Try and fix data races

main.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io"
 	"log"
 	"net/http"
 	"os"
@@ -21,6 +20,20 @@ import (
 	"github.com/gorilla/websocket"
 )
 
+type PeerSet struct {
+	sync.Mutex
+	m map[string]struct{}
+}
+
+var userPeersMutex sync.Mutex = sync.Mutex{}
+var userPeers = make(map[string]*PeerSet)
+
+var peerConnectionsMutex sync.Mutex = sync.Mutex{}
+var peerConnections = make(map[string]*Peer)
+
+var connectionPeersMutex sync.Mutex = sync.Mutex{}
+var connectionPeers = make(map[*websocket.Conn]string)
+
 var upgrader = websocket.Upgrader{
 	CheckOrigin: func(r *http.Request) bool {
 		origin := r.Header.Get("Origin")
@@ -68,20 +81,24 @@ type Peer struct {
 	conn            *websocket.Conn
 	send            chan []byte
 	lastActive      time.Time
-	m          sync.Mutex
+	lastActiveMutex sync.Mutex
 	closeOnce       sync.Once
 }
 
 func removePeer(peerID string, peer *Peer) {
 	delete(peerConnections, peerID)
 
+	userPeersMutex.Lock()
+	defer userPeersMutex.Unlock()
+
 	for userID, peers := range userPeers {
-		delete(peers, peerID)
+		delete(peers.m, peerID)
-		if len(peers) == 0 {
+		if len(peers.m) == 0 {
 			delete(userPeers, userID) // not safe need mutex
 		}
 	}
-
+	connectionPeersMutex.Lock()
+	defer connectionPeersMutex.Unlock()
 	delete(connectionPeers, peer.conn)
 
 	// Close the peer's send channel safely
@@ -105,7 +122,8 @@ func handleWebSocket(w http.ResponseWriter, r *http.Request) {
 	// Create a Peer object with a buffered channel for sending messages
 	peer := &Peer{
 		conn:            conn,
-		send:       make(chan []byte, 256),
+		send:            make(chan []byte, 4096),
+		lastActiveMutex: sync.Mutex{},
 		lastActive:      time.Now(),
 	}
 
@@ -119,9 +137,9 @@ func handleWebSocket(w http.ResponseWriter, r *http.Request) {
 			break
 		}
 
-		peer.m.Lock()
+		peer.lastActiveMutex.Lock()
 		peer.lastActive = time.Now()
-		peer.m.Unlock()
+		peer.lastActiveMutex.Unlock()
 
 		// fmt.Println("ws<-", connectionPeers[conn], ":", string(message[:min(80, len(message))]))
 
@@ -187,12 +205,6 @@ func handlePing(message []byte, peer *Peer) ([]byte, error) {
 	return []byte(`{"type":"pong"}`), nil
 }
 
-type PeerSet map[string]struct{}
-
-var userPeers = make(map[string]PeerSet)
-var peerConnections = make(map[string]*Peer)
-var connectionPeers = make(map[*websocket.Conn]string)
-
 func handleHello(message []byte, peer *Peer) ([]byte, error) {
 
 	var m struct {
@@ -209,21 +221,32 @@ func handleHello(message []byte, peer *Peer) ([]byte, error) {
 	}
 
 	log.Printf("Received hello from peer %s:%s, user %s:%s", m.PeerID[0:5], m.PeerName, m.UserID[0:5], m.UserName)
+	userPeersMutex.Lock()
+	defer userPeersMutex.Unlock()
+
 	if userPeers[m.UserID] == nil {
-		userPeers[m.UserID] = make(PeerSet)
+		userPeers[m.UserID] = &PeerSet{
+			sync.Mutex{},
+			make(map[string]struct{}),
+		}
 	}
 
 	for _, knownUserID := range m.KnownUsers {
 		fmt.Printf("Adding user %s for peer %s\n", knownUserID, m.PeerID)
 		if userPeers[knownUserID] == nil {
-			userPeers[knownUserID] = make(PeerSet)
+			userPeers[knownUserID] = &PeerSet{
+				sync.Mutex{},
+				make(map[string]struct{}),
+			}
 		}
 
-		userPeers[knownUserID][m.PeerID] = struct{}{}
+		userPeers[knownUserID].Mutex.Lock()
+		defer userPeers[knownUserID].Mutex.Unlock()
+		userPeers[knownUserID].m[m.PeerID] = struct{}{}
 
 	}
 
-	userPeers[m.UserID][m.PeerID] = struct{}{}
+	userPeers[m.UserID].m[m.PeerID] = struct{}{}
 	peerConnections[m.PeerID] = peer
 	connectionPeers[peer.conn] = m.PeerID
 
@@ -278,23 +301,29 @@ func handlePeerMessage(message []byte, peer *Peer) ([]byte, error) {
 }
 
 // BrotliResponseWriter wraps http.ResponseWriter to support Brotli compression
-type brotliResponseWriter struct {
+// type brotliResponseWriter struct {
-	http.ResponseWriter
+// 	http.ResponseWriter
-	Writer io.Writer
+// 	Writer io.Writer
-}
+// }
 
-func (w *brotliResponseWriter) Write(b []byte) (int, error) {
+// func (w *brotliResponseWriter) Write(b []byte) (int, error) {
-	return w.Writer.Write(b)
+// 	return w.Writer.Write(b)
-}
+// }
 
 // noDirListing wraps an http.FileServer handler to prevent directory listings
 func noDirListing(h http.Handler, root string) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 
+		if r.URL.Path == "/" {
+			// Early out for root.
+			http.ServeFile(w, r, filepath.Join(root, "/static/index.html"))
+			return
+		}
+
 		// For anything under /static/, we serve it, unless it's a directory
 		// Otherwise we serve index.html and the app does the routing nad rendering.
 
-		log.Printf("%s %s %s", r.URL.Path, r.RemoteAddr, r.UserAgent())
+		// log.Printf("%s %s %s", r.URL.Path, r.RemoteAddr, r.UserAgent())
 
 		if r.URL.Path == "/sw.js" {
 			http.ServeFile(w, r, filepath.Join(root, "static/sw.js"))
@@ -330,7 +359,7 @@ func noDirListing(h http.Handler, root string) http.HandlerFunc {
 
 		// // Serve index.html when root is requested
 		// if r.URL.Path == "/" {
-		log.Printf("Serving index %s", r.URL.Path)
+		// log.Printf("Serving index %s", r.URL.Path)
 		http.ServeFile(w, r, filepath.Join(root, "/static/index.html"))
 		// return
 		// }
@@ -415,12 +444,14 @@ func main() {
 
 				// Collect inactive peers
 				var inactivePeers []string
+				peerConnectionsMutex.Lock()
+				defer peerConnectionsMutex.Unlock()
 				for peerID, peer := range peerConnections {
-					peer.m.Lock()
+					peer.lastActiveMutex.Lock()
+					defer peer.lastActiveMutex.Unlock()
 					if now.Sub(peer.lastActive) > 60*time.Second {
 						inactivePeers = append(inactivePeers, peerID)
 					}
-					peer.m.Unlock()
 				}
 
 				// Remove inactive peers