Better handling of everything with ChatServer struct

WubWub!

Cargo.toml

@@ -9,4 +9,3 @@ edition = "2021"
 [dependencies]
 clap = { version = "3.0.0-rc.9", features = ["derive"] }
 chrono = "0.4"
-retain_mut = "0.1.5"

src/main.rs

@@ -5,31 +5,11 @@ use clap::Parser;
 use std::io::Write;
 use std::io::{self, BufRead};
 use chrono::{DateTime, Utc};
-use std::borrow::{Borrow, BorrowMut};
-use retain_mut::RetainMut;
+//use std::borrow::{Borrow, BorrowMut};
+//use retain_mut::RetainMut;
 use std::collections::BTreeMap;
 
 
-fn send_to_all(clients: &Arc<Mutex<Vec<ChatUser>>>, msg: &str) -> Result<(), ChatError> {
-    let now: DateTime<Utc> = Utc::now();
-    let time_msg = format!("[{}] {}", now.format("%H:%M:%S"), msg);
-    let mut broken_clients = vec![];
-    clients.lock()?.borrow_mut().retain_mut(
-        | client | {
-            if write!(client.socket, "{}\n", time_msg).is_err() {
-                broken_clients.push(client.name.clone());
-                return false
-            }
-            true
-        });
-
-    for name in broken_clients {
-        send_to_all(clients, &format!("* {} left the chat (broken pipe)", name))?;
-    }
-
-    Ok(())
-}
-
 
 /// Represent one single chat user and their network stuff
 struct ChatUser {
@@ -56,15 +36,50 @@ struct ChatServer {
 
 impl ChatServer {
     pub fn new() -> Self {
-        Self{user_map: BtreeMap::new(), user_id_counter: 1}
+        Self{user_map: BTreeMap::new(), user_id_counter: 1}
+    }
+
+    pub fn get_user_count(&self) -> usize {
+        self.user_map.len()
     }
 
-    // register a client by creating a ChatUser for it and assigning it a user id
-    pub fn register(&mut self, name: String, socket: TcpStream) {
-        let chat_user = ChatUser::new(user_id_counter, name, socket);
+    /// register a client by creating a ChatUser for it and assigning it a user id
+    pub fn register(&mut self, name: String, socket: TcpStream) -> u64 {
+        let chat_user = ChatUser::new(self.user_id_counter, name, socket);
+        let client_id = chat_user.id;
         self.user_map.insert(chat_user.id, chat_user);
         self.user_id_counter += 1;
+
+        client_id
+    }
+
+    pub fn deregister(&mut self, client_id: u64) -> Option<ChatUser> {
+        self.user_map.remove(&client_id)
     }
+
+    pub fn send_to_all(&mut self, msg: &str) -> Result<(), ChatError> {
+        let now: DateTime<Utc> = Utc::now();
+        let time_msg = format!("[{}] {}", now.format("%H:%M:%S"), msg);
+        let mut broken_clients = vec![];
+        for (user_id, user) in self.user_map.iter_mut() {
+            if write!(user.socket, "{}\n", time_msg).is_err() {
+                broken_clients.push((*user_id, user.name.clone()));
+            }
+        }
+
+        // remove users from map
+        for (user_id, _) in broken_clients.iter() {
+            self.deregister(*user_id);
+        }
+
+        // send out the news
+        for (_, name) in broken_clients.iter() {
+            self.send_to_all(&format!("* {} has left the chat (broken pipe)", name))?;
+        }
+
+        Ok(())
+    }
+
 }
 
 #[derive(Debug)]
@@ -86,7 +101,7 @@ impl <'a, T> From<std::sync::PoisonError<std::sync::MutexGuard<'a, T>>> for Chat
     }
 }
 
-fn handle_client(mut stream: TcpStream, clients: Arc<Mutex<Vec<ChatUser>>>) -> Result<(), ChatError> {
+fn handle_client(mut stream: TcpStream, server: Arc<Mutex<ChatServer>>, client_id: &mut Option<u64>) -> Result<(), ChatError> {
     let mut writer = stream.try_clone()?;
     let reader = io::BufReader::new(&mut stream);
     let mut lines = reader.lines();
@@ -97,11 +112,12 @@ fn handle_client(mut stream: TcpStream, clients: Arc<Mutex<Vec<ChatUser>>>) -> R
     // FIXME: check for nick name uniqueness
 
     // print joined msg and register at server
-    send_to_all(&clients, &format!("* {} has joined the chat", nick))?;
-    let curr_users = clients.lock()?.borrow().len();
+    server.lock()?.send_to_all(&format!("* {} has joined the chat", nick))?;
+    let curr_users = server.lock()?.get_user_count();
     let users_in_room_msg = if curr_users == 1 { String::from("is 1 user") } else { format!("are {} users", curr_users) };
     write!(writer, "Welcome, {}! You can now start to chat! There {} in the room.\n", nick, users_in_room_msg)?;
-    clients.lock()?.borrow_mut().push(ChatUser::new(nick.clone(), writer));
+    // server.lock()?.borrow_mut().push(ChatUser::new(nick.clone(), writer));
+    *client_id = Some(server.lock()?.register(nick.clone(), writer));
 
     // read lines
     for line in lines {
@@ -110,19 +126,29 @@ fn handle_client(mut stream: TcpStream, clients: Arc<Mutex<Vec<ChatUser>>>) -> R
             continue;
         }
         let msg = format!("<{}> {}", nick, msg_raw);
-        send_to_all(&clients, &msg)?;
+        server.lock()?.send_to_all(&msg)?;
         println!("{}", msg);
     }
     Ok(())
 }
 
 
-fn run_thread(stream: TcpStream, clients: Arc<Mutex<Vec<ChatUser>>>) {
-    let quit_msg = match handle_client(stream, clients) {
+fn run_thread(stream: TcpStream, server: Arc<Mutex<ChatServer>>) {
+    let mut client_id = None;
+    let quit_reason = match handle_client(stream, Arc::clone(&server), &mut client_id) {
         Ok(()) => String::from("Connection closed by user's choice"),
         Err(err) => format!("Client foobar't their thread: {:?}", err),
     };
-    println!(" * Client has left the chat ({})", quit_msg);
+
+    if let Some(client_id) = client_id {
+        let mut srv = server.lock().unwrap();
+        let name = srv.deregister(client_id).map(|client| client.name).unwrap_or("<unknown user>".into());
+        let quit_msg = format!("* {} has left the chat ({})", name, quit_reason);
+        println!("{}", quit_msg);
+        srv.send_to_all(&quit_msg).unwrap();
+    } else {
+        println!("Client thread terminated before identifying themselves");
+    }
 }
 
 
@@ -145,13 +171,13 @@ fn main() -> std::io::Result<()> {
     println!("Binding to {}", binding_host);
 
     let listener = TcpListener::bind(binding_host)?;
-    let clients = Arc::new(Mutex::new(vec!()));
+    let server = Arc::new(Mutex::new(ChatServer::new()));
 
     // accept connections and process them serially
     for stream in listener.incoming() {
         if let Ok(stream) = stream {
-            let clients_clone = Arc::clone(&clients);
-            thread::spawn(move || { run_thread(stream, clients_clone); });
+            let server_clone = Arc::clone(&server);
+            thread::spawn(move || { run_thread(stream, server_clone); });
         }
     }
     Ok(())