Add YAML hot reloading (#1571)

* Implement hot reloading for entity prototypes

* Implement automatic prototype hot-reloading

* Merge fixes

* Add yaml hot reloading and a message to notify the client

* Add reloading only changed files, remove cooldown, add retries and remove IPrototype

* Remove reload command

* Make the client listen for reloads instead and only when focused

* Fix errors

* Only queue a reload when the queue has items in it

* Make fails after 10 retries log instead of throw if reloading

Co-authored-by: Jackson Lewis <inquisitivepenguin@protonmail.com>

Robust.Client.Injectors/MathParsing.cs

@@ -0,0 +1,37 @@
+using System.Linq;
+using Pidgin;
+using static Pidgin.Parser;
+
+
+namespace Robust.Build.Tasks
+{
+    public static class MathParsing
+    {
+        public static Parser<char, float> Single { get; } = Real.Select(c => (float) c);
+
+        public static Parser<char, float> Single1 { get; }
+            = Single.Between(SkipWhitespaces);
+
+        public static Parser<char, (float, float)> Single2 { get; }
+            = Single.Before(SkipWhitespaces).Repeat(2).Select(e =>
+            {
+                var arr = e.ToArray();
+                return (arr[0], arr[1]);
+            });
+
+        public static Parser<char, (float, float, float, float)> Single4 { get; }
+            = Single.Before(SkipWhitespaces).Repeat(4).Select(e =>
+            {
+                var arr = e.ToArray();
+                return (arr[0], arr[1], arr[2], arr[3]);
+            });
+
+        public static Parser<char, float[]> Thickness { get; }
+            = SkipWhitespaces.Then(
+                OneOf(
+                    Try(Single1.Select(c => new[] {c})),
+                    Try(Single2.Select(c => new[] {c.Item1, c.Item2})),
+                    Try(Single4.Select(c => new[] {c.Item1, c.Item2, c.Item3, c.Item4}))
+                ));
+    }
+}

Robust.Client.Injectors/RXamlVecLikeConstAstNode.cs

@@ -0,0 +1,93 @@
+using System;
+using System.Linq;
+using System.Reflection.Emit;
+using XamlX.Ast;
+using XamlX.Emit;
+using XamlX.IL;
+using XamlX.TypeSystem;
+
+namespace Robust.Build.Tasks
+{
+    public abstract class RXamlVecLikeConstAstNode<T>
+        : XamlAstNode, IXamlAstValueNode, IXamlAstILEmitableNode
+        where T : unmanaged
+    {
+        private readonly IXamlConstructor _constructor;
+        protected readonly T[] Values;
+
+        public RXamlVecLikeConstAstNode(
+            IXamlLineInfo lineInfo,
+            IXamlType type, IXamlConstructor constructor,
+            IXamlType componentType, T[] values)
+            : base(lineInfo)
+        {
+            _constructor = constructor;
+            Values = values;
+
+            var @params = constructor.Parameters;
+
+            if (@params.Count != values.Length)
+                throw new ArgumentException("Invalid amount of parameters");
+
+            if (@params.Any(c => c != componentType))
+                throw new ArgumentException("Invalid constructor: not all parameters match component type");
+
+            Type = new XamlAstClrTypeReference(lineInfo, type, false);
+        }
+
+        public IXamlAstTypeReference Type { get; }
+
+        public virtual XamlILNodeEmitResult Emit(
+            XamlEmitContext<IXamlILEmitter, XamlILNodeEmitResult> context,
+            IXamlILEmitter codeGen)
+        {
+            codeGen.Newobj(_constructor);
+
+            return XamlILNodeEmitResult.Type(0, Type.GetClrType());
+        }
+    }
+
+    public sealed class RXamlSingleVecLikeConstAstNode : RXamlVecLikeConstAstNode<float>
+    {
+        public RXamlSingleVecLikeConstAstNode(
+            IXamlLineInfo lineInfo,
+            IXamlType type, IXamlConstructor constructor,
+            IXamlType componentType, float[] values)
+            : base(lineInfo, type, constructor, componentType, values)
+        {
+        }
+
+        public override XamlILNodeEmitResult Emit(XamlEmitContext<IXamlILEmitter, XamlILNodeEmitResult> context,
+            IXamlILEmitter codeGen)
+        {
+            foreach (var value in Values)
+            {
+                codeGen.Emit(OpCodes.Ldc_R4, value);
+            }
+
+            return base.Emit(context, codeGen);
+        }
+    }
+
+    public sealed class RXamlInt32VecLikeConstAstNode : RXamlVecLikeConstAstNode<int>
+    {
+        public RXamlInt32VecLikeConstAstNode(
+            IXamlLineInfo lineInfo,
+            IXamlType type, IXamlConstructor constructor,
+            IXamlType componentType, int[] values)
+            : base(lineInfo, type, constructor, componentType, values)
+        {
+        }
+
+        public override XamlILNodeEmitResult Emit(XamlEmitContext<IXamlILEmitter, XamlILNodeEmitResult> context,
+            IXamlILEmitter codeGen)
+        {
+            foreach (var value in Values)
+            {
+                codeGen.Emit(OpCodes.Ldc_I4, value);
+            }
+
+            return base.Emit(context, codeGen);
+        }
+    }
+}

Robust.Client.Injectors/RXamlWellKnownTypes.cs

@@ -0,0 +1,47 @@
+using System.Linq;
+using XamlX.Transform;
+using XamlX.TypeSystem;
+
+namespace Robust.Build.Tasks
+{
+    class RXamlWellKnownTypes
+    {
+        public XamlTypeWellKnownTypes XamlIlTypes { get; }
+        public IXamlType Single { get; }
+        public IXamlType Int32 { get; }
+        public IXamlType Vector2 { get; }
+        public IXamlConstructor Vector2ConstructorFull { get; }
+        public IXamlType Vector2i { get; }
+        public IXamlConstructor Vector2iConstructorFull { get; }
+
+        public RXamlWellKnownTypes(TransformerConfiguration cfg)
+        {
+            var ts = cfg.TypeSystem;
+            XamlIlTypes = cfg.WellKnownTypes;
+            Single = ts.GetType("System.Single");
+            Int32 = ts.GetType("System.Int32");
+
+            (Vector2, Vector2ConstructorFull) = GetNumericTypeInfo("Robust.Shared.Maths.Vector2", Single, 2);
+            (Vector2i, Vector2iConstructorFull) = GetNumericTypeInfo("Robust.Shared.Maths.Vector2i", Int32, 2);
+
+            (IXamlType, IXamlConstructor) GetNumericTypeInfo(string name, IXamlType componentType, int componentCount)
+            {
+                var type = cfg.TypeSystem.GetType(name);
+                var ctor = type.GetConstructor(Enumerable.Repeat(componentType, componentCount).ToList());
+
+                return (type, ctor);
+            }
+        }
+    }
+
+    static class RXamlWellKnownTypesExtensions
+    {
+        public static RXamlWellKnownTypes GetRobustTypes(this AstTransformationContext ctx)
+        {
+            if (ctx.TryGetItem<RXamlWellKnownTypes>(out var rv))
+                return rv;
+            ctx.SetItem(rv = new RXamlWellKnownTypes(ctx.Configuration));
+            return rv;
+        }
+    }
+}

Robust.Client.Injectors/Robust.Client.Injectors.csproj

@@ -8,6 +8,7 @@
     <ItemGroup>
       <PackageReference Include="Microsoft.Build.Framework" Version="16.8.0" />
       <PackageReference Include="Mono.Cecil" Version="0.11.3" />
+      <PackageReference Include="Pidgin" Version="2.5.0" />
     </ItemGroup>
 
     <ItemGroup>

Robust.Client.Injectors/XamlCompiler.cs

@@ -6,6 +6,7 @@ using Microsoft.Build.Framework;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 using Mono.Cecil.Rocks;
+using Pidgin;
 using XamlX;
 using XamlX.Ast;
 using XamlX.Emit;
@@ -70,7 +71,7 @@ namespace Robust.Build.Tasks
             {
                 XmlnsAttributes =
                 {
-                    typeSystem.GetType("Robust.Client.UserInterface.XAML.XmlnsDefinitionAttribute"),
+                    typeSystem.GetType("Avalonia.Metadata.XmlnsDefinitionAttribute"),
 
                 },
                 ContentAttributes =
@@ -98,7 +99,7 @@ namespace Robust.Build.Tasks
                 typeSystem,
                 typeSystem.TargetAssembly,
                 xamlLanguage,
-                XamlXmlnsMappings.Resolve(typeSystem, xamlLanguage));
+                XamlXmlnsMappings.Resolve(typeSystem, xamlLanguage), CustomValueConverter);
 
             var contextDef = new TypeDefinition("CompiledRobustXaml", "XamlIlContext",
                 TypeAttributes.Class, asm.MainModule.TypeSystem.Object);
@@ -297,6 +298,41 @@ namespace Robust.Build.Tasks
             return true;
         }
 
+        private static bool CustomValueConverter(
+            AstTransformationContext context,
+            IXamlAstValueNode node,
+            IXamlType type,
+            out IXamlAstValueNode result)
+        {
+            if (!(node is XamlAstTextNode textNode))
+            {
+                result = null;
+                return false;
+            }
+
+            var text = textNode.Text;
+            var types = context.GetRobustTypes();
+
+            if (type.Equals(types.Vector2))
+            {
+                var foo = MathParsing.Single2.Parse(text);
+
+                if (!foo.Success)
+                    throw new XamlLoadException($"Unable to parse \"{text}\" as a Vector2", node);
+
+                var (x, y) = foo.Value;
+
+                result = new RXamlSingleVecLikeConstAstNode(
+                    node,
+                    types.Vector2, types.Vector2ConstructorFull,
+                    types.Single, new[] {x, y});
+                return true;
+            }
+
+            result = null;
+            return false;
+        }
+
         public const string ContextNameScopeFieldName = "RobustNameScope";
 
         private static void EmitNameScopeField(XamlLanguageTypeMappings xamlLanguage, CecilTypeSystem typeSystem, IXamlTypeBuilder<IXamlILEmitter> typeBuilder, IXamlILEmitter constructor)

Robust.Client.NameGenerator/XamlUiPartialClassGenerator.cs

@@ -24,6 +24,7 @@ namespace Robust.Client.NameGenerator
     {
         private const string AttributeName = "Robust.Client.AutoGenerated.GenerateTypedNameReferencesAttribute";
         private const string AttributeFile = "GenerateTypedNameReferencesAttribute";
+
         private const string AttributeCode = @"// <auto-generated />
 using System;
 namespace Robust.Client.AutoGenerated
@@ -54,8 +55,8 @@ namespace Robust.Client.AutoGenerated
                 {
                     var clrtype = objectNode.Type.GetClrType();
                     var isControl = IsControl(clrtype);
-                        //clrtype.Interfaces.Any(i =>
-                        //i.IsInterface && i.FullName == "Robust.Client.UserInterface.IControl");
+                    //clrtype.Interfaces.Any(i =>
+                    //i.IsInterface && i.FullName == "Robust.Client.UserInterface.IControl");
 
                     if (!isControl)
                         return node;
@@ -80,9 +81,13 @@ namespace Robust.Client.AutoGenerated
                 return node;
             }
 
-            public void Push(IXamlAstNode node) { }
+            public void Push(IXamlAstNode node)
+            {
+            }
 
-            public void Pop() { }
+            public void Pop()
+            {
+            }
         }
 
         private static string GenerateSourceCode(
@@ -97,16 +102,20 @@ namespace Robust.Client.AutoGenerated
             var compiler =
                 new XamlILCompiler(
                     new TransformerConfiguration(typeSystem, typeSystem.Assemblies[0],
-                        new XamlLanguageTypeMappings(typeSystem)),
+                        new XamlLanguageTypeMappings(typeSystem)
+                        {
+                            XmlnsAttributes = {typeSystem.GetType("Avalonia.Metadata.XmlnsDefinitionAttribute")}
+                        }),
                     new XamlLanguageEmitMappings<IXamlILEmitter, XamlILNodeEmitResult>(), false);
             compiler.Transformers.Add(new TypeReferenceResolver());
             compiler.Transform(parsed);
             var initialRoot = (XamlAstObjectNode) parsed.Root;
             var names = NameVisitor.GetNames(initialRoot);
+            var fieldAccess = classSymbol.IsSealed ? "private" : "protected";
             //var names = NameVisitor.GetNames((XamlAstObjectNode)XDocumentXamlParser.Parse(xamlFile).Root);
             var namedControls = names.Select(info => "        " +
-                                $"protected global::{info.type} {info.name} => " +
-                                $"this.FindControl<global::{info.type}>(\"{info.name}\");");
+                                                     $"{fieldAccess} global::{info.type} {info.name} => " +
+                                                     $"this.FindControl<global::{info.type}>(\"{info.name}\");");
             return $@"// <auto-generated />
 using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
@@ -124,7 +133,7 @@ namespace {nameSpace}
         public void Execute(GeneratorExecutionContext context)
         {
             var comp = (CSharpCompilation) context.Compilation;
-            if(comp.GetTypeByMetadataName(AttributeName) == null)
+            if (comp.GetTypeByMetadataName(AttributeName) == null)
                 context.AddSource(AttributeFile, SourceText.From(AttributeCode, Encoding.UTF8));
             if (!(context.SyntaxReceiver is NameReferenceSyntaxReceiver receiver))
             {
@@ -132,7 +141,7 @@ namespace {nameSpace}
             }
 
             var symbols = UnpackAnnotatedTypes(context, comp, receiver);
-            if(symbols == null)
+            if (symbols == null)
                 return;
 
             foreach (var typeSymbol in symbols)
@@ -168,7 +177,8 @@ namespace {nameSpace}
                                 "Usage",
                                 DiagnosticSeverity.Error,
                                 true),
-                            Location.Create(xamlFileName, new TextSpan(0,0), new LinePositionSpan(new LinePosition(0,0),new LinePosition(0,0)))));
+                            Location.Create(xamlFileName, new TextSpan(0, 0),
+                                new LinePositionSpan(new LinePosition(0, 0), new LinePosition(0, 0)))));
                     continue;
                 }
 
@@ -194,7 +204,8 @@ namespace {nameSpace}
             }
         }
 
-        private IReadOnlyList<INamedTypeSymbol> UnpackAnnotatedTypes(in GeneratorExecutionContext context, CSharpCompilation comp, NameReferenceSyntaxReceiver receiver)
+        private IReadOnlyList<INamedTypeSymbol> UnpackAnnotatedTypes(in GeneratorExecutionContext context,
+            CSharpCompilation comp, NameReferenceSyntaxReceiver receiver)
         {
             var options = (CSharpParseOptions) comp.SyntaxTrees[0].Options;
             var compilation =

Robust.Client/ClientIoC.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using Robust.Client.Audio.Midi;
 using Robust.Client.Console;
 using Robust.Client.Debugging;
@@ -10,6 +10,7 @@ using Robust.Client.Input;
 using Robust.Client.Map;
 using Robust.Client.Placement;
 using Robust.Client.Player;
+using Robust.Client.Prototypes;
 using Robust.Client.Reflection;
 using Robust.Client.ResourceManagement;
 using Robust.Client.State;
@@ -17,6 +18,7 @@ using Robust.Client.UserInterface;
 using Robust.Client.Utility;
 using Robust.Client.ViewVariables;
 using Robust.Shared;
+using Robust.Shared.Console;
 using Robust.Shared.ContentPack;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
@@ -33,7 +35,7 @@ namespace Robust.Client
         {
             SharedIoC.RegisterIoC();
 
-            IoCManager.Register<IPrototypeManager, PrototypeManager>();
+            IoCManager.Register<IPrototypeManager, ClientPrototypeManager>();
             IoCManager.Register<IEntityManager, ClientEntityManager>();
             IoCManager.Register<IComponentFactory, ClientComponentFactory>();
             IoCManager.Register<ITileDefinitionManager, ClydeTileDefinitionManager>();
@@ -59,6 +61,7 @@ namespace Robust.Client
             IoCManager.Register<ILightManager, LightManager>();
             IoCManager.Register<IDiscordRichPresence, DiscordRichPresence>();
             IoCManager.Register<IClientConsoleHost, ClientConsoleHost>();
+            IoCManager.Register<IConsoleHost, ClientConsoleHost>();
             IoCManager.Register<IFontManager, FontManager>();
             IoCManager.Register<IFontManagerInternal, FontManager>();
             IoCManager.Register<IMidiManager, MidiManager>();

Robust.Client/GameController.cs

@@ -26,7 +26,6 @@ using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization;
-using Robust.Shared.Timers;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -163,6 +162,7 @@ namespace Robust.Client
             _serializer.Initialize();
             _inputManager.Initialize();
             _consoleHost.Initialize();
+            _prototypeManager.Initialize();
             _prototypeManager.LoadDirectory(new ResourcePath(@"/Prototypes/"));
             _prototypeManager.Resync();
             _mapManager.Initialize();

Robust.Client/GameObjects/Components/IgnorePauseComponent.cs

@@ -1,11 +0,0 @@
-using Robust.Shared.GameObjects;
-
-namespace Robust.Client.GameObjects
-{
-    [RegisterComponent]
-    [ComponentReference(typeof(SharedIgnorePauseComponent))]
-    public sealed class IgnorePauseComponent : SharedIgnorePauseComponent
-    {
-
-    }
-}

Robust.Client/GameObjects/EntitySystems/InputSystem.cs

@@ -40,7 +40,7 @@ namespace Robust.Client.GameObjects
         /// <param name="message">Arguments for this event.</param>
         /// <param name="replay">if true, current cmd state will not be checked or updated - use this for "replaying" an
         /// old input that was saved or buffered until further processing could be done</param>
-        public bool HandleInputCommand(ICommonSession session, BoundKeyFunction function, FullInputCmdMessage message, bool replay = false)
+        public bool HandleInputCommand(ICommonSession? session, BoundKeyFunction function, FullInputCmdMessage message, bool replay = false)
         {
             #if DEBUG
 

Robust.Client/GameStates/ClientGameStateManager.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using Robust.Client.GameObjects;
 using Robust.Client.Input;
 using Robust.Shared.GameStates;
@@ -352,7 +353,10 @@ namespace Robust.Client.GameStates
 
                 foreach (var component in _componentManager.GetNetComponents(createdEntity))
                 {
-                    var state = component.GetComponentState();
+                    Debug.Assert(_players.LocalPlayer != null, "_players.LocalPlayer != null");
+
+                    var player = _players.LocalPlayer.Session;
+                    var state = component.GetComponentState(player);
 
                     if (state.GetType() == typeof(ComponentState))
                     {

Robust.Client/Graphics/Clyde/Clyde.Windowing.cs

@@ -55,6 +55,7 @@ namespace Robust.Client.Graphics.Clyde
         private GLFWCallbacks.WindowSizeCallback _windowSizeCallback = default!;
         private GLFWCallbacks.WindowContentScaleCallback _windowContentScaleCallback = default!;
         private GLFWCallbacks.WindowIconifyCallback _windowIconifyCallback = default!;
+        private GLFWCallbacks.WindowFocusCallback _windowFocusCallback = default!;
 
         private bool _glfwInitialized;
 
@@ -62,6 +63,7 @@ namespace Robust.Client.Graphics.Clyde
         private Window* _glfwWindow;
 
         private Vector2i _framebufferSize;
+        private bool _isFocused;
         private Vector2i _windowSize;
         private Vector2i _prevWindowSize;
         private Vector2i _prevWindowPos;
@@ -74,6 +76,7 @@ namespace Robust.Client.Graphics.Clyde
         // NOTE: in engine we pretend the framebuffer size is the screen size..
         // For practical reasons like UI rendering.
         public override Vector2i ScreenSize => _framebufferSize;
+        public override bool IsFocused => _isFocused;
         public Vector2 DefaultWindowScale => _windowScale;
         public Vector2 MouseScreenPosition => _lastMousePos;
 
@@ -231,6 +234,7 @@ namespace Robust.Client.Graphics.Clyde
             GLFW.SetMouseButtonCallback(_glfwWindow, _mouseButtonCallback);
             GLFW.SetWindowContentScaleCallback(_glfwWindow, _windowContentScaleCallback);
             GLFW.SetWindowIconifyCallback(_glfwWindow, _windowIconifyCallback);
+            GLFW.SetWindowFocusCallback(_glfwWindow, _windowFocusCallback);
 
             GLFW.MakeContextCurrent(_glfwWindow);
 
@@ -548,6 +552,19 @@ namespace Robust.Client.Graphics.Clyde
             }
         }
 
+        private void OnGlfwWindowFocus(Window* window, bool focused)
+        {
+            try
+            {
+                _isFocused = focused;
+                OnWindowFocused?.Invoke(new WindowFocusedEventArgs(focused));
+            }
+            catch (Exception e)
+            {
+                CatchCallbackException(e);
+            }
+        }
+
         private void StoreCallbacks()
         {
             _errorCallback = OnGlfwError;
@@ -560,6 +577,7 @@ namespace Robust.Client.Graphics.Clyde
             _windowSizeCallback = OnGlfwWindowSize;
             _windowContentScaleCallback = OnGlfwWindownContentScale;
             _windowIconifyCallback = OnGlfwWindowIconify;
+            _windowFocusCallback = OnGlfwWindowFocus;
         }
 
         public override void SetWindowTitle(string title)

Robust.Client/Graphics/Clyde/Clyde.cs

@@ -88,7 +88,7 @@ namespace Robust.Client.Graphics.Clyde
         public override bool Initialize()
         {
             base.Initialize();
-            
+
             _configurationManager.OnValueChanged(CVars.DisplayOGLCheckErrors, b => _checkGLErrors = b, true);
 
             if (!InitWindowing())
@@ -152,6 +152,8 @@ namespace Robust.Client.Graphics.Clyde
 
         public override event Action<WindowResizedEventArgs>? OnWindowResized;
 
+        public override event Action<WindowFocusedEventArgs>? OnWindowFocused;
+
         public void Screenshot(ScreenshotType type, Action<Image<Rgb24>> callback)
         {
             _queuedScreenshots.Add((type, callback));

Robust.Client/Graphics/Clyde/ClydeHeadless.cs

@@ -21,6 +21,7 @@ namespace Robust.Client.Graphics.Clyde
         public IRenderWindow MainWindowRenderTarget { get; }
         public override Vector2i ScreenSize { get; } = (1280, 720);
         public Vector2 DefaultWindowScale => (1, 1);
+        public override bool IsFocused => true;
 
         public ShaderInstance InstanceShader(ClydeHandle handle)
         {
@@ -79,6 +80,12 @@ namespace Robust.Client.Graphics.Clyde
             remove { }
         }
 
+        public override event Action<WindowFocusedEventArgs> OnWindowFocused
+        {
+            add { }
+            remove { }
+        }
+
         public void Render()
         {
             // Nada.

Robust.Client/Graphics/ClydeBase.cs

@@ -25,6 +25,8 @@ namespace Robust.Client.Graphics
         protected bool VSync { get; private set; } = true;
 
         public abstract Vector2i ScreenSize { get; }
+        public abstract bool IsFocused { get; }
+
         public abstract void SetWindowTitle(string title);
 
         public virtual bool Initialize()
@@ -45,6 +47,8 @@ namespace Robust.Client.Graphics
 
         public abstract event Action<WindowResizedEventArgs> OnWindowResized;
 
+        public abstract event Action<WindowFocusedEventArgs> OnWindowFocused;
+
         protected virtual void ReadConfig()
         {
             WindowMode = (WindowMode) _configurationManager.GetCVar(CVars.DisplayWindowMode);

Robust.Client/Graphics/IClyde.cs

@@ -13,6 +13,8 @@ namespace Robust.Client.Graphics
 
         Vector2i ScreenSize { get; }
 
+        bool IsFocused { get; }
+
         /// <summary>
         ///     The default scale ratio for window contents, given to us by the OS.
         /// </summary>
@@ -27,6 +29,8 @@ namespace Robust.Client.Graphics
 
         event Action<WindowResizedEventArgs> OnWindowResized;
 
+        event Action<WindowFocusedEventArgs> OnWindowFocused;
+
         Texture LoadTextureFromPNGStream(Stream stream, string? name = null,
             TextureLoadParameters? loadParams = null);
 

Robust.Client/Graphics/Shaders/ShaderPrototype.cs

@@ -12,7 +12,7 @@ using YamlDotNet.RepresentationModel;
 namespace Robust.Client.Graphics
 {
     [Prototype("shader")]
-    public sealed class ShaderPrototype : IPrototype, IIndexedPrototype
+    public sealed class ShaderPrototype : IPrototype
     {
         [Dependency] private readonly IClydeInternal _clyde = default!;
         [Dependency] private readonly IResourceCache _resourceCache = default!;

Robust.Client/Graphics/WindowFocusedEventArgs.cs

@@ -0,0 +1,14 @@
+using System;
+
+namespace Robust.Client.Graphics
+{
+    public class WindowFocusedEventArgs : EventArgs
+    {
+        public WindowFocusedEventArgs(bool focused)
+        {
+            Focused = focused;
+        }
+
+        public bool Focused { get; }
+    }
+}

Robust.Client/Player/IPlayerManager.cs

@@ -12,6 +12,11 @@ namespace Robust.Client.Player
 
         LocalPlayer? LocalPlayer { get; }
 
+        /// <summary>
+        /// Invoked after LocalPlayer is changed
+        /// </summary>
+        event Action<LocalPlayerChangedEventArgs>? LocalPlayerChanged;
+
         int PlayerCount { get; }
         int MaxPlayers { get; }
         event EventHandler PlayerListUpdated;
@@ -23,4 +28,15 @@ namespace Robust.Client.Player
 
         void ApplyPlayerStates(IEnumerable<PlayerState>? list);
     }
+
+    public class LocalPlayerChangedEventArgs : EventArgs
+    {
+        public readonly LocalPlayer? OldPlayer;
+        public readonly LocalPlayer? NewPlayer;
+        public LocalPlayerChangedEventArgs(LocalPlayer? oldPlayer, LocalPlayer? newPlayer)
+        {
+            OldPlayer = oldPlayer;
+            NewPlayer = newPlayer;
+        }
+    }
 }

Robust.Client/Player/PlayerManager.cs

@@ -37,7 +37,21 @@ namespace Robust.Client.Player
         public int MaxPlayers => _client.GameInfo?.ServerMaxPlayers ?? 0;
 
         /// <inheritdoc />
-        [ViewVariables] public LocalPlayer? LocalPlayer { get; private set; }
+        [ViewVariables]
+        public LocalPlayer? LocalPlayer
+        {
+            get => _localPlayer;
+            private set
+            {
+                if (_localPlayer == value) return;
+                var oldValue = _localPlayer;
+                _localPlayer = value;
+                LocalPlayerChanged?.Invoke(new LocalPlayerChangedEventArgs(oldValue, _localPlayer));
+            }
+        }
+        private LocalPlayer? _localPlayer;
+        public event Action<LocalPlayerChangedEventArgs>? LocalPlayerChanged;
+
 
         /// <inheritdoc />
         [ViewVariables] public IEnumerable<IPlayerSession> Sessions => _sessions.Values;

Robust.Client/Prototypes/ClientPrototypeManager.cs

@@ -0,0 +1,119 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using Robust.Client.Graphics;
+using Robust.Shared.ContentPack;
+using Robust.Shared.IoC;
+using Robust.Shared.Log;
+using Robust.Shared.Network;
+using Robust.Shared.Network.Messages;
+using Robust.Shared.Prototypes;
+using Robust.Shared.Utility;
+using Timer = Robust.Shared.Timing.Timer;
+
+namespace Robust.Client.Prototypes
+{
+    public sealed class ClientPrototypeManager : PrototypeManager
+    {
+        [Dependency] private readonly IClyde _clyde = default!;
+
+        private readonly List<FileSystemWatcher> _watchers = new();
+        private readonly TimeSpan _reloadDelay = TimeSpan.FromMilliseconds(10);
+        private CancellationTokenSource _reloadToken = new();
+        private readonly HashSet<ResourcePath> _reloadQueue = new();
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            NetManager.RegisterNetMessage<MsgReloadPrototypes>(MsgReloadPrototypes.NAME, accept: NetMessageAccept.Server);
+
+            _clyde.OnWindowFocused += WindowFocusedChanged;
+
+            WatchResources();
+        }
+
+        private void WindowFocusedChanged(WindowFocusedEventArgs args)
+        {
+#if !FULL_RELEASE
+            if (args.Focused && _reloadQueue.Count > 0)
+            {
+                Timer.Spawn(_reloadDelay, ReloadPrototypeQueue, _reloadToken.Token);
+            }
+            else
+            {
+                _reloadToken.Cancel();
+                _reloadToken = new CancellationTokenSource();
+            }
+#endif
+        }
+
+        private void ReloadPrototypeQueue()
+        {
+            var then = DateTime.Now;
+
+            var msg = NetManager.CreateNetMessage<MsgReloadPrototypes>();
+            msg.Paths = _reloadQueue.ToArray();
+            NetManager.ClientSendMessage(msg);
+
+            foreach (var path in _reloadQueue)
+            {
+                ReloadPrototypes(path);
+            }
+
+            Logger.Info($"Reloaded prototypes in {(int) (DateTime.Now - then).TotalMilliseconds} ms");
+        }
+
+        private void WatchResources()
+        {
+#if !FULL_RELEASE
+            foreach (var path in Resources.GetContentRoots().Select(r => r.ToString())
+                .Where(r => Directory.Exists(r + "/Prototypes")).Select(p => p + "/Prototypes"))
+            {
+                var watcher = new FileSystemWatcher(path, "*.yml")
+                {
+                    IncludeSubdirectories = true,
+                    NotifyFilter = NotifyFilters.LastWrite
+                };
+
+                watcher.Changed += (_, args) =>
+                {
+                    switch (args.ChangeType)
+                    {
+                        case WatcherChangeTypes.Renamed:
+                        case WatcherChangeTypes.Deleted:
+                            return;
+                        case WatcherChangeTypes.Created:
+                        // case WatcherChangeTypes.Deleted:
+                        case WatcherChangeTypes.Changed:
+                        case WatcherChangeTypes.All:
+                            break;
+                        default:
+                            throw new ArgumentOutOfRangeException();
+                    }
+
+                    TaskManager.RunOnMainThread(() =>
+                    {
+                        var file = new ResourcePath(args.FullPath);
+
+                        foreach (var root in IoCManager.Resolve<IResourceManager>().GetContentRoots())
+                        {
+                            if (!file.TryRelativeTo(root, out var relative))
+                            {
+                                continue;
+                            }
+
+                            _reloadQueue.Add(relative);
+                        }
+                    });
+                };
+
+                watcher.EnableRaisingEvents = true;
+                _watchers.Add(watcher);
+            }
+#endif
+        }
+    }
+}

Robust.Client/UserInterface/Controls/ItemList.cs

@@ -5,7 +5,7 @@ using System.Diagnostics.Contracts;
 using Robust.Client.Graphics;
 using Robust.Shared.Input;
 using Robust.Shared.Maths;
-using Timer = Robust.Shared.Timers.Timer;
+using Timer = Robust.Shared.Timing.Timer;
 
 namespace Robust.Client.UserInterface.Controls
 {

Robust.Client/UserInterface/Controls/OptionButton.cs

@@ -15,15 +15,36 @@ namespace Robust.Client.UserInterface.Controls
         private readonly Popup _popup;
         private readonly VBoxContainer _popupVBox;
         private readonly Label _label;
+        private readonly TextureRect _triangle;
 
         public int ItemCount => _buttonData.Count;
 
+        /// <summary>
+        /// If true, hides the triangle that normally appears to the right of the button label
+        /// </summary>
+        public bool HideTriangle
+        {
+            get => _hideTriangle;
+            set
+            {
+                _hideTriangle = value;
+                _triangle.Visible = !_hideTriangle;
+            }
+        }
+        private bool _hideTriangle;
+
+        /// <summary>
+        /// StyleClasses to apply to the options that popup when clicking this button.
+        /// </summary>
+        public ICollection<string> OptionStyleClasses { get; }
+
         public event Action<ItemSelectedEventArgs>? OnItemSelected;
 
         public string Prefix { get; set; }
 
         public OptionButton()
         {
+            OptionStyleClasses = new List<string>();
             AddStyleClass(StyleClassButton);
             Prefix = "";
             OnPressed += OnPressedInternal;
@@ -43,12 +64,13 @@ namespace Robust.Client.UserInterface.Controls
             };
             hBox.AddChild(_label);
 
-            var textureRect = new TextureRect
+            _triangle = new TextureRect
             {
                 StyleClasses = { StyleClassOptionTriangle },
                 SizeFlagsVertical = SizeFlags.ShrinkCenter,
+                Visible = !HideTriangle
             };
-            hBox.AddChild(textureRect);
+            hBox.AddChild(_triangle);
         }
 
         public void AddItem(Texture icon, string label, int? id = null)
@@ -73,6 +95,10 @@ namespace Robust.Client.UserInterface.Controls
                 Text = label,
                 ToggleMode = true
             };
+            foreach (var styleClass in OptionStyleClasses)
+            {
+                button.AddStyleClass(styleClass);
+            }
             button.OnPressed += ButtonOnPressed;
             var data = new ButtonData(label, button)
             {
@@ -170,6 +196,10 @@ namespace Robust.Client.UserInterface.Controls
             }
         }
 
+        /// <summary>
+        /// Select by index rather than id. Throws exception if item with that index
+        /// not in this control.
+        /// </summary>
         public void Select(int idx)
         {
             if (_idMap.TryGetValue(SelectedId, out var prevIdx))
@@ -182,11 +212,29 @@ namespace Robust.Client.UserInterface.Controls
             data.Button.Pressed = true;
         }
 
+        /// <summary>
+        /// Select by index rather than id.
+        /// </summary>
+        /// <returns>false if item with that index not in this control</returns>
+        public bool TrySelect(int idx)
+        {
+            if (idx < 0 || idx >= _buttonData.Count) return false;
+            Select(idx);
+            return true;
+        }
+
+        /// throws exception if item with this ID is not in this control
         public void SelectId(int id)
         {
             Select(GetIdx(id));
         }
 
+        /// <returns>false if item with id not in this control</returns>
+        public bool TrySelectId(int id)
+        {
+            return _idMap.TryGetValue(id, out var idx) && TrySelect(idx);
+        }
+
         public int GetIdx(int id)
         {
             return _idMap[id];

Robust.Client/UserInterface/CustomControls/SS14Window.xaml

@@ -1,15 +1,17 @@
-<cc:SS14Window xmlns:cc="clr-namespace:Robust.Client.UserInterface.CustomControls"
-                           xmlns:c="clr-namespace:Robust.Client.UserInterface.Controls">
-    <c:PanelContainer StyleClasses="windowPanel"/>
-    <c:VBoxContainer SeparationOverride="0">
-        <c:PanelContainer Name="WindowHeader" StyleClasses="windowHeader">
-            <c:HBoxContainer>
-                <c:MarginContainer MarginLeftOverride="5" SizeFlagsHorizontal="FillExpand">
-                    <c:Label Name="TitleLabel" StyleIdentifier="foo" ClipText="True" Text="Exemplary Window Title Here" VAlign="Center" StyleClasses="windowTitle"/>
-                </c:MarginContainer>
-                <c:TextureButton Name="CloseButton" StyleClasses="windowCloseButton" SizeFlagsVertical="ShrinkCenter"></c:TextureButton>
-            </c:HBoxContainer>
-        </c:PanelContainer>
-        <c:MarginContainer Name="ContentsContainer" MarginBottomOverride="10" MarginLeftOverride="10" MarginRightOverride="10" MarginTopOverride="10" RectClipContent="True" SizeFlagsVertical="FillExpand" />
-    </c:VBoxContainer>
-</cc:SS14Window>
+<SS14Window xmlns="https://spacestation14.io">
+    <PanelContainer StyleClasses="windowPanel" />
+    <VBoxContainer SeparationOverride="0">
+        <PanelContainer Name="WindowHeader" StyleClasses="windowHeader">
+            <HBoxContainer>
+                <MarginContainer MarginLeftOverride="5" SizeFlagsHorizontal="FillExpand">
+                    <Label Name="TitleLabel" StyleIdentifier="foo" ClipText="True"
+                             Text="{Loc Exemplary Window Title Here}" VAlign="Center" StyleClasses="windowTitle" />
+                </MarginContainer>
+                <TextureButton Name="CloseButton" StyleClasses="windowCloseButton" SizeFlagsVertical="ShrinkCenter" />
+            </HBoxContainer>
+        </PanelContainer>
+        <MarginContainer Name="ContentsContainer" MarginBottomOverride="10" MarginLeftOverride="10"
+                           MarginRightOverride="10" MarginTopOverride="10" RectClipContent="True"
+                           SizeFlagsVertical="FillExpand" />
+    </VBoxContainer>
+</SS14Window>

Robust.Client/UserInterface/LocExtension.cs

@@ -0,0 +1,23 @@
+using JetBrains.Annotations;
+using Robust.Shared.Localization;
+
+namespace Robust.Client.UserInterface
+{
+    // TODO: Code a XAML compiler transformer to remove references to this type at compile time.
+    // And just replace them with the Loc.GetString() call.
+    [PublicAPI]
+    public class LocExtension
+    {
+        public string Key { get; }
+
+        public LocExtension(string key)
+        {
+            Key = key;
+        }
+
+        public object ProvideValue()
+        {
+            return Loc.GetString(Key);
+        }
+    }
+}

Robust.Client/UserInterface/XAML/Attributes.cs

@@ -6,13 +6,6 @@ namespace Robust.Client.UserInterface.XAML
     {
     }
 
-    public class XmlnsDefinitionAttribute : Attribute
-    {
-        public XmlnsDefinitionAttribute(string xmlNamespace, string clrNamespace)
-        {
-        }
-    }
-
     public class UsableDuringInitializationAttribute : Attribute
     {
         public UsableDuringInitializationAttribute(bool usable)

Robust.Client/UserInterface/XAML/Binding.cs

@@ -0,0 +1,16 @@
+using System;
+using JetBrains.Annotations;
+
+// ReSharper disable once CheckNamespace
+namespace Avalonia.Data
+{
+    [UsedImplicitly]
+    public class Binding
+    {
+        public Binding()
+        {
+            throw new InvalidOperationException(
+                "Data binding is not currently supported and this type exists only to make Rider work.");
+        }
+    }
+}

Robust.Client/UserInterface/XAML/Namespaces.cs

@@ -0,0 +1,6 @@
+using Avalonia.Metadata;
+
+[assembly: XmlnsDefinition("http://schemas.microsoft.com/winfx/2006/xaml", "Robust.Client.UserInterface.XAML.XNamespace")]
+[assembly: XmlnsDefinition("https://spacestation14.io", "Robust.Client.UserInterface")]
+[assembly: XmlnsDefinition("https://spacestation14.io", "Robust.Client.UserInterface.Controls")]
+[assembly: XmlnsDefinition("https://spacestation14.io", "Robust.Client.UserInterface.CustomControls")]

Robust.Client/UserInterface/XAML/NullExtension.cs

@@ -0,0 +1,12 @@
+using JetBrains.Annotations;
+
+// ReSharper disable once CheckNamespace
+namespace Robust.Client.UserInterface.XAML.XNamespace
+{
+    // x:Null
+    [UsedImplicitly]
+    public sealed class NullExtension
+    {
+
+    }
+}

Robust.Client/UserInterface/XAML/RiderNotes.md

@@ -0,0 +1,28 @@
+# XamlUI notes about Rider
+
+XAML support in both Rider and VS is pretty hardcoded for all supported frameworks. Rider seems less bad about this but they still hardcode a lot of type paths and do other silly stuff. Luckily, they support Avalonia. So... let's pretend to be Avalonia!
+
+**JetBrains, if you're reading this, please don't sue me or take away our licenses pls I only reverse engineered your program to avoid wasting time on your issue tracker.**
+
+## Where to find this info
+
+The primary XAML support in Rider appears to be in `lib/ReSharperHost/JetBrains.ReSharper.Psi.Xaml.dll`. I recommend you decompile it with DotPeek to a project for navigating around. You can then look around the decompiled code (it's not obfuscated at all) to figure out how Rider does all this stuff.
+
+**JetBrains, if you're reading this, please don't sue me or take away our licenses pls I only reverse engineered your program to avoid wasting time on your issue tracker.**
+
+## Attributes
+
+Attributes like `XmlnsAttributionAttribute` are hardcoded for full name with namespace. That's also where it stops, so we just define our own `Avalonia.Metadata.XmlnsDefinitionAttribute` and this fools Rider into recognizing it and working. Hooray!
+
+## `http://schemas.microsoft.com/winfx/2006/xaml` Namespace
+
+As far as I can tell, at least in Avalonia, the things in this namespace are not backed by any real .NET symbols and are just made up by Rider. This is a problem because it only does this making up if it detects that you're using Avalonia.
+
+The heuristic for "are we using Avalonia" appears to be finding an assembly or project reference for `Avalonia.Base`. You can see this in `XamlModulePlatformCache.cs` in the decompiled ReSharper source code and also the `XamlPlatform` flags enum.
+
+For the time being I decided to hold off on actually fully pretending we're Avalonia so did *not* commit to a reference to `Avalonia.Base` yet. Instead we just manually created stuff like a dummy `StaticExtension` class (with a constructor that always throws) and put it into the `http://schemas.microsoft.com/winfx/2006/xaml` namespace. This seems to satisfy Rider without interfering with the actual XamlIL compilation.
+
+## Markup Extensions
+
+Markup extensions have to be classes with a method of signature either `object ProvideValue(IServiceProvider)` or `object ProvideValue()`.
+It should be noted that Rider refuses to acknowledge markup extensions unless it finds Avalonia's `Avalonia.Data.Binding` type (or `Avalonia.Markup.Xaml.Data.Binding`). Yes, this is an actual requirement.

Robust.Client/UserInterface/XAML/StaticExtension.cs

@@ -0,0 +1,22 @@
+using System;
+using JetBrains.Annotations;
+
+// ReSharper disable once CheckNamespace
+namespace Robust.Client.UserInterface.XAML.XNamespace
+{
+    // x:Static
+    [UsedImplicitly]
+    public sealed class StaticExtension
+    {
+        public StaticExtension(string _)
+        {
+            throw new InvalidOperationException(
+                "This type only exists to make Rider work and should never be instantiated.");
+        }
+
+        public static object ProvideValue()
+        {
+            throw new InvalidOperationException();
+        }
+    }
+}

Robust.Client/UserInterface/XAML/TypeExtension.cs

@@ -0,0 +1,22 @@
+using System;
+using JetBrains.Annotations;
+
+// ReSharper disable once CheckNamespace
+namespace Robust.Client.UserInterface.XAML.XNamespace
+{
+    // x:Type
+    [UsedImplicitly]
+    public sealed class TypeExtension
+    {
+        public TypeExtension(string _)
+        {
+            throw new InvalidOperationException(
+                "This type only exists to make Rider work and should never be instantiated.");
+        }
+
+        public static object ProvideValue()
+        {
+            throw new InvalidOperationException();
+        }
+    }
+}

Robust.Client/UserInterface/XAML/XmlnsDefinitionAttribute.cs

@@ -0,0 +1,20 @@
+using System;
+using JetBrains.Annotations;
+
+// ReSharper disable once CheckNamespace
+namespace Avalonia.Metadata
+{
+    [AttributeUsage(AttributeTargets.Assembly, AllowMultiple = true)]
+    [PublicAPI]
+    public sealed class XmlnsDefinitionAttribute : Attribute
+    {
+        public XmlnsDefinitionAttribute(string xmlNamespace, string clrNamespace)
+        {
+            XmlNamespace = xmlNamespace;
+            ClrNamespace = clrNamespace;
+        }
+
+        public string XmlNamespace { get; }
+        public string ClrNamespace { get; }
+    }
+}

Robust.Client/ViewVariables/Instances/ViewVariablesInstanceObject.cs

@@ -1,21 +1,27 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
+using System.Threading;
 using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Client.UserInterface.CustomControls;
 using Robust.Client.ViewVariables.Traits;
+using Robust.Shared.Input;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 using Robust.Shared.Utility;
+using Timer = Robust.Shared.Timing.Timer;
 
 namespace Robust.Client.ViewVariables.Instances
 {
     internal class ViewVariablesInstanceObject : ViewVariablesInstance
     {
         private TabContainer _tabs = default!;
+        private Button _refreshButton = default!;
         private int _tabCount;
 
         private readonly List<ViewVariablesTrait> _traits = new();
 
+        private CancellationTokenSource _refreshCancelToken = new();
+
         public ViewVariablesRemoteSession? Session { get; private set; }
         public object? Object { get; private set; }
 
@@ -72,9 +78,10 @@ namespace Robust.Client.ViewVariables.Instances
                 name.SizeFlagsHorizontal = Control.SizeFlags.FillExpand;
                 headBox.AddChild(name);
 
-                var button = new Button {Text = "Refresh"};
-                button.OnPressed += _ => _refresh();
-                headBox.AddChild(button);
+                _refreshButton = new Button {Text = "Refresh", ToolTip = "RMB to toggle auto-refresh."};
+                _refreshButton.OnPressed += _ => _refresh();
+                _refreshButton.OnKeyBindDown += OnButtonKeybindDown;
+                headBox.AddChild(_refreshButton);
                 vBoxContainer.AddChild(headBox);
             }
 
@@ -82,10 +89,32 @@ namespace Robust.Client.ViewVariables.Instances
             vBoxContainer.AddChild(_tabs);
         }
 
+        private void OnButtonKeybindDown(GUIBoundKeyEventArgs eventArgs)
+        {
+            if (eventArgs.Function == EngineKeyFunctions.UIRightClick)
+            {
+                _refreshButton.ToggleMode = !_refreshButton.ToggleMode;
+                _refreshButton.Pressed = !_refreshButton.Pressed;
+
+                _refreshCancelToken.Cancel();
+
+                if (!_refreshButton.Pressed) return;
+
+                _refreshCancelToken = new CancellationTokenSource();
+                Timer.SpawnRepeating(500, _refresh, _refreshCancelToken.Token);
+
+            } else if (eventArgs.Function == EngineKeyFunctions.UIClick)
+            {
+                _refreshButton.ToggleMode = false;
+            }
+        }
+
         public override void Close()
         {
             base.Close();
 
+            _refreshCancelToken.Cancel();
+
             if (Session != null && !Session.Closed)
             {
                 ViewVariablesManager.CloseSession(Session);

Robust.Server/BaseServer.cs

@@ -31,7 +31,6 @@ using Robust.Shared.Localization;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Serialization;
-using Robust.Shared.Timers;
 using Serilog.Debugging;
 using Serilog.Sinks.Loki;
 using Stopwatch = Robust.Shared.Timing.Stopwatch;
@@ -273,12 +272,17 @@ namespace Robust.Server
 
             //IoCManager.Resolve<IMapLoader>().LoadedMapData +=
             //    IoCManager.Resolve<IRobustMappedStringSerializer>().AddStrings;
-            IoCManager.Resolve<IPrototypeManager>().LoadedData +=
-                (yaml, name) => _stringSerializer.AddStrings(yaml);
+            IoCManager.Resolve<IPrototypeManager>().LoadedData += (yaml, name) =>
+            {
+                if (!_stringSerializer.Locked)
+                {
+                    _stringSerializer.AddStrings(yaml);
+                }
+            };
 
             // Initialize Tier 2 services
             IoCManager.Resolve<IGameTiming>().InSimulation = true;
-            
+
             IoCManager.Resolve<INetConfigurationManager>().SetupNetworking();
 
             _stateManager.Initialize();
@@ -297,6 +301,7 @@ namespace Robust.Server
             // because of 'reasons' this has to be called after the last assembly is loaded
             // otherwise the prototypes will be cleared
             var prototypeManager = IoCManager.Resolve<IPrototypeManager>();
+            prototypeManager.Initialize();
             prototypeManager.LoadDirectory(new ResourcePath(@"/Prototypes"));
             prototypeManager.Resync();
 

Robust.Server/Console/Commands/AddCompCommand.cs

@@ -1,64 +0,0 @@
-using JetBrains.Annotations;
-using Robust.Shared.Console;
-using Robust.Shared.GameObjects;
-using Robust.Shared.IoC;
-
-namespace Robust.Server.Console.Commands
-{
-    [UsedImplicitly]
-    internal sealed class AddCompCommand : IConsoleCommand
-    {
-        public string Command => "addcomp";
-        public string Description => "Adds a component to an entity";
-        public string Help => "addcomp <uid> <componentName>";
-
-        public void Execute(IConsoleShell shell, string argStr, string[] args)
-        {
-            if (args.Length != 2)
-            {
-                shell.WriteLine("Wrong number of arguments");
-                return;
-            }
-
-            var entityUid = EntityUid.Parse(args[0]);
-            var componentName = args[1];
-
-            var compManager = IoCManager.Resolve<IComponentManager>();
-            var compFactory = IoCManager.Resolve<IComponentFactory>();
-            var entityManager = IoCManager.Resolve<IEntityManager>();
-
-            var entity = entityManager.GetEntity(entityUid);
-            var component = (Component) compFactory.GetComponent(componentName);
-
-            component.Owner = entity;
-
-            compManager.AddComponent(entity, component);
-        }
-    }
-
-    [UsedImplicitly]
-    internal sealed class RemoveCompCommand : IConsoleCommand
-    {
-        public string Command => "rmcomp";
-        public string Description => "Removes a component from an entity.";
-        public string Help => "rmcomp <uid> <componentName>";
-        public void Execute(IConsoleShell shell, string argStr, string[] args)
-        {
-            if (args.Length != 2)
-            {
-                shell.WriteLine("Wrong number of arguments");
-                return;
-            }
-
-            var entityUid = EntityUid.Parse(args[0]);
-            var componentName = args[1];
-
-            var compManager = IoCManager.Resolve<IComponentManager>();
-            var compFactory = IoCManager.Resolve<IComponentFactory>();
-
-            var registration = compFactory.GetRegistration(componentName);
-
-            compManager.RemoveComponent(entityUid, registration.Type);
-        }
-    }
-}

Robust.Server/Console/Commands/AddComponentCommand.cs

@@ -0,0 +1,61 @@
+using JetBrains.Annotations;
+using Robust.Shared.Console;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+
+namespace Robust.Server.Console.Commands
+{
+    [UsedImplicitly]
+    internal sealed class AddComponentCommand : IConsoleCommand
+    {
+        public string Command => "addcomp";
+        public string Description => "Adds a component to an entity";
+        public string Help => $"{Command} <uid> <componentName>";
+
+        public void Execute(IConsoleShell shell, string argStr, string[] args)
+        {
+            if (args.Length != 2)
+            {
+                shell.WriteLine($"Invalid amount of arguments.\n{Help}");
+                return;
+            }
+
+            if (!EntityUid.TryParse(args[0], out var uid))
+            {
+                shell.WriteLine($"{uid} is not a valid entity uid.");
+                return;
+            }
+
+            var entityManager = IoCManager.Resolve<IEntityManager>();
+
+            if (!entityManager.TryGetEntity(uid, out var entity))
+            {
+                shell.WriteLine($"No entity found with id {uid}.");
+                return;
+            }
+
+            var componentName = args[1];
+
+            var compManager = IoCManager.Resolve<IComponentManager>();
+            var compFactory = IoCManager.Resolve<IComponentFactory>();
+
+            if (!compFactory.TryGetRegistration(componentName, out var registration, true))
+            {
+                shell.WriteLine($"No component found with name {componentName}.");
+                return;
+            }
+
+            if (entity.HasComponent(registration.Type))
+            {
+                shell.WriteLine($"Entity {entity.Name} already has a {componentName} component.");
+            }
+
+            var component = (Component) compFactory.GetComponent(registration.Type);
+
+            component.Owner = entity;
+            compManager.AddComponent(entity, component);
+
+            shell.WriteLine($"Added {componentName} component to entity {entity.Name}.");
+        }
+    }
+}

Robust.Server/Console/Commands/MapCommands.cs

@@ -1,15 +1,14 @@
-using System.Globalization;
+using System.Globalization;
 using System.Linq;
 using System.Text;
 using Robust.Server.Maps;
 using Robust.Server.Player;
-using Robust.Server.Timing;
 using Robust.Shared.Console;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.Localization;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
+using Robust.Shared.Timing;
 
 namespace Robust.Server.Console.Commands
 {
@@ -237,81 +236,6 @@ namespace Robust.Server.Console.Commands
         }
     }
 
-    class PauseMapCommand : IConsoleCommand
-    {
-        public string Command => "pausemap";
-        public string Description => "Pauses a map, pausing all simulation processing on it.";
-        public string Help => "Usage: pausemap <map ID>";
-        public void Execute(IConsoleShell shell, string argStr, string[] args)
-        {
-            if (args.Length != 1)
-            {
-                shell.WriteLine(Loc.GetString("Need to supply a valid MapId"));
-                return;
-            }
-
-            var arg = args[0];
-            var mapId = new MapId(int.Parse(arg, CultureInfo.InvariantCulture));
-
-            var pauseManager = IoCManager.Resolve<IPauseManager>();
-            var mapManager = IoCManager.Resolve<IMapManager>();
-            if (!mapManager.MapExists(mapId))
-            {
-                shell.WriteLine("That map does not exist.");
-                return;
-            }
-            pauseManager.SetMapPaused(mapId, true);
-        }
-    }
-
-    class UnpauseMapCommand : IConsoleCommand
-    {
-        public string Command => "unpausemap";
-        public string Description => "unpauses a map, resuming all simulation processing on it.";
-        public string Help => "Usage: unpausemap <map ID>";
-        public void Execute(IConsoleShell shell, string argStr, string[] args)
-        {
-            if (args.Length != 1)
-            {
-                shell.WriteLine(Loc.GetString("Need to supply a valid MapId"));
-                return;
-            }
-
-            var arg = args[0];
-            var mapId = new MapId(int.Parse(arg, CultureInfo.InvariantCulture));
-
-            var pauseManager = IoCManager.Resolve<IPauseManager>();
-            var mapManager = IoCManager.Resolve<IMapManager>();
-            if (!mapManager.MapExists(mapId))
-            {
-                shell.WriteLine("That map does not exist.");
-                return;
-            }
-            pauseManager.SetMapPaused(mapId, false);
-        }
-    }
-
-    class QueryMapPausedCommand : IConsoleCommand
-    {
-        public string Command => "querymappaused";
-        public string Description => "Check whether a map is paused or not.";
-        public string Help => "Usage: querymappaused <map ID>";
-        public void Execute(IConsoleShell shell, string argStr, string[] args)
-        {
-            var arg = args[0];
-            var mapId = new MapId(int.Parse(arg, CultureInfo.InvariantCulture));
-
-            var pauseManager = IoCManager.Resolve<IPauseManager>();
-            var mapManager = IoCManager.Resolve<IMapManager>();
-            if (!mapManager.MapExists(mapId))
-            {
-                shell.WriteLine("That map does not exist.");
-                return;
-            }
-            shell.WriteLine(pauseManager.IsMapPaused(mapId).ToString());
-        }
-    }
-
     class TpGridCommand : IConsoleCommand
     {
         public string Command => "tpgrid";

Robust.Server/Console/Commands/RemoveComponentCommand.cs

@@ -0,0 +1,59 @@
+using JetBrains.Annotations;
+using Robust.Shared.Console;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+
+namespace Robust.Server.Console.Commands
+{
+    [UsedImplicitly]
+    internal sealed class RemoveComponentCommand : IConsoleCommand
+    {
+        public string Command => "rmcomp";
+        public string Description => "Removes a component from an entity.";
+        public string Help => $"{Command} <uid> <componentName>";
+
+        public void Execute(IConsoleShell shell, string argStr, string[] args)
+        {
+            if (args.Length != 2)
+            {
+                shell.WriteLine($"Invalid amount of arguments.\n{Help}.");
+                return;
+            }
+
+            if (!EntityUid.TryParse(args[0], out var uid))
+            {
+                shell.WriteLine($"{uid} is not a valid entity uid.");
+                return;
+            }
+
+            var entityManager = IoCManager.Resolve<IEntityManager>();
+
+            if (!entityManager.TryGetEntity(uid, out var entity))
+            {
+                shell.WriteLine($"No entity found with id {uid}.");
+                return;
+            }
+
+            var componentName = args[1];
+
+            var compManager = IoCManager.Resolve<IComponentManager>();
+            var compFactory = IoCManager.Resolve<IComponentFactory>();
+
+            if (!compFactory.TryGetRegistration(componentName, out var registration, true))
+            {
+                shell.WriteLine($"No component found with name {componentName}.");
+                return;
+            }
+
+            if (!entity.HasComponent(registration.Type))
+            {
+                shell.WriteLine($"No {componentName} component found on entity {entity.Name}.");
+                return;
+            }
+
+            compManager.RemoveComponent(uid, registration.Type);
+
+            shell.WriteLine($"Removed {componentName} component from entity {entity.Name}.");
+        }
+    }
+}

Robust.Server/Console/ConGroupController.cs

@@ -30,5 +30,10 @@ namespace Robust.Server.Console
         {
             return Implementation?.CanAdminMenu(session) ?? false;
         }
+
+        public bool CanAdminReloadPrototypes(IPlayerSession session)
+        {
+            return Implementation?.CanAdminReloadPrototypes(session) ?? false;
+        }
     }
 }

Robust.Server/Console/IConGroupControllerImplementation.cs

@@ -9,5 +9,6 @@ namespace Robust.Server.Console
         bool CanAdminPlace(IPlayerSession session);
         bool CanScript(IPlayerSession session);
         bool CanAdminMenu(IPlayerSession session);
+        bool CanAdminReloadPrototypes(IPlayerSession session);
     }
 }

Robust.Server/GameObjects/Components/Appearance/AppearanceComponent.cs

@@ -3,6 +3,7 @@ using Robust.Shared.ViewVariables;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using Robust.Shared.Players;
 
 namespace Robust.Server.GameObjects
 {
@@ -61,7 +62,7 @@ namespace Robust.Server.GameObjects
             return false;
         }
 
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new AppearanceComponentState(data);
         }

Robust.Server/GameObjects/Components/Container/ContainerManagerComponent.cs

@@ -5,6 +5,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
+using Robust.Shared.Players;
 using Robust.Shared.Reflection;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
@@ -256,7 +257,7 @@ namespace Robust.Server.GameObjects
             _entitiesWaitingResolve = null;
         }
 
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new ContainerManagerComponentState(
                 _allContainers.ToDictionary(

Robust.Server/GameObjects/Components/Eye/EyeComponent.cs

@@ -1,5 +1,6 @@
 using Robust.Shared.GameObjects;
 using Robust.Shared.Maths;
+using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 
 namespace Robust.Server.GameObjects
@@ -63,7 +64,7 @@ namespace Robust.Server.GameObjects
             }
         }
 
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new EyeComponentState(DrawFov, Zoom, Offset, Rotation);
         }

Robust.Server/GameObjects/Components/Light/PointLightComponent.cs

@@ -1,5 +1,6 @@
 using Robust.Shared.GameObjects;
 using Robust.Shared.Maths;
+using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 
@@ -73,7 +74,7 @@ namespace Robust.Server.GameObjects
             serializer.DataField(ref _offset, "offset", Vector2.Zero);
         }
 
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new PointLightComponentState(Enabled, Color, Radius, Offset);
         }

Robust.Server/GameObjects/Components/Renderable/SpriteComponent.cs

@@ -4,6 +4,7 @@ using Robust.Shared.GameObjects;
 using DrawDepthTag = Robust.Shared.GameObjects.DrawDepth;
 using Robust.Shared.Log;
 using Robust.Shared.Maths;
+using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
@@ -441,7 +442,7 @@ namespace Robust.Server.GameObjects
             Layers = layerData;
         }
 
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new SpriteComponentState(Visible, DrawDepth, Scale, Rotation, Offset, Color, Directional,
                 BaseRSIPath, Layers, RenderOrder);

Robust.Server/GameObjects/IServerEntityManager.cs

@@ -10,7 +10,7 @@ namespace Robust.Server.GameObjects
         /// <summary>
         ///     Gets all entity states that have been modified after and including the provided tick.
         /// </summary>
-        List<EntityState>? GetEntityStates(GameTick fromTick);
+        List<EntityState>? GetEntityStates(GameTick fromTick, IPlayerSession player);
 
         /// <summary>
         ///     Gets all entity states within an AABB that have been modified after and including the provided tick.

Robust.Server/GameObjects/ServerEntityManager.cs

@@ -4,7 +4,6 @@ using System.Linq;
 using System.Threading;
 using Prometheus;
 using Robust.Server.Player;
-using Robust.Server.Timing;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.GameObjects;
@@ -13,6 +12,7 @@ using Robust.Shared.Maths;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
+using static Robust.Shared.GameObjects.TransformComponent;
 
 namespace Robust.Server.GameObjects
 {
@@ -139,7 +139,7 @@ namespace Robust.Server.GameObjects
         }
 
         /// <inheritdoc />
-        public List<EntityState>? GetEntityStates(GameTick fromTick)
+        public List<EntityState>? GetEntityStates(GameTick fromTick, IPlayerSession player)
         {
             var stateEntities = new List<EntityState>();
             foreach (var entity in AllEntities)
@@ -154,7 +154,7 @@ namespace Robust.Server.GameObjects
                 if (entity.LastModifiedTick <= fromTick)
                     continue;
 
-                stateEntities.Add(GetEntityState(ComponentManager, entity.Uid, fromTick));
+                stateEntities.Add(GetEntityState(ComponentManager, entity.Uid, fromTick, player));
             }
 
             // no point sending an empty collection
@@ -336,7 +336,7 @@ namespace Robust.Server.GameObjects
             if (playerEnt == null)
             {
                 // super-observer?
-                return GetEntityStates(fromTick);
+                return GetEntityStates(fromTick, player);
             }
 
             var playerUid = playerEnt.Uid;
@@ -390,7 +390,7 @@ namespace Robust.Server.GameObjects
                     }
                 }
 
-                var state = GetEntityState(ComponentManager, uid, fromTick);
+                var state = GetEntityState(ComponentManager, uid, fromTick, player);
 
                 if (checkedEnts.Add(uid))
                 {
@@ -404,14 +404,14 @@ namespace Robust.Server.GameObjects
                         {
                             // mover changed and can't be seen
                             var idx = Array.FindIndex(state.ComponentStates,
-                                x => x is TransformComponent.TransformComponentState);
+                                x => x is TransformComponentState);
 
                             if (idx != -1)
                             {
                                 // mover changed positional data and can't be seen
                                 var oldState =
-                                    (TransformComponent.TransformComponentState) state.ComponentStates[idx];
-                                var newState = new TransformComponent.TransformComponentState(Vector2NaN,
+                                    (TransformComponentState) state.ComponentStates[idx];
+                                var newState = new TransformComponentState(Vector2NaN,
                                     oldState.Rotation, oldState.ParentID, oldState.NoLocalRotation);
                                 state.ComponentStates[idx] = newState;
                                 seenMovers.Remove(uid);
@@ -441,7 +441,7 @@ namespace Robust.Server.GameObjects
                     {
                         // mover can't be seen
                         var oldState =
-                            (TransformComponent.TransformComponentState) entity.Transform.GetComponentState();
+                            (TransformComponentState) entity.Transform.GetComponentState(player);
                         entityStates.Add(new EntityState(uid,
                             new ComponentChanged[]
                             {
@@ -449,7 +449,7 @@ namespace Robust.Server.GameObjects
                             },
                             new ComponentState[]
                             {
-                                new TransformComponent.TransformComponentState(Vector2NaN, oldState.Rotation,
+                                new TransformComponentState(Vector2NaN, oldState.Rotation,
                                     oldState.ParentID, oldState.NoLocalRotation)
                             }));
 
@@ -517,7 +517,7 @@ namespace Robust.Server.GameObjects
                 }
 
                 // should this be lastSeen or fromTick?
-                var entityState = GetEntityState(ComponentManager, uid, lastSeen);
+                var entityState = GetEntityState(ComponentManager, uid, lastSeen, player);
 
                 checkedEnts.Add(uid);
 
@@ -577,7 +577,7 @@ namespace Robust.Server.GameObjects
                     continue;
                 }
 
-                var state = GetEntityState(ComponentManager, uid, fromTick);
+                var state = GetEntityState(ComponentManager, uid, fromTick, player);
 
                 if (state.ComponentStates == null)
                 {
@@ -591,7 +591,7 @@ namespace Robust.Server.GameObjects
                 seenMovers.Remove(uid);
                 ClearLastSeenTick(lSeen, uid);
 
-                var idx = Array.FindIndex(state.ComponentStates, x => x is TransformComponent.TransformComponentState);
+                var idx = Array.FindIndex(state.ComponentStates, x => x is TransformComponentState);
 
                 if (idx == -1)
                 {
@@ -599,9 +599,9 @@ namespace Robust.Server.GameObjects
                     continue;
                 }
 
-                var oldState = (TransformComponent.TransformComponentState) state.ComponentStates[idx];
+                var oldState = (TransformComponentState) state.ComponentStates[idx];
                 var newState =
-                    new TransformComponent.TransformComponentState(Vector2NaN, oldState.Rotation, oldState.ParentID, oldState.NoLocalRotation);
+                    new TransformComponentState(Vector2NaN, oldState.Rotation, oldState.ParentID, oldState.NoLocalRotation);
                 state.ComponentStates[idx] = newState;
 
 
@@ -630,7 +630,7 @@ namespace Robust.Server.GameObjects
                     }
 
                     var entity = GetEntity(uid);
-                    var state = GetEntityState(ComponentManager, uid, fromTick);
+                    var state = GetEntityState(ComponentManager, uid, fromTick, player);
 
                     if (state.ComponentStates == null || viewbox.Intersects(GetWorldAabbFromEntity(entity)))
                     {
@@ -643,7 +643,7 @@ namespace Robust.Server.GameObjects
                     entityStates.Add(state);
 
                     var idx = Array.FindIndex(state.ComponentStates,
-                        x => x is TransformComponent.TransformComponentState);
+                        x => x is TransformComponentState);
 
                     if (idx == -1)
                     {
@@ -651,9 +651,9 @@ namespace Robust.Server.GameObjects
                         continue;
                     }
 
-                    var oldState = (TransformComponent.TransformComponentState) state.ComponentStates[idx];
+                    var oldState = (TransformComponentState) state.ComponentStates[idx];
                     var newState =
-                        new TransformComponent.TransformComponentState(Vector2NaN, oldState.Rotation,
+                        new TransformComponentState(Vector2NaN, oldState.Rotation,
                             oldState.ParentID, oldState.NoLocalRotation);
                     state.ComponentStates[idx] = newState;
                     seenMovers.Remove(uid);
@@ -881,8 +881,9 @@ namespace Robust.Server.GameObjects
         /// <param name="compMan">ComponentManager that contains the components for the entity.</param>
         /// <param name="entityUid">Uid of the entity to generate the state from.</param>
         /// <param name="fromTick">Only provide delta changes from this tick.</param>
+        /// <param name="player">The player to generate this state for.</param>
         /// <returns>New entity State for the given entity.</returns>
-        private static EntityState GetEntityState(IComponentManager compMan, EntityUid entityUid, GameTick fromTick)
+        private static EntityState GetEntityState(IComponentManager compMan, EntityUid entityUid, GameTick fromTick, IPlayerSession player)
         {
             var compStates = new List<ComponentState>();
             var changed = new List<ComponentChanged>();
@@ -899,7 +900,7 @@ namespace Robust.Server.GameObjects
                 // As such, we can avoid sending this data in this case since the client "already has it".
 
                 if (comp.NetSyncEnabled && comp.LastModifiedTick != GameTick.Zero && comp.LastModifiedTick >= fromTick)
-                    compStates.Add(comp.GetComponentState());
+                    compStates.Add(comp.GetComponentState(player));
 
                 if (comp.CreationTick != GameTick.Zero && comp.CreationTick >= fromTick && !comp.Deleted)
                 {

Robust.Server/GameStates/ServerGameStateManager.cs

@@ -135,7 +135,7 @@ namespace Robust.Server.GameStates
                 }
 
                 var entStates = lastAck == GameTick.Zero || !PvsEnabled
-                    ? _entityManager.GetEntityStates(lastAck)
+                    ? _entityManager.GetEntityStates(lastAck, session)
                     : _entityManager.UpdatePlayerSeenEntityStates(lastAck, session, _entityManager.MaxUpdateRange);
                 var playerStates = _playerManager.GetPlayerStates(lastAck);
                 var deletions = _entityManager.GetDeletedEntities(lastAck);

Robust.Server/Maps/MapLoader.cs

@@ -12,9 +12,9 @@ using Robust.Shared.GameObjects;
 using System.Globalization;
 using System.Linq;
 using Robust.Server.GameObjects;
-using Robust.Server.Timing;
 using Robust.Shared.ContentPack;
 using Robust.Shared.Prototypes;
+using Robust.Shared.Timing;
 using YamlDotNet.Core;
 
 namespace Robust.Server.Maps

Robust.Server/Prototypes/ServerPrototypeManager.cs

@@ -1,12 +1,50 @@
+using System;
+using Robust.Server.Console;
+using Robust.Server.Player;
+using Robust.Shared.IoC;
+using Robust.Shared.Log;
+using Robust.Shared.Network;
+using Robust.Shared.Network.Messages;
 using Robust.Shared.Prototypes;
 
 namespace Robust.Server.Prototypes
 {
     public sealed class ServerPrototypeManager : PrototypeManager
     {
+        [Dependency] private readonly IPlayerManager _playerManager = default!;
+        [Dependency] private readonly IConGroupController _conGroups = default!;
+
         public ServerPrototypeManager() : base()
         {
             RegisterIgnore("shader");
         }
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            NetManager.RegisterNetMessage<MsgReloadPrototypes>(MsgReloadPrototypes.NAME, HandleReloadPrototypes, NetMessageAccept.Server);
+        }
+
+        private void HandleReloadPrototypes(MsgReloadPrototypes msg)
+        {
+#if !FULL_RELEASE
+            if (!_playerManager.TryGetSessionByChannel(msg.MsgChannel, out var player) ||
+                !_conGroups.CanAdminReloadPrototypes(player))
+            {
+                return;
+            }
+
+            var then = DateTime.Now;
+
+            foreach (var path in msg.Paths)
+            {
+                ReloadPrototypes(path);
+            }
+
+            Logger.Info($"Reloaded prototypes in {(int) (DateTime.Now - then).TotalMilliseconds} ms");
+#endif
+        }
+
     }
 }

Robust.Server/ServerIoC.cs

@@ -10,9 +10,9 @@ using Robust.Server.Prototypes;
 using Robust.Server.Reflection;
 using Robust.Server.Scripting;
 using Robust.Server.ServerStatus;
-using Robust.Server.Timing;
 using Robust.Server.ViewVariables;
 using Robust.Shared;
+using Robust.Shared.Console;
 using Robust.Shared.ContentPack;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
@@ -20,6 +20,7 @@ using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
+using Robust.Shared.Timing;
 
 namespace Robust.Server
 {
@@ -37,11 +38,11 @@ namespace Robust.Server
             IoCManager.Register<IComponentFactory, ServerComponentFactory>();
             IoCManager.Register<IConGroupController, ConGroupController>();
             IoCManager.Register<IServerConsoleHost, ServerConsoleHost>();
+            IoCManager.Register<IConsoleHost, ServerConsoleHost>();
             IoCManager.Register<IEntityManager, ServerEntityManager>();
             IoCManager.Register<IEntityNetworkManager, ServerEntityNetworkManager>();
             IoCManager.Register<IServerEntityNetworkManager, ServerEntityNetworkManager>();
             IoCManager.Register<IMapLoader, MapLoader>();
-            IoCManager.Register<IPauseManager, PauseManager>();
             IoCManager.Register<IPlacementManager, PlacementManager>();
             IoCManager.Register<IPlayerManager, PlayerManager>();
             IoCManager.Register<IPrototypeManager, ServerPrototypeManager>();

Robust.Server/ServerStatus/StatusHost.cs

@@ -152,21 +152,21 @@ namespace Robust.Server.ServerStatus
 
         private void RegisterCVars()
         {
-            try
+            var path = PathHelpers.ExecutableRelativeFile("build.json");
+            if (!File.Exists(path))
             {
-                var buildInfo = File.ReadAllText(PathHelpers.ExecutableRelativeFile("build.json"));
-                var info = JsonConvert.DeserializeObject<BuildInfo>(buildInfo);
+                return;
+            }
 
-                // Don't replace cvars with contents of build.json if overriden by --cvar or such.
-                SetCVarIfUnmodified(CVars.BuildEngineVersion, info.EngineVersion);
-                SetCVarIfUnmodified(CVars.BuildForkId, info.ForkId);
-                SetCVarIfUnmodified(CVars.BuildVersion, info.Version);
-                SetCVarIfUnmodified(CVars.BuildDownloadUrl, info.Download ?? "");
-                SetCVarIfUnmodified(CVars.BuildHash, info.Hash ?? "");
-            }
-            catch (FileNotFoundException)
-            {
-            }
+            var buildInfo = File.ReadAllText(path);
+            var info = JsonConvert.DeserializeObject<BuildInfo>(buildInfo);
+
+            // Don't replace cvars with contents of build.json if overriden by --cvar or such.
+            SetCVarIfUnmodified(CVars.BuildEngineVersion, info.EngineVersion);
+            SetCVarIfUnmodified(CVars.BuildForkId, info.ForkId);
+            SetCVarIfUnmodified(CVars.BuildVersion, info.Version);
+            SetCVarIfUnmodified(CVars.BuildDownloadUrl, info.Download ?? "");
+            SetCVarIfUnmodified(CVars.BuildHash, info.Hash ?? "");
 
             void SetCVarIfUnmodified(CVarDef<string> cvar, string val)
             {

Robust.Server/Timing/PauseManager.cs

@@ -1,98 +0,0 @@
-using System;
-using System.Collections.Generic;
-using Robust.Server.GameObjects;
-using Robust.Shared.GameObjects;
-using Robust.Shared.IoC;
-using Robust.Shared.Map;
-using Robust.Shared.ViewVariables;
-
-namespace Robust.Server.Timing
-{
-    internal sealed class PauseManager : IPauseManager, IPostInjectInit
-    {
-        [Dependency] private readonly IMapManager _mapManager = default!;
-        [Dependency] private readonly IEntityManager _entityManager = default!;
-
-        [ViewVariables] private readonly HashSet<MapId> _pausedMaps = new();
-        [ViewVariables] private readonly HashSet<MapId> _unInitializedMaps = new();
-
-        public void SetMapPaused(MapId mapId, bool paused)
-        {
-            if (paused)
-            {
-                _pausedMaps.Add(mapId);
-                foreach (var entity in _entityManager.GetEntitiesInMap(mapId))
-                {
-                    entity.Paused = true;
-                }
-            }
-            else
-            {
-                _pausedMaps.Remove(mapId);
-                foreach (var entity in _entityManager.GetEntitiesInMap(mapId))
-                {
-                    entity.Paused = false;
-                }
-            }
-        }
-
-        public void DoMapInitialize(MapId mapId)
-        {
-            if (IsMapInitialized(mapId))
-            {
-                throw new ArgumentException("That map is already initialized.");
-            }
-
-            _unInitializedMaps.Remove(mapId);
-
-            foreach (var entity in _entityManager.GetEntitiesInMap(mapId))
-            {
-                entity.RunMapInit();
-                entity.Paused = false;
-            }
-        }
-
-        public void DoGridMapInitialize(IMapGrid grid) => DoGridMapInitialize(grid.Index);
-        public void DoGridMapInitialize(GridId gridId)
-        {
-            var mapId = _mapManager.GetGrid(gridId).ParentMapId;
-
-            foreach (var entity in _entityManager.GetEntitiesInMap(mapId))
-            {
-                if (entity.Transform.GridID != gridId)
-                    continue;
-
-                entity.RunMapInit();
-                entity.Paused = false;
-            }
-        }
-
-        public void AddUninitializedMap(MapId mapId)
-        {
-            _unInitializedMaps.Add(mapId);
-        }
-
-        public bool IsMapPaused(MapId mapId) => _pausedMaps.Contains(mapId) || _unInitializedMaps.Contains(mapId);
-        public bool IsGridPaused(IMapGrid grid) => IsMapPaused(grid.ParentMapId);
-
-        public bool IsGridPaused(GridId gridId)
-        {
-            var grid = _mapManager.GetGrid(gridId);
-            return IsGridPaused(grid);
-        }
-
-        public bool IsMapInitialized(MapId mapId)
-        {
-            return !_unInitializedMaps.Contains(mapId);
-        }
-
-        public void PostInject()
-        {
-            _mapManager.MapDestroyed += (sender, args) =>
-            {
-                _pausedMaps.Remove(args.Map);
-                _unInitializedMaps.Add(args.Map);
-            };
-        }
-    }
-}

Robust.Server/Timing/PauseManagerExt.cs

@@ -1,16 +0,0 @@
-using System;
-using JetBrains.Annotations;
-using Robust.Shared.GameObjects;
-
-namespace Robust.Server.Timing
-{
-    public static class PauseManagerExt
-    {
-        [Pure]
-        [Obsolete("Use IEntity.Paused directly")]
-        public static bool IsEntityPaused(this IPauseManager manager, IEntity entity)
-        {
-            return entity.Paused;
-        }
-    }
-}

Robust.Shared.Scripting/ScriptInstanceShared.cs

@@ -32,7 +32,6 @@ namespace Robust.Shared.Scripting
             "Robust.Shared.IoC",
             "Robust.Shared.Maths",
             "Robust.Shared.GameObjects",
-            "Robust.Shared.Interfaces.GameObjects",
             "Robust.Shared.Map",
             "Robust.Shared.Prototypes"
         };

Robust.Shared/ContentPack/AssemblyTypeChecker.cs

@@ -767,14 +767,14 @@ namespace Robust.Shared.ContentPack
                 var dllName = $"{simpleName}.dll";
                 foreach (var diskLoadPath in _diskLoadPaths)
                 {
-                    try
-                    {
-                        var path = Path.Combine(diskLoadPath, dllName);
-                        return new PEReader(File.OpenRead(path));
-                    }
-                    catch (FileNotFoundException)
+                    var path = Path.Combine(diskLoadPath, dllName);
+
+                    if (!File.Exists(path))
                     {
+                        continue;
                     }
+
+                    return new PEReader(File.OpenRead(path));
                 }
 
                 var extraStream = _parent.ExtraRobustLoader?.Invoke(dllName);

Robust.Shared/ContentPack/DirLoader.cs

@@ -90,7 +90,7 @@ namespace Robust.Shared.ContentPack
                     {
                         var prevDir = new DirectoryInfo(prevPath);
                         var found = false;
-                        foreach (var info in prevDir.GetFileSystemInfos())
+                        foreach (var info in prevDir.EnumerateFileSystemInfos())
                         {
                             if (!string.Equals(info.Name, segment, StringComparison.InvariantCultureIgnoreCase))
                             {

Robust.Shared/ContentPack/IResourceManager.cs

@@ -116,6 +116,12 @@ namespace Robust.Shared.ContentPack
         /// <exception cref="ArgumentNullException">Thrown if <paramref name="path"/> is null.</exception>
         IEnumerable<ResourcePath> ContentFindFiles(string path);
 
+        /// <summary>
+        ///     Returns a list of paths to all top-level content directories
+        /// </summary>
+        /// <returns></returns>
+        IEnumerable<ResourcePath> GetContentRoots();
+
         /// <summary>
         ///     Read a file from the mounted content paths to a string.
         /// </summary>
@@ -168,4 +174,4 @@ namespace Robust.Shared.ContentPack
             return new StreamReader(stream, encoding);
         }
     }
-}
+}

Robust.Shared/ContentPack/ResourceManager.cs

@@ -305,6 +305,17 @@ namespace Robust.Shared.ContentPack
             AddRoot(ResourcePath.Root, loader);
         }
 
+        public IEnumerable<ResourcePath> GetContentRoots()
+        {
+            foreach (var (_, root) in _contentRoots)
+            {
+                if (root is DirLoader loader)
+                {
+                    yield return new ResourcePath(loader.GetPath(new ResourcePath(@"/")));
+                }
+            }
+        }
+
         internal static bool IsPathValid(ResourcePath path)
         {
             var asString = path.ToString();

Robust.Shared/ContentPack/Sandbox.yml

@@ -330,6 +330,7 @@ Types:
   System.Globalization:
     CompareOptions: { }
     CultureInfo: { All: True }
+    DateTimeStyles: { All: True } # Enum
     TextInfo:
       Methods:
       - "bool get_IsRightToLeft()"
@@ -894,6 +895,7 @@ Types:
     MidpointRounding: { } # Enum
     MulticastDelegate:
       Inherit: Allow
+    NotImplementedException: { All: True }
     NotSupportedException: { All: True }
     Nullable: { All: True }
     Nullable`1: { All: True }

Robust.Shared/GameObjects/Component.cs

@@ -202,8 +202,9 @@ namespace Robust.Shared.GameObjects
         /// <inheritdoc />
         public virtual void HandleNetworkMessage(ComponentMessage message, INetChannel netChannel, ICommonSession? session = null) { }
 
+        /// <param name="player"></param>
         /// <inheritdoc />
-        public virtual ComponentState GetComponentState()
+        public virtual ComponentState GetComponentState(ICommonSession player)
         {
             if (NetID == null)
                 throw new InvalidOperationException($"Cannot make state for component without Net ID: {GetType()}");

Robust.Shared/GameObjects/Components/Collidable/PhysicsComponent.Collision.cs

@@ -5,6 +5,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Physics;
+using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 
@@ -132,8 +133,9 @@ namespace Robust.Shared.GameObjects
             serializer.DataField(ref _mass, "mass", 1.0f);
         }
 
+        /// <param name="player"></param>
         /// <inheritdoc />
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new PhysicsComponentState(_canCollide, _status, _physShapes, _isHard, _mass, LinearVelocity, AngularVelocity, Anchored);
         }

Robust.Shared/GameObjects/Components/GrammarComponent.cs

@@ -1,5 +1,6 @@
 using System;
 using Robust.Shared.Localization.Macros;
+using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 
@@ -33,7 +34,7 @@ namespace Robust.Shared.GameObjects
             serializer.DataField(this, x => x.Proper, "proper", false);
         }
 
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new GrammarComponentState(Proper);
         }

Robust.Shared/GameObjects/Components/IgnorePauseComponent.cs

@@ -1,13 +1,13 @@
-using Robust.Server.Timing;
-using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
+using Robust.Shared.Timing;
 
-namespace Robust.Server.GameObjects
+namespace Robust.Shared.GameObjects
 {
     [RegisterComponent]
-    [ComponentReference(typeof(SharedIgnorePauseComponent))]
-    public sealed class IgnorePauseComponent : SharedIgnorePauseComponent
+    public class IgnorePauseComponent : Component
     {
+        public override string Name => "IgnorePause";
+
         public override void OnAdd()
         {
             base.OnAdd();

Robust.Shared/GameObjects/Components/Light/OccluderComponent.cs

@@ -1,6 +1,7 @@
 using System;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
+using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 
@@ -73,7 +74,7 @@ namespace Robust.Shared.GameObjects
             }
         }
 
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new OccluderComponentState(Enabled, BoundingBox);
         }

Robust.Shared/GameObjects/Components/Map/MapComponent.cs

@@ -1,5 +1,6 @@
 using System;
 using Robust.Shared.Map;
+using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 
@@ -39,8 +40,9 @@ namespace Robust.Shared.GameObjects
             _mapIndex = MapId.Nullspace;
         }
 
+        /// <param name="player"></param>
         /// <inheritdoc />
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new MapComponentState(_mapIndex);
         }

Robust.Shared/GameObjects/Components/Map/MapGridComponent.cs

@@ -2,6 +2,7 @@
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
+using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 
@@ -61,8 +62,9 @@ namespace Robust.Shared.GameObjects
             base.OnRemove();
         }
 
+        /// <param name="player"></param>
         /// <inheritdoc />
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new MapGridComponentState(_gridIndex, Grid.HasGravity);
         }

Robust.Shared/GameObjects/Components/MetaDataComponent.cs

@@ -1,5 +1,6 @@
 using System;
 using Robust.Shared.IoC;
+using Robust.Shared.Players;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
@@ -137,8 +138,9 @@ namespace Robust.Shared.GameObjects
             }
         }
 
+        /// <param name="player"></param>
         /// <inheritdoc />
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new MetaDataComponentState(_entityName, _entityDescription, EntityPrototype?.ID);
         }

Robust.Shared/GameObjects/Components/SharedIgnorePauseComponent.cs

@@ -1,7 +0,0 @@
-namespace Robust.Shared.GameObjects
-{
-    public abstract class SharedIgnorePauseComponent : Component
-    {
-        public override string Name => "IgnorePause";
-    }
-}

Robust.Shared/GameObjects/Components/Timers/TimerComponent.cs

@@ -4,7 +4,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Robust.Shared.Exceptions;
 using Robust.Shared.IoC;
-using Timer = Robust.Shared.Timers.Timer;
+using Timer = Robust.Shared.Timing.Timer;
 
 namespace Robust.Shared.GameObjects
 {

Robust.Shared/GameObjects/Components/Timers/TimerExtensions.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Threading;
 using System.Threading.Tasks;
-using Timer = Robust.Shared.Timers.Timer;
+using Timer = Robust.Shared.Timing.Timer;
 
 namespace Robust.Shared.GameObjects
 {

Robust.Shared/GameObjects/Components/Transform/TransformComponent.cs

@@ -6,6 +6,7 @@ using Robust.Shared.Containers;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
+using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
@@ -698,8 +699,9 @@ namespace Robust.Shared.GameObjects
             serializer.DataField(ref _noLocalRotation, "noRot", false);
         }
 
+        /// <param name="player"></param>
         /// <inheritdoc />
-        public override ComponentState GetComponentState()
+        public override ComponentState GetComponentState(ICommonSession player)
         {
             return new TransformComponentState(_localPosition, LocalRotation, _parent, _noLocalRotation);
         }

Robust.Shared/GameObjects/Entity.cs

@@ -79,7 +79,7 @@ namespace Robust.Shared.GameObjects
             get => _paused;
             set
             {
-                if (_paused == value || value && HasComponent<SharedIgnorePauseComponent>())
+                if (_paused == value || value && HasComponent<IgnorePauseComponent>())
                     return;
 
                 _paused = value;

Robust.Shared/GameObjects/IComponent.cs

@@ -32,7 +32,7 @@ namespace Robust.Shared.GameObjects
         ///     Whether the Owner has been paused.
         /// </summary>
         bool Paused { get; }
-        
+
         /// <summary>
         ///     Whether the client should synchronize component additions and removals.
         ///     If this is false and the component gets added or removed server side, the client will not do the same.
@@ -125,8 +125,9 @@ namespace Robust.Shared.GameObjects
         /// <summary>
         ///     Get the component's state for replicating on the client.
         /// </summary>
+        /// <param name="player"></param>
         /// <returns>ComponentState object</returns>
-        ComponentState GetComponentState();
+        ComponentState GetComponentState(ICommonSession player);
 
         /// <summary>
         ///     Handles an incoming component state from the server.

Robust.Shared/GameObjects/IMapInit.cs

@@ -1,11 +1,9 @@
-using Robust.Shared.GameObjects;
-
-namespace Robust.Server.GameObjects
+namespace Robust.Shared.GameObjects
 {
     /// <summary>
-    ///     Defines a component that has "map initialization" behavior.
-    ///     Basically irreversible behavior that moves the map from "map editor" to playable,
-    ///     like spawning preset objects.
+    /// Defines a component that has "map initialization" behavior.
+    /// Basically irreversible behavior that moves the map from "map editor" to playable,
+    /// like spawning preset objects.
     /// </summary>
     public interface IMapInit
     {

Robust.Shared/Network/Messages/MsgReloadPrototypes.cs

@@ -0,0 +1,42 @@
+using Lidgren.Network;
+using Robust.Shared.Utility;
+
+namespace Robust.Shared.Network.Messages
+{
+    public class MsgReloadPrototypes : NetMessage
+    {
+        #region REQUIRED
+
+        public const MsgGroups GROUP = MsgGroups.Command;
+        public const string NAME = nameof(MsgReloadPrototypes);
+
+        public MsgReloadPrototypes(INetChannel channel) : base(NAME, GROUP)
+        {
+        }
+
+        #endregion
+
+        public ResourcePath[] Paths = default!;
+
+        public override void ReadFromBuffer(NetIncomingMessage buffer)
+        {
+            var count = buffer.ReadInt32();
+            Paths = new ResourcePath[count];
+
+            for (var i = 0; i < count; i++)
+            {
+                Paths[i] = new ResourcePath(buffer.ReadString());
+            }
+        }
+
+        public override void WriteToBuffer(NetOutgoingMessage buffer)
+        {
+            buffer.Write(Paths.Length);
+
+            foreach (var path in Paths)
+            {
+                buffer.Write(path.ToString());
+            }
+        }
+    }
+}

Robust.Shared/Network/NetManager.ServerAuth.cs

@@ -179,9 +179,33 @@ namespace Robust.Shared.Network
                 // Well they're in. Kick a connected client with the same GUID if we have to.
                 if (_assignedUserIds.TryGetValue(userId, out var existing))
                 {
-                    existing.Disconnect("Another connection has been made with your account.");
-                    // Have to wait until they're properly off the server to avoid any collisions.
-                    await AwaitDisconnectAsync(existing);
+                    if (_awaitingDisconnectToConnect.Contains(userId))
+                    {
+                        connection.Disconnect("Stop trying to connect multiple times at once.");
+                        return;
+                    }
+
+                    _awaitingDisconnectToConnect.Add(userId);
+                    try
+                    {
+                        existing.Disconnect("Another connection has been made with your account.");
+                        // Have to wait until they're properly off the server to avoid any collisions.
+                        await AwaitDisconnectAsync(existing);
+                    }
+                    finally
+                    {
+                        _awaitingDisconnectToConnect.Remove(userId);
+                    }
+                }
+
+                if (connection.Status == NetConnectionStatus.Disconnecting ||
+                    connection.Status == NetConnectionStatus.Disconnected)
+                {
+                    Logger.InfoS("net",
+                        "{ConnectionEndpoint} disconnected during handshake",
+                        connection.RemoteEndPoint, userName, userId);
+
+                    return;
                 }
 
                 var msg = peer.Peer.CreateMessage();
@@ -242,8 +266,12 @@ namespace Robust.Shared.Network
 
         private Task AwaitDisconnectAsync(NetConnection connection)
         {
-            var tcs = new TaskCompletionSource<object?>();
-            _awaitingDisconnect.Add(connection, tcs);
+            if (!_awaitingDisconnect.TryGetValue(connection, out var tcs))
+            {
+                tcs = new TaskCompletionSource<object?>();
+                _awaitingDisconnect.Add(connection, tcs);
+            }
+
             return tcs.Task;
         }
 

Robust.Shared/Network/NetManager.cs

@@ -135,6 +135,8 @@ namespace Robust.Shared.Network
         private readonly Dictionary<NetConnection, TaskCompletionSource<object?>> _awaitingDisconnect
             = new();
 
+        private readonly HashSet<NetUserId> _awaitingDisconnectToConnect = new HashSet<NetUserId>();
+
         /// <inheritdoc />
         public int Port => _config.GetCVar(CVars.NetPort);
 

Robust.Shared/Physics/B2DynamicTree.cs

@@ -870,7 +870,7 @@ namespace Robust.Shared.Physics
 
         public void Query<TState>(ref TState state, QueryCallback<TState> callback, in Box2 aabb)
         {
-            using var stack = new GrowableStack<Proxy>(stackalloc Proxy[256]);
+            var stack = new GrowableStack<Proxy>(stackalloc Proxy[256]);
             stack.Push(_root);
 
             ref var baseRef = ref _nodes[0];
@@ -915,7 +915,7 @@ namespace Robust.Shared.Physics
         {
             // NOTE: This is not Box2D's normal ray cast function, since our rays have infinite length.
 
-            using var stack = new GrowableStack<Proxy>(stackalloc Proxy[256]);
+            var stack = new GrowableStack<Proxy>(stackalloc Proxy[256]);
 
             stack.Push(_root);
 

Robust.Shared/Prototypes/EntityPrototype.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
@@ -6,6 +6,7 @@ using JetBrains.Annotations;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
+using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Serialization;
 using Robust.Shared.Utility;
@@ -18,7 +19,7 @@ namespace Robust.Shared.Prototypes
     /// Prototype that represents game entities.
     /// </summary>
     [Prototype("entity")]
-    public class EntityPrototype : IPrototype, IIndexedPrototype, ISyncingPrototype
+    public class EntityPrototype : IPrototype, ISyncingPrototype
     {
         [Dependency] private readonly IComponentFactory _componentFactory = default!;
 
@@ -257,6 +258,11 @@ namespace Robust.Shared.Prototypes
             }
         }
 
+        public void Reset()
+        {
+            Children.Clear();
+        }
+
         // Resolve inheritance.
         public bool Sync(IPrototypeManager manager, int stage)
         {
@@ -424,6 +430,68 @@ namespace Robust.Shared.Prototypes
             }
         }
 
+        public void UpdateEntity(Entity entity)
+        {
+            bool HasBeenModified(string name, YamlMappingNode data, EntityPrototype prototype, IComponent currentComponent, IComponentFactory factory)
+            {
+                var component = factory.GetComponent(name);
+                prototype.CurrentDeserializingComponent = name;
+                ObjectSerializer ser = YamlObjectSerializer.NewReader(data, new PrototypeSerializationContext(prototype));
+                component.ExposeData(ser);
+                return component == (Component) currentComponent;
+            }
+
+            if (Name != entity.Prototype?.Name)
+            {
+                Logger.Error($"Reloaded prototype used to update entity did not match entity's existing prototype: Expected '{entity.Prototype?.Name}', got '{Name}'");
+                return;
+            }
+
+            var factory = IoCManager.Resolve<IComponentFactory>();
+            var componentManager = IoCManager.Resolve<IComponentManager>();
+            var oldPrototype = entity.Prototype;
+
+            var oldPrototypeComponents = oldPrototype.Components.Keys
+                .Where(n => n != "Transform" && n != "MetaData")
+                .Select(name => (name, factory.GetRegistration(name).Type))
+                .ToList();
+            var newPrototypeComponents = Components.Keys
+                .Where(n => n != "Transform" && n != "MetaData")
+                .Select(name => (name, factory.GetRegistration(name).Type))
+                .ToList();
+
+            var ignoredComponents = new List<string>();
+
+            // Find components to be removed, and remove them
+            foreach (var (name, type) in oldPrototypeComponents.Except(newPrototypeComponents))
+            {
+                if (!HasBeenModified(name, oldPrototype.Components[name], oldPrototype, entity.GetComponent(type),
+                    factory) && Components.Keys.Contains(name))
+                {
+                    ignoredComponents.Add(name);
+                    Logger.Debug(name);
+                    continue;
+                }
+                componentManager.RemoveComponent(entity.Uid, type);
+            }
+            componentManager.CullRemovedComponents();
+
+            // Add new components
+            foreach (var (name, type) in newPrototypeComponents.Where(t => !ignoredComponents.Contains(t.name)).Except(oldPrototypeComponents))
+            {
+                var data = Components[name];
+                var component = (Component) factory.GetComponent(name);
+                ObjectSerializer ser = YamlObjectSerializer.NewReader(data, new PrototypeSerializationContext(this));
+                CurrentDeserializingComponent = name;
+                component.Owner = entity;
+                component.ExposeData(ser);
+                entity.AddComponent(component);
+            }
+
+            // Update entity metadata
+            entity.MetaData.EntityPrototype = this;
+        }
+
         internal static void LoadEntity(EntityPrototype? prototype, Entity entity, IComponentFactory factory, IEntityLoadContext? context)
         {
             YamlObjectSerializer.Context? defaultContext = null;

Robust.Shared/Prototypes/IPrototype.cs

@@ -3,30 +3,24 @@
 namespace Robust.Shared.Prototypes
 {
     /// <summary>
-    /// An IPrototype is a prototype that can be loaded from the global YAML prototypes.
+    ///     An IPrototype is a prototype that can be loaded from the global YAML prototypes.
     /// </summary>
     /// <remarks>
-    /// To use this, the prototype must be accessible through IoC with <see cref="IoCTargetAttribute"/>
-    /// and it must have a <see cref="PrototypeAttribute"/> to give it a type string.
+    ///     To use this, the prototype must be accessible through IoC with <see cref="IoCTargetAttribute"/>
+    ///     and it must have a <see cref="PrototypeAttribute"/> to give it a type string.
     /// </remarks>
     public interface IPrototype
-    {
-        /// <summary>
-        /// Load data from the YAML mappings in the prototype files.
-        /// </summary>
-        void LoadFrom(YamlMappingNode mapping);
-    }
-
-    /// <summary>
-    /// Extension on <see cref="IPrototype"/> that allows it to be "indexed" by a string ID.
-    /// </summary>
-    public interface IIndexedPrototype
     {
         /// <summary>
         /// An ID for this prototype instance.
         /// If this is a duplicate, an error will be thrown.
         /// </summary>
         string ID { get; }
+
+        /// <summary>
+        /// Load data from the YAML mappings in the prototype files.
+        /// </summary>
+        void LoadFrom(YamlMappingNode mapping);
     }
 
     /// <summary>
@@ -35,6 +29,8 @@ namespace Robust.Shared.Prototypes
     /// </summary>
     public interface ISyncingPrototype
     {
+        void Reset();
+
         /// <summary>
         /// Sync and update cross-referencing data.
         /// Syncing works in stages, each time it will be called with the stage it's currently on.

Robust.Shared/Prototypes/PrototypeManager.cs

@@ -4,11 +4,16 @@ using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using System.Runtime.Serialization;
+using System.Threading;
+using System.Threading.Tasks;
 using JetBrains.Annotations;
+using Robust.Shared.Asynchronous;
 using Robust.Shared.ContentPack;
+using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.IoC.Exceptions;
 using Robust.Shared.Log;
+using Robust.Shared.Network;
 using Robust.Shared.Reflection;
 using Robust.Shared.Utility;
 using YamlDotNet.Core;
@@ -21,6 +26,8 @@ namespace Robust.Shared.Prototypes
     /// </summary>
     public interface IPrototypeManager
     {
+        void Initialize();
+
         /// <summary>
         /// Return an IEnumerable to iterate all prototypes of a certain type.
         /// </summary>
@@ -28,6 +35,7 @@ namespace Robust.Shared.Prototypes
         /// Thrown if the type of prototype is not registered.
         /// </exception>
         IEnumerable<T> EnumeratePrototypes<T>() where T : class, IPrototype;
+
         /// <summary>
         /// Return an IEnumerable to iterate all prototypes of a certain type.
         /// </summary>
@@ -35,31 +43,44 @@ namespace Robust.Shared.Prototypes
         /// Thrown if the type of prototype is not registered.
         /// </exception>
         IEnumerable<IPrototype> EnumeratePrototypes(Type type);
+
         /// <summary>
-        /// Index for a <see cref="IIndexedPrototype"/> by ID.
+        /// Index for a <see cref="IPrototype"/> by ID.
         /// </summary>
         /// <exception cref="KeyNotFoundException">
         /// Thrown if the type of prototype is not registered.
         /// </exception>
-        T Index<T>(string id) where T : class, IIndexedPrototype;
+        T Index<T>(string id) where T : class, IPrototype;
+
         /// <summary>
-        /// Index for a <see cref="IIndexedPrototype"/> by ID.
+        /// Index for a <see cref="IPrototype"/> by ID.
         /// </summary>
         /// <exception cref="KeyNotFoundException">
         /// Thrown if the ID does not exist or the type of prototype is not registered.
         /// </exception>
-        IIndexedPrototype Index(Type type, string id);
-        bool HasIndex<T>(string id) where T : IIndexedPrototype;
-        bool TryIndex<T>(string id, out T prototype) where T : IIndexedPrototype;
+        IPrototype Index(Type type, string id);
+        bool HasIndex<T>(string id) where T : IPrototype;
+        bool TryIndex<T>(string id, out T prototype) where T : IPrototype;
+
         /// <summary>
         /// Load prototypes from files in a directory, recursively.
         /// </summary>
-        void LoadDirectory(ResourcePath path);
-        void LoadFromStream(TextReader stream);
+        Task<List<IPrototype>> LoadDirectory(ResourcePath path);
+
+        List<IPrototype> LoadFromStream(TextReader stream);
+
+        List<IPrototype> LoadString(string str);
+
         /// <summary>
         /// Clear out all prototypes and reset to a blank slate.
         /// </summary>
         void Clear();
+
+        /// <summary>
+        ///     Performs a reload on all prototypes, updating the game state accordingly
+        /// </summary>
+        void ReloadPrototypes(ResourcePath file);
+
         /// <summary>
         /// Syncs all inter-prototype data. Call this when operations adding new prototypes are done.
         /// </summary>
@@ -78,7 +99,6 @@ namespace Robust.Shared.Prototypes
         void RegisterType(Type protoClass);
 
         event Action<YamlStream, string>? LoadedData;
-
     }
 
     /// <summary>
@@ -102,25 +122,40 @@ namespace Robust.Shared.Prototypes
     {
         [Dependency] private readonly IReflectionManager ReflectionManager = default!;
         [Dependency] private readonly IDynamicTypeFactoryInternal _dynamicTypeFactory = default!;
-        [Dependency] private readonly IResourceManager _resources = default!;
+        [Dependency] public readonly IResourceManager Resources = default!;
+        [Dependency] private readonly IEntityManager _entityManager = default!;
+        [Dependency] public readonly ITaskManager TaskManager = default!;
+        [Dependency] public readonly INetManager NetManager = default!;
 
         private readonly Dictionary<string, Type> prototypeTypes = new();
 
+        private bool _initialized;
         private bool _hasEverBeenReloaded;
+        private bool _hasEverResynced;
 
         #region IPrototypeManager members
-        private readonly Dictionary<Type, List<IPrototype>> prototypes = new();
-        private readonly Dictionary<Type, Dictionary<string, IIndexedPrototype>> indexedPrototypes = new();
+        private readonly Dictionary<Type, Dictionary<string, IPrototype>> prototypes = new();
 
         private readonly HashSet<string> IgnoredPrototypeTypes = new();
 
+        public virtual void Initialize()
+        {
+            if (_initialized)
+            {
+                throw new InvalidOperationException($"{nameof(PrototypeManager)} has already been initialized.");
+            }
+
+            _initialized = true;
+        }
+
         public IEnumerable<T> EnumeratePrototypes<T>() where T : class, IPrototype
         {
             if (!_hasEverBeenReloaded)
             {
                 throw new InvalidOperationException("No prototypes have been loaded yet.");
             }
-            return prototypes[typeof(T)].Select((IPrototype p) => (T)p);
+
+            return prototypes[typeof(T)].Values.Select(p => (T) p);
         }
 
         public IEnumerable<IPrototype> EnumeratePrototypes(Type type)
@@ -129,10 +164,11 @@ namespace Robust.Shared.Prototypes
             {
                 throw new InvalidOperationException("No prototypes have been loaded yet.");
             }
-            return prototypes[type];
+
+            return prototypes[type].Values;
         }
 
-        public T Index<T>(string id) where T : class, IIndexedPrototype
+        public T Index<T>(string id) where T : class, IPrototype
         {
             if (!_hasEverBeenReloaded)
             {
@@ -140,7 +176,7 @@ namespace Robust.Shared.Prototypes
             }
             try
             {
-                return (T)indexedPrototypes[typeof(T)][id];
+                return (T)prototypes[typeof(T)][id];
             }
             catch (KeyNotFoundException)
             {
@@ -148,24 +184,60 @@ namespace Robust.Shared.Prototypes
             }
         }
 
-        public IIndexedPrototype Index(Type type, string id)
+        public IPrototype Index(Type type, string id)
         {
             if (!_hasEverBeenReloaded)
             {
                 throw new InvalidOperationException("No prototypes have been loaded yet.");
             }
-            return indexedPrototypes[type][id];
+
+            return prototypes[type][id];
         }
 
         public void Clear()
         {
-            prototypes.Clear();
             prototypeTypes.Clear();
-            indexedPrototypes.Clear();
+            prototypes.Clear();
+        }
+
+        public virtual async void ReloadPrototypes(ResourcePath file)
+        {
+#if !FULL_RELEASE
+            var changed = await LoadFile(file.ToRootedPath(), true);
+            Resync();
+
+            foreach (var prototype in changed)
+            {
+                if (prototype is not EntityPrototype entityPrototype)
+                {
+                    continue;
+                }
+
+                foreach (var entity in _entityManager.GetEntities(new PredicateEntityQuery(e => e.Prototype != null && e.Prototype.ID == entityPrototype.ID)))
+                {
+                    entityPrototype.UpdateEntity((Entity) entity);
+                }
+            }
+#endif
         }
 
         public void Resync()
         {
+            // TODO Make this smarter and only resync changed prototypes
+            if (_hasEverResynced)
+            {
+                foreach (var prototypeList in prototypes.Values)
+                {
+                    foreach (var prototype in prototypeList.Values)
+                    {
+                        if (prototype is ISyncingPrototype syncing)
+                        {
+                            syncing.Reset();
+                        }
+                    }
+                }
+            }
+
             foreach (Type type in prototypeTypes.Values.Where(t => typeof(ISyncingPrototype).IsAssignableFrom(t)))
             {
                 // This list is the list of prototypes we're syncing.
@@ -177,17 +249,18 @@ namespace Robust.Shared.Prototypes
                 // When we get to the end, do the whole thing again!
                 // Yes this is ridiculously overengineered BUT IT PERFORMS WELL.
                 // I hope.
-                List<ISyncingPrototype> currentRun = prototypes[type].Select(p => (ISyncingPrototype)p).ToList();
-                int stage = 0;
+                List<ISyncingPrototype> currentRun = prototypes[type].Values.Select(p => (ISyncingPrototype) p).ToList();
+
+                var stage = 0;
                 // Outer loop to iterate stages.
                 while (currentRun.Count > 0)
                 {
                     // Increase positions to iterate over list.
                     // If we need to stick, i gets reduced down below.
-                    for (int i = 0; i < currentRun.Count; i++)
+                    for (var i = 0; i < currentRun.Count; i++)
                     {
                         ISyncingPrototype prototype = currentRun[i];
-                        bool result = prototype.Sync(this, stage);
+                        var result = prototype.Sync(this, stage);
                         // Keep prototype and move on to next one if it returns true.
                         // Thus it stays in the list for next stage.
                         if (result)
@@ -204,80 +277,128 @@ namespace Robust.Shared.Prototypes
                     stage++;
                 }
             }
+
+            _hasEverResynced = true;
         }
 
         /// <inheritdoc />
-        public void LoadDirectory(ResourcePath path)
+        public async Task<List<IPrototype>> LoadDirectory(ResourcePath path)
         {
-            var sawmill = Logger.GetSawmill("eng");
+            var changedPrototypes = new List<IPrototype>();
+
             _hasEverBeenReloaded = true;
-            var yamlStreams = _resources.ContentFindFiles(path).ToList().AsParallel()
-                .Where(filePath => filePath.Extension == "yml" && !filePath.Filename.StartsWith("."))
-                .Select(filePath =>
-                {
-                    try
-                    {
-                        using var reader = new StreamReader(_resources.ContentFileRead(filePath), EncodingHelpers.UTF8);
-                        var yamlStream = new YamlStream();
-                        yamlStream.Load(reader);
+            var streams = Resources.ContentFindFiles(path).ToList().AsParallel()
+                .Where(filePath => filePath.Extension == "yml" && !filePath.Filename.StartsWith("."));
 
-                        var result = ((YamlStream? yamlStream, ResourcePath?))(yamlStream, filePath);
-
-                        LoadedData?.Invoke(yamlStream, filePath.ToString());
-
-                        return result;
-                    }
-                    catch (YamlException e)
-                    {
-                        sawmill.Error("YamlException whilst loading prototypes from {0}: {1}", filePath, e.Message);
-                        return (null, null);
-                    }
-                })
-                .Where(p => p.yamlStream != null) // Filter out loading errors.
-                .ToList();
-
-            foreach (var (stream, filePath) in yamlStreams)
+            foreach (var resourcePath in streams)
             {
-                for (var i = 0; i < stream!.Documents.Count; i++)
+                var filePrototypes = await LoadFile(resourcePath);
+                changedPrototypes.AddRange(filePrototypes);
+            }
+
+            return changedPrototypes;
+        }
+
+        private Task<StreamReader?> ReadFile(ResourcePath file, bool @throw = true)
+        {
+            var retries = 0;
+
+            while (true)
+            {
+                try
                 {
-                    try
+                    var reader = new StreamReader(Resources.ContentFileRead(file), EncodingHelpers.UTF8);
+
+                    return Task.FromResult<StreamReader?>(reader);
+                }
+                catch (IOException e)
+                {
+                    if (retries > 10)
                     {
-                        LoadFromDocument(stream.Documents[i]);
-                    }
-                    catch (Exception e)
-                    {
-                        Logger.ErrorS("eng", $"Exception whilst loading prototypes from {filePath}#{i}:\n{e}");
+                        if (@throw)
+                        {
+                            throw;
+                        }
+
+                        Logger.Error($"Error reloading prototypes in file {file}.", e);
+                        return Task.FromResult<StreamReader?>(null);
                     }
+
+                    retries++;
+                    Thread.Sleep(10);
                 }
             }
         }
 
-        public void LoadFromStream(TextReader stream)
+        public async Task<List<IPrototype>> LoadFile(ResourcePath file, bool overwrite = false)
         {
+            var changedPrototypes = new List<IPrototype>();
+
+            try
+            {
+                using var reader = await ReadFile(file, !overwrite);
+                var yamlStream = new YamlStream();
+                yamlStream.Load(reader);
+
+                LoadedData?.Invoke(yamlStream, file.ToString());
+
+                for (var i = 0; i < yamlStream.Documents.Count; i++)
+                {
+                    try
+                    {
+                        var documentPrototypes = LoadFromDocument(yamlStream.Documents[i], overwrite);
+                        changedPrototypes.AddRange(documentPrototypes);
+                    }
+                    catch (Exception e)
+                    {
+                        Logger.ErrorS("eng", $"Exception whilst loading prototypes from {file}#{i}:\n{e}");
+                    }
+                }
+            }
+            catch (YamlException e)
+            {
+                var sawmill = Logger.GetSawmill("eng");
+                sawmill.Error("YamlException whilst loading prototypes from {0}: {1}", file, e.Message);
+            }
+
+            return changedPrototypes;
+        }
+
+        public List<IPrototype> LoadFromStream(TextReader stream)
+        {
+            var changedPrototypes = new List<IPrototype>();
             _hasEverBeenReloaded = true;
             var yaml = new YamlStream();
             yaml.Load(stream);
 
-            for (int i = 0; i < yaml.Documents.Count; i++)
+            for (var i = 0; i < yaml.Documents.Count; i++)
             {
                 try
                 {
-                    LoadFromDocument(yaml.Documents[i]);
+                    var documentPrototypes = LoadFromDocument(yaml.Documents[i]);
+                    changedPrototypes.AddRange(documentPrototypes);
                 }
                 catch (Exception e)
                 {
-                    throw new PrototypeLoadException(string.Format("Failed to load prototypes from document#{0}", i), e);
+                    throw new PrototypeLoadException($"Failed to load prototypes from document#{i}", e);
                 }
             }
 
             LoadedData?.Invoke(yaml, "anonymous prototypes YAML stream");
+
+            return changedPrototypes;
+        }
+
+        public List<IPrototype> LoadString(string str)
+        {
+            return LoadFromStream(new StreamReader(str));
         }
 
         #endregion IPrototypeManager members
 
         public void PostInject()
         {
-            ReflectionManager.OnAssemblyAdded += (_, __) => ReloadPrototypeTypes();
+            ReflectionManager.OnAssemblyAdded += (_, _) => ReloadPrototypeTypes();
             ReloadPrototypeTypes();
         }
 
@@ -290,9 +411,11 @@ namespace Robust.Shared.Prototypes
             }
         }
 
-        private void LoadFromDocument(YamlDocument document)
+        private List<IPrototype> LoadFromDocument(YamlDocument document, bool overwrite = false)
         {
-            var rootNode = (YamlSequenceNode)document.RootNode;
+            var changedPrototypes = new List<IPrototype>();
+            var rootNode = (YamlSequenceNode) document.RootNode;
+
             foreach (YamlMappingNode node in rootNode.Cast<YamlMappingNode>())
             {
                 var type = node.GetNode("type").AsString();
@@ -302,38 +425,41 @@ namespace Robust.Shared.Prototypes
                     {
                         continue;
                     }
-                    throw new PrototypeLoadException(string.Format("Unknown prototype type: '{0}'", type));
+
+                    throw new PrototypeLoadException($"Unknown prototype type: '{type}'");
                 }
 
                 var prototypeType = prototypeTypes[type];
                 var prototype = _dynamicTypeFactory.CreateInstanceUnchecked<IPrototype>(prototypeType);
+
                 prototype.LoadFrom(node);
-                prototypes[prototypeType].Add(prototype);
-                var indexedPrototype = prototype as IIndexedPrototype;
-                if (indexedPrototype != null)
+                changedPrototypes.Add(prototype);
+
+                var id = prototype.ID;
+
+                if (!overwrite && prototypes[prototypeType].ContainsKey(id))
                 {
-                    var id = indexedPrototype.ID;
-                    if (indexedPrototypes[prototypeType].ContainsKey(id))
-                    {
-                        throw new PrototypeLoadException(string.Format("Duplicate ID: '{0}'", id));
-                    }
-                    indexedPrototypes[prototypeType][id] = (IIndexedPrototype)prototype;
+                    throw new PrototypeLoadException($"Duplicate ID: '{id}'");
                 }
+
+                prototypes[prototypeType][id] = prototype;
             }
+
+            return changedPrototypes;
         }
 
-        public bool HasIndex<T>(string id) where T : IIndexedPrototype
+        public bool HasIndex<T>(string id) where T : IPrototype
         {
-            if (!indexedPrototypes.TryGetValue(typeof(T), out var index))
+            if (!prototypes.TryGetValue(typeof(T), out var index))
             {
                 throw new UnknownPrototypeException(id);
             }
             return index.ContainsKey(id);
         }
 
-        public bool TryIndex<T>(string id, [MaybeNullWhen(false)] out T prototype) where T : IIndexedPrototype
+        public bool TryIndex<T>(string id, [MaybeNullWhen(false)] out T prototype) where T : IPrototype
         {
-            if (!indexedPrototypes.TryGetValue(typeof(T), out var index))
+            if (!prototypes.TryGetValue(typeof(T), out var index))
             {
                 throw new UnknownPrototypeException(id);
             }
@@ -370,11 +496,10 @@ namespace Robust.Shared.Prototypes
             }
 
             prototypeTypes[attribute.Type] = type;
-            prototypes[type] = new List<IPrototype>();
 
-            if (typeof(IIndexedPrototype).IsAssignableFrom(type))
+            if (typeof(IPrototype).IsAssignableFrom(type))
             {
-                indexedPrototypes[type] = new Dictionary<string, IIndexedPrototype>();
+                prototypes[type] = new Dictionary<string, IPrototype>();
             }
         }
 
@@ -398,11 +523,6 @@ namespace Robust.Shared.Prototypes
         public PrototypeLoadException(SerializationInfo info, StreamingContext context) : base(info, context)
         {
         }
-
-        public override void GetObjectData(SerializationInfo info, StreamingContext context)
-        {
-            base.GetObjectData(info, context);
-        }
     }
 
     [Serializable]

Robust.Shared/Reflection/IReflectionManager.cs

@@ -69,7 +69,7 @@ namespace Robust.Shared.Reflection
         /// </summary>
         /// <typeparam name="T">Attribute to search for.</typeparam>
         /// <returns>Enumeration of all types with the specified attribute.</returns>
-        IEnumerable<Type> FindTypesWithAttribute<T>();
+        IEnumerable<Type> FindTypesWithAttribute<T>() where T : Attribute;
 
         /// <summary>
         /// Loads assemblies into the manager and get all the types.

Robust.Shared/Reflection/ReflectionManager.cs

@@ -4,6 +4,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Reflection;
 using Robust.Shared.Log;
+using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 
 namespace Robust.Shared.Reflection
@@ -158,7 +159,7 @@ namespace Robust.Shared.Reflection
         }
 
         /// <inheritdoc />
-        public IEnumerable<Type> FindTypesWithAttribute<T>()
+        public IEnumerable<Type> FindTypesWithAttribute<T>() where T : Attribute
         {
             var types = new List<Type>();
 
@@ -217,7 +218,21 @@ namespace Robust.Shared.Reflection
             Type? found = null;
             foreach (var derivedType in GetAllChildren(baseType))
             {
-                if (derivedType.Name == typeName && (derivedType.IsPublic))
+                if (!derivedType.IsPublic)
+                {
+                    continue;
+                }
+
+                if (derivedType.Name == typeName)
+                {
+                    found = derivedType;
+                    break;
+                }
+
+                var serializedAttribute = derivedType.GetCustomAttribute<SerializedTypeAttribute>();
+
+                if (serializedAttribute != null &&
+                    serializedAttribute.SerializeName == typeName)
                 {
                     found = derivedType;
                     break;

Robust.Shared/Serialization/IRobustMappedStringSerializer.cs

@@ -14,6 +14,8 @@ namespace Robust.Shared.Serialization
     [PublicAPI]
     internal interface IRobustMappedStringSerializer
     {
+        bool Locked { get; }
+
         /// <summary>
         ///     The type serializer to register with NetSerializer.
         /// </summary>

Robust.Shared/Serialization/RobustMappedStringSerializer.cs

@@ -133,6 +133,7 @@ namespace Robust.Shared.Serialization
                 | RegexOptions.IgnorePatternWhitespace
             );
 
+        public bool Locked => _dict.Locked;
 
         public ITypeSerializer TypeSerializer => this;
 

Robust.Shared/Serialization/SerializedTypeAttribute.cs

@@ -0,0 +1,18 @@
+using System;
+
+namespace Robust.Shared.Serialization
+{
+    [AttributeUsage(AttributeTargets.Class, Inherited = false)]
+    public class SerializedTypeAttribute : Attribute
+    {
+        /// <summary>
+        ///     Name of this type in serialized files.
+        /// </summary>
+        public string SerializeName { get; }
+
+        public SerializedTypeAttribute(string serializeName)
+        {
+            SerializeName = serializeName;
+        }
+    }
+}

Robust.Shared/Serialization/YamlCustomFormatSerializer.cs

@@ -17,7 +17,7 @@ namespace Robust.Shared.Serialization
             _formatter = formatter;
         }
 
-        public override object NodeToType(Type _type, YamlNode node, YamlObjectSerializer serializer)
+        public override object NodeToType(Type type, YamlNode node, YamlObjectSerializer serializer)
         {
             return _formatter.FromCustomFormat(serializer.NodeToType(_formatter.Format, node));
         }

Robust.Shared/Serialization/YamlObjectSerializer.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
@@ -38,6 +39,7 @@ namespace Robust.Shared.Serialization
             {
                 { typeof(Color), new ColorSerializer() },
                 { typeof(Vector2), new Vector2Serializer() },
+                { typeof(Vector2i), new Vector2iSerializer() },
                 { typeof(Vector3), new Vector3Serializer() },
                 { typeof(Vector4), new Vector4Serializer() },
                 { typeof(Angle), new AngleSerializer() },
@@ -510,6 +512,24 @@ namespace Robust.Shared.Serialization
                 return newList;
             }
 
+            if (TryGenericImmutableListType(type, out var immutableListType))
+            {
+                var listNode = (YamlSequenceNode) node;
+                var elems = listNode.Children;
+
+                var newList = Array.CreateInstance(immutableListType, elems.Count);
+
+                for (var i = 0; i < elems.Count; i++)
+                {
+                    newList.SetValue(NodeToType(immutableListType, elems[i]), i);
+                }
+
+                var list = typeof(ImmutableList);
+                var add = list.GetMethod("CreateRange")!.MakeGenericMethod(immutableListType);
+
+                return add.Invoke(null, new object?[] {newList})!;
+            }
+
             // Dictionary<K,V>/IReadOnlyDictionary<K,V>
             if (TryGenericReadDictType(type, out var keyType, out var valType, out var dictType))
             {
@@ -584,12 +604,8 @@ namespace Robust.Shared.Serialization
             // IExposeData.
             if (typeof(IExposeData).IsAssignableFrom(type))
             {
-                if (!(node is YamlMappingNode mapNode))
-                {
-                    throw new InvalidOperationException($"Cannot read from IExposeData on non-mapping node. Type: '{type}'");
-                }
-
                 var concreteType = type;
+
                 if (type.IsAbstract || type.IsInterface)
                 {
                     var tag = node.Tag;
@@ -607,6 +623,12 @@ namespace Robust.Shared.Serialization
                 }
 
                 var instance = (IExposeData)Activator.CreateInstance(concreteType)!;
+
+                if (node is not YamlMappingNode mapNode)
+                {
+                    return instance;
+                }
+
                 // TODO: Might be worth it to cut down on allocations here by using ourselves instead of creating a fork.
                 // Seems doable.
                 if (_context != null)
@@ -639,7 +661,7 @@ namespace Robust.Shared.Serialization
             throw new ArgumentException($"Type {type.FullName} is not supported.", nameof(type));
         }
 
-        public T NodeToType<T>(YamlNode node)
+        public T NodeToType<T>(YamlNode node, string name)
         {
             return (T) NodeToType(typeof(T), node);
         }
@@ -723,6 +745,28 @@ namespace Robust.Shared.Serialization
                 return node;
             }
 
+            if (TryGenericImmutableListType(type, out var immutableListType))
+            {
+                var node = new YamlSequenceNode {Tag = TagSkipTag};
+
+                foreach (var entry in (IEnumerable) obj)
+                {
+                    if (entry == null)
+                    {
+                        throw new ArgumentException("Cannot serialize null value inside list.");
+                    }
+
+                    var entryNode = TypeToNode(entry);
+
+                    // write the concrete type tag
+                    AssignTag<object?>(immutableListType, entry, null, entryNode);
+
+                    node.Add(entryNode);
+                }
+
+                return node;
+            }
+
             // Dictionary<K,V>
             if (TryGenericDictType(type, out var keyType, out var valType)
                 || TryGenericReadOnlyDictType(type, out keyType, out valType))
@@ -861,7 +905,8 @@ namespace Robust.Shared.Serialization
                 return true;
             }
 
-            if (TryGenericListType(type!, out _))
+            if (TryGenericListType(type!, out _) ||
+                TryGenericImmutableListType(type!, out _))
             {
                 var listA = (IList) a;
                 var listB = (IList) b!;
@@ -1023,6 +1068,21 @@ namespace Robust.Shared.Serialization
             return false;
         }
 
+        private static bool TryGenericImmutableListType(Type type, [NotNullWhen(true)] out Type? listType)
+        {
+            var isImmutableList = type.GetTypeInfo().IsGenericType &&
+                                  type.GetGenericTypeDefinition() == typeof(ImmutableList<>);
+
+            if (isImmutableList)
+            {
+                listType = type.GetGenericArguments()[0];
+                return true;
+            }
+
+            listType = default;
+            return false;
+        }
+
         private static bool TryGenericReadOnlyDictType(Type type, [NotNullWhen(true)] out Type? keyType, [NotNullWhen(true)] out Type? valType)
         {
             var isDict = type.GetTypeInfo().IsGenericType && type.GetGenericTypeDefinition() == typeof(IReadOnlyDictionary<,>);
@@ -1287,6 +1347,20 @@ namespace Robust.Shared.Serialization
             }
         }
 
+        class Vector2iSerializer : TypeSerializer
+        {
+            public override object NodeToType(Type type, YamlNode node, YamlObjectSerializer serializer)
+            {
+                return node.AsVector2i();
+            }
+
+            public override YamlNode TypeToNode(object obj, YamlObjectSerializer serializer)
+            {
+                var vec = (Vector2i)obj;
+                return new YamlScalarNode($"{vec.X.ToString(CultureInfo.InvariantCulture)},{vec.Y.ToString(CultureInfo.InvariantCulture)}");
+            }
+        }
+
         class Vector3Serializer : TypeSerializer
         {
             public override object NodeToType(Type type, YamlNode node, YamlObjectSerializer serializer)

Robust.Shared/SharedIoC.cs

@@ -13,7 +13,6 @@ using Robust.Shared.Physics;
 using Robust.Shared.Random;
 using Robust.Shared.Sandboxing;
 using Robust.Shared.Serialization;
-using Robust.Shared.Timers;
 using Robust.Shared.Timing;
 
 namespace Robust.Shared
@@ -35,6 +34,7 @@ namespace Robust.Shared
             IoCManager.Register<ILogManager, LogManager>();
             IoCManager.Register<IMapManager, MapManager>();
             IoCManager.Register<IMapManagerInternal, MapManager>();
+            IoCManager.Register<IPauseManager, PauseManager>();
             IoCManager.Register<IModLoader, ModLoader>();
             IoCManager.Register<IModLoaderInternal, ModLoader>();
             IoCManager.Register<INetManager, NetManager>();

Robust.Shared/Timing/GameLoop.cs

@@ -123,8 +123,6 @@ namespace Robust.Shared.Timing
             FrameEventArgs realFrameEvent;
             FrameEventArgs simFrameEvent;
 
-            _timing.ResetRealTime();
-
             while (Running)
             {
                 // maximum number of ticks to queue before the loop slows down.

Robust.Shared/Timing/GameTiming.cs

@@ -92,18 +92,13 @@ namespace Robust.Shared.Timing
         {
             get
             {
-                if (_netManager.IsServer)
-                {
-                    return RealTime;
-                }
-
-                var clientNetManager = (IClientNetManager) _netManager;
-                if (clientNetManager.ServerChannel == null)
+                var offset = GetServerOffset();
+                if (offset == null)
                 {
                     return TimeSpan.Zero;
                 }
 
-                return clientNetManager.ServerChannel.RemoteTime;
+                return RealTime + offset.Value;
             }
         }
 
@@ -236,15 +231,6 @@ namespace Robust.Shared.Timing
             _cachedCurTimeInfo = (newTime, CurTick);
         }
 
-        /// <summary>
-        ///     Resets the real uptime of the server.
-        /// </summary>
-        public void ResetRealTime()
-        {
-            _realTimer.Restart();
-            _lastRealTime = TimeSpan.Zero;
-        }
-
         /// <summary>
         /// Resets the simulation time.
         /// </summary>
@@ -256,6 +242,35 @@ namespace Robust.Shared.Timing
             Paused = true;
         }
 
+        public TimeSpan RealLocalToServer(TimeSpan local)
+        {
+            var offset = GetServerOffset();
+            if (offset == null)
+                return TimeSpan.Zero;
+
+            return local + offset.Value;
+        }
+
+        public TimeSpan RealServerToLocal(TimeSpan server)
+        {
+            var offset = GetServerOffset();
+            if (offset == null)
+                return TimeSpan.Zero;
+
+            return server - offset.Value;
+        }
+
+        private TimeSpan? GetServerOffset()
+        {
+            if (_netManager.IsServer)
+            {
+                return TimeSpan.Zero;
+            }
+
+            var clientNetManager = (IClientNetManager) _netManager;
+            return clientNetManager.ServerChannel?.RemoteTimeOffset;
+        }
+
         public bool IsFirstTimePredicted { get; private set; } = true;
 
         /// <inheritdoc />

Robust.Shared/Timing/IGameTiming.cs

@@ -123,11 +123,6 @@ namespace Robust.Shared.Timing
         /// </summary>
         void StartFrame();
 
-        /// <summary>
-        ///     Resets the real uptime of the server.
-        /// </summary>
-        void ResetRealTime();
-
         /// <summary>
         /// Is this the first time CurTick has been predicted?
         /// </summary>
@@ -162,5 +157,8 @@ namespace Robust.Shared.Timing
         /// Resets the simulation time. This should be called on round restarts.
         /// </summary>
         void ResetSimTime();
+
+        TimeSpan RealLocalToServer(TimeSpan local);
+        TimeSpan RealServerToLocal(TimeSpan server);
     }
 }

Robust.Shared/Timing/IPauseManager.cs

@@ -1,7 +1,7 @@
-using JetBrains.Annotations;
+using JetBrains.Annotations;
 using Robust.Shared.Map;
 
-namespace Robust.Server.Timing
+namespace Robust.Shared.Timing
 {
     public interface IPauseManager
     {
@@ -26,4 +26,4 @@ namespace Robust.Server.Timing
         [Pure]
         bool IsMapInitialized(MapId mapId);
     }
-}
+}

Robust.Shared/Timing/ITimerManager.cs

@@ -1,7 +1,6 @@
 using System.Threading;
-using Robust.Shared.Timing;
 
-namespace Robust.Shared.Timers
+namespace Robust.Shared.Timing
 {
     public interface ITimerManager
     {

Robust.Shared/Timing/PauseManager.cs

@@ -0,0 +1,179 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using Robust.Shared.Console;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Localization;
+using Robust.Shared.Map;
+using Robust.Shared.ViewVariables;
+
+namespace Robust.Shared.Timing
+{
+    internal sealed class PauseManager : IPauseManager, IPostInjectInit
+    {
+        [Dependency] private readonly IConsoleHost _conhost = default!;
+        [Dependency] private readonly IEntityManager _entityManager = default!;
+        [Dependency] private readonly IMapManager _mapManager = default!;
+
+        [ViewVariables] private readonly HashSet<MapId> _pausedMaps = new();
+        [ViewVariables] private readonly HashSet<MapId> _unInitializedMaps = new();
+
+        public void SetMapPaused(MapId mapId, bool paused)
+        {
+            if (paused)
+            {
+                _pausedMaps.Add(mapId);
+
+                foreach (var entity in _entityManager.GetEntitiesInMap(mapId))
+                {
+                    entity.Paused = true;
+                }
+            }
+            else
+            {
+                _pausedMaps.Remove(mapId);
+
+                foreach (var entity in _entityManager.GetEntitiesInMap(mapId))
+                {
+                    entity.Paused = false;
+                }
+            }
+        }
+
+        public void DoMapInitialize(MapId mapId)
+        {
+            if (IsMapInitialized(mapId))
+                throw new ArgumentException("That map is already initialized.");
+
+            _unInitializedMaps.Remove(mapId);
+
+            foreach (var entity in _entityManager.GetEntitiesInMap(mapId))
+            {
+                entity.RunMapInit();
+                entity.Paused = false;
+            }
+        }
+
+        public void DoGridMapInitialize(IMapGrid grid)
+        {
+            DoGridMapInitialize(grid.Index);
+        }
+
+        public void DoGridMapInitialize(GridId gridId)
+        {
+            var mapId = _mapManager.GetGrid(gridId).ParentMapId;
+
+            foreach (var entity in _entityManager.GetEntitiesInMap(mapId))
+            {
+                if (entity.Transform.GridID != gridId)
+                    continue;
+
+                entity.RunMapInit();
+                entity.Paused = false;
+            }
+        }
+
+        public void AddUninitializedMap(MapId mapId)
+        {
+            _unInitializedMaps.Add(mapId);
+        }
+
+        public bool IsMapPaused(MapId mapId)
+        {
+            return _pausedMaps.Contains(mapId) || _unInitializedMaps.Contains(mapId);
+        }
+
+        public bool IsGridPaused(IMapGrid grid)
+        {
+            return IsMapPaused(grid.ParentMapId);
+        }
+
+        public bool IsGridPaused(GridId gridId)
+        {
+            var grid = _mapManager.GetGrid(gridId);
+            return IsGridPaused(grid);
+        }
+
+        public bool IsMapInitialized(MapId mapId)
+        {
+            return !_unInitializedMaps.Contains(mapId);
+        }
+
+        /// <inheritdoc />
+        public void PostInject()
+        {
+            _mapManager.MapDestroyed += (_, args) =>
+            {
+                _pausedMaps.Remove(args.Map);
+                _unInitializedMaps.Add(args.Map);
+            };
+
+            if(_conhost.IsClient)
+                return;
+
+            _conhost.RegisterCommand("pausemap",
+                "Pauses a map, pausing all simulation processing on it.",
+                "pausemap <map ID>",
+                (shell, _, args) =>
+                {
+                    if (args.Length != 1)
+                    {
+                        shell.WriteError("Need to supply a valid MapId");
+                        return;
+                    }
+
+                    string? arg = args[0];
+                    var mapId = new MapId(int.Parse(arg, CultureInfo.InvariantCulture));
+
+                    if (!_mapManager.MapExists(mapId))
+                    {
+                        shell.WriteError("That map does not exist.");
+                        return;
+                    }
+
+                    SetMapPaused(mapId, true);
+                });
+
+            _conhost.RegisterCommand("querymappaused",
+                "Check whether a map is paused or not.",
+                "querymappaused <map ID>",
+                (shell, _, args) =>
+                {
+                    string? arg = args[0];
+                    var mapId = new MapId(int.Parse(arg, CultureInfo.InvariantCulture));
+
+                    if (!_mapManager.MapExists(mapId))
+                    {
+                        shell.WriteError("That map does not exist.");
+                        return;
+                    }
+
+                    shell.WriteLine(IsMapPaused(mapId).ToString());
+                });
+
+            _conhost.RegisterCommand("unpausemap",
+                "unpauses a map, resuming all simulation processing on it.",
+                "Usage: unpausemap <map ID>",
+                (shell, _, args) =>
+                {
+                    if (args.Length != 1)
+                    {
+                        shell.WriteLine(Loc.GetString("Need to supply a valid MapId"));
+                        return;
+                    }
+
+                    string? arg = args[0];
+                    var mapId = new MapId(int.Parse(arg, CultureInfo.InvariantCulture));
+
+                    if (!_mapManager.MapExists(mapId))
+                    {
+                        shell.WriteLine("That map does not exist.");
+                        return;
+                    }
+
+                    SetMapPaused(mapId, false);
+                });
+        }
+    }
+}

Robust.Shared/Timing/Timer.cs

@@ -4,7 +4,7 @@ using System.Threading.Tasks;
 using Robust.Shared.Exceptions;
 using Robust.Shared.IoC;
 
-namespace Robust.Shared.Timers
+namespace Robust.Shared.Timing
 {
     public class Timer
     {

Robust.Shared/Timing/TimerManager.cs

@@ -2,9 +2,8 @@
 using System.Threading;
 using Robust.Shared.Exceptions;
 using Robust.Shared.IoC;
-using Robust.Shared.Timing;
 
-namespace Robust.Shared.Timers
+namespace Robust.Shared.Timing
 {
     internal sealed class TimerManager : ITimerManager
     {

Robust.Shared/Utility/FormattedMessage.MarkupParser.cs

@@ -15,7 +15,8 @@ namespace Robust.Shared.Utility
         private static readonly Parser<char, char> ParseEscapeSequence =
             Char('\\').Then(OneOf(
                 Char('\\'),
-                Char(TagBegin)));
+                Char(TagBegin),
+                Char(TagEnd)));
 
         private static readonly Parser<char, TagText> ParseTagText =
             ParseEscapeSequence.Or(Token(c => c != TagBegin && c != '\\'))