From 015586ac178f0ff2c4035ef37b4b8e31b89a3aed Mon Sep 17 00:00:00 2001
From: Koen Bollen <meneer@koenbollen.nl>
Date: Wed, 6 Sep 2023 15:41:34 +0200
Subject: [PATCH] Ping the websocket every 30 second disconencts are noticed.

---
 internal/signaling/handler.go | 18 ++++++++++++++++++
 internal/signaling/types.go   |  4 ++++
 lib/signaling.ts              |  2 ++
 lib/types.ts                  |  5 +++++
 4 files changed, 29 insertions(+)

diff --git a/internal/signaling/handler.go b/internal/signaling/handler.go
index 3ac63aa..8a763bf 100644
--- a/internal/signaling/handler.go
+++ b/internal/signaling/handler.go
@@ -66,6 +66,21 @@ func Handler(ctx context.Context, store stores.Store, cloudflare *cloudflare.Cre
 			}
 		}()
 
+		go func() { // Sending ping packet every 30 to check if the tcp connection is still alive.
+			ticker := time.NewTicker(30 * time.Second)
+			defer ticker.Stop()
+			for {
+				select {
+				case <-ticker.C:
+					if err := peer.Send(ctx, PingPacket{Type: "ping"}); err != nil {
+						util.ErrorAndDisconnect(ctx, conn, err)
+					}
+				case <-ctx.Done():
+					return
+				}
+			}
+		}()
+
 		for ctx.Err() == nil {
 			var raw []byte
 			if _, raw, err = conn.Read(ctx); err != nil {
@@ -104,6 +119,9 @@ func Handler(ctx context.Context, store stores.Store, cloudflare *cloudflare.Cre
 				}
 				go metrics.RecordEvent(ctx, params)
 
+			case "pong":
+				// ignore, ping/pong is just for the tcp keepalive.
+
 			default:
 				if err := peer.HandlePacket(ctx, typeOnly.Type, raw); err != nil {
 					util.ErrorAndDisconnect(ctx, conn, err)
diff --git a/internal/signaling/types.go b/internal/signaling/types.go
index 243cb40..6a29690 100644
--- a/internal/signaling/types.go
+++ b/internal/signaling/types.go
@@ -8,6 +8,10 @@ import (
 	"github.com/poki/netlib/internal/signaling/stores"
 )
 
+type PingPacket struct {
+	Type string `json:"type"`
+}
+
 type HelloPacket struct {
 	Type string `json:"type"`
 
diff --git a/lib/signaling.ts b/lib/signaling.ts
index 76ae4a4..b8042de 100644
--- a/lib/signaling.ts
+++ b/lib/signaling.ts
@@ -209,6 +209,8 @@ export default class Signaling extends EventEmitter<SignalingListeners> {
         case 'credentials':
           this.emit('credentials', packet)
           break
+        case 'ping':
+          break
       }
     } catch (e) {
       const error = new SignalingError('unknown-error', e as string)
diff --git a/lib/types.ts b/lib/types.ts
index b9f8c84..d2084bd 100644
--- a/lib/types.ts
+++ b/lib/types.ts
@@ -42,8 +42,13 @@ export type SignalingPacketTypes =
 | JoinPacket
 | ListPacket
 | LobbiesPacket
+| PingPacket
 | WelcomePacket
 
+export interface PingPacket extends Base {
+  type: 'ping'
+}
+
 export interface ErrorPacket extends Base {
   type: 'error'
   message: string