Added a background service which caches/fetches game server details f…

…or some specific games, to ensure that these games always have available servers for display
BerntA · Mar 8, 2024 · dd496fb · dd496fb
1 parent 15e7f71
commit dd496fb
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Showing 5 changed files with 91 additions and 43 deletions.
diff --git a/GameServerList.App/Helpers/GameList.cs b/GameServerList.App/Helpers/GameList.cs
@@ -1,6 +1,5 @@
 using GameServerList.Common.Model;
 using GameServerList.Common.Utils;
-using Newtonsoft.Json;
 
 namespace GameServerList.Helpers;
 

diff --git a/GameServerList.App/Helpers/GameServerWorker.cs b/GameServerList.App/Helpers/GameServerWorker.cs
@@ -0,0 +1,83 @@
+using GameServerList.Common.External;
+using GameServerList.Common.Model.A2S;
+using GameServerList.Common.Model;
+using System.Collections.Concurrent;
+
+namespace GameServerList.Helpers;
+
+public class GameServerWorker : BackgroundService
+{
+    public GameServerWorker()
+    {
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        var nextUpdateAt = DateTime.MinValue;
+        var games = GameList
+            .Games
+            .Where(g => (g.UseDefinedServerList.HasValue && g.UseDefinedServerList.Value) || g.MasterServer.HasValue)
+            .ToList();
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            if (DateTime.UtcNow <= nextUpdateAt)
+            {
+                Thread.Sleep(100); // put the thread on hold while waiting
+                continue;
+            }
+
+            foreach (var game in games)
+            {
+                try
+                {
+                    List<GameServerItem> servers = null;
+
+                    if (game.UseDefinedServerList ?? false)
+                        servers = await QueryServers(game, game.Servers);
+                    else if (game.MasterServer.HasValue)
+                    {
+                        var legacyServers = await A2SQuery.QueryServerList(
+                            A2SQuery.GetMasterServerAddress(game.MasterServer.Value), game
+                        );
+                        servers = await QueryServers(game, legacyServers.Select(s => s.Address).ToList());
+                    }
+
+                    game.GameServers = servers;
+                }
+                catch
+                {
+                    // skip
+                }
+            }
+
+            nextUpdateAt = DateTime.UtcNow.AddMinutes(15);
+        }
+    }
+
+    private static bool IsServerValid(Game game, ServerInfo? server)
+    {
+        if (server is null || !server.HasValue)
+            return false;
+
+        if (server.Value.MaxPlayers > 128 || server.Value.MaxPlayers <= 1 || server.Value.Players > server.Value.MaxPlayers)
+            return false;
+
+        if (game.MasterServer.HasValue && game.MasterServer.Value == MasterServer.GoldSrc && !server.Value.Version.EndsWith("/Stdio"))
+            return false;
+
+        return true;
+    }
+
+    private static async Task<List<GameServerItem>> QueryServers(Game game, List<string> servers, int timeout = 1500)
+    {
+        var items = new ConcurrentBag<GameServerItem>();
+        await Parallel.ForEachAsync(servers, async (address, _) =>
+        {
+            var obj = await A2SQuery.QueryServerInfo(address, timeout);
+            if (IsServerValid(game, obj))
+                items.Add(obj.Value.MapToGameServerItem(game));
+        });
+        return [.. items];
+    }
+}
diff --git a/GameServerList.App/Program.cs b/GameServerList.App/Program.cs
@@ -15,6 +15,8 @@
 services.AddSingleton<SteamServerBrowserApiService>();
 services.AddSingleton<SteamPlayerDetailApiService>();
 
+services.AddHostedService<GameServerWorker>();
+
 services.AddRazorComponents()
     .AddInteractiveServerComponents();
 

diff --git a/GameServerList.Common/Model/Game.cs b/GameServerList.Common/Model/Game.cs
@@ -15,4 +15,7 @@ public class Game
 
     [JsonIgnore]
     public List<string>? Servers { get; set; }
+
+    [JsonIgnore]
+    public List<GameServerItem>? GameServers { get; set; }
 }
diff --git a/GameServerList.Common/Services/SteamServerBrowserApiService.cs b/GameServerList.Common/Services/SteamServerBrowserApiService.cs
@@ -1,11 +1,8 @@
-using GameServerList.Common.External;
-using GameServerList.Common.Model;
-using GameServerList.Common.Model.A2S;
+using GameServerList.Common.Model;
 using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.Configuration;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
-using System.Collections.Concurrent;
 using System.Net;
 
 namespace GameServerList.Common.Services;
@@ -48,18 +45,8 @@ public async Task<List<GameServerItem>> FetchServers(Game? game)
         {
             entry.AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(1);
 
-            if (game.UseDefinedServerList ?? false)
-            {
-                entry.AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(10);
-                return await QueryServers(game, game.Servers);
-            }
-            else if (game.MasterServer.HasValue)
-            {
-                var legacyServers = await A2SQuery.QueryServerList(
-                    A2SQuery.GetMasterServerAddress(game.MasterServer.Value), game
-                );
-                return await QueryServers(game, legacyServers.Select(s => s.Address).ToList());
-            }
+            if ((game.UseDefinedServerList ?? false) || game.MasterServer.HasValue)
+                return (game.GameServers is null) ? [] : game.GameServers;
             else
             {
                 var gamedirFilter = string.IsNullOrEmpty(game.GameDir) ? string.Empty : $"\\gamedir\\{game.GameDir}";
@@ -72,20 +59,6 @@ public async Task<List<GameServerItem>> FetchServers(Game? game)
         });
     }
 
-    private static bool IsServerValid(Game game, ServerInfo? server)
-    {
-        if (server is null || !server.HasValue)
-            return false;
-
-        if (server.Value.MaxPlayers > 128 || server.Value.MaxPlayers <= 1)
-            return false;
-
-        if (game.MasterServer.HasValue && game.MasterServer.Value == MasterServer.GoldSrc && !server.Value.Version.EndsWith("/Stdio"))
-            return false;
-
-        return true;
-    }
-
     private async Task<List<T>> Fetch<T>(string url)
     {
         try
@@ -105,16 +78,4 @@ private async Task<List<T>> Fetch<T>(string url)
             return [];
         }
     }
-
-    private static async Task<List<GameServerItem>> QueryServers(Game game, List<string> servers, int timeout = 1500)
-    {
-        var items = new ConcurrentBag<GameServerItem>();
-        await Parallel.ForEachAsync(servers, async (address, _) =>
-        {
-            var obj = await A2SQuery.QueryServerInfo(address, timeout);
-            if (IsServerValid(game, obj))
-                items.Add(obj.Value.MapToGameServerItem(game));
-        });
-        return [.. items];
-    }
 }