
+		go func(c chan Message, wg *sync.WaitGroup) {
+			for {
+				message, ok := <-c
+				if !ok {
+					break
+				}
+				handlerFunc(message)
+				wg.Done()
 			}
-
-			handlerFunc(message)
-
-			wg.Done()
-		}
-	}(channel, &e.wg)
+		}(channel, &e.wg)
+	}
 
 	e.channels[event] = append(e.channels[event], channel)
 }
 
+// Listen Subscribe on event where
+// event - the event name,
+// handlerFunc - handler function
+func (e *Events) Listen(event string, handlerFunc func(message Message)) {
+	e.ListenN(event, handlerFunc, 1)
+}
+
 // Ring Call event there
 // event - event name
 // message - data that will be passed to the event handler
@@ -142,6 +150,14 @@ func (e *Events) Wait() {
 // globalState store of global event handlers
 var globalState = New()
 
+// ListenN Subscribe on event where
+// event - the event name,
+// handlerFunc - handler function
+// copiesCount - count handlers copies run
+func ListenN(event string, handlerFunc func(message Message), copiesCount uint) {
+	globalState.ListenN(event, handlerFunc, copiesCount)
+}
+
 // Listen Subscribe on event where
 // event - the event name,
 // handlerFunc - handler function

bell_test.go

@@ -19,6 +19,27 @@ func resetSystem() {
 	globalState = &Events{channels: map[string][]chan Message{}}
 }
 
+// TestListenN checking the function of adding multiple copies of event listeners
+func TestListenN(t *testing.T) {
+	resetSystem()
+	defer resetSystem()
+
+	eventName := "event"
+	var wasRunning int32
+	ListenN(eventName, func(Message) { atomic.AddInt32(&wasRunning, 1) }, 3)
+
+	require.NoError(t, Ring(eventName, nil))
+	Wait()
+
+	assert.Equal(t, int32(1), wasRunning)
+
+	require.NoError(t, Ring(eventName, nil))
+	require.NoError(t, Ring(eventName, nil))
+	Wait()
+
+	assert.Equal(t, int32(3), wasRunning)
+}
+
 // TestListen Testing the function of adding event listeners
 func TestListen(t *testing.T) {
 	resetSystem()