Small fix + attempt to improve socket messages reliability...

[vchess.git] / server / sockets.js

diff --git a/server/sockets.js b/server/sockets.js
index c2b41e8..520b8b7 100644 (file)
--- a/server/sockets.js
+++ b/server/sockets.js
@@ -18,6 +18,12 @@ function send(socket, message) {
     socket.send(JSON.stringify(message));
 }
 
+// https://www.npmjs.com/package/ws - detect lost connections...
+function noop() {}
+function heartbeat() {
+  this.isAlive = true;
+}
+
 module.exports = function(wss) {
   // Associative array page --> sid --> tmpId --> socket
   // "page" is either "/" for hall or "/game/some_gid" for Game,
@@ -36,6 +42,8 @@ module.exports = function(wss) {
     });
   }
   wss.on("connection", (socket, req) => {
+    socket.isAlive = true;
+    socket.on('pong', heartbeat);
     const query = getJsonFromUrl(req.url);
     const sid = query["sid"];
     const id = query["id"];
@@ -368,4 +376,15 @@ module.exports = function(wss) {
     socket.on("message", messageListener);
     socket.on("close", closeListener);
   });
+  const interval = setInterval(
+    () => {
+      wss.clients.forEach(ws => {
+        if (ws.isAlive === false) return ws.terminate();
+        ws.isAlive = false;
+        ws.ping(noop);
+      });
+    },
+    30000
+  );
+  wss.on('close', () => clearInterval(interval));
 }