Go语言结合grpc和protobuf实现去中心化的聊天室

syntax = "proto3";

option go_package = "proximity-chat/message";

package message;

service Chat {
    rpc NewNode (stream NodeRequest) returns (stream NodeReply){ }
}

message NodeRequest {
    string msg = 1;
}

message NodeReply {
    string msg = 1;
}

type ChatServer interface {
	NewNode(Chat_NewNodeServer) error
	mustEmbedUnimplementedChatServer()
}

type MessageWriter interface {
	Write(string)
}

type Message struct {
	Writer MessageWriter
	message.UnimplementedChatServer
}
...
func (m *Message) NewNode(ss message.Chat_NewNodeServer) error {
	head, err := ss.Recv()
	if err != nil {
		m.Writer.Write(fmt.Sprint(err))
		return err
	}
	addr := head.GetMsg()
	if controller.IsChatNodeExist(addr) {
		return nil
	}
	if !controller.AddChatNode(&ServerChatNode{s: ss}, addr) {
		return nil
	}
	err = ss.Send(&message.NodeReply{Msg: "ok"})
	if err != nil {
		return err
	}
	m.Writer.Write("new node " + addr + " has joined")
	for {
		msg, err := ss.Recv()
		if err != nil {
			controller.RemoveNode(addr)
			fmt.Println(err)
			return err
		}
		m.Writer.Write(msg.GetMsg())
	}
}

package controller

import (
	"sync"
)

type ChatNode interface {
	SendChatMsg(string) error
	RecvChatMsg() (string, error)
}

var nodeMap map[string]ChatNode = make(map[string]ChatNode)
var nodeMapLock sync.RWMutex

func AddChatNode(node ChatNode, addr string) bool {
	nodeMapLock.Lock()
	defer nodeMapLock.Unlock()
	_, ok := nodeMap[addr]
	if !ok {
		nodeMap[addr] = node
		return true
	}
	return false
}

func RemoveNode(addr string) {
	nodeMapLock.Lock()
	defer nodeMapLock.Unlock()
	delete(nodeMap, addr)
}

func IsChatNodeExist(addr string) bool {
	nodeMapLock.RLock()
	defer nodeMapLock.RUnlock()
	_, ok := nodeMap[addr]
	return ok
}

func Publish(s string) {
	nodeMapLock.RLock()
	defer nodeMapLock.RUnlock()
	for _, n := range nodeMap {
		n.SendChatMsg(s)
	}
}

func BeginDiscoverService() {
	minPort := config.GetConfig().GetMinPort()
	maxPort := config.GetConfig().GetMaxPort()
	if minPort > maxPort {
		minPort = maxPort
	}
	for {
		time.Sleep(time.Second)
		gen, err := ipnetgen.New(config.GetConfig().GetCIDR())
		if err != nil {
			panic(err)
		}
		for ip := gen.Next(); ip != nil; ip = gen.Next() {
			for i := minPort; i <= maxPort; i++ {
				addr := fmt.Sprintf("%s:%d", ip.String(), i)
				if addr == GetAddr() {
					continue
				}
				if controller.IsChatNodeExist(addr) {
					continue
				}
				conn, err := grpc.Dial(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
				if err != nil {
					fmt.Printf("did not connect: %v\n", err)
					continue
				}
				client := message.NewChatClient(conn)
				cli, err := client.NewNode(context.Background())
				if err != nil {
					continue
				}
				err = cli.Send(&message.NodeRequest{Msg: GetAddr()})
				if err != nil {
					writer.Write(fmt.Sprint(err))
					continue
				}
				resp, err := cli.Recv()
				if err != nil {
					cli.CloseSend()
					writer.Write(fmt.Sprint(err))
					continue
				}
				if resp.GetMsg() != "ok" {
					cli.CloseSend()
					continue
				}
				if !controller.AddChatNode(&service.ClientChatNode{C: cli}, addr) {
					cli.CloseSend()
					continue
				}
				writer.Write("discover " + addr)
				go func() {
					for {
						msg, err := cli.Recv()
						if err != nil {
							writer.Write(fmt.Sprint(err))
							controller.RemoveNode(addr)
							return
						}
						writer.Write(msg.GetMsg())
					}
				}()
			}
		}
	}
}

package config

type NetworkConfig struct {
	CIDR    string `json:"cidr"`
	MaxPort int    `json:"max_port"`
	MinPort int    `json:"min_port"`
}

func DefaultNetworkConfig() *NetworkConfig {
	return &NetworkConfig{
		"127.0.0.1/32", 4569, 4565,
	}
}

type ConstNetworkConfig struct {
	c *NetworkConfig
}

func (c *ConstNetworkConfig) GetCIDR() string { return c.c.CIDR }
func (c *ConstNetworkConfig) GetMaxPort() int { return c.c.MaxPort }
func (c *ConstNetworkConfig) GetMinPort() int { return c.c.MinPort }

var config = &ConstNetworkConfig{DefaultNetworkConfig()}

func GetConfig() *ConstNetworkConfig { return config }
func SetConfig(nc *NetworkConfig)    { config = &ConstNetworkConfig{nc} }