chore(examples/event): add memory and rename Message to Event (#1282)

* chore(examples/event): add memory and rename Message to Event

examples/event/event/event.go

@@ -2,16 +2,15 @@ package event
 
 import "context"
 
-type Message interface {
+type Event interface {
 	Key() string
 	Value() []byte
-	Header() map[string]string
 }
 
-type Handler func(context.Context, Message) error
+type Handler func(context.Context, Event) error
 
 type Sender interface {
-	Send(ctx context.Context, msg Message) error
+	Send(ctx context.Context, msg Event) error
 	Close() error
 }
 

examples/event/kafka/kafka.go

@@ -4,35 +4,30 @@ import (
 	"context"
 	"github.com/go-kratos/kratos/examples/event/event"
 	"github.com/segmentio/kafka-go"
-	"github.com/segmentio/kafka-go/protocol"
 	"log"
 )
 
 var _ event.Sender = (*kafkaSender)(nil)
 var _ event.Receiver = (*kafkaReceiver)(nil)
-var _ event.Message = (*Message)(nil)
+var _ event.Event = (*Message)(nil)
 
 type Message struct {
-	key    string
-	value  []byte
-	header map[string]string
+	key   string
+	value []byte
 }
 
 func (m *Message) Key() string {
 	return m.key
 }
+
 func (m *Message) Value() []byte {
 	return m.value
 }
-func (m *Message) Header() map[string]string {
-	return m.header
-}
 
-func NewMessage(key string, value []byte, header map[string]string) event.Message {
+func NewMessage(key string, value []byte) event.Event {
 	return &Message{
-		key:    key,
-		value:  value,
-		header: header,
+		key:   key,
+		value: value,
 	}
 }
 
@@ -41,20 +36,10 @@ type kafkaSender struct {
 	topic  string
 }
 
-func (s *kafkaSender) Send(ctx context.Context, message event.Message) error {
-	var h []kafka.Header
-	if len(message.Header()) > 0 {
-		for k, v := range message.Header() {
-			h = append(h, protocol.Header{
-				Key:   k,
-				Value: []byte(v),
-			})
-		}
-	}
+func (s *kafkaSender) Send(ctx context.Context, message event.Event) error {
 	err := s.writer.WriteMessages(ctx, kafka.Message{
-		Key:     []byte(message.Key()),
-		Value:   message.Value(),
-		Headers: h,
+		Key:   []byte(message.Key()),
+		Value: message.Value(),
 	})
 	if err != nil {
 		return err
@@ -71,7 +56,6 @@ func (s *kafkaSender) Close() error {
 }
 
 func NewKafkaSender(address []string, topic string) (event.Sender, error) {
-
 	w := &kafka.Writer{
 		Topic:    topic,
 		Addr:     kafka.TCP(address...),
@@ -92,16 +76,9 @@ func (k *kafkaReceiver) Receive(ctx context.Context, handler event.Handler) erro
 			if err != nil {
 				break
 			}
-			h := make(map[string]string)
-			if len(m.Headers) > 0 {
-				for _, header := range m.Headers {
-					h[header.Key] = string(header.Value)
-				}
-			}
 			err = handler(context.Background(), &Message{
-				key:    string(m.Key),
-				value:  m.Value,
-				header: h,
+				key:   string(m.Key),
+				value: m.Value,
 			})
 			if err != nil {
 				log.Fatal("message handling exception:", err)

examples/event/memory/memory.go

@@ -0,0 +1,84 @@
+package memory
+
+import (
+	"context"
+	"github.com/go-kratos/kratos/examples/event/event"
+	"log"
+	"sync"
+)
+
+var _ event.Sender = (*memorySender)(nil)
+var _ event.Receiver = (*memoryReceiver)(nil)
+var _ event.Event = (*Message)(nil)
+
+var (
+	chanMap = struct {
+		sync.RWMutex
+		cm map[string]chan *Message
+	}{}
+	ChanSize = 256
+)
+
+func init() {
+	chanMap.cm = make(map[string]chan *Message)
+}
+
+type Message struct {
+	key   string
+	value []byte
+}
+
+func (m *Message) Key() string {
+	return m.key
+}
+
+func (m *Message) Value() []byte {
+	return m.value
+}
+
+type memorySender struct {
+	topic string
+}
+
+func (m *memorySender) Send(ctx context.Context, msg event.Event) error {
+	chanMap.cm[m.topic] <- &Message{
+		key:   msg.Key(),
+		value: msg.Value(),
+	}
+	return nil
+}
+func (m *memorySender) Close() error {
+	return nil
+}
+
+type memoryReceiver struct {
+	topic string
+}
+
+func (m *memoryReceiver) Receive(ctx context.Context, handler event.Handler) error {
+	go func() {
+		for msg := range chanMap.cm[m.topic] {
+			err := handler(context.Background(), msg)
+			if err != nil {
+				log.Fatal("message handling exception:", err)
+			}
+		}
+	}()
+	return nil
+}
+
+func (m *memoryReceiver) Close() error {
+	return nil
+}
+
+func NewMemory(topic string) (event.Sender, event.Receiver) {
+	chanMap.RLock()
+	if _, ok := chanMap.cm[topic]; !ok {
+		//chanMap.Lock()
+		chanMap.cm[topic] = make(chan *Message, ChanSize)
+		//chanMap.Unlock()
+	}
+	defer chanMap.RUnlock()
+
+	return &memorySender{topic: topic}, &memoryReceiver{topic: topic}
+}

examples/event/memory/memory_test.go

@@ -0,0 +1,33 @@
+package memory
+
+import (
+	"context"
+	"fmt"
+	"github.com/go-kratos/kratos/examples/event/event"
+	"testing"
+	"time"
+)
+
+func TestSendAndReceive(t *testing.T) {
+	send, receive := NewMemory("test")
+	err := receive.Receive(context.Background(), func(ctx context.Context, event event.Event) error {
+		t.Log(fmt.Sprintf("key:%s, value:%s\n", event.Key(), event.Value()))
+		return nil
+	})
+
+	if err != nil {
+		t.Error(err)
+	}
+
+	for i := 0; i < 5; i++ {
+		err := send.Send(context.Background(), &Message{
+			key:   "kratos",
+			value: []byte("hello world"),
+		})
+		if err != nil {
+			t.Error(err)
+		}
+	}
+
+	time.Sleep(5 * time.Second)
+}

examples/event/receiver/main.go

@@ -27,8 +27,8 @@ func main() {
 
 func receive(receiver event.Receiver) {
 	fmt.Println("start receiver")
-	err := receiver.Receive(context.Background(), func(ctx context.Context, message event.Message) error {
-		fmt.Printf("key:%s, value:%s, header:%s\n", message.Key(), message.Value(), message.Header())
+	err := receiver.Receive(context.Background(), func(ctx context.Context, msg event.Event) error {
+		fmt.Printf("key:%s, value:%s\n", msg.Key(), msg.Value())
 		return nil
 	})
 	if err != nil {

examples/event/sender/main.go

@@ -21,13 +21,10 @@ func main() {
 }
 
 func send(sender event.Sender) {
-	msg := kafka.NewMessage("kratos", []byte("hello world"), map[string]string{
-		"user":  "kratos",
-		"phone": "123456",
-	})
+	msg := kafka.NewMessage("kratos", []byte("hello world"))
 	err := sender.Send(context.Background(), msg)
 	if err != nil {
 		panic(err)
 	}
-	fmt.Printf("key:%s, value:%s, header:%s\n", msg.Key(), msg.Value(), msg.Header())
+	fmt.Printf("key:%s, value:%s\n", msg.Key(), msg.Value())
 }