From b1196885d73dc9511b639340d3dbe7e75f8bdf07 Mon Sep 17 00:00:00 2001
From: Fabian Dill <fabian.dill@web.de>
Date: Sat, 11 Sep 2021 03:59:12 +0200
Subject: [PATCH] CommonClient: implement active keep-alive

---
 CommonClient.py | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/CommonClient.py b/CommonClient.py
index 1e085885..7c996ada 100644
--- a/CommonClient.py
+++ b/CommonClient.py
@@ -17,6 +17,7 @@ logger = logging.getLogger("Client")
 
 gui_enabled = Utils.is_frozen() or "--nogui" not in sys.argv
 
+
 class ClientCommandProcessor(CommandProcessor):
     def __init__(self, ctx: CommonContext):
         self.ctx = ctx
@@ -86,11 +87,12 @@ class ClientCommandProcessor(CommandProcessor):
 
 
 class CommonContext():
-    starting_reconnect_delay = 5
-    current_reconnect_delay = starting_reconnect_delay
-    command_processor = ClientCommandProcessor
-    game: None
-    ui: None
+    starting_reconnect_delay: int = 5
+    current_reconnect_delay: int = starting_reconnect_delay
+    command_processor: int = ClientCommandProcessor
+    game = None
+    ui = None
+    keep_alive_task = None
 
     def __init__(self, server_address, password):
         # server state
@@ -127,6 +129,9 @@ class CommonContext():
         self.jsontotextparser = JSONtoTextParser(self)
         self.set_getters(network_data_package)
 
+        # execution
+        self.keep_alive_task = asyncio.create_task(keep_alive(self))
+
     async def connection_closed(self):
         self.auth = None
         self.items_received = []
@@ -219,6 +224,16 @@ class CommonContext():
         pass
 
 
+async def keep_alive(ctx: CommonContext):
+    """ some ISPs/network configurations drop TCP connections if no payload is sent (ignore TCP-keep-alive)
+     so we send a payload to prevent drop and if we were dropped anyway this will cause a reconnect."""
+    while not ctx.exit_event.is_set():
+        await asyncio.sleep(100)
+        if ctx.server and ctx.slot:
+            await ctx.send_msgs([{"cmd": "Bounce", "slots": [ctx.slot]}])
+            logger.info("Bouncy")
+
+
 async def server_loop(ctx: CommonContext, address=None):
     cached_address = None
     if ctx.server and ctx.server.socket: