perf: use fast setter for preload util

Osmi/Game/PreloadUtil.cs

@@ -1,20 +1,13 @@
 namespace Osmi.Game;
 
 public static class PreloadUtil {
-	private static readonly LazyMap<Type, (FieldInfo fi, string sceneName, string path)[]> fields = new(t => t
-		.GetRuntimeFields()
+	private static readonly LazyMap<Type, (string sceneName, string path, Action<GameObject> setter)[]> entries = new(t => t
+		.GetFields(BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic)
 		.Filter(fi => {
 			if (!Attribute.IsDefined(fi, typeof(PreloadAttribute))) {
 				return false;
 			}
 
-			if (!fi.IsStatic) {
-				Logger.LogError(
-					$"[PreloadUtil] Preload field {fi.Name} on type {t.FullName} is not static"
-				);
-				return false;
-			}
-
 			if (fi.IsLiteral) {
 				Logger.LogError(
 					$"[PreloadUtil] Preload field {fi.Name} on type {t.FullName} is const"
@@ -33,12 +26,12 @@ public static class PreloadUtil {
 		})
 		.Map(fi => {
 			PreloadAttribute attr = fi.GetCustomAttribute<PreloadAttribute>();
-			return (fi, attr.SceneName, attr.Path);
+			return (attr.SceneName, attr.Path, fi.GetFastStaticSetter<GameObject>());
 		})
 		.ToArray()
 	);
 
-	public static List<(string, string)> GetPreloadNames<T>() => fields[typeof(T)]
+	public static List<(string, string)> GetPreloadNames<T>() => entries[typeof(T)]
 		.Map(tuple => (tuple.sceneName, tuple.path))
 		.ToList();
 
@@ -47,12 +40,12 @@ public static void SavePreloads<T>(Dictionary<string, Dictionary<string, GameObj
 			return;
 		}
 
-		fields[typeof(T)].ForEach(
-			tuple => tuple.fi.SetValue(null, preloadedObjects[tuple.sceneName][tuple.path])
+		entries[typeof(T)].ForEach(
+			tuple => tuple.setter.Invoke(preloadedObjects[tuple.sceneName][tuple.path])
 		);
 
-		fields.Remove(typeof(T));
+		entries.Remove(typeof(T));
 	}
 
-	static PreloadUtil() => OsmiHooks.GameInitializedHook += fields.Clear;
+	static PreloadUtil() => OsmiHooks.GameInitializedHook += entries.Clear;
 }