Used ReflectionOnly and/or public types where possible to avoid loading related assemblies unnecessarily

Fixes #4763

Co-Authored-By: taloth <taloth@users.noreply.github.com>

src/NzbDrone.Common/Composition/ContainerBuilderBase.cs

@@ -30,14 +30,14 @@ namespace NzbDrone.Common.Composition
 #if !NETCOREAPP
             foreach (var assembly in assemblies)
             {
-                _loadedTypes.AddRange(Assembly.Load(assembly).GetTypes());
+                _loadedTypes.AddRange(Assembly.Load(assembly).GetExportedTypes());
             }
 #else
             var startupPath = AppDomain.CurrentDomain.BaseDirectory;
 
             foreach (var assemblyName in assemblies)
             {
-                _loadedTypes.AddRange(AssemblyLoadContext.Default.LoadFromAssemblyPath(Path.Combine(startupPath, $"{assemblyName}.dll")).GetTypes());
+                _loadedTypes.AddRange(AssemblyLoadContext.Default.LoadFromAssemblyPath(Path.Combine(startupPath, $"{assemblyName}.dll")).GetExportedTypes());
             }
 
             var toRegisterResolver = new List<string> { "System.Data.SQLite" };

src/NzbDrone.Common/Reflection/ReflectionExtensions.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
@@ -17,7 +17,7 @@ namespace NzbDrone.Common.Reflection
 
         public static List<Type> ImplementationsOf<T>(this Assembly assembly)
         {
-            return assembly.GetTypes().Where(c => typeof(T).IsAssignableFrom(c)).ToList();
+            return assembly.GetExportedTypes().Where(c => typeof(T).IsAssignableFrom(c)).ToList();
         }
 
         public static bool IsSimpleType(this Type type)
@@ -68,7 +68,7 @@ namespace NzbDrone.Common.Reflection
 
         public static Type FindTypeByName(this Assembly assembly, string name)
         {
-            return assembly.GetTypes().SingleOrDefault(c => c.Name.Equals(name, StringComparison.InvariantCultureIgnoreCase));
+            return assembly.GetExportedTypes().SingleOrDefault(c => c.Name.Equals(name, StringComparison.InvariantCultureIgnoreCase));
         }
 
         public static bool HasAttribute<TAttribute>(this Type type)

src/NzbDrone.Core/Datastore/DbFactory.cs

@@ -37,6 +37,7 @@ namespace NzbDrone.Core.Datastore
             Environment.SetEnvironmentVariable("No_Expand", "true");
             Environment.SetEnvironmentVariable("No_SQLiteXmlConfigFile", "true");
             Environment.SetEnvironmentVariable("No_PreLoadSQLite", "true");
+            Environment.SetEnvironmentVariable("No_SQLiteFunctions", "true");
         }
 
         public static void RegisterDatabase(IContainer container)

src/NzbDrone.Host/CancelHandler.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using NLog;
 using NzbDrone.Core.Lifecycle;
 
@@ -9,7 +9,7 @@ namespace Radarr.Host
         void Attach();
     }
 
-    internal class CancelHandler : ICancelHandler
+    public class CancelHandler : ICancelHandler
     {
         private readonly ILifecycleService _lifecycleService;
         private object _syncRoot;