add delete channel

weed/messaging/msgclient/chan_pub.go

@@ -0,0 +1,76 @@
+package msgclient
+
+import (
+	"crypto/md5"
+	"hash"
+	"io"
+	"log"
+
+	"google.golang.org/grpc"
+
+	"github.com/chrislusf/seaweedfs/weed/messaging/broker"
+	"github.com/chrislusf/seaweedfs/weed/pb/messaging_pb"
+)
+
+type PubChannel struct {
+	client         messaging_pb.SeaweedMessaging_PublishClient
+	grpcConnection *grpc.ClientConn
+	md5hash        hash.Hash
+}
+
+func (mc *MessagingClient) NewPubChannel(chanName string) (*PubChannel, error) {
+	tp := broker.TopicPartition{
+		Namespace: "chan",
+		Topic:     chanName,
+		Partition: 0,
+	}
+	grpcConnection, err := mc.findBroker(tp)
+	if err != nil {
+		return nil, err
+	}
+	pc, err := setupPublisherClient(grpcConnection, tp)
+	if err != nil {
+		return nil, err
+	}
+	return &PubChannel{
+		client:         pc,
+		grpcConnection: grpcConnection,
+		md5hash:        md5.New(),
+	}, nil
+}
+
+func (pc *PubChannel) Publish(m []byte) error {
+	err := pc.client.Send(&messaging_pb.PublishRequest{
+		Data: &messaging_pb.Message{
+			Value: m,
+		},
+	})
+	if err == nil {
+		pc.md5hash.Write(m)
+	}
+	return err
+}
+func (pc *PubChannel) Close() error {
+
+	// println("send closing")
+	if err := pc.client.Send(&messaging_pb.PublishRequest{
+		Data: &messaging_pb.Message{
+			IsClose: true,
+		},
+	}); err != nil {
+		log.Printf("err send close: %v", err)
+	}
+	// println("receive closing")
+	if _, err := pc.client.Recv(); err != nil && err != io.EOF {
+		log.Printf("err receive close: %v", err)
+	}
+	// println("close connection")
+	if err := pc.grpcConnection.Close(); err != nil {
+		log.Printf("err connection close: %v", err)
+	}
+	return nil
+}
+
+func (pc *PubChannel) Md5() []byte {
+	return pc.md5hash.Sum(nil)
+}