From b717b1b5eaac3672efa518509b3d3871e84900b9 Mon Sep 17 00:00:00 2001
From: Alex Karle <alex@karle.co>
Date: Fri, 10 Apr 2020 22:28:16 -0400
Subject: [PATCH] Euchre::Dealer: Add ping/pong heartbeat msg

It seems one waay to have a keepalive for Websockets is with a heartbeat
(ping/pong).

Given that we don't expect millions of users at a time ;) this seems
totally reasonable to fire off every 5-10 seconds to keep the connection
alive.
---
 lib/Euchre/Dealer.pm | 6 ++++++
 public/debug.html    | 6 +++++-
 run.sh               | 3 ---
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/lib/Euchre/Dealer.pm b/lib/Euchre/Dealer.pm
index 146f783..03da972 100644
--- a/lib/Euchre/Dealer.pm
+++ b/lib/Euchre/Dealer.pm
@@ -102,6 +102,7 @@ sub handle_msg {
     # assertions (like, needs to be their turn)
     my %dispatch = (
         # Game management endpoints
+        ping        => [\&pong],
         join_game   => [\&join_game],
         take_seat   => [\&take_seat, 'lobby', "Can't change seats during game"],
         stand_up    => [\&stand_up, 'lobby', "Can't change seats during game"],
@@ -128,6 +129,11 @@ sub handle_msg {
     }
 }
 
+sub pong {
+    my ($p) = @_;
+    $p->{ws}->send({ json => { msg_type => 'pong' } });
+}
+
 # player_name
 # game_id
 sub join_game {
diff --git a/public/debug.html b/public/debug.html
index 2764cb0..2783612 100644
--- a/public/debug.html
+++ b/public/debug.html
@@ -15,7 +15,7 @@
     var ws = new WebSocket('ws://localhost:3000/play');
     ws.onmessage = function (event) { 
       msg = JSON.parse(event.data);
-      console.log(msg)
+      if (msg.msg_type !== 'pong') { console.log(msg) }
 
       if (msg.msg_type === 'game_state') {
         gameState = '<br>Game:          ' + msg.game.id + '<br>' +
@@ -51,6 +51,8 @@
           var c = msg.hand[i]
           document.getElementById('hand').innerHTML += '<img onclick="play(' + "'" +  c + "'" + ')" class="card" src="cards/' + c + '.svg">'
         }
+      //} else if (msg.msg_type === 'pong') {
+      //  console.log('pong!');
       }
     };
 
@@ -79,6 +81,8 @@
     function play(card) {
       ws.send(JSON.stringify({action:'play_card', card: card}))
     }
+
+    window.setInterval(() => { ws.send(JSON.stringify({action:'ping'})) }, 5000);
   </script>
  <h1>Hello, World</h1>
 
diff --git a/run.sh b/run.sh
index 2980278..8feaed2 100755
--- a/run.sh
+++ b/run.sh
@@ -19,7 +19,4 @@ depends mojo
 DIR=`dirname $0`
 cd $DIR
 
-# XXX: this should be handled by the server...
-export MOJO_INACTIVITY_TIMEOUT=1000
-
 exec mojo webpack ./gloat.pl
--
libgit2 1.1.1