1 files changed, 118 insertions, 0 deletions
diff --git a/weed/messaging/msgclient/publisher.go b/weed/messaging/msgclient/publisher.go
new file mode 100644
index 000000000..1aa483ff8
--- /dev/null
+++ b/weed/messaging/msgclient/publisher.go
@@ -0,0 +1,118 @@
+package msgclient
+
+import (
+	"context"
+
+	"github.com/OneOfOne/xxhash"
+	"google.golang.org/grpc"
+
+	"github.com/chrislusf/seaweedfs/weed/messaging/broker"
+	"github.com/chrislusf/seaweedfs/weed/pb/messaging_pb"
+)
+
+type Publisher struct {
+	publishClients     []messaging_pb.SeaweedMessaging_PublishClient
+	topicConfiguration *messaging_pb.TopicConfiguration
+	messageCount       uint64
+	publisherId        string
+}
+
+func (mc *MessagingClient) NewPublisher(publisherId, namespace, topic string) (*Publisher, error) {
+	// read topic configuration
+	topicConfiguration := &messaging_pb.TopicConfiguration{
+		PartitionCount: 4,
+	}
+	publishClients := make([]messaging_pb.SeaweedMessaging_PublishClient, topicConfiguration.PartitionCount)
+	for i := 0; i < int(topicConfiguration.PartitionCount); i++ {
+		tp := broker.TopicPartition{
+			Namespace: namespace,
+			Topic:     topic,
+			Partition: int32(i),
+		}
+		grpcClientConn, err := mc.findBroker(tp)
+		if err != nil {
+			return nil, err
+		}
+		client, err := setupPublisherClient(grpcClientConn, tp)
+		if err != nil {
+			return nil, err
+		}
+		publishClients[i] = client
+	}
+	return &Publisher{
+		publishClients:     publishClients,
+		topicConfiguration: topicConfiguration,
+	}, nil
+}
+
+func setupPublisherClient(grpcConnection *grpc.ClientConn, tp broker.TopicPartition) (messaging_pb.SeaweedMessaging_PublishClient, error) {
+
+	stream, err := messaging_pb.NewSeaweedMessagingClient(grpcConnection).Publish(context.Background())
+	if err != nil {
+		return nil, err
+	}
+
+	// send init message
+	err = stream.Send(&messaging_pb.PublishRequest{
+		Init: &messaging_pb.PublishRequest_InitMessage{
+			Namespace: tp.Namespace,
+			Topic:     tp.Topic,
+			Partition: tp.Partition,
+		},
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	// process init response
+	initResponse, err := stream.Recv()
+	if err != nil {
+		return nil, err
+	}
+	if initResponse.Redirect != nil {
+		// TODO follow redirection
+	}
+	if initResponse.Config != nil {
+	}
+
+	// setup looks for control messages
+	doneChan := make(chan error, 1)
+	go func() {
+		for {
+			in, err := stream.Recv()
+			if err != nil {
+				doneChan <- err
+				return
+			}
+			if in.Redirect != nil {
+			}
+			if in.Config != nil {
+			}
+		}
+	}()
+
+	return stream, nil
+
+}
+
+func (p *Publisher) Publish(m *messaging_pb.Message) error {
+	hashValue := p.messageCount
+	p.messageCount++
+	if p.topicConfiguration.Partitoning == messaging_pb.TopicConfiguration_NonNullKeyHash {
+		if m.Key != nil {
+			hashValue = xxhash.Checksum64(m.Key)
+		}
+	} else if p.topicConfiguration.Partitoning == messaging_pb.TopicConfiguration_KeyHash {
+		hashValue = xxhash.Checksum64(m.Key)
+	} else {
+		// round robin
+	}
+
+	idx := int(hashValue) % len(p.publishClients)
+	if idx < 0 {
+		idx += len(p.publishClients)
+	}
+	return p.publishClients[idx].Send(&messaging_pb.PublishRequest{
+		Data: m,
+	})
+}