From 9f2b715d9ffbecbfeec1799f7137e2af6c34f013 Mon Sep 17 00:00:00 2001
From: Jakob Ketterl <jakob.ketterl@gmx.de>
Date: Sat, 13 Jul 2019 21:40:48 +0200
Subject: [PATCH 1/2] exponential backoff

---
 htdocs/openwebrx.js | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/htdocs/openwebrx.js b/htdocs/openwebrx.js
index e004ae4..6917541 100644
--- a/htdocs/openwebrx.js
+++ b/htdocs/openwebrx.js
@@ -1472,6 +1472,7 @@ function on_ws_opened()
 {
 	ws.send("SERVER DE CLIENT client=openwebrx.js type=receiver");
 	divlog("WebSocket opened to "+ws_url);
+	reconnect_timeout = false;
 }
 
 var was_error=0;
@@ -1852,6 +1853,8 @@ function audio_init()
 
 }
 
+var reconnect_timeout = false;
+
 function on_ws_closed()
 {
 	try
@@ -1860,9 +1863,16 @@ function on_ws_closed()
 	}
 	catch (dont_care) {}
 	audio_initialized = 0;
-	divlog("WebSocket has closed unexpectedly. Attempting to reconnect in 5 seconds...", 1);
+	if (reconnect_timeout) {
+	    // max value: roundabout 8 and a half minutes
+    	reconnect_timeout = Math.min(reconnect_timeout * 2, 512000);
+	} else {
+	    // initial value: 1s
+	    reconnect_timeout = 1000;
+	}
+	divlog("WebSocket has closed unexpectedly. Attempting to reconnect in " + reconnect_timeout / 1000 + " seconds...", 1);
 
-	setTimeout(open_websocket, 5000);
+	setTimeout(open_websocket, reconnect_timeout);
 }
 
 function on_ws_error(event)

From 420b0c60d75241f92f56dc8d8311a49c86bb4092 Mon Sep 17 00:00:00 2001
From: Jakob Ketterl <jakob.ketterl@gmx.de>
Date: Sat, 13 Jul 2019 21:44:48 +0200
Subject: [PATCH 2/2] exponential backoff, part 2

---
 htdocs/map.js | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/htdocs/map.js b/htdocs/map.js
index 82f4a59..b5f905a 100644
--- a/htdocs/map.js
+++ b/htdocs/map.js
@@ -115,10 +115,13 @@
         rectangles = {};
     };
 
+    var reconnect_timeout = false;
+
     var connect = function(){
         var ws = new WebSocket(ws_url);
         ws.onopen = function(){
             ws.send("SERVER DE CLIENT client=map.js type=map");
+            reconnect_timeout = false
         };
 
         ws.onmessage = function(e){
@@ -163,7 +166,14 @@
         };
         ws.onclose = function(){
             clearMap();
-            setTimeout(connect, 5000);
+            if (reconnect_timeout) {
+                // max value: roundabout 8 and a half minutes
+                reconnect_timeout = Math.min(reconnect_timeout * 2, 512000);
+            } else {
+                // initial value: 1s
+                reconnect_timeout = 1000;
+            }
+            setTimeout(connect, reconnect_timeout);
         };
 
         window.onbeforeunload = function() { //http://stackoverflow.com/questions/4812686/closing-websocket-correctly-html5-javascript