百木园效果
使用gRPC一元通信模式和双向流通信模式写一个简单的控制台聊天室。实现创建用户和实时聊天两个功能，不考虑高性能。复习了内存同步访问Sync包的使用。用切片缓存聊天记录，新用户可以同步聊天记录。
PS C:\\Users\\小能喵喵喵\\Desktop\\Go\\gRPC\\chatroom> tree /f
├───client
│ │ go.mod
│ │ go.sum
│ │ main.go
│ │
│ └───chatroom
│ chat_room.pb.go
│ chat_room_grpc.pb.go
│
├───proto
│ │ chat_room.pb.go
│ │ chat_room.proto
│ │ chat_room_grpc.pb.go
│ │
│ └───google
│ └───protobuf
│ wrappers.proto
│
└───server
│ go.mod
│ go.sum
│ main.go
│ service.go
│
└───chatroom
chat_room.pb.go
chat_room_grpc.pb.go
server.code-workspace
Proto
syntax = \"proto3\";
import \"google/protobuf/wrappers.proto\";
package chatroom;
option go_package=\".\";
service ChatRoom{
rpc login(User) returns(google.protobuf.StringValue);
rpc chat(stream ChatMessage) returns(stream ChatMessage);
}
message User{
string id = 1;
string name = 2;
}
message ChatMessage{
string id = 1;
string name = 2;
uint64 time = 3;
string content = 4;
}
protoc --go_out=. --go-grpc_out=. --go_opt=paths=source_relative --go-grpc_opt=paths=source_relative ./chat_room.proto
Server
service.go
package main
import (
\"context\"
\"fmt\"
\"sync\"
\"time\"
\"github.com/golang/protobuf/ptypes/wrappers\"
\"github.com/google/uuid\"
\"google.golang.org/grpc/codes\"
\"google.golang.org/grpc/metadata\"
\"google.golang.org/grpc/status\"
pb \"wolflong.com/chatroom_server/chatroom\"
)
// ^ 实现服务
type service struct {
pb.UnimplementedChatRoomServer
chatMessageCache []*pb.ChatMessage
userMap sync.Map
L sync.RWMutex
}
var (
workers map[pb.ChatRoom_ChatServer]pb.ChatRoom_ChatServer = make(map[pb.ChatRoom_ChatServer]pb.ChatRoom_ChatServer)
)
// ^ 实现login用户注册方法
func (s *service) Login(ctx context.Context, in *pb.User) (*wrappers.StringValue, error) {
in.Id = uuid.New().String()
if _, ok := s.userMap.Load(in.Id); ok {
return nil, status.Errorf(codes.AlreadyExists, \"已有同名用户,请换个用户名\")
}
s.userMap.Store(in.Id, in)
go s.sendMessage(nil, &pb.ChatMessage{Id: \"server\", Content: fmt.Sprintf(\"%v 加入聊天室\", in.Name), Time: uint64(time.Now().Unix())})
// some work...
return &wrappers.StringValue{Value: in.Id}, status.New(codes.OK, \"\").Err()
}
// ^ 实现聊天室
func (s *service) Chat(stream pb.ChatRoom_ChatServer) error {
if s.chatMessageCache == nil {
s.chatMessageCache = make([]*pb.ChatMessage, 0, 1024)
}
workers[stream] = stream
for _, v := range s.chatMessageCache {
stream.Send(v)
}
s.recvMessage(stream)
return status.New(codes.OK, \"\").Err()
}
func (s *service) recvMessage(stream pb.ChatRoom_ChatServer) {
md, _ := metadata.FromIncomingContext(stream.Context())
for {
mes, err := stream.Recv()
if err != nil {
s.L.Lock()
delete(workers, stream)
s.L.Unlock()
s.userMap.Delete(md.Get(\"uuid\")[0])
fmt.Println(\"某个用户掉线,目前用户在线数量\", len(workers))
break
}
s.chatMessageCache = append(s.chatMessageCache, mes)
v, ok := s.userMap.Load(md.Get(\"uuid\")[0])
if !ok {
fmt.Println(\"致命错误,用户不存在\")
return
}
mes.Name = v.(*pb.User).Name
mes.Time = uint64(time.Now().Unix())
s.sendMessage(stream, mes)
}
}
func (s *service) sendMessage(stream pb.ChatRoom_ChatServer, mes *pb.ChatMessage) {
s.L.Lock()
for _, v := range workers {
if v != stream {
err := v.Send(mes)
if err != nil {
// err handle
continue
}
}
}
s.L.Unlock()
}
main.go
package main
import (
\"fmt\"
\"log\"
\"net\"
\"google.golang.org/grpc\"
pb \"wolflong.com/chatroom_server/chatroom\"
)
const (
ip = \"127.0.0.1\"
port = \"23333\"
)
func main() {
lis, err := net.Listen(\"tcp\", fmt.Sprintf(\"%v:%v\", ip, port))
if err != nil {
log.Fatalf(\"无法监听端口 %v %v\", port, err)
}
s := grpc.NewServer()
// ^ 注册服务
pb.RegisterChatRoomServer(s, &service{})
log.Println(\"gRPC服务器开始监听\", port)
if err := s.Serve(lis); err != nil {
log.Fatalf(\"提供服务失败: %v\", err)
}
}
Client
package main
import (
\"bufio\"
\"context\"
\"os\"
\"strings\"
\"time\"
\"github.com/pterm/pterm\"
\"google.golang.org/grpc\"
\"google.golang.org/grpc/credentials/insecure\"
\"google.golang.org/grpc/metadata\"
\"google.golang.org/protobuf/types/known/wrapperspb\"
pb \"wolflong.com/chatroom_client/chatroom\"
)
const (
address = \"localhost:23333\"
)
func main() {
/* ---------------------------------- 连接服务器 --------------------------------- */
spinner, _ := pterm.DefaultSpinner.Start(\"正在连接聊天室\")
conn, err := grpc.Dial(address, grpc.WithTransportCredentials(insecure.NewCredentials()))
if err != nil {
spinner.Fail(\"连接失败\")
pterm.Fatal.Printfln(\"无法连接至服务器: %v\", err)
return
}
c := pb.NewChatRoomClient(conn)
spinner.Success(\"连接成功\")
/* ---------------------------------- 注册用户名 --------------------------------- */
var val *wrapperspb.StringValue
var user *pb.User
for {
result, _ := pterm.DefaultInteractiveTextInput.Show(\"创建用户名\")
if strings.TrimSpace(result) == \"\" {
pterm.Error.Printfln(\"进入聊天室失败,没有取名字\")
continue
}
user = &pb.User{Name: result}
val, err = c.Login(context.TODO(), user)
if err != nil {
pterm.Error.Printfln(\"进入聊天室失败 %v\", err)
continue
} else {
break
}
}
user.Id = val.Value
pterm.Success.Println(\"创建成功！开始聊天吧！\")
/* ---------------------------------- 聊天室逻辑 --------------------------------- */
stream, _ := c.Chat(metadata.AppendToOutgoingContext(context.Background(), \"uuid\", user.Id))
go func(pb.ChatRoom_ChatClient) {
for {
res, _ := stream.Recv()
switch res.Id {
case \"server\":
pterm.Success.Printfln(\"(%[2]v) [服务器] %[1]s \", res.Content, time.Unix(int64(res.Time), 0).Format(time.ANSIC))
default:
pterm.Info.Printfln(\"(%[3]v) %[1]s : %[2]s\", res.Name, res.Content, time.Unix(int64(res.Time), 0).Format(time.ANSIC))
}
}
}(stream)
for {
inputReader := bufio.NewReader(os.Stdin)
input, _ := inputReader.ReadString(\'\\n\')
input = strings.TrimRight(input, \"\\r \\n\")
// pterm.Info.Printfln(\"%s : %s\", user.Name, input)
stream.Send(&pb.ChatMessage{Id: user.Id, Content: input})
}
}
资料
Welcome - PTerm Docs
一口气搞懂Go sync-map 所有知识点- 阅坊 (readfog.com)
Go语言sync.Map（在并发环境中使用的map） (biancheng.net)
Golang 转换 Unix 时间戳为 date 字符串示例
来源：https://www.cnblogs.com/linxiaoxu/p/16712548.html
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