Codechange: track version of network servers to prune once out-of-date

src/network/network.cpp

@@ -699,9 +699,11 @@ void NetworkQueryLobbyServer(const std::string &connection_string)
  * the list. If you use this function, the games will be marked
  * as manually added.
  * @param connection_string The IP:port of the server to add.
+ * @param manually Whether the enter should be marked as manual added.
+ * @param never_expire Whether the entry can expire (removed when no longer found in the public listing).
  * @return The entry on the game list.
  */
-NetworkGameList *NetworkAddServer(const std::string &connection_string, bool manually)
+NetworkGameList *NetworkAddServer(const std::string &connection_string, bool manually, bool never_expire)
 {
 	if (connection_string.empty()) return nullptr;
 
@@ -717,6 +719,7 @@ NetworkGameList *NetworkAddServer(const std::string &connection_string, bool man
 	}
 
 	if (manually) item->manually = true;
+	if (never_expire) item->version = INT32_MAX;
 
 	return item;
 }
@@ -1288,7 +1291,7 @@ extern "C" {
 
 void CDECL em_openttd_add_server(const char *connection_string)
 {
-	NetworkAddServer(connection_string, false);
+	NetworkAddServer(connection_string, false, true);
 }
 
 }

src/network/network_gamelist.cpp

@@ -20,7 +20,8 @@
 
 #include "../safeguards.h"
 
-NetworkGameList *_network_game_list = nullptr;
+NetworkGameList *_network_game_list = nullptr; ///< Game list of this client.
+int _network_game_list_version = 0; ///< Current version of all items in the list.
 
 /** The games to insert when the GUI thread has time for us. */
 static std::atomic<NetworkGameList *> _network_game_delayed_insertion_list(nullptr);
@@ -81,6 +82,7 @@ NetworkGameList *NetworkGameListAddItem(const std::string &connection_string)
 	}
 
 	item = new NetworkGameList(resolved_connection_string);
+	item->version = _network_game_list_version;
 
 	if (prev_item == nullptr) {
 		_network_game_list = item;
@@ -120,6 +122,33 @@ void NetworkGameListRemoveItem(NetworkGameList *remove)
 	}
 }
 
+/**
+ * Remove all servers that have not recently been updated.
+ * Call this after you received all the servers from the Game Coordinator, so
+ * the ones that are no longer listed are removed.
+ */
+void NetworkGameListRemoveExpired()
+{
+	NetworkGameList **prev_item = &_network_game_list;
+
+	for (NetworkGameList *item = _network_game_list; item != nullptr;) {
+		if (!item->manually && item->version < _network_game_list_version) {
+			NetworkGameList *remove = item;
+			item = item->next;
+			*prev_item = item;
+
+			/* Remove GRFConfig information */
+			ClearGRFConfigList(&remove->info.grfconfig);
+			delete remove;
+		} else {
+			prev_item = &item->next;
+			item = item->next;
+		}
+	}
+
+	UpdateNetworkGameWindow();
+}
+
 static const uint MAX_GAME_LIST_REQUERY_COUNT  = 10; ///< How often do we requery in number of times per server?
 static const uint REQUERY_EVERY_X_GAMELOOPS    = 60; ///< How often do we requery in time?
 static const uint REFRESH_GAMEINFO_X_REQUERIES = 50; ///< Refresh the game info itself after REFRESH_GAMEINFO_X_REQUERIES * REQUERY_EVERY_X_GAMELOOPS game loops

src/network/network_gamelist.h

@@ -26,15 +26,17 @@ struct NetworkGameList {
 	bool online = false;             ///< False if the server did not respond (default status)
 	bool manually = false;           ///< True if the server was added manually
 	uint8 retries = 0;               ///< Number of retries (to stop requerying)
+	int version = 0;                 ///< Used to see which servers are no longer available on the Game Coordinator and can be removed.
 	NetworkGameList *next = nullptr; ///< Next pointer to make a linked game list
 };
 
-/** Game list of this client */
 extern NetworkGameList *_network_game_list;
+extern int _network_game_list_version;
 
 void NetworkGameListAddItemDelayed(NetworkGameList *item);
 NetworkGameList *NetworkGameListAddItem(const std::string &connection_string);
 void NetworkGameListRemoveItem(NetworkGameList *remove);
+void NetworkGameListRemoveExpired();
 void NetworkGameListRequery();
 
 #endif /* NETWORK_GAMELIST_H */

src/network/network_internal.h

@@ -91,7 +91,7 @@ void NetworkQueryServer(const std::string &connection_string);
 void NetworkQueryLobbyServer(const std::string &connection_string);
 
 void GetBindAddresses(NetworkAddressList *addresses, uint16 port);
-struct NetworkGameList *NetworkAddServer(const std::string &connection_string, bool manually = true);
+struct NetworkGameList *NetworkAddServer(const std::string &connection_string, bool manually = true, bool never_expire = false);
 void NetworkRebuildHostList();
 void UpdateNetworkGameWindow();
 

src/network/network_udp.cpp

@@ -327,6 +327,8 @@ void ClientNetworkUDPSocketHandler::Receive_SERVER_RESPONSE(Packet *p, NetworkAd
 	CheckGameCompatibility(item->info);
 	/* Ensure we consider the server online. */
 	item->online = true;
+	/* Make sure this entry never expires. */
+	item->version = INT32_MAX;
 
 	{
 		/* Checks whether there needs to be a request for names of GRFs and makes