145 lines
2.9 KiB
Go
145 lines
2.9 KiB
Go
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package main
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import (
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"bufio"
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"io"
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"log"
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"net"
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)
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type Client struct {
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Connection *net.Conn
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Name string
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Send chan string
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}
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type Message struct {
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cli *Client
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message string
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}
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type Server struct {
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net.Listener
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Clients []Client
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NewClients chan Client
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NewMessages chan Message
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}
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func (cli Client) Prompt() string {
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return "<" + cli.Name + "> "
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}
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func (cli Client) SendMessages() {
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for msg := range cli.Send {
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io.WriteString(*cli.Connection, msg)
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}
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}
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func (cli Client) WaitMessage(server *Server) {
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scanner := bufio.NewScanner(*cli.Connection)
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io.WriteString(*cli.Connection, cli.Prompt())
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for scanner.Scan() {
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msg := Message{&cli, scanner.Text()}
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if len(msg.message) > 0 {
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log.Println("New message from", cli.Name, msg.message)
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server.NewMessages <- msg
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}
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io.WriteString(*cli.Connection, cli.Prompt())
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}
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}
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func NewServer(addr string) (*Server, error) {
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ln, err := net.Listen("tcp", addr)
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if err != nil {
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return nil, err
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}
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return &Server{
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ln,
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make([]Client, 0),
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make(chan Client),
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make(chan Message),
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}, nil
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}
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func (server *Server) NewClient(conn *net.Conn) {
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io.WriteString(*conn, "What is your name? ")
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scanner := bufio.NewScanner(*conn)
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for scanner.Scan() {
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str := scanner.Text()
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log.Println("New client", str)
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cli := &Client{
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conn,
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str,
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make(chan string),
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}
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server.NewClients <- *cli
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return
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}
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}
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func (server *Server) MessageDispatcher() {
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for msg := range server.NewMessages {
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log.Println("Dispatching message", msg.message, "from", msg.cli.Name)
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for _, dest := range server.Clients {
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if dest.Name != msg.cli.Name {
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log.Println("Send message", msg.message, "from", msg.cli.Name, "to", dest.Name)
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dest.Send <- "\n" + msg.cli.Prompt() + msg.message + "\n" + dest.Prompt()
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}
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}
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}
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}
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func (server *Server) CreateClients() {
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for cli := range server.NewClients {
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exists := false
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for _, c := range server.Clients {
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if c.Name == cli.Name {
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exists = true
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}
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}
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if exists {
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io.WriteString(*cli.Connection, "Name already in use\n")
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go server.NewClient(cli.Connection)
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} else {
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server.Clients = append(server.Clients, cli)
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log.Println("Client ready to chat", cli.Name)
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log.Println(len(server.Clients), "clients connected")
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go cli.WaitMessage(server)
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go cli.SendMessages()
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}
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}
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}
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// wait connections from clients
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func (server *Server) handle() {
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for {
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conn, err := server.Accept()
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if err != nil {
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log.Println("Connection error", err)
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}
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go server.NewClient(&conn)
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// TODO disconnect?
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}
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defer server.stop()
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}
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func (server *Server) stop() {
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// TODO close connections
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defer server.Close()
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}
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func (server *Server) start() {
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log.Println("Starting server...")
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go server.MessageDispatcher()
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go server.CreateClients() // create client one at a time (race condition)
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server.handle()
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}
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func main() {
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server, err := NewServer(":9000")
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if err != nil {
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panic(err)
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}
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server.start()
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}
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