Update arch (#4605)

Co-authored-by: DrSmugleaf <drsmugleaf@gmail.com>
Co-authored-by: ElectroJr <leonsfriedrich@gmail.com>

.github/CODEOWNERS

@@ -7,3 +7,6 @@
 **/Toolshed/** @moonheart08
 *Command.cs @moonheart08
 *Commands.cs @moonheart08
+
+# Physics
+**/Robust.Shared/Physics/** @metalgearsloth

.gitmodules

@@ -13,3 +13,6 @@
 [submodule "cefglue"]
 	path = cefglue
 	url = https://github.com/space-wizards/cefglue.git
+[submodule "Arch/Arch"]
+	path = Arch/Arch
+	url = https://github.com/space-wizards/Arch.git

Arch/Arch.csproj

@@ -0,0 +1,94 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <LangVersion>latest</LangVersion>
+    <TargetFramework>net7.0</TargetFramework>
+
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
+    <Nullable>enable</Nullable>
+    <IncludeSymbols>true</IncludeSymbols>
+    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
+    <DocumentationFile>bin\$(Configuration)\$(TargetFramework)\$(AssemblyName).xml</DocumentationFile>
+
+    <PackageId>Arch</PackageId>
+    <Title>Arch</Title>
+    <Version>1.2.7.1-alpha</Version>
+    <Authors>genaray</Authors>
+    <PackageLicenseExpression>Apache-2.0</PackageLicenseExpression>
+    <Description>A high performance c# net.6 and net.7 archetype based ECS ( Entity component system ).</Description>
+    <PackageReleaseNotes>Updated LowLevel which fixes bugs. </PackageReleaseNotes>
+    <PackageTags>c#;.net;.net6;.net7;ecs;game;entity;gamedev; game-development; game-engine; entity-component-system;stride;unity;godot;</PackageTags>
+
+    <PackageProjectUrl>https://github.com/genaray/Arch</PackageProjectUrl>
+    <RepositoryUrl>https://github.com/genaray/Arch.git</RepositoryUrl>
+    <RepositoryType>git</RepositoryType>
+    <IsPackable>true</IsPackable>
+
+    <LangVersion>11</LangVersion>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <Copyright>Apache2.0</Copyright>
+
+    <NoWarn>1701;1702;1591</NoWarn>
+
+    <Configurations>Debug;Debug-PureECS;Debug-Events;Release;Release-PureECS;Release-Events;</Configurations>
+
+    <AssemblyName>Arch</AssemblyName>
+    <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
+    <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
+    <DefaultItemExcludes>src/Arch/**/*</DefaultItemExcludes>
+    <DefineConstants>$(DefineConstants);PURE_ECS;CONTRACTS_FULL</DefineConstants>
+  </PropertyGroup>
+
+  <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
+    <DefineConstants>$(DefineConstants);PURE_ECS;CONTRACTS_FULL;TRACE;</DefineConstants>
+    <Optimize>false</Optimize>
+    <PlatformTarget>AnyCPU</PlatformTarget>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <InternalsVisibleTo Include="Arch.Benchmarks" />
+    <InternalsVisibleTo Include="Arch.Tests" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="System" />
+    <Using Include="System.Collections" />
+    <Using Include="System.Collections.Generic" />
+    <Using Include="System.Diagnostics" />
+    <Using Include="System.Diagnostics.CodeAnalysis" />
+    <Using Include="System.IO" />
+    <Using Include="System.Linq" />
+    <Using Include="System.Runtime.CompilerServices" />
+    <Using Include="System.Runtime.InteropServices" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include=".\Arch\src\Arch.SourceGen\Arch.SourceGen.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Arch.LowLevel" Version="1.1.0" />
+    <PackageReference Include="Collections.Pooled" Version="2.0.0-preview.27" />
+    <PackageReference Include="CommunityToolkit.HighPerformance" Version="7.1.2" />
+    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="6.0.0" />
+    <PackageReference Include="ZeroAllocJobScheduler" Version="1.0.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="Arch\src\Arch\**\*.cs">
+      <Link>Arch\%(RecursiveDir)%(Filename)%(Extension)</Link>
+    </Compile>
+    <Compile Remove="Arch\src\Arch\obj\**\*.cs" />
+    <InternalsVisibleTo Include="Arch.Benchmarks" />
+    <InternalsVisibleTo Include="Arch.Tests" />
+  </ItemGroup>
+
+  <Import Project="../MSBuild/Robust.Properties.targets" />
+
+</Project>

MSBuild/Robust.Engine.Version.props

@@ -1,4 +1,4 @@
 <Project>
 
-    <!-- This file automatically reset by Tools/version.py -->
+    <!-- This file automatically reset by Tools/version.py -->
 

RELEASE-NOTES.md

@@ -54,6 +54,240 @@ END TEMPLATE-->
 *None yet*
 
 
+## 182.0.0
+
+### Breaking changes
+
+* Add EntityUid's generation / version to the hashcode.
+
+
+## 181.0.2
+
+### Bugfixes
+
+* Fix exceptions from having too many lights on screen and causing the game to go black.
+* Fix components having events raised in ClientGameStateManager before fully set and causing nullable reference exceptions.
+* Replace tile intersection IEnumerables with TileEnumerator internally. Also made it public for external callers that wish to avoid IEnumerable.
+
+
+## 181.0.1
+
+### Bugfixes
+
+* Fix the non-generic HasComp and add a test for good measure.
+
+
+## 181.0.0
+
+### Breaking changes
+
+- Arch is merged refactoring how components are stored on engine. There's minimal changes on the API end to facilitate component nullability with much internal refactoring.
+
+
+## 180.2.1
+
+
+## 180.2.0
+
+### New features
+
+* Add EnsureEntity variants that take in collections.
+* Add more MapSystem helper methods.
+
+### Internal
+
+* Cache some more PVS data to avoid re-allocating every tick.
+
+
+## 180.1.0
+
+### New features
+
+* Add the map name to lsmap.
+* Add net.pool_size to CVars to control the message data pool size in Lidgren and to also toggle pooling.
+
+### Bugfixes
+
+* Fix physics contraints causing enormous heap allocations.
+* Fix potential error when writing a runtime log.
+* Fix shape lookups for non-hard fixtures in EntityLookupSystem from 180.0.0
+
+
+## 180.0.0
+
+### Breaking changes
+
+* Removed some obsolete methods from EntityLookupSystem.
+
+### New features
+
+* PhysicsSystem.TryGetNearest now supports chain shapes.
+* Add IPhysShape methods to EntityLookupSystem rather than relying on AABB checks.
+* Add some more helper methods to SharedTransformSystem.
+* Add GetOrNew dictionary extension that also returns a bool on whether the key existed.
+* Add a GetAnchoredEntities overload that takes in a list.
+
+### Other
+
+* Use NetEntities for the F3 debug panel to align with command usage.
+
+
+## 179.0.0
+
+### Breaking changes
+
+* EyeComponent.Eye is no longer nullable
+
+### New features
+
+* Light rendering can now be enabled or disable per eye.
+
+### Bugfixes
+
+* Deserializing old maps with empty grid chunks should now just ignore those chunks.
+
+### Other
+
+* UnknownPrototypeException now also tells you the prototype kind instead of just the unkown ID.
+* Adding or removing networked components while resetting predicted entities now results in a more informative exception.
+
+
+## 178.0.0
+
+### Breaking changes
+
+* Most methods in ActorSystem have been moved to ISharedPlayerManager. 
+* Several actor/player related components and events have been moved to shared.
+
+### New features
+
+* Added `NetListAsArray<T>.Value` to the sandbox whitelist
+
+
+## 177.0.0
+
+### Breaking changes
+
+* Removed toInsertXform and added containerXform in SharedContainerSystem.CanInsert.
+* Removed EntityQuery parameters from SharedContainerSystem.IsEntityOrParentInContainer.
+* Changed the signature of ContainsEntity in SharedTransformSystem to use Entity<T>.
+* Removed one obsoleted SharedTransformSystem.AnchorEntity method.
+* Changed signature of SharedTransformSystem.SetCoordinates to use Entity<T>.
+
+### New features
+
+* Added more Entity<T> query methods.
+* Added BeforeApplyState event to replay playback.
+
+### Bugfixes
+
+* Fixed inverted GetAllMapGrids map id check.
+* Fixed transform test warnings.
+* Fixed PlacementManager warnings.
+* Fixed reparenting bug for entities that are being deleted.
+
+### Other
+
+* Changed VerticalAlignment of RichTextLabel to Center to be consistent with Label.
+* Changed PVS error log to be a warning instead.
+* Marked insert and remove container methods as obsolete, added container system methods to replace them.
+* Marked TransformComponent.MapPosition as obsolete, added GetMapCoordinates system method to replace it.
+
+### Internal
+
+* Moved TryGetUi/TryToggleUi/ToggleUi/TryOpen/OpenUi/TryClose/CloseUi methods from UserInterfaceSystem to SharedUserInterfaceSystem.
+
+
+## 176.0.0
+
+### Breaking changes
+
+* Reverted audio rework temporarily until packaging is fixed.
+* Changes to Robust.Packaging to facilitate Content.Packaging ports from the python packaging scripts.
+
+### New features
+
+* Add a cvar for max game state buffer size.
+* Add an overload for GetEntitiesInRange that takes in a set.
+
+### Bugfixes
+
+* Fix PVS initial list capacity always being 0.
+* Fix replay lerp error spam.
+
+
+## 175.0.0
+
+### Breaking changes
+
+* Removed static SoundSystem.Play methods.
+* Moved IPlayingAudioStream onto AudioComponent and entities instead of an abstract stream.
+* IResourceCache is in shared and IClientResourceCache is the client version to use for textures.
+* Default audio attenuation changed from InverseDistanceClamped to LinearDistanceClamped.
+* Removed per-source audio attenuation.
+
+### New features
+
+* Add preliminary support for EFX Reverb presets + auxiliary slots; these are also entities.
+* Audio on grid entities is now attached to the grid.
+
+### Bugfixes
+
+* If an audio entity comes into PVS range its track will start at the relevant offset and not the beginning.
+* Z-Axis offset is considered for ReferenceDistance / MaxDistance for audio.
+* Audio will now pause if the attached entity is paused.
+
+### Other
+
+* Changed audio Z-Axis offset from -5m to -1m.
+
+
+## 174.0.0
+
+### Breaking changes
+
+* ActorComponent has been moved to `Robust.Shared.Player` (namespace changed).
+
+### New features
+
+* Added `SpriteSystem.GetFrame()` method, which takes in an animated RSI and a time and returns a frame/texture.
+* Added `IRobustRandom.NextAngle()`
+
+
+## 173.1.0
+
+### New features
+
+* Add physics chain shapes from Box2D.
+
+
+## 173.0.0
+
+### Breaking changes
+
+* Remove GridModifiedEvent in favor of TileChangedEvent.
+
+### Bugfixes
+
+* Fix some grid rendering bugs where chunks don't get destroyed correctly.
+
+
+## 172.0.0
+
+### Breaking changes
+
+* Remove TryLifestage helper methods.
+* Refactor IPlayerManager to remove more IPlayerSession, changed PlayerAttachedEvent etc on client to have the Local prefix, and shuffled namespaces around.
+
+### New features
+
+* Add EnsureComponent(ref Entity<\T?>)
+
+### Bugfixes
+
+* Re-add force ask threshold and fix other PVS bugs.
+
+
 ## 171.0.0
 
 ### Breaking changes

Resources/EngineCredits/Libraries.yml

@@ -2203,3 +2203,207 @@
     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     SOFTWARE.
+
+- name: Arch
+  license: |
+    Apache License
+                            Version 2.0, January 2004
+                         http://www.apache.org/licenses/
+    
+    TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+    
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+    
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+    
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Robust.Benchmarks/Arch/ArchComponentAccessBenchmark.cs

@@ -0,0 +1,177 @@
+using System;
+using System.Runtime.CompilerServices;
+using Arch.Core;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Engines;
+using Robust.Shared.Analyzers;
+using static Robust.Benchmarks.EntityManager.ArchetypeComponentAccessBenchmark;
+
+namespace Robust.Benchmarks.Arch;
+
+[MemoryDiagnoser]
+[Virtual]
+public class ArchComponentAccessBenchmark
+{
+    private const int N = 10000;
+
+    private static readonly Consumer Consumer = new();
+    private Entity _entity;
+    private World _world = default!;
+    private QueryDescription _singleQuery;
+    private QueryDescription _tenQuery;
+
+    [GlobalSetup]
+    public void GlobalSetup()
+    {
+        var _ = new JobScheduler.JobScheduler("ArchBenchmark");
+
+        _world = World.Create();
+
+        for (var i = 0; i < N; i++)
+        {
+            var entity = _world.Create();
+
+            // Randomly chosen id
+            if (entity.Id == 1584)
+                _entity = entity;
+
+            _world.Add(
+                entity,
+                new Struct1(),
+                new Struct2(),
+                new Struct3(),
+                new Struct4(),
+                new Struct5(),
+                new Struct6(),
+                new Struct7(),
+                new Struct8(),
+                new Struct9(),
+                new Struct10()
+            );
+        }
+
+        _singleQuery = new QueryDescription().WithAll<Struct1>();
+        _tenQuery = new QueryDescription().WithAll<Struct1, Struct2, Struct3, Struct4, Struct5, Struct6, Struct7, Struct8, Struct9, Struct10>();
+    }
+
+    [GlobalCleanup]
+    public void GlobalCleanup()
+    {
+        JobScheduler.JobScheduler.Instance.Dispose();
+        Environment.Exit(0);
+    }
+
+    [Benchmark]
+    public Struct1 GetSingle()
+    {
+        return _world.Get<Struct1>(_entity);
+    }
+
+    [Benchmark]
+    public (Struct1, Struct2, Struct3, Struct4, Struct5, Struct6, Struct7, Struct8, Struct9, Struct10)
+        GetTen()
+    {
+        return (
+                _world.Get<Struct1>(_entity),
+                _world.Get<Struct2>(_entity),
+                _world.Get<Struct3>(_entity),
+                _world.Get<Struct4>(_entity),
+                _world.Get<Struct5>(_entity),
+                _world.Get<Struct6>(_entity),
+                _world.Get<Struct7>(_entity),
+                _world.Get<Struct8>(_entity),
+                _world.Get<Struct9>(_entity),
+                _world.Get<Struct10>(_entity)
+        );
+    }
+
+    [Benchmark]
+    public bool HasSingle()
+    {
+        return _world.Has<Struct1>(_entity);
+    }
+
+    [Benchmark]
+    public bool HasTen()
+    {
+        return _world.Has<Struct1>(_entity) &&
+               _world.Has<Struct2>(_entity) &&
+               _world.Has<Struct3>(_entity) &&
+               _world.Has<Struct4>(_entity) &&
+               _world.Has<Struct5>(_entity) &&
+               _world.Has<Struct6>(_entity) &&
+               _world.Has<Struct7>(_entity) &&
+               _world.Has<Struct8>(_entity) &&
+               _world.Has<Struct9>(_entity) &&
+               _world.Has<Struct10>(_entity);
+    }
+
+    [Benchmark]
+    public void IterateSingle()
+    {
+        _world.Query(_singleQuery, static (ref Struct1 s) => Consumer.Consume(s));
+    }
+
+    [Benchmark]
+    public void IterateSingleInline()
+    {
+        _world.InlineQuery<QueryConsumer>(_singleQuery);
+    }
+
+    [Benchmark]
+    public void IterateSingleParallel()
+    {
+        _world.ParallelQuery(_singleQuery, static (ref Struct1 s) => Consumer.Consume(s));
+    }
+
+    [Benchmark]
+    public void IterateSingleInlineParallel()
+    {
+        _world.InlineParallelQuery<QueryConsumer>(_singleQuery);
+    }
+
+    [Benchmark]
+    public void IterateTen()
+    {
+        _world.Query(_tenQuery,
+            static (
+                    ref Struct1 s1, ref Struct2 s2, ref Struct3 s3, ref Struct4 s4,
+                    ref Struct5 s5, ref Struct6 s6, ref Struct7 s7, ref Struct8 s8,
+                    ref Struct9 s9, ref Struct10 s10) =>
+                Consumer.Consume((s1, s2, s3, s4, s5, s6, s7, s8, s9, s10)));
+    }
+
+    [Benchmark]
+    public void IterateTenInline()
+    {
+        _world.InlineQuery<QueryConsumer>(_tenQuery);
+    }
+
+    [Benchmark]
+    public void IterateTenParallel()
+    {
+        _world.ParallelQuery(_tenQuery,
+            static (
+                    ref Struct1 s1, ref Struct2 s2, ref Struct3 s3, ref Struct4 s4,
+                    ref Struct5 s5, ref Struct6 s6, ref Struct7 s7, ref Struct8 s8,
+                    ref Struct9 s9, ref Struct10 s10) =>
+                Consumer.Consume((s1, s2, s3, s4, s5, s6, s7, s8, s9, s10)));
+    }
+
+    [Benchmark]
+    public void IterateTenInlineParallel()
+    {
+        _world.InlineParallelQuery<QueryConsumer>(_tenQuery);
+    }
+
+    private struct QueryConsumer : IForEach
+    {
+        private static readonly Consumer Consumer = new();
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public void Update(Entity entity)
+        {
+            Consumer.Consume(entity);
+        }
+    }
+}

Robust.Benchmarks/EntityManager/AddRemoveComponentBenchmark.cs

@@ -41,7 +41,7 @@ public partial class AddRemoveComponentBenchmark
     {
         for (var i = 2; i <= N+1; i++)
         {
-            var uid = new EntityUid(i);
+            var uid = new EntityUid(i, -1);
             _entityManager.AddComponent<A>(uid);
             _entityManager.RemoveComponent<A>(uid);
         }

Robust.Benchmarks/EntityManager/ComponentIndexBenchmark.cs

@@ -57,7 +57,7 @@ public class ComponentIndexBenchmark
     private static class CompArrayIndex<T>
     {
         // ReSharper disable once StaticMemberInGenericType
-        public static readonly CompIdx Idx = new(Interlocked.Increment(ref _compIndexMaster));
+        public static readonly CompIdx Idx = new(Interlocked.Increment(ref _compIndexMaster), typeof(T));
     }
 
     private static CompIdx GetCompIdIndex(Type type)

Robust.Benchmarks/EntityManager/GetComponentBenchmark.cs

@@ -46,7 +46,7 @@ public partial class GetComponentBenchmark
     {
         for (var i = 2; i <= N+1; i++)
         {
-            Comps[i] = _entityManager.GetComponent<A>(new EntityUid(i));
+            Comps[i] = _entityManager.GetComponent<A>(new EntityUid(i, -1));
         }
 
         // Return something so the JIT doesn't optimize out all the GetComponent calls.

Robust.Benchmarks/Robust.Benchmarks.csproj

@@ -8,6 +8,7 @@
       <NoWarn>RA0003</NoWarn>
   </PropertyGroup>
   <ItemGroup>
+    <ProjectReference Include="..\Arch\Arch.csproj" />
     <ProjectReference Include="..\Robust.Server\Robust.Server.csproj" />
     <ProjectReference Include="..\Robust.Shared\Robust.Shared.csproj" />
     <ProjectReference Include="..\Robust.UnitTesting\Robust.UnitTesting.csproj" />

Robust.Client/BaseClient.cs

@@ -1,8 +1,6 @@
 using System;
-using System.Linq;
 using System.Net;
 using Robust.Client.Configuration;
-using Robust.Client.Debugging;
 using Robust.Client.GameObjects;
 using Robust.Client.GameStates;
 using Robust.Client.Player;
@@ -10,13 +8,12 @@ using Robust.Client.Utility;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.Enums;
-using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -65,12 +62,12 @@ namespace Robust.Client
 
             _configManager.OnValueChanged(CVars.NetTickrate, TickRateChanged, invokeImmediately: true);
 
-            _playMan.Initialize();
+            _playMan.Initialize(0);
             _playMan.PlayerListUpdated += OnPlayerListUpdated;
             Reset();
         }
 
-        private void OnPlayerListUpdated(object? sender, EventArgs e)
+        private void OnPlayerListUpdated()
         {
             var serverPlayers = _playMan.PlayerCount;
             if (_net.ServerChannel != null && GameInfo != null && _net.IsConnected)
@@ -130,9 +127,10 @@ namespace Robust.Client
         {
             DebugTools.Assert(RunLevel < ClientRunLevel.Connecting);
             DebugTools.Assert(!_net.IsConnected);
-            _playMan.Startup();
-            _playMan.LocalPlayer!.Name = PlayerNameOverride ?? _configManager.GetCVar(CVars.PlayerName);
+            var name = PlayerNameOverride ?? _configManager.GetCVar(CVars.PlayerName);
+            _playMan.SetupSinglePlayer(name);
             OnRunLevelChanged(ClientRunLevel.SinglePlayerGame);
+            _playMan.JoinGame(_playMan.LocalSession!);
             GameStartedSetup();
         }
 
@@ -173,22 +171,14 @@ namespace Robust.Client
                 info.ServerName = serverName;
             }
 
-            var maxPlayers = _configManager.GetCVar<int>("game.maxplayers");
-            info.ServerMaxPlayers = maxPlayers;
-
-            var userName = _net.ServerChannel!.UserName;
-            var userId = _net.ServerChannel.UserId;
+            var channel = _net.ServerChannel!;
 
             // start up player management
-            _playMan.Startup();
-
-            _playMan.LocalPlayer!.UserId = userId;
-            _playMan.LocalPlayer.Name = userName;
-
-            _playMan.LocalPlayer.StatusChanged += OnLocalStatusChanged;
+            _playMan.SetupMultiplayer(channel);
+            _playMan.PlayerStatusChanged += OnStatusChanged;
 
             var serverPlayers = _playMan.PlayerCount;
-            _discord.Update(info.ServerName, userName, info.ServerMaxPlayers.ToString(), serverPlayers.ToString());
+            _discord.Update(info.ServerName, channel.UserName, info.ServerMaxPlayers.ToString(), serverPlayers.ToString());
 
         }
 
@@ -221,6 +211,8 @@ namespace Robust.Client
 
         private void Reset()
         {
+            _configManager.ReceivedInitialNwVars -= OnReceivedClientData;
+            _playMan.PlayerStatusChanged -= OnStatusChanged;
             _configManager.ClearReceivedInitialNwVars();
             OnRunLevelChanged(ClientRunLevel.Initialize);
         }
@@ -263,19 +255,17 @@ namespace Robust.Client
             Reset();
         }
 
-        private void OnLocalStatusChanged(object? obj, StatusEventArgs eventArgs)
+        private void OnStatusChanged(object? sender, SessionStatusEventArgs e)
         {
+            if (e.Session != _playMan.LocalSession)
+                return;
+
             // player finished fully connecting to the server.
             // OldStatus is used here because it can go from connecting-> connected or connecting-> ingame
-            if (eventArgs.OldStatus == SessionStatus.Connecting)
-            {
-                OnPlayerJoinedServer(_playMan.LocalPlayer!.Session);
-            }
-
-            if (eventArgs.NewStatus == SessionStatus.InGame)
-            {
-                OnPlayerJoinedGame(_playMan.LocalPlayer!.Session);
-            }
+            if (e.OldStatus == SessionStatus.Connecting)
+                OnPlayerJoinedServer(e.Session);
+            else if (e.NewStatus == SessionStatus.InGame)
+                OnPlayerJoinedGame(e.Session);
         }
 
         private void OnRunLevelChanged(ClientRunLevel newRunLevel)

Robust.Client/ClientIoC.cs

@@ -37,7 +37,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Physics;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
 using Robust.Shared.Replays;

Robust.Client/Console/ClientConsoleHost.cs

@@ -13,7 +13,7 @@ using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Reflection;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;

Robust.Client/Console/Commands/Debug.cs

@@ -256,7 +256,7 @@ namespace Robust.Client.Console.Commands
                 return;
             }
 
-            var uid = EntityUid.Parse(args[0]);
+            var uid = EntityUid.Parse(args[0], "-1");
             var entmgr = _entityManager;
             if (!entmgr.EntityExists(uid))
             {

Robust.Client/Console/Commands/ProfileEntitySpawningCommand.cs

@@ -43,6 +43,7 @@ public sealed class ProfileEntitySpawningCommand : IConsoleCommand
 
         GC.Collect();
 
+        Span<EntityUid> ents = stackalloc EntityUid[amount];
         var stopwatch = new Stopwatch();
         stopwatch.Start();
 
@@ -50,12 +51,17 @@ public sealed class ProfileEntitySpawningCommand : IConsoleCommand
 
         for (var i = 0; i < amount; i++)
         {
-            _entities.SpawnEntity(prototype, MapCoordinates.Nullspace);
+            ents[i] = _entities.SpawnEntity(prototype, MapCoordinates.Nullspace);
         }
 
         MeasureProfiler.SaveData();
 
         shell.WriteLine($"Client: Profiled spawning {amount} entities in {stopwatch.Elapsed.TotalMilliseconds:N3} ms");
+
+        foreach (var ent in ents)
+        {
+            _entities.DeleteEntity(ent);
+        }
     }
 }
 #endif

Robust.Client/Debugging/DebugPhysicsSystem.cs

@@ -366,6 +366,9 @@ namespace Robust.Client.Debugging
 
                 _debugPhysicsSystem.PointCount = 0;
             }
+
+            worldHandle.UseShader(null);
+            worldHandle.SetTransform(Matrix3.Identity);
         }
 
         private void DrawScreen(DrawingHandleScreen screenHandle, OverlayDrawArgs args)
@@ -438,6 +441,9 @@ namespace Robust.Client.Debugging
                     }
                 }
             }
+
+            screenHandle.UseShader(null);
+            screenHandle.SetTransform(Matrix3.Identity);
         }
 
         protected internal override void Draw(in OverlayDrawArgs args)
@@ -459,11 +465,26 @@ namespace Robust.Client.Debugging
         {
             switch (fixture.Shape)
             {
+                case ChainShape cShape:
+                {
+                    var count = cShape.Count;
+                    var vertices = cShape.Vertices;
+
+                    var v1 = Transform.Mul(xform, vertices[0]);
+                    for (var i = 1; i < count; ++i)
+                    {
+                        var v2 = Transform.Mul(xform, vertices[i]);
+                        worldHandle.DrawLine(v1, v2, color);
+                        v1 = v2;
+                    }
+                }
+                    break;
                 case PhysShapeCircle circle:
                     var center = Transform.Mul(xform, circle.Position);
                     worldHandle.DrawCircle(center, circle.Radius, color);
                     break;
                 case EdgeShape edge:
+                {
                     var v1 = Transform.Mul(xform, edge.Vertex1);
                     var v2 = Transform.Mul(xform, edge.Vertex2);
                     worldHandle.DrawLine(v1, v2, color);
@@ -473,6 +494,7 @@ namespace Robust.Client.Debugging
                         worldHandle.DrawCircle(v1, 0.1f, color);
                         worldHandle.DrawCircle(v2, 0.1f, color);
                     }
+                }
 
                     break;
                 case PolygonShape poly:

Robust.Client/GameController/GameController.cs

@@ -632,7 +632,6 @@ namespace Robust.Client
             logManager.GetSawmill("ogl.debug.other").Level = LogLevel.Warning;
             logManager.GetSawmill("gdparse").Level = LogLevel.Error;
             logManager.GetSawmill("discord").Level = LogLevel.Warning;
-            logManager.GetSawmill("net.predict").Level = LogLevel.Info;
             logManager.GetSawmill("szr").Level = LogLevel.Info;
             logManager.GetSawmill("loc").Level = LogLevel.Warning;
 

Robust.Client/GameObjects/ClientEntityManager.cs

@@ -44,7 +44,7 @@ namespace Robust.Client.GameObjects
 
         EntityUid IClientEntityManagerInternal.CreateEntity(string? prototypeName, out MetaDataComponent metadata)
         {
-            return base.CreateEntity(prototypeName, out metadata);
+            return base.CreateEntity(prototypeName, out metadata, out _);
         }
 
         void IClientEntityManagerInternal.InitializeEntity(EntityUid entity, MetaDataComponent? meta)
@@ -170,7 +170,7 @@ namespace Robust.Client.GameObjects
         }
 
         /// <inheritdoc />
-        public void SendSystemNetworkMessage(EntityEventArgs message, INetChannel channel)
+        public void SendSystemNetworkMessage(EntityEventArgs message, INetChannel? channel)
         {
             throw new NotSupportedException();
         }

Robust.Client/GameObjects/EntitySystems/AnimationPlayerSystem.cs

@@ -3,21 +3,17 @@ using System.Collections.Generic;
 using Robust.Client.Animations;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.Log;
 using Robust.Shared.Utility;
 
 namespace Robust.Client.GameObjects
 {
-    public sealed class AnimationPlayerSystem : EntitySystem, IPostInjectInit
+    public sealed class AnimationPlayerSystem : EntitySystem
     {
         private readonly List<Entity<AnimationPlayerComponent>> _activeAnimations = new();
 
         private EntityQuery<MetaDataComponent> _metaQuery;
 
         [Dependency] private readonly IComponentFactory _compFact = default!;
-        [Dependency] private readonly ILogManager _logManager = default!;
-
-        private ISawmill _sawmill = default!;
 
         public override void Initialize()
         {
@@ -123,13 +119,13 @@ namespace Robust.Client.GameObjects
 
                 if (compTrack.ComponentType == null)
                 {
-                    _sawmill.Error("Attempted to play a component animation without any component specified.");
+                    Log.Error("Attempted to play a component animation without any component specified.");
                     return;
                 }
 
                 if (!EntityManager.TryGetComponent(ent, compTrack.ComponentType, out var animatedComp))
                 {
-                    _sawmill.Error(
+                    Log.Error(
                         $"Attempted to play a component animation, but the entity {ToPrettyString(ent)} does not have the component to be animated: {compTrack.ComponentType}.");
                     return;
                 }
@@ -147,7 +143,7 @@ namespace Robust.Client.GameObjects
                     if (animatedComp.GetType().GetProperty(compTrack.Property) is { } property &&
                         property.HasCustomAttribute<AutoNetworkedFieldAttribute>())
                     {
-                        _sawmill.Warning($"Playing a component animation on a networked component {reg.Name} belonging to {ToPrettyString(ent)}");
+                        Log.Warning($"Playing a component animation on a networked component {reg.Name} belonging to {ToPrettyString(ent)}");
                     }
                 }
             }
@@ -182,19 +178,18 @@ namespace Robust.Client.GameObjects
 
         public void Stop(EntityUid uid, string key)
         {
-            if (!TryComp<AnimationPlayerComponent>(uid, out var player)) return;
+            if (!TryComp<AnimationPlayerComponent>(uid, out var player))
+                return;
+
             player.PlayingAnimations.Remove(key);
         }
 
         public void Stop(EntityUid uid, AnimationPlayerComponent? component, string key)
         {
-            if (!Resolve(uid, ref component, false)) return;
-            component.PlayingAnimations.Remove(key);
-        }
+            if (!Resolve(uid, ref component, false))
+                return;
 
-        void IPostInjectInit.PostInject()
-        {
-            _sawmill = _logManager.GetSawmill("anim");
+            component.PlayingAnimations.Remove(key);
         }
     }
 

Robust.Client/GameObjects/EntitySystems/AudioSystem.cs

@@ -17,7 +17,6 @@ using Robust.Shared.Physics;
 using Robust.Shared.Physics.Components;
 using Robust.Shared.Physics.Systems;
 using Robust.Shared.Player;
-using Robust.Shared.Players;
 using Robust.Shared.Random;
 using Robust.Shared.Replays;
 using Robust.Shared.Threading;

Robust.Client/GameObjects/EntitySystems/EyeSystem.cs

@@ -1,9 +1,8 @@
 using Robust.Client.Graphics;
 using Robust.Client.Physics;
 using Robust.Shared.GameObjects;
-using Robust.Shared.GameStates;
-using Robust.Shared.Graphics;
 using Robust.Shared.IoC;
+using Robust.Shared.Player;
 
 namespace Robust.Client.GameObjects;
 
@@ -15,8 +14,8 @@ public sealed class EyeSystem : SharedEyeSystem
     {
         base.Initialize();
         SubscribeLocalEvent<EyeComponent, ComponentInit>(OnInit);
-        SubscribeLocalEvent<EyeComponent, PlayerDetachedEvent>(OnEyeDetached);
-        SubscribeLocalEvent<EyeComponent, PlayerAttachedEvent>(OnEyeAttached);
+        SubscribeLocalEvent<EyeComponent, LocalPlayerDetachedEvent>(OnEyeDetached);
+        SubscribeLocalEvent<EyeComponent, LocalPlayerAttachedEvent>(OnEyeAttached);
         SubscribeLocalEvent<EyeComponent, AfterAutoHandleStateEvent>(OnEyeAutoState);
 
         // Make sure this runs *after* entities have been moved by interpolation and movement.
@@ -26,35 +25,25 @@ public sealed class EyeSystem : SharedEyeSystem
 
     private void OnEyeAutoState(EntityUid uid, EyeComponent component, ref AfterAutoHandleStateEvent args)
     {
-        UpdateEye(component);
+        UpdateEye((uid, component));
     }
 
-    private void OnEyeAttached(EntityUid uid, EyeComponent component, PlayerAttachedEvent args)
+    private void OnEyeAttached(EntityUid uid, EyeComponent component, LocalPlayerAttachedEvent args)
     {
-        // TODO: This probably shouldn't be nullable bruv.
-        if (component._eye != null)
-        {
-            _eyeManager.CurrentEye = component._eye;
-        }
-
+        UpdateEye((uid, component));
+        _eyeManager.CurrentEye = component.Eye;
         var ev = new EyeAttachedEvent(uid, component);
         RaiseLocalEvent(uid, ref ev, true);
     }
 
-    private void OnEyeDetached(EntityUid uid, EyeComponent component, PlayerDetachedEvent args)
+    private void OnEyeDetached(EntityUid uid, EyeComponent component, LocalPlayerDetachedEvent args)
     {
         _eyeManager.ClearCurrentEye();
     }
 
     private void OnInit(EntityUid uid, EyeComponent component, ComponentInit args)
     {
-        component._eye = new Eye
-        {
-            Position = Transform(uid).MapPosition,
-            Zoom = component.Zoom,
-            DrawFov = component.DrawFov,
-            Rotation = component.Rotation,
-        };
+        UpdateEye((uid, component));
     }
 
     /// <inheritdoc />
@@ -64,7 +53,7 @@ public sealed class EyeSystem : SharedEyeSystem
 
         while (query.MoveNext(out var uid, out var eyeComponent))
         {
-            if (eyeComponent._eye == null)
+            if (eyeComponent.Eye == null)
                 continue;
 
             if (!TryComp<TransformComponent>(eyeComponent.Target, out var xform))
@@ -73,7 +62,7 @@ public sealed class EyeSystem : SharedEyeSystem
                 eyeComponent.Target = null;
             }
 
-            eyeComponent._eye.Position = xform.MapPosition;
+            eyeComponent.Eye.Position = xform.MapPosition;
         }
     }
 }

Robust.Client/GameObjects/EntitySystems/InputSystem.cs

@@ -3,16 +3,13 @@ using System.Numerics;
 using Robust.Client.GameStates;
 using Robust.Client.Input;
 using Robust.Client.Player;
-using Robust.Shared;
-using Robust.Shared.Configuration;
 using Robust.Shared.Console;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Input;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
-using Robust.Shared.Maths;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -131,7 +128,7 @@ namespace Robust.Client.GameObjects
 
         public override void Initialize()
         {
-            SubscribeLocalEvent<PlayerAttachSysMessage>(OnAttachedEntityChanged);
+            SubscribeLocalEvent<LocalPlayerAttachedEvent>(OnAttachedEntityChanged);
 
             _conHost.RegisterCommand("incmd",
                 "Inserts an input command into the simulation",
@@ -171,11 +168,11 @@ namespace Robust.Client.GameObjects
             HandleInputCommand(localPlayer.Session, keyFunction, message);
         }
 
-        private void OnAttachedEntityChanged(PlayerAttachSysMessage message)
+        private void OnAttachedEntityChanged(LocalPlayerAttachedEvent message)
         {
-            if (message.AttachedEntity != default) // attach
+            if (message.Entity != default) // attach
             {
-                SetEntityContextActive(_inputManager, message.AttachedEntity);
+                SetEntityContextActive(_inputManager, message.Entity);
             }
             else // detach
             {
@@ -227,44 +224,4 @@ namespace Robust.Client.GameObjects
             _sawmillInputContext = _logManager.GetSawmill("input.context");
         }
     }
-
-    /// <summary>
-    ///     Entity system message that is raised when the player changes attached entities.
-    /// </summary>
-    public sealed class PlayerAttachSysMessage : EntityEventArgs
-    {
-        /// <summary>
-        ///     New entity the player is attached to.
-        /// </summary>
-        public EntityUid AttachedEntity { get; }
-
-        /// <summary>
-        ///     Creates a new instance of <see cref="PlayerAttachSysMessage"/>.
-        /// </summary>
-        /// <param name="attachedEntity">New entity the player is attached to.</param>
-        public PlayerAttachSysMessage(EntityUid attachedEntity)
-        {
-            AttachedEntity = attachedEntity;
-        }
-    }
-
-    public sealed class PlayerAttachedEvent : EntityEventArgs
-    {
-        public PlayerAttachedEvent(EntityUid entity)
-        {
-            Entity = entity;
-        }
-
-        public EntityUid Entity { get; }
-    }
-
-    public sealed class PlayerDetachedEvent : EntityEventArgs
-    {
-        public PlayerDetachedEvent(EntityUid entity)
-        {
-            Entity = entity;
-        }
-
-        public EntityUid Entity { get; }
-    }
 }

Robust.Client/GameObjects/EntitySystems/MapSystem.cs

@@ -1,12 +1,9 @@
 using Robust.Client.Graphics;
 using Robust.Client.Map;
-using Robust.Client.Physics;
 using Robust.Client.ResourceManagement;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
-using Robust.Shared.Map.Components;
-using Robust.Shared.Physics.Dynamics;
 
 namespace Robust.Client.GameObjects
 {
@@ -28,10 +25,5 @@ namespace Robust.Client.GameObjects
             base.Shutdown();
             _overlayManager.RemoveOverlay<TileEdgeOverlay>();
         }
-
-        protected override void OnMapAdd(EntityUid uid, MapComponent component, ComponentAdd args)
-        {
-            EnsureComp<PhysicsMapComponent>(uid);
-        }
     }
 }

Robust.Client/GameObjects/EntitySystems/SpriteSystem.cs

@@ -1,13 +1,16 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Numerics;
 using JetBrains.Annotations;
 using Robust.Client.ComponentTrees;
 using Robust.Client.Graphics;
 using Robust.Client.ResourceManagement;
+using Robust.Client.Utility;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.GameObjects;
+using Robust.Shared.Graphics.RSI;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
@@ -15,6 +18,7 @@ using Robust.Shared.Maths;
 using Robust.Shared.Physics;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Timing;
+using Robust.Shared.Utility;
 using static Robust.Client.GameObjects.SpriteComponent;
 
 namespace Robust.Client.GameObjects
@@ -183,6 +187,48 @@ namespace Robust.Client.GameObjects
         {
             _queuedFrameUpdate.Add(uid);
         }
+
+        /// <summary>
+        /// Gets the specified frame for this sprite at the specified time.
+        /// </summary>
+        public Texture GetFrame(SpriteSpecifier spriteSpec, TimeSpan curTime)
+        {
+            Texture? sprite = null;
+
+            switch (spriteSpec)
+            {
+                case SpriteSpecifier.Rsi rsi:
+                    var rsiActual = _resourceCache.GetResource<RSIResource>(rsi.RsiPath).RSI;
+                    rsiActual.TryGetState(rsi.RsiState, out var state);
+                    var frames = state!.GetFrames(RsiDirection.South);
+                    var delays = state.GetDelays();
+                    var totalDelay = delays.Sum();
+                    var time = curTime.TotalSeconds % totalDelay;
+                    var delaySum = 0f;
+
+                    for (var i = 0; i < delays.Length; i++)
+                    {
+                        var delay = delays[i];
+                        delaySum += delay;
+
+                        if (time > delaySum)
+                            continue;
+
+                        sprite = frames[i];
+                        break;
+                    }
+
+                    sprite ??= Frame0(spriteSpec);
+                    break;
+                case SpriteSpecifier.Texture texture:
+                    sprite = texture.GetTexture(_resourceCache);
+                    break;
+                default:
+                    throw new NotImplementedException();
+            }
+
+            return sprite;
+        }
     }
 
     /// <summary>

Robust.Client/GameObjects/EntitySystems/TransformSystem.cs

@@ -54,9 +54,10 @@ namespace Robust.Client.GameObjects
             //   should show the entity lerping.
             // - If the client predicts an entity will move while already lerping due to a state-application, it should
             //   clear the state's lerp, under the assumption that the client predicted the state and already rendered
-            //   the entity in the final position.
+            //   the entity in the state's final position.
             // - If the client predicts that an entity moves, then we only lerp if this is the first time that the tick
-            //   was predicted. I.e., we assume the entity was already rendered in it's final of that lerp.
+            //   was predicted. I.e., we assume the entity was already rendered in the final position that was
+            //   previously predicted.
             // - If the client predicts that an entity should lerp twice in the same tick, then we need to combine them.
             //   I.e. moving from a->b then b->c, the client should lerp from a->c.
 

Robust.Client/GameStates/ClientDirtySystem.cs

@@ -39,7 +39,7 @@ public sealed class ClientDirtySystem : EntitySystem
 
     private void OnTerminate(ref EntityTerminatingEvent ev)
     {
-        if (!_timing.InPrediction || IsClientSide(ev.Entity))
+        if (!_timing.InPrediction || IsClientSide(ev.Entity, ev.Metadata))
             return;
 
         // Client-side entity deletion is not supported and will cause errors.

Robust.Client/GameStates/ClientGameStateManager.cs

@@ -5,6 +5,8 @@ using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Runtime.InteropServices;
+using Arch.Core;
+using Collections.Pooled;
 using JetBrains.Annotations;
 using Microsoft.Extensions.ObjectPool;
 using Robust.Client.GameObjects;
@@ -26,18 +28,18 @@ using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Physics;
-using Robust.Shared.Physics.Components;
 using Robust.Shared.Profiling;
 using Robust.Shared.Replays;
 using Robust.Shared.Timing;
+using Robust.Shared.Toolshed.TypeParsers;
 using Robust.Shared.Utility;
+using ComponentType = Arch.Core.Utils.ComponentType;
 
 namespace Robust.Client.GameStates
 {
     /// <inheritdoc />
     [UsedImplicitly]
-    public sealed class ClientGameStateManager : IClientGameStateManager, IPostInjectInit
+    public sealed class ClientGameStateManager : IClientGameStateManager
     {
         private GameStateProcessor _processor = default!;
 
@@ -54,11 +56,12 @@ namespace Robust.Client.GameStates
         private readonly Dictionary<ushort, (IComponent Component, ComponentState? curState, ComponentState? nextState)> _compStateWork = new();
         private readonly Dictionary<EntityUid, HashSet<Type>> _pendingReapplyNetStates = new();
         private readonly HashSet<NetEntity> _stateEnts = new();
-        private readonly List<EntityUid> _toDelete = new();
-        private readonly List<IComponent> _toRemove = new();
         private readonly Dictionary<NetEntity, Dictionary<ushort, ComponentState>> _outputData = new();
         private readonly List<(EntityUid, TransformComponent)> _queuedBroadphaseUpdates = new();
 
+        private readonly List<NetEntity> _created = new();
+        private readonly List<NetEntity> _detached = new();
+
         private readonly ObjectPool<Dictionary<ushort, ComponentState>> _compDataPool =
             new DefaultObjectPool<Dictionary<ushort, ComponentState>>(new DictPolicy<ushort, ComponentState>(), 256);
 
@@ -82,6 +85,13 @@ namespace Robust.Client.GameStates
 
         private ISawmill _sawmill = default!;
 
+        /// <summary>
+        /// If we are waiting for a full game state from the server, we will automatically re-send full state requests
+        /// if they do not arrive in time. Ideally this should never happen, this here just in case a client gets
+        /// stuck waiting for a full state that the server doesn't know the client even wants.
+        /// </summary>
+        public static readonly TimeSpan FullStateTimeout = TimeSpan.FromSeconds(10);
+
         /// <inheritdoc />
         public int MinBufferSize => _processor.MinBufferSize;
 
@@ -89,7 +99,8 @@ namespace Robust.Client.GameStates
         public int TargetBufferSize => _processor.TargetBufferSize;
 
         /// <inheritdoc />
-        public int CurrentBufferSize => _processor.CalculateBufferSize(_timing.LastRealTick);
+        public int GetApplicableStateCount() => _processor.GetApplicableStateCount();
+        public int StateCount => _processor.StateCount;
 
         public bool IsPredictionEnabled { get; private set; }
         public bool PredictionNeedsResetting { get; private set; }
@@ -118,10 +129,15 @@ namespace Robust.Client.GameStates
         public bool DropStates;
 #endif
 
+        private bool _resettingPredictedEntities;
+
         /// <inheritdoc />
         public void Initialize()
         {
-            _processor = new GameStateProcessor(_timing);
+            _sawmill = _logMan.GetSawmill("state");
+            _sawmill.Level = LogLevel.Info;
+
+            _processor = new GameStateProcessor(this, _timing, _sawmill);
 
             _network.RegisterNetMessage<MsgState>(HandleStateMessage);
             _network.RegisterNetMessage<MsgStateLeavePvs>(HandlePvsLeaveMessage);
@@ -137,6 +153,7 @@ namespace Robust.Client.GameStates
             _config.OnValueChanged(CVars.NetPredictLagBias, i => PredictLagBias = i, true);
             _config.OnValueChanged(CVars.NetStateBufMergeThreshold, i => StateBufferMergeThreshold = i, true);
             _config.OnValueChanged(CVars.NetPVSEntityExitBudget, i => _pvsDetachBudget = i, true);
+            _config.OnValueChanged(CVars.NetMaxBufferSize, i => _processor.MaxBufferSize = i, true);
 
             _processor.Interpolation = _config.GetCVar(CVars.NetInterp);
             _processor.BufferSize = _config.GetCVar(CVars.NetBufferSize);
@@ -151,6 +168,8 @@ namespace Robust.Client.GameStates
             _conHost.RegisterCommand("localdelete", Loc.GetString("cmd-local-delete-desc"), Loc.GetString("cmd-local-delete-help"), LocalDeleteEntCommand);
             _conHost.RegisterCommand("fullstatereset", Loc.GetString("cmd-full-state-reset-desc"), Loc.GetString("cmd-full-state-reset-help"), (_,_,_) => RequestFullState());
 
+            _entities.ComponentAdded += OnComponentAdded;
+
             var metaId = _compFactory.GetRegistration(typeof(MetaDataComponent)).NetID;
             if (!metaId.HasValue)
                 throw new InvalidOperationException("MetaDataComponent does not have a NetId.");
@@ -158,6 +177,23 @@ namespace Robust.Client.GameStates
             _metaCompNetId = metaId.Value;
         }
 
+        private void OnComponentAdded(AddedComponentEventArgs args)
+        {
+            if (_resettingPredictedEntities)
+            {
+                var comp = args.ComponentType;
+
+                if (comp.NetID == null)
+                    return;
+
+                _sawmill.Error($"""
+                    Added component {comp.Name} with net id {comp.NetID} while resetting predicted entities.
+                    Stack trace:
+                    {Environment.StackTrace}
+                    """);
+            }
+        }
+
         /// <inheritdoc />
         public void Reset()
         {
@@ -245,9 +281,19 @@ namespace Robust.Client.GameStates
         /// <inheritdoc />
         public void ApplyGameState()
         {
+            // If we have been waiting for a full state for a long time, re-request a full state.
+            if (_processor.WaitingForFull
+                && _processor.LastFullStateRequested is {} last
+                && DateTime.UtcNow - last.Time > FullStateTimeout)
+            {
+                // Re-request a full state.
+                // We use the previous from-tick, just in case the full state is already on the way,
+                RequestFullState(null, last.Tick);
+            }
+
             // Calculate how many states we need to apply this tick.
             // Always at least one, but can be more based on StateBufferMergeThreshold.
-            var curBufSize = CurrentBufferSize;
+            var curBufSize = GetApplicableStateCount();
             var targetBufSize = TargetBufferSize;
 
             var bufferOverflow = curBufSize - targetBufSize - StateBufferMergeThreshold;
@@ -300,9 +346,9 @@ namespace Robust.Client.GameStates
                 }
 
                 // If we were waiting for a new state, we are now applying it.
-                if (_processor.LastFullStateRequested.HasValue)
+                if (_processor.WaitingForFull)
                 {
-                    _processor.LastFullStateRequested = null;
+                    _processor.OnFullStateReceived();
                     _timing.LastProcessedTick = curState.ToSequence;
                     DebugTools.Assert(curState.FromSequence == GameTick.Zero);
                     PartialStateReset(curState, true);
@@ -367,7 +413,7 @@ namespace Robust.Client.GameStates
             if (_processor.WaitingForFull)
                 _timing.TickTimingAdjustment = 0f;
             else
-                _timing.TickTimingAdjustment = (CurrentBufferSize - (float)TargetBufferSize) * 0.10f;
+                _timing.TickTimingAdjustment = (GetApplicableStateCount() - (float)TargetBufferSize) * 0.10f;
 
             // If we are about to process an another tick in the same frame, lets not bother unnecessarily running prediction ticks
             // Really the main-loop ticking just needs to be more specialized for clients.
@@ -412,11 +458,11 @@ namespace Robust.Client.GameStates
             }
         }
 
-        public void RequestFullState(NetEntity? missingEntity = null)
+        public void RequestFullState(NetEntity? missingEntity = null, GameTick? tick = null)
         {
             _sawmill.Info("Requesting full server state");
             _network.ClientSendMessage(new MsgStateRequestFull { Tick = _timing.LastRealTick , MissingEntity = missingEntity ?? NetEntity.Invalid });
-            _processor.RequestFullState();
+            _processor.OnFullStateRequested(tick ?? _timing.LastRealTick);
         }
 
         public void PredictTicks(GameTick predictionTarget)
@@ -499,7 +545,9 @@ namespace Robust.Client.GameStates
             var countReset = 0;
             var system = _entitySystemManager.GetEntitySystem<ClientDirtySystem>();
             var metaQuery = _entityManager.GetEntityQuery<MetaDataComponent>();
-            RemQueue<IComponent> toRemove = new();
+            using var toRemove = new PooledList<IComponent>();
+            using var toAdd = new PooledList<ushort>();
+            using var toAddStates = new PooledList<ComponentState>();
 
             foreach (var entity in system.DirtyEntities)
             {
@@ -517,48 +565,63 @@ namespace Robust.Client.GameStates
 
                 countReset += 1;
 
-                foreach (var (netId, comp) in meta.NetComponents)
+                try
                 {
-                    if (!comp.NetSyncEnabled)
-                        continue;
+                    _resettingPredictedEntities = true;
 
-                    // Was this component added during prediction?
-                    if (comp.CreationTick > _timing.LastRealTick)
+                    foreach (var (netId, comp) in meta.NetComponents)
                     {
-                        if (last.ContainsKey(netId))
+                        if (!comp.NetSyncEnabled)
+                            continue;
+
+                        // Was this component added during prediction?
+                        if (comp.CreationTick > _timing.LastRealTick)
                         {
-                            // Component was probably removed and then re-addedd during a single prediction run
-                            // Just reset state as normal.
-                            comp.ClearCreationTick();
+                            if (last.ContainsKey(netId))
+                            {
+                                // Component was probably removed and then re-addedd during a single prediction run
+                                // Just reset state as normal.
+                                comp.ClearCreationTick();
+                            }
+                            else
+                            {
+                                toRemove.Add(comp);
+                                if (_sawmill.Level <= LogLevel.Debug)
+                                    _sawmill.Debug($"  A new component was added: {comp.GetType()}");
+                                continue;
+                            }
                         }
-                        else
+
+                        if (comp.LastModifiedTick <= _timing.LastRealTick ||
+                            !last.TryGetValue(netId, out var compState))
                         {
-                            toRemove.Add(comp);
-                            if (_sawmill.Level <= LogLevel.Debug)
-                                _sawmill.Debug($"  A new component was added: {comp.GetType()}");
                             continue;
                         }
+
+                        if (_sawmill.Level <= LogLevel.Debug)
+                            _sawmill.Debug($"  A component was dirtied: {comp.GetType()}");
+
+                        var handleState = new ComponentHandleState(compState, null);
+                        _entities.EventBus.RaiseComponentEvent(comp, ref handleState);
+                        comp.LastModifiedTick = _timing.LastRealTick;
                     }
-
-                    if (comp.LastModifiedTick <= _timing.LastRealTick || !last.TryGetValue(netId, out var compState))
-                    {
-                        continue;
-                    }
-
-                    if (_sawmill.Level <= LogLevel.Debug)
-                        _sawmill.Debug($"  A component was dirtied: {comp.GetType()}");
-
-                    var handleState = new ComponentHandleState(compState, null);
-                    _entities.EventBus.RaiseComponentEvent(comp, ref handleState);
-                    comp.LastModifiedTick = _timing.LastRealTick;
                 }
-
-                // Remove predicted component additions
-                foreach (var comp in toRemove)
+                finally
                 {
-                    _entities.RemoveComponent(entity, comp);
+                    _resettingPredictedEntities = false;
+                }
+
+                if (toRemove.Count > 0)
+                {
+                    // Remove predicted component additions
+                    // TODO: 1 archetype change.
+                    foreach (var comp in toRemove)
+                    {
+                        _entities.RemoveComponent(entity, comp, meta);
+                    }
+
+                    toRemove.Clear();
                 }
-                toRemove.Clear();
 
                 // Re-add predicted removals
                 if (system.RemovedComponents.TryGetValue(entity, out var netIds))
@@ -571,15 +634,29 @@ namespace Robust.Client.GameStates
                         if (!last.TryGetValue(netId, out var state))
                             continue;
 
-                        var comp = _entityManager.AddComponent(entity, netId, meta);
+                        toAdd.Add(netId);
+                        toAddStates.Add(state);
+                    }
 
-                        if (_sawmill.Level <= LogLevel.Debug)
-                            _sawmill.Debug($"  A component was removed: {comp.GetType()}");
+                    if (toAdd.Count > 0)
+                    {
+                        for (var i = 0; i < toAdd.Count; i++)
+                        {
+                            var netId = toAdd[i];
+                            var state = toAddStates[i];
+                            var comp = _entityManager.AddComponent(entity, netId, meta);
 
-                        var stateEv = new ComponentHandleState(state, null);
-                        _entities.EventBus.RaiseComponentEvent(comp, ref stateEv);
-                        comp.ClearCreationTick(); // don't undo the re-adding.
-                        comp.LastModifiedTick = _timing.LastRealTick;
+                            if (_sawmill.Level <= LogLevel.Debug)
+                                _sawmill.Debug($"  A component was removed: {comp.GetType()}");
+
+                            var stateEv = new ComponentHandleState(state, null);
+                            _entities.EventBus.RaiseComponentEvent(comp, ref stateEv);
+                            comp.ClearCreationTick(); // don't undo the re-adding.
+                            comp.LastModifiedTick = _timing.LastRealTick;
+                        }
+
+                        toAdd.Clear();
+                        toAddStates.Clear();
                     }
                 }
 
@@ -662,26 +739,25 @@ namespace Robust.Client.GameStates
                 _config.TickProcessMessages();
             }
 
-            (IEnumerable<NetEntity> Created, List<NetEntity> Detached) output;
             using (_prof.Group("Entity"))
             {
-                output = ApplyEntityStates(curState, nextState);
+                ApplyEntityStates(curState, nextState);
             }
 
             using (_prof.Group("Player"))
             {
-                _players.ApplyPlayerStates(curState.PlayerStates.Value ?? Array.Empty<PlayerState>());
+                _players.ApplyPlayerStates(curState.PlayerStates.Value ?? Array.Empty<SessionState>());
             }
 
             using (_prof.Group("Callback"))
             {
-                GameStateApplied?.Invoke(new GameStateAppliedArgs(curState, output.Detached));
+                GameStateApplied?.Invoke(new GameStateAppliedArgs(curState, _detached));
             }
 
-            return output.Created;
+            return _created;
         }
 
-        private (IEnumerable<NetEntity> Created, List<NetEntity> Detached) ApplyEntityStates(GameState curState, GameState? nextState)
+        private void ApplyEntityStates(GameState curState, GameState? nextState)
         {
             var metas = _entities.GetEntityQuery<MetaDataComponent>();
             var xforms = _entities.GetEntityQuery<TransformComponent>();
@@ -690,6 +766,8 @@ namespace Robust.Client.GameStates
             var enteringPvs = 0;
             _toApply.Clear();
             _toCreate.Clear();
+            _detached.Clear();
+            _created.Clear();
             _pendingReapplyNetStates.Clear();
             var curSpan = curState.EntityStates.Span;
 
@@ -714,6 +792,7 @@ namespace Robust.Client.GameStates
 
                     var uid = _entities.CreateEntity(metaState.PrototypeId, out var newMeta);
                     _toCreate.Add(es.NetEntity, es);
+                    _created.Add(es.NetEntity);
                     _toApply.Add(uid, (es.NetEntity, newMeta, false, GameTick.Zero, es, null));
 
                     // Client creates a client-side net entity for the newly created entity.
@@ -767,7 +846,7 @@ namespace Robust.Client.GameStates
             // Detach entities to null space
             var containerSys = _entitySystemManager.GetEntitySystem<ContainerSystem>();
             var lookupSys = _entitySystemManager.GetEntitySystem<EntityLookupSystem>();
-            var detached = ProcessPvsDeparture(curState.ToSequence, metas, xforms, xformSys, containerSys, lookupSys);
+            ProcessPvsDeparture(_detached, curState.ToSequence, metas, xforms, xformSys, containerSys, lookupSys);
 
             // Check next state (AFTER having created new entities introduced in curstate)
             if (nextState != null)
@@ -869,8 +948,6 @@ namespace Robust.Client.GameStates
 
             _prof.WriteValue("State Size", ProfData.Int32(curSpan.Length));
             _prof.WriteValue("Entered PVS", ProfData.Int32(enteringPvs));
-
-            return (_toCreate.Keys, detached);
         }
 
         /// <inheritdoc />
@@ -901,7 +978,7 @@ namespace Robust.Client.GameStates
             var xforms = _entities.GetEntityQuery<TransformComponent>();
             var xformSys = _entitySystemManager.GetEntitySystem<SharedTransformSystem>();
 
-            _toDelete.Clear();
+            using var toDelete = new PooledList<EntityUid>();
 
             // Client side entities won't need the transform, but that should always be a tiny minority of entities
             var metaQuery = _entityManager.AllEntityQueryEnumerator<MetaDataComponent, TransformComponent>();
@@ -912,7 +989,7 @@ namespace Robust.Client.GameStates
                 if (metadata.NetEntity.IsClientSide())
                 {
                     if (deleteClientEntities)
-                        _toDelete.Add(ent);
+                        toDelete.Add(ent);
 
                     continue;
                 }
@@ -939,14 +1016,14 @@ namespace Robust.Client.GameStates
                         && !deleteClientEntities // don't add duplicates
                         && _entities.IsClientSide(child.Value))
                     {
-                        _toDelete.Add(child.Value);
+                        toDelete.Add(child.Value);
                     }
                 }
 
-                _toDelete.Add(ent);
+                toDelete.Add(ent);
             }
 
-            foreach (var ent in _toDelete)
+            foreach (var ent in toDelete)
             {
                 _entities.DeleteEntity(ent);
             }
@@ -1006,7 +1083,8 @@ namespace Robust.Client.GameStates
             Detach(GameTick.MaxValue, null, entities, metas, xforms, xformSys, containerSys, lookupSys);
         }
 
-        private List<NetEntity> ProcessPvsDeparture(
+        private void ProcessPvsDeparture(
+            IList<NetEntity> detached,
             GameTick toTick,
             EntityQuery<MetaDataComponent> metas,
             EntityQuery<TransformComponent> xforms,
@@ -1014,18 +1092,17 @@ namespace Robust.Client.GameStates
             ContainerSystem containerSys,
             EntityLookupSystem lookupSys)
         {
-            var toDetach = _processor.GetEntitiesToDetach(toTick, _pvsDetachBudget);
-            var detached = new List<NetEntity>();
+            using var toDetach = new PooledList<(GameTick Tick, List<NetEntity> Entities)>();
+            _processor.GetEntitiesToDetach(toDetach, toTick, _pvsDetachBudget);
 
             if (toDetach.Count == 0)
-                return detached;
+                return;
 
             // TODO optimize
             // If an entity is leaving PVS, so are all of its children. If we can preserve the hierarchy we can avoid
             // things like container insertion and ejection.
 
             using var _ = _prof.Group("Leave PVS");
-            detached.EnsureCapacity(toDetach.Count);
 
             foreach (var (tick, ents) in toDetach)
             {
@@ -1033,7 +1110,6 @@ namespace Robust.Client.GameStates
             }
 
             _prof.WriteValue("Count", ProfData.Int32(detached.Count));
-            return detached;
         }
 
         private void Detach(GameTick maxTick,
@@ -1044,7 +1120,7 @@ namespace Robust.Client.GameStates
             SharedTransformSystem xformSys,
             ContainerSystem containerSys,
             EntityLookupSystem lookupSys,
-            List<NetEntity>? detached = null)
+            IList<NetEntity>? detached = null)
         {
             foreach (var netEntity in entities)
             {
@@ -1098,7 +1174,7 @@ namespace Robust.Client.GameStates
             var metaQuery = _entityManager.GetEntityQuery<MetaDataComponent>();
 
 #if EXCEPTION_TOLERANCE
-            var brokenEnts = new List<EntityUid>();
+            using var brokenEnts = new PooledList<EntityUid>();
 #endif
             using (_prof.Group("Initialize Entity"))
             {
@@ -1162,18 +1238,28 @@ namespace Robust.Client.GameStates
             // First remove any deleted components
             if (curState?.NetComponents != null)
             {
-                _toRemove.Clear();
+                using var toRemove = new PooledList<IComponent>();
+                using var compTypes = new PooledList<ComponentType>();
 
                 foreach (var (id, comp) in meta.NetComponents)
                 {
                     if (comp.NetSyncEnabled && !curState.NetComponents.Contains(id))
-                        _toRemove.Add(comp);
+                    {
+                        toRemove.Add(comp);
+                        compTypes.Add(comp.GetType());
+                    }
                 }
 
-                foreach (var comp in _toRemove)
+                if (toRemove.Count > 0)
                 {
-                    _entities.RemoveComponent(uid, comp, meta);
+                    foreach (var comp in toRemove)
+                    {
+                        _entityManager.RemoveComponentInternal(uid, comp, terminating: false, archetypeChange: false, meta);
+                    }
                 }
+
+                if (compTypes.Count > 0)
+                    _entityManager.RemoveComponentRange(uid, compTypes);
             }
 
             if (enteringPvs)
@@ -1188,7 +1274,7 @@ namespace Robust.Client.GameStates
                     if (!meta.NetComponents.TryGetValue(id, out var comp))
                     {
                         comp = _compFactory.GetComponent(id);
-                        _entityManager.AddComponent(uid, comp, true, metadata: meta);
+                        _entityManager.AddComponent(uid, comp, metadata: meta);
                     }
 
                     _compStateWork[id] = (comp, state, null);
@@ -1196,18 +1282,49 @@ namespace Robust.Client.GameStates
             }
             else if (curState != null)
             {
+                using var addedComps = new PooledList<IComponent>();
+                using var addedCompTypes = new PooledList<ComponentType>();
+                using var addedRegistrations = new PooledList<ComponentRegistration>();
+
                 foreach (var compChange in curState.ComponentChanges.Span)
                 {
                     if (!meta.NetComponents.TryGetValue(compChange.NetID, out var comp))
                     {
-                        comp = _compFactory.GetComponent(compChange.NetID);
-                        _entityManager.AddComponent(uid, comp, true, metadata:meta);
+                        var registration = _compFactory.GetRegistration(compChange.NetID);
+                        addedRegistrations.Add(registration);
+                        comp = _compFactory.GetComponent(registration);
+                        comp.Owner = uid;
+                        addedComps.Add(comp);
+                        addedCompTypes.Add(comp.GetType());
                     }
                     else if (compChange.LastModifiedTick <= lastApplied && lastApplied != GameTick.Zero)
                         continue;
 
                     _compStateWork[compChange.NetID] = (comp, compChange.State, null);
                 }
+
+                // To avoid shuffling the archetype we'll set the component range up-front.
+                if (addedComps.Count > 0)
+                {
+                    // TODO: This fucking sucks but
+                    // - Frequent archetype changes PER COMPONENT sucks
+                    // - the components will be null in event handlers until it's done.
+                    _entityManager.AddComponentRange(uid, addedCompTypes);
+
+                    for (var i = 0; i < addedComps.Count; i++)
+                    {
+                        var component = addedComps[i];
+                        var reg = addedRegistrations[i];
+                        _entityManager.AddComponentInternalOnly(uid, component, reg, meta);
+                    }
+
+                    for (var i = 0; i < addedComps.Count; i++)
+                    {
+                        var component = addedComps[i];
+                        var reg = addedRegistrations[i];
+                        _entityManager.AddComponentEvents(uid, component, reg, false, meta);
+                    }
+                }
             }
 
             if (nextState != null)
@@ -1297,7 +1414,7 @@ namespace Robust.Client.GameStates
                 return false;
             }
 
-            if (!EntityUid.TryParse(args[0], out uid))
+            if (!EntityUid.TryParse(args[0], "-1", out uid))
             {
                 shell.WriteError(Loc.GetString("cmd-parse-failure-uid", ("arg", args[0])));
                 meta = null;
@@ -1429,23 +1546,22 @@ namespace Robust.Client.GameStates
                 if (!meta.NetComponents.TryGetValue(id, out var comp))
                 {
                     comp = _compFactory.GetComponent(id);
-                    _entityManager.AddComponent(uid, comp, true, meta);
+                    _entityManager.AddComponent(uid, comp, meta);
                 }
 
                 var handleState = new ComponentHandleState(state, null);
                 _entityManager.EventBus.RaiseComponentEvent(comp, ref handleState);
             }
 
-            // ensure we don't have any extra components
-            _toRemove.Clear();
+            using var toRemove = new PooledList<IComponent>();
 
             foreach (var (id, comp) in meta.NetComponents)
             {
                 if (comp.NetSyncEnabled && !lastState.ContainsKey(id))
-                    _toRemove.Add(comp);
+                    toRemove.Add(comp);
             }
 
-            foreach (var comp in _toRemove)
+            foreach (var comp in toRemove)
             {
                 _entities.RemoveComponent(uid, comp);
             }
@@ -1454,19 +1570,14 @@ namespace Robust.Client.GameStates
 
         public bool IsQueuedForDetach(NetEntity entity)
             => _processor.IsQueuedForDetach(entity);
-
-        void IPostInjectInit.PostInject()
-        {
-            _sawmill = _logMan.GetSawmill(CVars.NetPredict.Name);
-        }
     }
 
     public sealed class GameStateAppliedArgs : EventArgs
     {
-        public GameState AppliedState { get; }
-        public readonly List<NetEntity> Detached;
+        public readonly GameState AppliedState;
+        public readonly IReadOnlyList<NetEntity> Detached;
 
-        public GameStateAppliedArgs(GameState appliedState, List<NetEntity> detached)
+        public GameStateAppliedArgs(GameState appliedState, IReadOnlyList<NetEntity> detached)
         {
             AppliedState = appliedState;
             Detached = detached;

Robust.Client/GameStates/GameStateProcessor.cs

@@ -1,46 +1,33 @@
+using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Runtime.InteropServices;
 using Robust.Client.Timing;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
-using Robust.Shared.IoC;
 using Robust.Shared.Log;
-using Robust.Shared.Network.Messages;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
 namespace Robust.Client.GameStates
 {
     /// <inheritdoc />
-    internal sealed class GameStateProcessor : IGameStateProcessor, IPostInjectInit
+    internal sealed class GameStateProcessor : IGameStateProcessor
     {
-        [Dependency] private ILogManager _logMan = default!;
-
         private readonly IClientGameTiming _timing;
+        private readonly IClientGameStateManager _state;
+        private readonly ISawmill _logger;
 
         private readonly List<GameState> _stateBuffer = new();
 
         private readonly Dictionary<GameTick, List<NetEntity>> _pvsDetachMessages = new();
-
-        private ISawmill _logger = default!;
-        private ISawmill _stateLogger = default!;
-
         public GameState? LastFullState { get; private set; }
         public bool WaitingForFull => LastFullStateRequested.HasValue;
-        public GameTick? LastFullStateRequested
-        {
-            get => _lastFullStateRequested;
-            set
-            {
-                _lastFullStateRequested = value;
-                LastFullState = null;
-            }
-        }
-
-        public GameTick? _lastFullStateRequested = GameTick.Zero;
+        public (GameTick Tick, DateTime Time)? LastFullStateRequested { get; private set; } = (GameTick.Zero, DateTime.MaxValue);
 
         private int _bufferSize;
+        private int _maxBufferSize = 512;
+        public const int MinimumMaxBufferSize = 256;
 
         /// <summary>
         /// This dictionary stores the full most recently received server state of any entity. This is used whenever predicted entities get reset.
@@ -61,7 +48,14 @@ namespace Robust.Client.GameStates
         public int BufferSize
         {
             get => _bufferSize;
-            set => _bufferSize = value < 0 ? 0 : value;
+            set => _bufferSize = Math.Max(value, 0);
+        }
+
+        public int MaxBufferSize
+        {
+            get => _maxBufferSize;
+            // We place a lower bound on the maximum size to avoid spamming servers with full game state requests.
+            set => _maxBufferSize = Math.Max(value, MinimumMaxBufferSize);
         }
 
         /// <inheritdoc />
@@ -71,9 +65,12 @@ namespace Robust.Client.GameStates
         ///     Constructs a new instance of <see cref="GameStateProcessor"/>.
         /// </summary>
         /// <param name="timing">Timing information of the current state.</param>
-        public GameStateProcessor(IClientGameTiming timing)
+        /// <param name="clientGameStateManager"></param>
+        public GameStateProcessor(IClientGameStateManager state, IClientGameTiming timing, ISawmill logger)
         {
             _timing = timing;
+            _state = state;
+            _logger = logger;
         }
 
         /// <inheritdoc />
@@ -83,7 +80,7 @@ namespace Robust.Client.GameStates
             if (state.ToSequence <= _timing.LastRealTick)
             {
                 if (Logging)
-                    _stateLogger.Debug($"Received Old GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
+                    _logger.Debug($"Received Old GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
 
                 return false;
             }
@@ -95,7 +92,7 @@ namespace Robust.Client.GameStates
                     continue;
 
                 if (Logging)
-                    _stateLogger.Debug($"Received Dupe GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
+                    _logger.Debug($"Received Dupe GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
 
                 return false;
             }
@@ -104,34 +101,68 @@ namespace Robust.Client.GameStates
             if (!WaitingForFull)
             {
                 // This is a good state that we will be using.
-                _stateBuffer.Add(state);
+                TryAdd(state);
                 if (Logging)
-                    _stateLogger.Debug($"Received New GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
+                    _logger.Debug($"Received New GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
                 return true;
             }
 
-            if (LastFullState == null && state.FromSequence == GameTick.Zero && state.ToSequence >= LastFullStateRequested!.Value)
+            if (LastFullState == null && state.FromSequence == GameTick.Zero)
             {
-                LastFullState = state;
-
-                if (Logging)
+                if (state.ToSequence >= LastFullStateRequested!.Value.Tick)
+                {
+                    LastFullState = state;
                     _logger.Info($"Received Full GameState: to={state.ToSequence}, sz={state.PayloadSize}");
+                    return true;
+                }
 
-                return true;
+                _logger.Info($"Received a late full game state. Received: {state.ToSequence}. Requested: {LastFullStateRequested.Value.Tick}");
             }
 
             if (LastFullState != null && state.ToSequence <= LastFullState.ToSequence)
             {
-                if (Logging)
-                    _logger.Info($"While waiting for full, received late GameState with lower to={state.ToSequence} than the last full state={LastFullState.ToSequence}");
-
+                _logger.Info($"While waiting for full, received late GameState with lower to={state.ToSequence} than the last full state={LastFullState.ToSequence}");
                 return false;
             }
 
-            _stateBuffer.Add(state);
+            TryAdd(state);
             return true;
         }
 
+        public void TryAdd(GameState state)
+        {
+            if (_stateBuffer.Count <= MaxBufferSize)
+            {
+                _stateBuffer.Add(state);
+                return;
+            }
+
+            // This can happen if a required state gets dropped somehow and the client keeps receiving future
+            // game states that they can't apply. I.e., GetApplicableStateCount() is zero, even though there are many
+            // states in the list.
+            //
+            // This can seemingly happen when the server sends ""reliable"" game states while the client is paused?
+            // For example, when debugging the client, while the server is running:
+            // - The client stops sending acks for states that the server sends out.
+            // - Thus the client will exceed the net.force_ack_threshold cvar
+            // - The server starts sending some packets ""reliably"" and just force updates the clients last ack.
+            //
+            // What should happen is that when the client resumes, it receives the reliably sent states and can just
+            // resume. However, even though the packets are sent ""reliably"", they just seem to get dropped.
+            // I don't quite understand how/why yet, but this ensures the client doesn't get stuck.
+#if FULL_RELEASE
+            _logger.Warning(@$"Exceeded maximum state buffer size!
+Tick: {_timing.CurTick}/{_timing.LastProcessedTick}/{_timing.LastRealTick}
+Size: {_stateBuffer.Count}
+Applicable states: {GetApplicableStateCount()}
+Was waiting for full: {WaitingForFull} {LastFullStateRequested}
+Had full state: {LastFullState != null}"
+            );
+#endif
+
+            _state.RequestFullState();
+        }
+
         /// <summary>
         ///     Attempts to get the current and next states to apply.
         /// </summary>
@@ -152,7 +183,7 @@ namespace Robust.Client.GameStates
                     "Tried to apply a non-extrapolated state that has too high of a FromSequence!");
 
                 if (Logging)
-                    _stateLogger.Debug($"Applying State:  cTick={_timing.LastProcessedTick}, fSeq={curState.FromSequence}, tSeq={curState.ToSequence}, buf={_stateBuffer.Count}");
+                    _logger.Debug($"Applying State:  cTick={_timing.LastProcessedTick}, fSeq={curState.FromSequence}, tSeq={curState.ToSequence}, buf={_stateBuffer.Count}");
             }
 
             return applyNextState;
@@ -273,9 +304,8 @@ namespace Robust.Client.GameStates
 
         public void ClearDetachQueue() => _pvsDetachMessages.Clear();
 
-        public List<(GameTick Tick, List<NetEntity> Entities)> GetEntitiesToDetach(GameTick toTick, int budget)
+        public void GetEntitiesToDetach(IList<(GameTick Tick, List<NetEntity> Entities)> result, GameTick toTick, int budget)
         {
-            var result = new List<(GameTick Tick, List<NetEntity> Entities)>();
             foreach (var (tick, entities) in _pvsDetachMessages)
             {
                 if (tick > toTick)
@@ -294,7 +324,6 @@ namespace Robust.Client.GameStates
                 entities.RemoveRange(index, budget);
                 break;
             }
-            return result;
         }
 
         private bool TryGetDeltaState(out GameState? curState, out GameState? nextState)
@@ -344,14 +373,20 @@ namespace Robust.Client.GameStates
         {
             _stateBuffer.Clear();
             LastFullState = null;
-            LastFullStateRequested = GameTick.Zero;
+            LastFullStateRequested = (GameTick.Zero, DateTime.MaxValue);
         }
 
-        public void RequestFullState()
+        public void OnFullStateRequested(GameTick tick)
         {
             _stateBuffer.Clear();
             LastFullState = null;
-            LastFullStateRequested = _timing.LastRealTick;
+            LastFullStateRequested = (tick, DateTime.UtcNow);
+        }
+
+        public void OnFullStateReceived()
+        {
+            LastFullState = null;
+            LastFullStateRequested = null;
         }
 
         public void MergeImplicitData(Dictionary<NetEntity, Dictionary<ushort, ComponentState>> implicitData)
@@ -416,10 +451,11 @@ namespace Robust.Client.GameStates
             return false;
         }
 
-        public int CalculateBufferSize(GameTick fromTick)
+        public int GetApplicableStateCount(GameTick? fromTick = null)
         {
+            fromTick ??= _timing.LastRealTick;
             bool foundState;
-            var nextTick = fromTick;
+            var nextTick = fromTick.Value;
 
             do
             {
@@ -437,13 +473,9 @@ namespace Robust.Client.GameStates
             }
             while (foundState);
 
-            return (int) (nextTick.Value - fromTick.Value);
+            return (int) (nextTick.Value - fromTick.Value.Value);
         }
 
-        void IPostInjectInit.PostInject()
-        {
-            _logger = _logMan.GetSawmill("net");
-            _stateLogger = _logMan.GetSawmill("net.state");
-        }
+        public int StateCount => _stateBuffer.Count;
     }
 }

Robust.Client/GameStates/IClientGameStateManager.cs

@@ -32,7 +32,15 @@ namespace Robust.Client.GameStates
         /// <summary>
         ///     Number of applicable game states currently in the state buffer.
         /// </summary>
-        int CurrentBufferSize { get; }
+        int GetApplicableStateCount();
+
+        [Obsolete("use GetApplicableStateCount()")]
+        int CurrentBufferSize => GetApplicableStateCount();
+
+        /// <summary>
+        ///     Total number of game states currently in the state buffer.
+        /// </summary>
+        int StateCount { get; }
 
         /// <summary>
         ///     If the buffer size is this many states larger than the target buffer size,
@@ -91,7 +99,7 @@ namespace Robust.Client.GameStates
         /// <summary>
         ///     Requests a full state from the server. This should override even implicit entity data.
         /// </summary>
-        void RequestFullState(NetEntity? missingEntity = null);
+        void RequestFullState(NetEntity? missingEntity = null, GameTick? tick = null);
 
         uint SystemMessageDispatched<T>(T message) where T : EntityEventArgs;
 

Robust.Client/GameStates/IGameStateProcessor.cs

@@ -96,7 +96,7 @@ namespace Robust.Client.GameStates
         ///     This includes only applicable states. If there is a gap, future buffers are not included.
         /// </summary>
         /// <param name="fromTick">The tick to calculate from.</param>
-        int CalculateBufferSize(GameTick fromTick);
+        int GetApplicableStateCount(GameTick? fromTick);
 
         bool TryGetLastServerStates(NetEntity entity,
             [NotNullWhen(true)] out Dictionary<ushort, ComponentState>? dictionary);

Robust.Client/GameStates/NetGraphOverlay.cs

@@ -68,7 +68,7 @@ namespace Robust.Client.GameStates
             var lag = _netManager.ServerChannel!.Ping;
 
             // calc interp info
-            var buffer = _gameStateManager.CurrentBufferSize;
+            var buffer = _gameStateManager.GetApplicableStateCount();
 
             _totalHistoryPayload += sz;
             _history.Add((toSeq, sz, lag, buffer));
@@ -268,7 +268,7 @@ namespace Robust.Client.GameStates
                 handle.DrawString(_font, new Vector2(LeftMargin + width, lastLagY), $"{lastLagMs.ToString()}ms");
 
             // buffer text
-            handle.DrawString(_font, new Vector2(LeftMargin, height + LowerGraphOffset), $"{_gameStateManager.CurrentBufferSize.ToString()} states");
+            handle.DrawString(_font, new Vector2(LeftMargin, height + LowerGraphOffset), $"{_gameStateManager.GetApplicableStateCount().ToString()} states");
         }
 
         protected override void DisposeBehavior()

Robust.Client/Graphics/Clyde/Clyde.GridRendering.cs

@@ -50,14 +50,18 @@ namespace Robust.Client.Graphics.Clyde
                 var transform = _entityManager.GetComponent<TransformComponent>(mapGrid);
                 gridProgram.SetUniform(UniIModelMatrix, transform.WorldMatrix);
                 var enumerator = mapGrid.Comp.GetMapChunks(worldBounds);
+                var data = _mapChunkData[mapGrid];
 
                 while (enumerator.MoveNext(out var chunk))
                 {
-                    if (_isChunkDirty(mapGrid, chunk))
-                        _updateChunkMesh(mapGrid, chunk);
+                    DebugTools.Assert(chunk.FilledTiles > 0);
+                    if (!data.TryGetValue(chunk.Indices, out MapChunkData? datum))
+                        data[chunk.Indices] = datum = _initChunkBuffers(mapGrid, chunk);
 
-                    var datum = _mapChunkData[mapGrid][chunk.Indices];
+                    if (datum.Dirty)
+                        _updateChunkMesh(mapGrid, chunk, datum);
 
+                    DebugTools.Assert(datum.TileCount > 0);
                     if (datum.TileCount == 0)
                         continue;
 
@@ -69,17 +73,31 @@ namespace Robust.Client.Graphics.Clyde
                     CheckGlError();
                 }
             }
+
+            CullEmptyChunks();
         }
 
-        private void _updateChunkMesh(Entity<MapGridComponent> grid, MapChunk chunk)
+        private void CullEmptyChunks()
         {
-            var data = _mapChunkData[grid];
-
-            if (!data.TryGetValue(chunk.Indices, out var datum))
+            foreach (var (grid, chunks) in _mapChunkData)
             {
-                datum = _initChunkBuffers(grid, chunk);
-            }
+                var gridComp = _mapManager.GetGridComp(grid);
+                foreach (var (index, chunk) in chunks)
+                {
+                    if (!chunk.Dirty || gridComp.Chunks.ContainsKey(index))
+                    {
+                        DebugTools.Assert(gridComp.Chunks[index].FilledTiles > 0);
+                        continue;
+                    }
 
+                    DeleteChunk(chunk);
+                    chunks.Remove(index);
+                }
+            }
+        }
+
+        private void _updateChunkMesh(Entity<MapGridComponent> grid, MapChunk chunk, MapChunkData datum)
+        {
             Span<ushort> indexBuffer = stackalloc ushort[_indicesPerChunk(chunk)];
             Span<Vertex2D> vertexBuffer = stackalloc Vertex2D[_verticesPerChunk(chunk)];
 
@@ -159,41 +177,22 @@ namespace Robust.Client.Graphics.Clyde
                 Dirty = true
             };
 
-            _mapChunkData[grid].Add(chunk.Indices, datum);
             return datum;
         }
 
-        private bool _isChunkDirty(Entity<MapGridComponent> grid, MapChunk chunk)
+        private void DeleteChunk(MapChunkData data)
         {
-            var data = _mapChunkData[grid];
-            return !data.TryGetValue(chunk.Indices, out var datum) || datum.Dirty;
-        }
-
-        public void _setChunkDirty(Entity<MapGridComponent> grid, Vector2i chunk)
-        {
-            var data = _mapChunkData.GetOrNew(grid);
-            if (data.TryGetValue(chunk, out var datum))
-            {
-                datum.Dirty = true;
-            }
-            // Don't need to set it if we don't have an entry since lack of an entry is treated as dirty.
-        }
-
-        private void _updateOnGridModified(GridModifiedEvent args)
-        {
-            foreach (var (pos, _) in args.Modified)
-            {
-                var grid = args.Grid;
-                var chunk = grid.GridTileToChunkIndices(pos);
-                _setChunkDirty((args.GridEnt, grid), chunk);
-            }
+            DeleteVertexArray(data.VAO);
+            CheckGlError();
+            data.VBO.Delete();
+            data.EBO.Delete();
         }
 
         private void _updateTileMapOnUpdate(ref TileChangedEvent args)
         {
-            var grid = _mapManager.GetGrid(args.NewTile.GridUid);
-            var chunk = grid.GridTileToChunkIndices(new Vector2i(args.NewTile.X, args.NewTile.Y));
-            _setChunkDirty((args.NewTile.GridUid, grid), chunk);
+            var gridData = _mapChunkData.GetOrNew(args.Entity);
+            if (gridData.TryGetValue(args.ChunkIndex, out var data))
+                data.Dirty = true;
         }
 
         private void _updateOnGridCreated(GridStartupEvent ev)
@@ -209,10 +208,7 @@ namespace Robust.Client.Graphics.Clyde
             var data = _mapChunkData[gridId];
             foreach (var chunkDatum in data.Values)
             {
-                DeleteVertexArray(chunkDatum.VAO);
-                CheckGlError();
-                chunkDatum.VBO.Delete();
-                chunkDatum.EBO.Delete();
+                DeleteChunk(chunkDatum);
             }
 
             _mapChunkData.Remove(gridId);

Robust.Client/Graphics/Clyde/Clyde.HLR.cs

@@ -512,7 +512,7 @@ namespace Robust.Client.Graphics.Clyde
                         RenderOverlays(viewport, OverlaySpace.WorldSpaceBelowFOV, worldAABB, worldBounds);
                     }
 
-                    if (_lightManager.Enabled && _lightManager.DrawHardFov && eye.DrawFov)
+                    if (_lightManager.Enabled && _lightManager.DrawHardFov && eye.DrawLight && eye.DrawFov)
                     {
                         ApplyFovToBuffer(viewport, eye);
                     }

Robust.Client/Graphics/Clyde/Clyde.LightRendering.cs

@@ -97,6 +97,9 @@ namespace Robust.Client.Graphics.Clyde
 
         private (PointLightComponent light, Vector2 pos, float distanceSquared, Angle rot)[] _lightsToRenderList = default!;
 
+        private LightCapacityComparer _lightCap = new();
+        private ShadowCapacityComparer _shadowCap = new ShadowCapacityComparer();
+
         private unsafe void InitLighting()
         {
 
@@ -332,7 +335,7 @@ namespace Robust.Client.Graphics.Clyde
 
         private void DrawLightsAndFov(Viewport viewport, Box2Rotated worldBounds, Box2 worldAABB, IEye eye)
         {
-            if (!_lightManager.Enabled)
+            if (!_lightManager.Enabled || !eye.DrawLight)
             {
                 return;
             }
@@ -570,6 +573,28 @@ namespace Robust.Client.Graphics.Clyde
             return true;
         }
 
+        private sealed class LightCapacityComparer : IComparer<(PointLightComponent light, Vector2 pos, float distanceSquared, Angle rot)>
+        {
+            public int Compare(
+                (PointLightComponent light, Vector2 pos, float distanceSquared, Angle rot) x,
+                (PointLightComponent light, Vector2 pos, float distanceSquared, Angle rot) y)
+            {
+                if (x.light.CastShadows && !y.light.CastShadows) return 1;
+                if (!x.light.CastShadows && y.light.CastShadows) return -1;
+                return 0;
+            }
+        }
+
+        private sealed class ShadowCapacityComparer : IComparer<(PointLightComponent light, Vector2 pos, float distanceSquared, Angle rot)>
+        {
+            public int Compare(
+                (PointLightComponent light, Vector2 pos, float distanceSquared, Angle rot) x,
+                (PointLightComponent light, Vector2 pos, float distanceSquared, Angle rot) y)
+            {
+                return x.distanceSquared.CompareTo(y.distanceSquared);
+            }
+        }
+
         private (int count, Box2 expandedBounds) GetLightsToRender(
             MapId map,
             in Box2Rotated worldBounds,
@@ -595,20 +620,10 @@ namespace Robust.Client.Graphics.Clyde
 
                 // First, partition the array based on whether the lights are shadow casting or not
                 // (non shadow casting lights should be the first partition, shadow casting lights the second)
-                Array.Sort(_lightsToRenderList, 0, state.count,
-                    Comparer<(PointLightComponent light, Vector2 pos, float distanceSquared)>.Create((x, y) =>
-                    {
-                        if (x.light.CastShadows && !y.light.CastShadows) return 1;
-                        else if (!x.light.CastShadows && y.light.CastShadows) return -1;
-                        else return 0;
-                    }));
+                Array.Sort(_lightsToRenderList, 0, state.count, _lightCap);
 
                 // Next, sort just the shadow casting lights by distance.
-                Array.Sort(_lightsToRenderList, state.count - state.shadowCastingCount, state.shadowCastingCount,
-                    Comparer<(PointLightComponent light, Vector2 pos, float distanceSquared)>.Create((x, y) =>
-                    {
-                        return x.distanceSquared.CompareTo(y.distanceSquared);
-                    }));
+                Array.Sort(_lightsToRenderList, state.count - state.shadowCastingCount, state.shadowCastingCount, _shadowCap);
 
                 // Then effectively delete the furthest lights, by setting the end of the array to exclude N
                 // number of shadow casting lights (where N is the number above the max number per scene.)

Robust.Client/Graphics/Clyde/Clyde.cs

@@ -173,7 +173,6 @@ namespace Robust.Client.Graphics.Clyde
             _entityManager.EventBus.SubscribeEvent<TileChangedEvent>(EventSource.Local, this, _updateTileMapOnUpdate);
             _entityManager.EventBus.SubscribeEvent<GridStartupEvent>(EventSource.Local, this, _updateOnGridCreated);
             _entityManager.EventBus.SubscribeEvent<GridRemovalEvent>(EventSource.Local, this, _updateOnGridRemoved);
-            _entityManager.EventBus.SubscribeEvent<GridModifiedEvent>(EventSource.Local, this, _updateOnGridModified);
         }
 
         public void ShutdownGridEcsEvents()
@@ -181,7 +180,6 @@ namespace Robust.Client.Graphics.Clyde
             _entityManager.EventBus.UnsubscribeEvent<TileChangedEvent>(EventSource.Local, this);
             _entityManager.EventBus.UnsubscribeEvent<GridStartupEvent>(EventSource.Local, this);
             _entityManager.EventBus.UnsubscribeEvent<GridRemovalEvent>(EventSource.Local, this);
-            _entityManager.EventBus.UnsubscribeEvent<GridModifiedEvent>(EventSource.Local, this);
         }
 
         private void GLInitBindings(bool gles)

Robust.Client/Map/TileEdgeOverlay.cs

@@ -42,15 +42,20 @@ public sealed class TileEdgeOverlay : Overlay
         _grids.Clear();
         _mapManager.FindGridsIntersecting(args.MapId, args.WorldBounds, ref _grids);
 
-        var xformQuery = _entManager.GetEntityQuery<TransformComponent>();
+        var mapSystem = _entManager.System<SharedMapSystem>();
+        var xformSystem = _entManager.System<SharedTransformSystem>();
+
         foreach (var grid in _grids)
         {
             var tileSize = grid.Comp.TileSize;
             var tileDimensions = new Vector2(tileSize, tileSize);
-            var xform = xformQuery.GetComponent(grid);
-            args.WorldHandle.SetTransform(xform.WorldMatrix);
+            var (_, _, worldMatrix, invMatrix) = xformSystem.GetWorldPositionRotationMatrixWithInv(grid.Owner);
+            args.WorldHandle.SetTransform(worldMatrix);
+            var localAABB = invMatrix.TransformBox(args.WorldBounds);
 
-            foreach (var tileRef in grid.Comp.GetTilesIntersecting(args.WorldBounds, false))
+            var enumerator = mapSystem.GetLocalTilesEnumerator(grid.Owner, grid.Comp, localAABB, false);
+
+            while (enumerator.MoveNext(out var tileRef))
             {
                 var tileDef = _tileDefManager[tileRef.Tile.TypeId];
 
@@ -66,7 +71,7 @@ public sealed class TileEdgeOverlay : Overlay
                             continue;
 
                         var neighborIndices = new Vector2i(tileRef.GridIndices.X + x, tileRef.GridIndices.Y + y);
-                        var neighborTile = grid.Comp.GetTileRef(neighborIndices);
+                        var neighborTile = mapSystem.GetTileRef(grid.Owner, grid.Comp, neighborIndices);
                         var neighborDef = _tileDefManager[neighborTile.Tile.TypeId];
 
                         // If it's the same tile then no edge to be drawn.
@@ -118,9 +123,9 @@ public sealed class TileEdgeOverlay : Overlay
                         }
 
                         if (angle == Angle.Zero)
-                            args.WorldHandle.DrawTextureRect(texture, box);
+                            args.WorldHandle.DrawTextureRect(texture.Texture, box);
                         else
-                            args.WorldHandle.DrawTextureRect(texture, new Box2Rotated(box, angle, box.Center));
+                            args.WorldHandle.DrawTextureRect(texture.Texture, new Box2Rotated(box, angle, box.Center));
                     }
                 }
             }

Robust.Client/Physics/PhysicsSystem.Predict.cs

@@ -1,6 +1,5 @@
 using System.Buffers;
 using System.Collections.Generic;
-using Robust.Client.GameObjects;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Map.Components;
 using Robust.Shared.Physics;
@@ -8,6 +7,7 @@ using Robust.Shared.Physics.Components;
 using Robust.Shared.Physics.Dynamics;
 using Robust.Shared.Physics.Dynamics.Contacts;
 using Robust.Shared.Physics.Systems;
+using Robust.Shared.Player;
 using Robust.Shared.Utility;
 
 namespace Robust.Client.Physics;
@@ -20,8 +20,8 @@ public sealed partial class PhysicsSystem
     public override void Initialize()
     {
         base.Initialize();
-        SubscribeLocalEvent<PlayerAttachedEvent>(OnAttach);
-        SubscribeLocalEvent<PlayerDetachedEvent>(OnDetach);
+        SubscribeLocalEvent<LocalPlayerAttachedEvent>(OnAttach);
+        SubscribeLocalEvent<LocalPlayerDetachedEvent>(OnDetach);
         SubscribeLocalEvent<PhysicsComponent, JointAddedEvent>(OnJointAdded);
         SubscribeLocalEvent<PhysicsComponent, JointRemovedEvent>(OnJointRemoved);
     }
@@ -63,12 +63,12 @@ public sealed partial class PhysicsSystem
         UpdateIsPredicted(args.Joint.BodyBUid);
     }
 
-    private void OnAttach(PlayerAttachedEvent ev)
+    private void OnAttach(LocalPlayerAttachedEvent ev)
     {
         UpdateIsPredicted(ev.Entity);
     }
 
-    private void OnDetach(PlayerDetachedEvent ev)
+    private void OnDetach(LocalPlayerDetachedEvent ev)
     {
         UpdateIsPredicted(ev.Entity);
     }

Robust.Client/Placement/Modes/AlignSimilar.cs

@@ -44,7 +44,7 @@ namespace Robust.Client.Placement.Modes
 
             var closestEntity = snapToEntities[0];
             var closestTransform = pManager.EntityManager.GetComponent<TransformComponent>(closestEntity);
-            if (!pManager.EntityManager.TryGetComponent<SpriteComponent?>(closestEntity, out var component) || component.BaseRSI == null)
+            if (!pManager.EntityManager.TryGetComponent(closestEntity, out SpriteComponent? component) || component.BaseRSI == null)
             {
                 return;
             }

Robust.Client/Placement/PlacementManager.cs

@@ -8,7 +8,6 @@ using Robust.Client.Player;
 using Robust.Client.ResourceManagement;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Graphics;
 using Robust.Shared.Input;
 using Robust.Shared.Input.Binding;
 using Robust.Shared.IoC;
@@ -287,23 +286,17 @@ namespace Robust.Client.Placement
                     }, outsidePrediction: true))
                 .Register<PlacementManager>();
 
-            var localPlayer = PlayerManager.LocalPlayer;
-            localPlayer!.EntityAttached += OnEntityAttached;
+            PlayerManager.LocalPlayerDetached += OnDetached;
         }
 
         private void TearDownInput()
         {
             CommandBinds.Unregister<PlacementManager>();
-
-            if (PlayerManager.LocalPlayer != null)
-            {
-                PlayerManager.LocalPlayer.EntityAttached -= OnEntityAttached;
-            }
+            PlayerManager.LocalPlayerDetached -= OnDetached;
         }
 
-        private void OnEntityAttached(EntityAttachedEventArgs eventArgs)
+        private void OnDetached(EntityUid obj)
         {
-            // player attached to a new entity, basically disable the editor
             Clear();
         }
 

Robust.Client/Player/IPlayerManager.cs

@@ -1,44 +1,52 @@
 using System;
 using System.Collections.Generic;
+using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.Network;
-using Robust.Shared.Players;
-using Robust.Shared.ViewVariables;
+using Robust.Shared.Player;
 
-namespace Robust.Client.Player
+namespace Robust.Client.Player;
+
+public interface IPlayerManager : ISharedPlayerManager
 {
-    public interface IPlayerManager : ISharedPlayerManager
-    {
-        new IEnumerable<ICommonSession> Sessions { get; }
+    /// <summary>
+    /// Invoked when the list of sessions/players gets updated.
+    /// </summary>
+    event Action? PlayerListUpdated;
 
-        [ViewVariables]
-        IReadOnlyDictionary<NetUserId, ICommonSession> SessionsDict { get; }
+    /// <summary>
+    /// Invoked when <see cref="ISharedPlayerManager.LocalSession"/> gets attached to a new entity, or when the local
+    /// session gets updated. See also <see cref="LocalPlayerAttachedEvent"/>
+    /// </summary>
+    event Action<EntityUid>? LocalPlayerAttached;
 
-        [ViewVariables]
-        LocalPlayer? LocalPlayer { get; }
+    /// <summary>
+    /// Invoked when <see cref="ISharedPlayerManager.LocalSession"/> gets detached from an entity, or when the local
+    /// session gets updated. See also <see cref="LocalPlayerDetachedEvent"/>
+    /// </summary>
+    event Action<EntityUid>? LocalPlayerDetached;
 
-        /// <summary>
-        /// Invoked after LocalPlayer is changed
-        /// </summary>
-        event Action<LocalPlayerChangedEventArgs>? LocalPlayerChanged;
+    /// <summary>
+    /// Invoked whenever <see cref="ISharedPlayerManager.LocalSession"/> changes.
+    /// </summary>
+    event Action<(ICommonSession? Old, ICommonSession? New)>? LocalSessionChanged;
 
-        event EventHandler PlayerListUpdated;
+    void ApplyPlayerStates(IReadOnlyCollection<SessionState> list);
 
-        void Initialize();
-        void Startup();
-        void Shutdown();
+    /// <summary>
+    /// Sets up a single player game. This creates a dummy <see cref="ISharedPlayerManager.LocalSession"/>  without an
+    /// <see cref="INetChannel"/>.
+    /// </summary>
+    void SetupSinglePlayer(string name);
 
-        void ApplyPlayerStates(IReadOnlyCollection<PlayerState> list);
-    }
+    /// <summary>
+    /// Sets up the manager for a multiplayer game. This creates a <see cref="ISharedPlayerManager.LocalSession"/>
+    /// using the given <see cref="INetChannel"/>.
+    /// </summary>
+    void SetupMultiplayer(INetChannel channel);
 
-    public sealed class LocalPlayerChangedEventArgs : EventArgs
-    {
-        public readonly LocalPlayer? OldPlayer;
-        public readonly LocalPlayer? NewPlayer;
-        public LocalPlayerChangedEventArgs(LocalPlayer? oldPlayer, LocalPlayer? newPlayer)
-        {
-            OldPlayer = oldPlayer;
-            NewPlayer = newPlayer;
-        }
-    }
+    void SetLocalSession(ICommonSession session);
+
+    [Obsolete("Use LocalSession instead")]
+    LocalPlayer? LocalPlayer { get;}
 }

Robust.Client/Player/LocalPlayer.cs

@@ -1,11 +1,6 @@
-using System;
-using Robust.Client.GameObjects;
-using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
-using Robust.Shared.IoC;
-using Robust.Shared.Log;
 using Robust.Shared.Network;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.ViewVariables;
 
 namespace Robust.Client.Player
@@ -15,163 +10,30 @@ namespace Robust.Client.Player
     /// </summary>
     public sealed class LocalPlayer
     {
-        /// <summary>
-        ///     An entity has been attached to the local player.
-        /// </summary>
-        public event Action<EntityAttachedEventArgs>? EntityAttached;
-
-        /// <summary>
-        ///     An entity has been detached from the local player.
-        /// </summary>
-        public event Action<EntityDetachedEventArgs>? EntityDetached;
+        public LocalPlayer(ICommonSession session)
+        {
+            Session = session;
+        }
 
         /// <summary>
         ///     Game entity that the local player is controlling. If this is default, the player is not attached to any
         ///     entity at all.
         /// </summary>
-        [ViewVariables] public EntityUid? ControlledEntity { get; private set; }
-
-        [ViewVariables] public NetUserId UserId { get; set; }
-
-        /// <summary>
-        ///     Session of the local client.
-        /// </summary>
         [ViewVariables]
-        public ICommonSession Session => InternalSession;
+        public EntityUid? ControlledEntity => Session.AttachedEntity;
 
-        internal PlayerSession InternalSession { get; set; } = default!;
+        [ViewVariables]
+        public NetUserId UserId => Session.UserId;
 
         /// <summary>
         ///     OOC name of the local player.
         /// </summary>
         [ViewVariables]
-        public string Name { get; set; } = default!;
+        public string Name => Session.Name;
 
         /// <summary>
-        ///     The status of the client's session has changed.
+        ///     Session of the local client.
         /// </summary>
-        public event EventHandler<StatusEventArgs>? StatusChanged;
-
-        /// <summary>
-        ///     Attaches a client to an entity.
-        /// </summary>
-        /// <param name="entity">Entity to attach the client to.</param>
-        public void AttachEntity(EntityUid entity, IEntityManager entMan, IBaseClient client)
-        {
-            if (ControlledEntity == entity)
-                return;
-
-            // Detach and cleanup first
-            DetachEntity();
-
-            if (!entMan.EntityExists(entity))
-            {
-                Logger.Error($"Attempting to attach player to non-existent entity {entity}!");
-                return;
-            }
-
-            ControlledEntity = entity;
-            InternalSession.AttachedEntity = entity;
-
-            if (!entMan.TryGetComponent<EyeComponent?>(entity, out var eye))
-            {
-                eye = entMan.AddComponent<EyeComponent>(entity);
-
-                if (client.RunLevel != ClientRunLevel.SinglePlayerGame)
-                {
-                    Logger.Warning($"Attaching local player to an entity {entMan.ToPrettyString(entity)} without an eye. This eye will not be netsynced and may cause issues.");
-                }
-                eye.NetSyncEnabled = false;
-            }
-
-            EntityAttached?.Invoke(new EntityAttachedEventArgs(entity));
-
-            // notify ECS Systems
-            var eventBus = entMan.EventBus;
-            eventBus.RaiseEvent(EventSource.Local, new PlayerAttachSysMessage(entity));
-            eventBus.RaiseLocalEvent(entity, new PlayerAttachedEvent(entity), true);
-        }
-
-        /// <summary>
-        ///     Detaches the client from an entity.
-        /// </summary>
-        public void DetachEntity()
-        {
-            var entMan = IoCManager.Resolve<IEntityManager>();
-            var previous = ControlledEntity;
-
-            ControlledEntity = null;
-            InternalSession.AttachedEntity = null;
-
-            if (previous != null)
-            {
-                entMan.EventBus.RaiseEvent(EventSource.Local, new PlayerAttachSysMessage(default));
-                entMan.EventBus.RaiseLocalEvent(previous.Value, new PlayerDetachedEvent(previous.Value), true);
-                EntityDetached?.Invoke(new EntityDetachedEventArgs(previous.Value));
-            }
-        }
-
-        /// <summary>
-        ///     Changes the state of the session.
-        /// </summary>
-        public void SwitchState(SessionStatus newStatus)
-        {
-            SwitchState(Session.Status, newStatus);
-        }
-
-        /// <summary>
-        ///     Changes the state of the session. This overload allows you to spoof the oldStatus, use with caution.
-        /// </summary>
-        public void SwitchState(SessionStatus oldStatus, SessionStatus newStatus)
-        {
-            var args = new StatusEventArgs(oldStatus, newStatus);
-            Session.Status = newStatus;
-            StatusChanged?.Invoke(this, args);
-        }
-    }
-
-    /// <summary>
-    ///     Event arguments for when the status of a session changes.
-    /// </summary>
-    public sealed class StatusEventArgs : EventArgs
-    {
-        /// <summary>
-        ///     Status that the session switched from.
-        /// </summary>
-        public SessionStatus OldStatus { get; }
-
-        /// <summary>
-        ///     Status that the session switched to.
-        /// </summary>
-        public SessionStatus NewStatus { get; }
-
-        /// <summary>
-        ///     Constructs a new instance of the class.
-        /// </summary>
-        public StatusEventArgs(SessionStatus oldStatus, SessionStatus newStatus)
-        {
-            OldStatus = oldStatus;
-            NewStatus = newStatus;
-        }
-    }
-
-    public sealed class EntityDetachedEventArgs : EventArgs
-    {
-        public EntityDetachedEventArgs(EntityUid oldEntity)
-        {
-            OldEntity = oldEntity;
-        }
-
-        public EntityUid OldEntity { get; }
-    }
-
-    public sealed class EntityAttachedEventArgs : EventArgs
-    {
-        public EntityAttachedEventArgs(EntityUid newEntity)
-        {
-            NewEntity = newEntity;
-        }
-
-        public EntityUid NewEntity { get; }
+        public  ICommonSession Session;
     }
 }

Robust.Client/Player/PlayerManager.cs

@@ -2,16 +2,13 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
-using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.IoC;
-using Robust.Shared.Log;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Utility;
-using Robust.Shared.ViewVariables;
 
 namespace Robust.Client.Player
 {
@@ -20,154 +17,212 @@ namespace Robust.Client.Player
     ///     Why not just attach the inputs directly? It's messy! This makes the whole thing nicely encapsulated.
     ///     This class also communicates with the server to let the server control what entity it is attached to.
     /// </summary>
-    public sealed class PlayerManager : IPlayerManager
+    internal sealed class PlayerManager : SharedPlayerManager, IPlayerManager
     {
         [Dependency] private readonly IClientNetManager _network = default!;
         [Dependency] private readonly IBaseClient _client = default!;
-        [Dependency] private readonly IEntityManager _entManager = default!;
-        [Dependency] private readonly ILogManager _logMan = default!;
 
         /// <summary>
-        ///     Active sessions of connected clients to the server.
+        /// Received player states that had an unknown <see cref="NetEntity"/>.
         /// </summary>
-        private readonly Dictionary<NetUserId, ICommonSession> _sessions = new();
+        private Dictionary<NetUserId, SessionState> _pendingStates = new ();
+        private List<SessionState> _pending = new();
 
         /// <inheritdoc />
-        public IEnumerable<ICommonSession> NetworkedSessions
+        public override ICommonSession[] NetworkedSessions
         {
             get
             {
-                if (LocalPlayer is not null)
-                    return new[] {LocalPlayer.Session};
-
-                return Enumerable.Empty<ICommonSession>();
+                return LocalSession != null
+                    ? new [] { LocalSession }
+                    : Array.Empty<ICommonSession>();
             }
         }
 
         /// <inheritdoc />
-        IEnumerable<ICommonSession> ISharedPlayerManager.Sessions => _sessions.Values;
+        public override int MaxPlayers => _client.GameInfo?.ServerMaxPlayers ?? -1;
+
+        public LocalPlayer? LocalPlayer { get; private set; }
+
+        public event Action<SessionStatusEventArgs>? LocalStatusChanged;
+        public event Action? PlayerListUpdated;
+        public event Action<EntityUid>? LocalPlayerDetached;
+        public event Action<EntityUid>? LocalPlayerAttached;
+        public event Action<(ICommonSession? Old, ICommonSession? New)>? LocalSessionChanged;
 
         /// <inheritdoc />
-        public int PlayerCount => _sessions.Values.Count;
-
-        /// <inheritdoc />
-        public int MaxPlayers => _client.GameInfo?.ServerMaxPlayers ?? 0;
-
-        public ICommonSession? LocalSession => LocalPlayer?.Session;
-
-        /// <inheritdoc />
-        [ViewVariables]
-        public LocalPlayer? LocalPlayer
+        public override void Initialize(int maxPlayers)
         {
-            get => _localPlayer;
-            private set
-            {
-                if (_localPlayer == value) return;
-                var oldValue = _localPlayer;
-                _localPlayer = value;
-                LocalPlayerChanged?.Invoke(new LocalPlayerChangedEventArgs(oldValue, _localPlayer));
-            }
-        }
-        private LocalPlayer? _localPlayer;
-        private ISawmill _sawmill = default!;
-
-        public event Action<LocalPlayerChangedEventArgs>? LocalPlayerChanged;
-
-        /// <inheritdoc />
-        [ViewVariables]
-        IEnumerable<ICommonSession> IPlayerManager.Sessions => _sessions.Values;
-
-        /// <inheritdoc />
-        public IReadOnlyDictionary<NetUserId, ICommonSession> SessionsDict => _sessions;
-
-        /// <inheritdoc />
-        public event EventHandler? PlayerListUpdated;
-
-        /// <inheritdoc />
-        public void Initialize()
-        {
-            _client.RunLevelChanged += OnRunLevelChanged;
-
-            _sawmill = _logMan.GetSawmill("player");
+            base.Initialize(maxPlayers);
             _network.RegisterNetMessage<MsgPlayerListReq>();
             _network.RegisterNetMessage<MsgPlayerList>(HandlePlayerList);
+            PlayerStatusChanged += StatusChanged;
+        }
+
+        private void StatusChanged(object? sender, SessionStatusEventArgs e)
+        {
+            if (e.Session == LocalPlayer?.Session)
+                LocalStatusChanged?.Invoke(e);
+        }
+
+        public void SetupSinglePlayer(string name)
+        {
+            if (LocalSession != null)
+                throw new InvalidOperationException($"Player manager already running?");
+
+            var session = CreateAndAddSession(default, name);
+            session.ClientSide = true;
+            SetLocalSession(session);
+            Startup();
+            PlayerListUpdated?.Invoke();
+        }
+
+        public void SetupMultiplayer(INetChannel channel)
+        {
+            if (LocalSession != null)
+                throw new InvalidOperationException($"Player manager already running?");
+
+            SetLocalSession(CreateAndAddSession(channel));
+            Startup();
+            _network.ClientSendMessage(new MsgPlayerListReq());
+        }
+
+        public void SetLocalSession(ICommonSession? session)
+        {
+            if (session == LocalSession)
+                return;
+
+            var old = LocalSession;
+
+            if (old?.AttachedEntity is {} oldUid)
+            {
+                LocalSession = null;
+                LocalPlayer = null;
+                Sawmill.Info($"Detaching local player from {EntManager.ToPrettyString(oldUid)}.");
+                EntManager.EventBus.RaiseLocalEvent(oldUid, new LocalPlayerDetachedEvent(oldUid), true);
+                LocalPlayerDetached?.Invoke(oldUid);
+            }
+
+            LocalSession = session;
+            LocalPlayer = session == null ? null : new LocalPlayer(session);
+            Sawmill.Info($"Changing local session from {old?.ToString() ?? "null"} to {session?.ToString() ?? "null"}.");
+            LocalSessionChanged?.Invoke((old, LocalSession));
+
+            if (session?.AttachedEntity is {} newUid)
+            {
+                Sawmill.Info($"Attaching local player to {EntManager.ToPrettyString(newUid)}.");
+                EntManager.EventBus.RaiseLocalEvent(newUid, new LocalPlayerAttachedEvent(newUid), true);
+                LocalPlayerAttached?.Invoke(newUid);
+            }
         }
 
         /// <inheritdoc />
-        public void Startup()
+        public override void Shutdown()
         {
-            DebugTools.Assert(LocalPlayer == null);
-            LocalPlayer = new LocalPlayer();
-
-            var msgList = new MsgPlayerListReq();
-            // message is empty
-            _network.ClientSendMessage(msgList);
-        }
-
-        /// <inheritdoc />
-        public void Shutdown()
-        {
-            LocalPlayer?.DetachEntity();
+            SetAttachedEntity(LocalSession, null, out _);
             LocalPlayer = null;
-            _sessions.Clear();
+            LocalSession = null;
+            _pendingStates.Clear();
+            base.Shutdown();
+            PlayerListUpdated?.Invoke();
         }
 
-        /// <inheritdoc />
-        public void ApplyPlayerStates(IReadOnlyCollection<PlayerState> list)
+        public override bool SetAttachedEntity(ICommonSession? session, EntityUid? uid, out ICommonSession? kicked, bool force = false)
+        {
+            kicked = null;
+            if (session == null)
+                return false;
+
+            if (session.AttachedEntity == uid)
+                return true;
+
+            var old = session.AttachedEntity;
+            if (!base.SetAttachedEntity(session, uid, out kicked, force))
+                return false;
+
+            if (session != LocalSession)
+                return true;
+
+            if (old.HasValue)
+            {
+                Sawmill.Info($"Detaching local player from {EntManager.ToPrettyString(old)}.");
+                EntManager.EventBus.RaiseLocalEvent(old.Value, new LocalPlayerDetachedEvent(old.Value), true);
+                LocalPlayerDetached?.Invoke(old.Value);
+            }
+
+            if (uid == null)
+            {
+                Sawmill.Info($"Local player is no longer attached to any entity.");
+                return true;
+            }
+
+            if (!EntManager.EntityExists(uid))
+            {
+                Sawmill.Error($"Attempted to attach player to non-existent entity {uid}!");
+                return true;
+            }
+
+            if (!EntManager.EnsureComponent(uid.Value, out EyeComponent eye))
+            {
+                if (_client.RunLevel != ClientRunLevel.SinglePlayerGame)
+                    Sawmill.Warning($"Attaching local player to an entity {EntManager.ToPrettyString(uid)} without an eye. This eye will not be netsynced and may cause issues.");
+                eye.NetSyncEnabled = false;
+            }
+
+            Sawmill.Info($"Attaching local player to {EntManager.ToPrettyString(uid)}.");
+            EntManager.EventBus.RaiseLocalEvent(uid.Value, new LocalPlayerAttachedEvent(uid.Value), true);
+            LocalPlayerAttached?.Invoke(uid.Value);
+            return true;
+        }
+
+        public void ApplyPlayerStates(IReadOnlyCollection<SessionState> list)
+        {
+            var dirty = ApplyStates(list, true);
+
+            if (_pendingStates.Count == 0)
+            {
+                // This is somewhat inefficient as it might try to re-apply states that failed just a moment ago.
+                _pending.Clear();
+                _pending.AddRange(_pendingStates.Values);
+                _pendingStates.Clear();
+                dirty |= ApplyStates(_pending, false);
+            }
+
+            if (dirty)
+                PlayerListUpdated?.Invoke();
+        }
+
+        private bool ApplyStates(IReadOnlyCollection<SessionState> list, bool fullList)
         {
             if (list.Count == 0)
-            {
-                // This happens when the server says "nothing changed!"
-                return;
-            }
+                return false;
+
             DebugTools.Assert(_network.IsConnected ||  _client.RunLevel == ClientRunLevel.SinglePlayerGame // replays use state application.
                 , "Received player state without being connected?");
-            DebugTools.Assert(LocalPlayer != null, "Call Startup()");
-            DebugTools.Assert(LocalPlayer!.Session != null, "Received player state before Session finished setup.");
+            DebugTools.Assert(LocalSession != null, "Received player state before Session finished setup.");
 
-            var myState = list.FirstOrDefault(s => s.UserId == LocalPlayer.UserId);
+            var state = list.FirstOrDefault(s => s.UserId == LocalSession.UserId);
 
-            if (myState != null)
+            bool dirty = false;
+            if (state != null)
             {
-                var uid = _entManager.GetEntity(myState.ControlledEntity);
-                if (myState.ControlledEntity is {Valid: true} && !_entManager.EntityExists(uid))
+                dirty = true;
+                if (!EntManager.TryGetEntity(state.ControlledEntity, out var uid)
+                    && state.ControlledEntity is { Valid:true } )
                 {
-                    _sawmill.Error($"Received player state for local player with an unknown net entity!");
+                    Sawmill.Error($"Received player state for local player with an unknown net entity!");
+                    _pendingStates[state.UserId] = state;
+                }
+                else
+                {
+                    _pendingStates.Remove(state.UserId);
                 }
 
-                UpdateAttachedEntity(uid);
-                UpdateSessionStatus(myState.Status);
+                SetAttachedEntity(LocalSession, uid, out _, true);
+                SetStatus(LocalSession, state.Status);
             }
 
-            UpdatePlayerList(list);
-        }
-
-        /// <summary>
-        ///     Compares the server sessionStatus to the client one, and updates if needed.
-        /// </summary>
-        private void UpdateSessionStatus(SessionStatus myStateStatus)
-        {
-            if (LocalPlayer!.Session.Status != myStateStatus)
-                LocalPlayer.SwitchState(myStateStatus);
-        }
-
-        /// <summary>
-        ///     Compares the server attachedEntity to the client one, and updates if needed.
-        /// </summary>
-        /// <param name="entity">AttachedEntity in the server session.</param>
-        private void UpdateAttachedEntity(EntityUid? entity)
-        {
-            if (LocalPlayer!.ControlledEntity == entity)
-            {
-                return;
-            }
-            if (entity == null)
-            {
-                LocalPlayer.DetachEntity();
-                return;
-            }
-
-            LocalPlayer.AttachEntity(entity.Value, _entManager, _client);
+            return UpdatePlayerList(list, fullList) || dirty;
         }
 
         /// <summary>
@@ -175,117 +230,88 @@ namespace Robust.Client.Player
         /// </summary>
         private void HandlePlayerList(MsgPlayerList msg)
         {
-            UpdatePlayerList(msg.Plyrs);
+            ApplyPlayerStates(msg.Plyrs);
         }
 
         /// <summary>
         ///     Compares the server player list to the client one, and updates if needed.
         /// </summary>
-        private void UpdatePlayerList(IEnumerable<PlayerState> remotePlayers)
+        private bool UpdatePlayerList(IEnumerable<SessionState> remotePlayers, bool fullList)
         {
             var dirty = false;
-
-            var hitSet = new List<NetUserId>();
-
+            var users = new List<NetUserId>();
             foreach (var state in remotePlayers)
             {
-                hitSet.Add(state.UserId);
+                users.Add(state.UserId);
 
-                if (_sessions.TryGetValue(state.UserId, out var session))
+                if (!EntManager.TryGetEntity(state.ControlledEntity, out var controlled)
+                    && state.ControlledEntity is {Valid: true})
                 {
-                    var local = (PlayerSession) session;
-                    var controlled = _entManager.GetEntity(state.ControlledEntity);
-
-                    // Exists, update data.
-                    if (local.Name == state.Name
-                        && local.Status == state.Status
-                        && local.Ping == state.Ping
-                        && local.AttachedEntity == controlled)
-                    {
-                        continue;
-                    }
-
-                    dirty = true;
-                    local.Name = state.Name;
-                    local.Status = state.Status;
-                    local.Ping = state.Ping;
-                    local.AttachedEntity = controlled;
+                    _pendingStates[state.UserId] = state;
                 }
                 else
                 {
-                    // New, give him a slot.
-                    dirty = true;
-
-                    var newSession = new PlayerSession(state.UserId)
-                    {
-                        Name = state.Name,
-                        Status = state.Status,
-                        Ping = state.Ping,
-                        AttachedEntity = _entManager.GetEntity(state.ControlledEntity),
-                    };
-                    _sessions.Add(state.UserId, newSession);
-                    if (state.UserId == LocalPlayer!.UserId)
-                    {
-                        LocalPlayer.InternalSession = newSession;
-                        newSession.ConnectedClient = _network.ServerChannel!;
-                        // We just connected to the server, hurray!
-                        LocalPlayer.SwitchState(SessionStatus.Connecting, newSession.Status);
-                    }
+                    _pendingStates.Remove(state.UserId);
                 }
-            }
 
-            foreach (var existing in _sessions.Keys.ToArray())
-            {
-                // clear slot, player left
-                if (!hitSet.Contains(existing))
+                if (!InternalSessions.TryGetValue(state.UserId, out var session))
                 {
-                    DebugTools.Assert(LocalPlayer!.UserId != existing || _client.RunLevel == ClientRunLevel.SinglePlayerGame, // replays apply player states.
-                        "I'm still connected to the server, but i left?");
-                    _sessions.Remove(existing);
+                    // This is a new userid, so we create a new session.
+                    DebugTools.Assert(state.UserId != LocalPlayer?.UserId);
+                    var newSession = (CommonSession) CreateAndAddSession(state.UserId, state.Name);
+                    newSession.Ping = state.Ping;
+                    SetStatus(newSession, state.Status);
+                    SetAttachedEntity(newSession, controlled, out _, true);
+                    dirty = true;
+                    continue;
+                }
+
+                // Check if the data is actually different
+                if (session.Name == state.Name
+                    && session.Status == state.Status
+                    && session.Ping == state.Ping
+                    && session.AttachedEntity == controlled)
+                {
+                    continue;
+                }
+
+                dirty = true;
+                var local = (CommonSession) session;
+                local.Name = state.Name;
+                local.Ping = state.Ping;
+                SetStatus(local, state.Status);
+                SetAttachedEntity(local, controlled, out _, true);
+            }
+
+            // Remove old users. This only works if the provided state is a list of all players
+            if (fullList)
+            {
+                foreach (var oldUser in InternalSessions.Keys.ToArray())
+                {
+                    if (users.Contains(oldUser))
+                        continue;
+
+                    if (InternalSessions[oldUser].ClientSide)
+                        continue;
+
+                    DebugTools.Assert(oldUser != LocalUser
+                                      || LocalUser == null
+                                      || LocalUser == default(NetUserId),
+                        "Client is still connected to the server but not in the list of players?");
+                    RemoveSession(oldUser);
+                    _pendingStates.Remove(oldUser);
                     dirty = true;
                 }
             }
 
-            if (dirty)
-            {
-                PlayerListUpdated?.Invoke(this, EventArgs.Empty);
-            }
+            return dirty;
         }
 
-        private void OnRunLevelChanged(object? sender, RunLevelChangedEventArgs e)
+        public override bool TryGetSessionByEntity(EntityUid uid, [NotNullWhen(true)] out ICommonSession? session)
         {
-            if (e.NewLevel != ClientRunLevel.SinglePlayerGame)
-                return;
-
-            DebugTools.AssertNotNull(LocalPlayer);
-
-            // We do some further setup steps for singleplayer here...
-
-            // The local player's GUID in singleplayer will always be the default.
-            var guid = default(NetUserId);
-
-            var session = new PlayerSession(guid)
+            if (LocalEntity == uid)
             {
-                Name = LocalPlayer!.Name,
-                Ping = 0,
-            };
-
-            LocalPlayer.UserId = guid;
-            LocalPlayer.InternalSession = session;
-
-            // Add the local session to the list.
-            _sessions.Add(guid, session);
-
-            LocalPlayer.SwitchState(SessionStatus.InGame);
-
-            PlayerListUpdated?.Invoke(this, EventArgs.Empty);
-        }
-
-        public bool TryGetSessionByEntity(EntityUid uid, [NotNullWhen(true)] out ICommonSession? session)
-        {
-            if (LocalPlayer?.ControlledEntity == uid)
-            {
-                session = LocalPlayer.Session;
+                session = LocalSession!;
                 return true;
             }
 

Robust.Client/Player/PlayerSession.cs

@@ -1,60 +0,0 @@
-using Robust.Shared.Enums;
-using Robust.Shared.GameObjects;
-using Robust.Shared.Network;
-using Robust.Shared.Players;
-using Robust.Shared.ViewVariables;
-
-namespace Robust.Client.Player
-{
-    internal sealed class PlayerSession : ICommonSession
-    {
-        internal SessionStatus Status { get; set; } = SessionStatus.Connecting;
-
-        /// <inheritdoc />
-        SessionStatus ICommonSession.Status
-        {
-            get => this.Status;
-            set => this.Status = value;
-        }
-
-        /// <inheritdoc />
-        [ViewVariables]
-        public EntityUid? AttachedEntity { get; set; }
-
-        /// <inheritdoc />
-        [ViewVariables]
-        public NetUserId UserId { get; }
-
-        [ViewVariables]
-        internal string Name { get; set; } = "<Unknown>";
-
-        /// <inheritdoc />
-        string ICommonSession.Name
-        {
-            get => this.Name;
-            set => this.Name = value;
-        }
-
-        [ViewVariables]
-        internal short Ping { get; set; }
-
-        /// <inheritdoc />
-        [ViewVariables]
-        public INetChannel ConnectedClient { get; internal set; } = null!;
-
-        /// <inheritdoc />
-        short ICommonSession.Ping
-        {
-            get => this.Ping;
-            set => this.Ping = value;
-        }
-
-        /// <summary>
-        ///     Creates an instance of a PlayerSession.
-        /// </summary>
-        public PlayerSession(NetUserId user)
-        {
-            UserId = user;
-        }
-    }
-}

Robust.Client/Replays/Loading/ReplayLoadManager.Checkpoints.cs

@@ -7,7 +7,6 @@ using Robust.Shared.Network;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 using System.Threading.Tasks;
-using Robust.Client.Upload.Commands;
 using Robust.Shared;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Replays;
@@ -101,7 +100,7 @@ public sealed partial class ReplayLoadManager
 
         await callback(0, states.Count, LoadingState.ProcessingFiles, true);
         var playerSpan = state0.PlayerStates.Value;
-        Dictionary<NetUserId, PlayerState> playerStates = new(playerSpan.Count);
+        Dictionary<NetUserId, SessionState> playerStates = new(playerSpan.Count);
         foreach (var player in playerSpan)
         {
             playerStates.Add(player.UserId, player);
@@ -391,7 +390,7 @@ public sealed partial class ReplayLoadManager
         return new EntityState(newState.NetEntity, combined, newState.EntityLastModified, newState.NetComponents ?? oldNetComps);
     }
 
-    private void UpdatePlayerStates(ReadOnlySpan<PlayerState> span, Dictionary<NetUserId, PlayerState> playerStates)
+    private void UpdatePlayerStates(ReadOnlySpan<SessionState> span, Dictionary<NetUserId, SessionState> playerStates)
     {
         foreach (var player in span)
         {

Robust.Client/Replays/Playback/IReplayPlaybackManager.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using Robust.Shared.GameObjects;
+using Robust.Shared.GameStates;
 using Robust.Shared.Network;
 using Robust.Shared.Replays;
 using Robust.Shared.Serialization.Markdown.Mapping;
@@ -128,6 +129,11 @@ public interface IReplayPlaybackManager
     /// </summary>
     event Action? ReplayUnpaused;
 
+    /// <summary>
+    /// Invoked just before a replay applies a game state.
+    /// </summary>
+    event Action<(GameState Current, GameState? Next)>? BeforeApplyState;
+
     /// <summary>
     /// If currently replaying a client-side recording, this is the user that recorded the replay.
     /// Useful for setting default observer spawn positions.
@@ -137,5 +143,5 @@ public interface IReplayPlaybackManager
     /// <summary>
     /// Fetches the entity that the <see cref="Recorder"/> is currently attached to.
     /// </summary>
-    public bool TryGetRecorderEntity([NotNullWhen(true)] out EntityUid? uid);
+    bool TryGetRecorderEntity([NotNullWhen(true)] out EntityUid? uid);
 }

Robust.Client/Replays/Playback/ReplayPlaybackManager.Checkpoint.cs

@@ -66,6 +66,7 @@ internal sealed partial class ReplayPlaybackManager
         _gameState.ClearDetachQueue();
         EnsureDetachedExist(checkpoint);
         _gameState.DetachImmediate(checkpoint.Detached);
+        BeforeApplyState?.Invoke((checkpoint.State, next));
         _gameState.ApplyGameState(checkpoint.State, next);
     }
 

Robust.Client/Replays/Playback/ReplayPlaybackManager.Time.cs

@@ -1,4 +1,5 @@
 using System;
+using Robust.Client.GameObjects;
 using Robust.Client.GameStates;
 using Robust.Shared.Utility;
 
@@ -58,7 +59,13 @@ internal sealed partial class ReplayPlaybackManager
 
             _timing.LastRealTick = _timing.LastProcessedTick = _timing.CurTick = Replay.CurTick;
             _gameState.UpdateFullRep(state, cloneDelta: true);
-            _gameState.ApplyGameState(state, Replay.NextState);
+
+            // Clear existing lerps
+            _entMan.EntitySysManager.GetEntitySystem<TransformSystem>().Reset();
+
+            var next = Replay.NextState;
+            BeforeApplyState?.Invoke((state, next));
+            _gameState.ApplyGameState(state, next);
             ProcessMessages(Replay.CurMessages, skipEffectEvents);
 
             // TODO REPLAYS block audio

Robust.Client/Replays/Playback/ReplayPlaybackManager.Update.cs

@@ -42,7 +42,9 @@ internal sealed partial class ReplayPlaybackManager
         {
             var state = Replay.CurState;
             _gameState.UpdateFullRep(state, cloneDelta: true);
-            _gameState.ApplyGameState(state, Replay.NextState);
+            var next = Replay.NextState;
+            BeforeApplyState?.Invoke((state, next));
+            _gameState.ApplyGameState(state, next);
             DebugTools.Assert(Replay.LastApplied >= state.FromSequence);
             DebugTools.Assert(Replay.LastApplied + 1 <= state.ToSequence);
             Replay.LastApplied = state.ToSequence;

Robust.Client/Replays/Playback/ReplayPlaybackManager.cs

@@ -12,6 +12,7 @@ using Robust.Client.Upload;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.GameObjects;
+using Robust.Shared.GameStates;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Network;
@@ -44,6 +45,7 @@ internal sealed partial class ReplayPlaybackManager : IReplayPlaybackManager
     public event Action? ReplayPlaybackStopped;
     public event Action? ReplayPaused;
     public event Action? ReplayUnpaused;
+    public event Action<(GameState Current, GameState? Next)>? BeforeApplyState;
 
     public ReplayData? Replay { get; private set; }
     public NetUserId? Recorder => Replay?.Recorder;

Robust.Client/Replays/ReplayRecordingManager.cs

@@ -9,7 +9,7 @@ using Robust.Shared.ContentPack;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.IoC;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Replays;
 using Robust.Shared.Serialization.Markdown.Mapping;
 using Robust.Shared.Serialization.Markdown.Value;
@@ -138,9 +138,9 @@ internal sealed class ReplayRecordingManager : SharedReplayRecordingManager
         return (state, detachMsg);
     }
 
-    private PlayerState GetPlayerState(ICommonSession session)
+    private SessionState GetPlayerState(ICommonSession session)
     {
-        return new PlayerState
+        return new SessionState
         {
             UserId = session.UserId,
             Status = session.Status,

Robust.Client/Robust.Client.csproj

@@ -27,9 +27,9 @@
     <PackageReference Include="SpaceWizards.Sodium" Version="0.2.1" PrivateAssets="compile" />
   </ItemGroup>
   <ItemGroup Condition="'$(EnableClientScripting)' == 'True'">
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Features" Version="4.0.1" PrivateAssets="compile" />
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Scripting" Version="4.0.1" PrivateAssets="compile" />
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.0.1" PrivateAssets="compile" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Features" Version="4.1.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Scripting" Version="4.1.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.1.0" />
 
     <ProjectReference Include="..\Robust.Shared.Scripting\Robust.Shared.Scripting.csproj" />
   </ItemGroup>

Robust.Client/UserInterface/Controls/RichTextLabel.cs

@@ -20,6 +20,7 @@ namespace Robust.Client.UserInterface.Controls
         public RichTextLabel()
         {
             IoCManager.InjectDependencies(this);
+            VerticalAlignment = VAlignment.Center;
         }
 
         public void SetMessage(FormattedMessage message, Type[]? tagsAllowed = null, Color? defaultColor = null)

Robust.Client/UserInterface/CustomControls/DebugMonitorControls/DebugCoordsPanel.cs

@@ -70,6 +70,7 @@ namespace Robust.Client.UserInterface.CustomControls.DebugMonitorControls
                 return;
 
             var mapSystem = _entityManager.System<SharedMapSystem>();
+            var xformSystem = _entityManager.System<SharedTransformSystem>();
 
             if (_mapManager.TryFindGridAt(mouseWorldMap, out var mouseGridUid, out var mouseGrid))
             {
@@ -80,7 +81,7 @@ namespace Robust.Client.UserInterface.CustomControls.DebugMonitorControls
             {
                 mouseGridPos = new EntityCoordinates(_mapManager.GetMapEntityId(mouseWorldMap.MapId),
                     mouseWorldMap.Position);
-                tile = new TileRef(EntityUid.Invalid, mouseGridPos.ToVector2i(_entityManager, _mapManager), Tile.Empty);
+                tile = new TileRef(EntityUid.Invalid, mouseGridPos.ToVector2i(_entityManager, _mapManager, xformSystem), Tile.Empty);
             }
 
             var controlHovered = UserInterfaceManager.CurrentlyHovered;
@@ -90,35 +91,35 @@ Screen Size: {screenSize} (scale: {screenScale})
 Mouse Pos:
     Screen: {mouseScreenPos}
     {mouseWorldMap}
-    {mouseGridPos}
+    {_entityManager.GetNetCoordinates(mouseGridPos)}
     {tile}
     GUI: {controlHovered}");
 
-            _textBuilder.AppendLine("\nAttached Entity:");
-            var controlledEntity = _playerManager?.LocalPlayer?.ControlledEntity ?? EntityUid.Invalid;
+            _textBuilder.AppendLine("\nAttached NetEntity:");
+            var controlledEntity = _playerManager.LocalSession?.AttachedEntity ?? EntityUid.Invalid;
+
             if (controlledEntity == EntityUid.Invalid)
             {
-                _textBuilder.AppendLine("No attached entity.");
+                _textBuilder.AppendLine("No attached netentity.");
             }
             else
             {
                 var entityTransform = _entityManager.GetComponent<TransformComponent>(controlledEntity);
-                var playerWorldOffset = entityTransform.MapPosition;
+                var playerWorldOffset = xformSystem.GetMapCoordinates(entityTransform);
                 var playerScreen = _eyeManager.WorldToScreen(playerWorldOffset.Position);
 
                 var playerCoordinates = entityTransform.Coordinates;
-                var playerRotation = entityTransform.WorldRotation;
+                var playerRotation = xformSystem.GetWorldRotation(entityTransform);
                 var gridRotation = entityTransform.GridUid != null
-                    ? _entityManager.GetComponent<TransformComponent>(entityTransform.GridUid.Value)
-                    .WorldRotation
+                    ? xformSystem.GetWorldRotation(entityTransform.GridUid.Value)
                     : Angle.Zero;
 
                 _textBuilder.Append($@"    Screen: {playerScreen}
     {playerWorldOffset}
-    {playerCoordinates}
+    {_entityManager.GetNetCoordinates(playerCoordinates)}
     Rotation: {playerRotation.Degrees:F2}°
-    EntId: {controlledEntity}
-    GridUid: {entityTransform.GridUid}
+    NEntId: {_entityManager.GetNetEntity(controlledEntity)}
+    Grid NEntId: {_entityManager.GetNetEntity(entityTransform.GridUid)}
     Grid Rotation: {gridRotation.Degrees:F2}°");
             }
 

Robust.Client/ViewVariables/ClientViewVariablesManager.cs

@@ -15,7 +15,7 @@ using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;

Robust.Client/ViewVariables/Editors/VVPropEditorEntityCoordinates.cs

@@ -62,7 +62,7 @@ namespace Robust.Client.ViewVariables.Editors
 
             void OnEntered(LineEdit.LineEditEventArgs e)
             {
-                var gridVal = EntityUid.Parse(gridId.Text);
+                var gridVal = EntityUid.Parse(gridId.Text, "-1");
                 var mapManager = IoCManager.Resolve<IMapManager>();
                 var xVal = float.Parse(x.Text, CultureInfo.InvariantCulture);
                 var yVal = float.Parse(y.Text, CultureInfo.InvariantCulture);

Robust.Client/ViewVariables/Editors/VVPropEditorEntityUid.cs

@@ -28,7 +28,7 @@ namespace Robust.Client.ViewVariables.Editors
             if (!ReadOnly)
             {
                 lineEdit.OnTextEntered += e =>
-                    ValueChanged(EntityUid.Parse(e.Text));
+                    ValueChanged(EntityUid.Parse(e.Text, ", -1"));
             }
 
             var vvButton = new Button()

Robust.Packaging/AssetProcessing/Passes/AssetPassPackRsis.cs

@@ -61,7 +61,7 @@ internal sealed class AssetPassPackRsis : AssetPass
         foreach (var (key, dat) in _foundRsis)
         {
             if (dat.MetaJson == null)
-                return;
+                continue;
 
             RunJob(() =>
             {

Robust.Packaging/RobustClientAssetGraph.cs

@@ -21,11 +21,11 @@ public sealed class RobustClientAssetGraph
     /// </summary>
     public IReadOnlyCollection<AssetPass> AllPasses { get; }
 
-    public RobustClientAssetGraph()
+    public RobustClientAssetGraph(bool parallel = true)
     {
         // The code injecting the list of source files is assumed to be pretty single-threaded.
         // We use a parallelizing input to break out all the work on files coming in onto multiple threads.
-        Input = new AssetPassPipe { Name = "RobustClientAssetGraphInput", Parallelize = true };
+        Input = new AssetPassPipe { Name = "RobustClientAssetGraphInput", Parallelize = parallel };
         PresetPasses = new AssetPassPipe { Name = "RobustClientAssetGraphPresetPasses" };
         Output = new AssetPassPipe { Name = "RobustClientAssetGraphOutput", CheckDuplicates = true };
         NormalizeText = new AssetPassNormalizeText { Name = "RobustClientAssetGraphNormalizeText" };

Robust.Packaging/RobustClientPackaging.cs

@@ -4,9 +4,10 @@ namespace Robust.Packaging;
 
 public sealed class RobustClientPackaging
 {
-    public static IReadOnlySet<string> ClientIgnoresResources { get; } = new HashSet<string>
+    public static IReadOnlySet<string> ClientIgnoredResources { get; } = new HashSet<string>
     {
         "Maps",
+        "ConfigPresets",
         // Leaving this here for future archaeologists to ponder at.
         "emotes.xml",
         "Groups",
@@ -18,48 +19,8 @@ public sealed class RobustClientPackaging
         AssetPass pass,
         CancellationToken cancel = default)
     {
-        var ignoreSet = ClientIgnoresResources.Union(RobustSharedPackaging.SharedIgnoredResources).ToHashSet();
+        var ignoreSet = ClientIgnoredResources.Union(RobustSharedPackaging.SharedIgnoredResources).ToHashSet();
 
-        await RobustSharedPackaging.DoResourceCopy(Path.Combine(contentDir, "Resources"), pass, ignoreSet, cancel);
-    }
-
-    public static async Task WriteContentAssemblies(
-        AssetPass pass,
-        string contentDir,
-        string binDir,
-        IEnumerable<string> contentAssemblies,
-        CancellationToken cancel = default)
-    {
-        await WriteContentAssemblies("Assemblies", pass, contentDir, binDir, contentAssemblies, cancel);
-    }
-
-    public static Task WriteContentAssemblies(
-        string target,
-        AssetPass pass,
-        string contentDir,
-        string binDir,
-        IEnumerable<string> contentAssemblies,
-        CancellationToken cancel = default)
-    {
-        var files = new List<string>();
-
-        var sourceDir = Path.Combine(contentDir, "bin", binDir);
-
-        foreach (var asm in contentAssemblies)
-        {
-            files.Add($"{asm}.dll");
-
-            var pdbPath = $"{asm}.pdb";
-            if (File.Exists(Path.Combine(sourceDir, pdbPath)))
-                files.Add(pdbPath);
-        }
-
-        foreach (var f in files)
-        {
-            cancel.ThrowIfCancellationRequested();
-            pass.InjectFileFromDisk($"{target}/{f}", Path.Combine(sourceDir, f));
-        }
-
-        return Task.CompletedTask;
+        await RobustSharedPackaging.DoResourceCopy(Path.Combine(contentDir, "Resources"), pass, ignoreSet, cancel: cancel);
     }
 }

Robust.Packaging/RobustServerPackaging.cs

@@ -0,0 +1,33 @@
+using Robust.Packaging.AssetProcessing;
+
+namespace Robust.Packaging;
+
+public sealed class RobustServerPackaging
+{
+    public static IReadOnlySet<string> ServerIgnoresResources { get; } = new HashSet<string>
+    {
+        "Audio",
+        "Textures",
+        "Fonts",
+        "Shaders",
+    };
+
+    public static async Task WriteServerResources(
+        string contentDir,
+        AssetPass pass,
+        CancellationToken cancel = default)
+    {
+        var ignoreSet = ServerIgnoresResources.Union(RobustSharedPackaging.SharedIgnoredResources).ToHashSet();
+
+        await RobustSharedPackaging.DoResourceCopy(Path.Combine(contentDir, "Resources"),
+            pass,
+            ignoreSet,
+            "Resources",
+            cancel);
+        await RobustSharedPackaging.DoResourceCopy(Path.Combine("RobustToolbox", "Resources"),
+            pass,
+            ignoreSet,
+            "Resources",
+            cancel);
+    }
+}

Robust.Packaging/RobustSharedPackaging.cs

@@ -15,10 +15,53 @@ public sealed class RobustSharedPackaging
         ".DS_Store"
     };
 
+    // IDK what these are supposed to correspond to but targetDir is the target directory.
+    public static async Task WriteContentAssemblies(
+        AssetPass pass,
+        string contentDir,
+        string binDir,
+        IEnumerable<string> contentAssemblies,
+        string targetDir = "Assemblies",
+        CancellationToken cancel = default)
+    {
+        await WriteContentAssemblies(targetDir, pass, contentDir, binDir, contentAssemblies, cancel);
+    }
+
+    public static Task WriteContentAssemblies(
+        string target,
+        AssetPass pass,
+        string contentDir,
+        string binDir,
+        IEnumerable<string> contentAssemblies,
+        CancellationToken cancel = default)
+    {
+        var files = new List<string>();
+
+        var sourceDir = Path.Combine(contentDir, "bin", binDir);
+
+        foreach (var asm in contentAssemblies)
+        {
+            files.Add($"{asm}.dll");
+
+            var pdbPath = $"{asm}.pdb";
+            if (File.Exists(Path.Combine(sourceDir, pdbPath)))
+                files.Add(pdbPath);
+        }
+
+        foreach (var f in files)
+        {
+            cancel.ThrowIfCancellationRequested();
+            pass.InjectFileFromDisk($"{target}/{f}", Path.Combine(sourceDir, f));
+        }
+
+        return Task.CompletedTask;
+    }
+
     public static Task DoResourceCopy(
         string diskSource,
         AssetPass pass,
         IReadOnlySet<string> ignoreSet,
+        string targetDir = "",
         CancellationToken cancel = default)
     {
         foreach (var path in Directory.EnumerateFileSystemEntries(diskSource))
@@ -29,7 +72,7 @@ public sealed class RobustSharedPackaging
             if (ignoreSet.Contains(filename))
                 continue;
 
-            var targetPath = filename;
+            var targetPath = Path.Combine(targetDir, filename);
             if (Directory.Exists(path))
                 CopyDirIntoZip(path, targetPath, pass);
             else
@@ -44,11 +87,11 @@ public sealed class RobustSharedPackaging
         foreach (var file in Directory.EnumerateFiles(directory, "*.*", SearchOption.AllDirectories))
         {
             var relPath = Path.GetRelativePath(directory, file);
-            if (Path.DirectorySeparatorChar != '/')
-                relPath = relPath.Replace(Path.DirectorySeparatorChar, '/');
-
             var zipPath = $"{basePath}/{relPath}";
 
+            if (Path.DirectorySeparatorChar != '/')
+                zipPath = zipPath.Replace(Path.DirectorySeparatorChar, '/');
+
             // Console.WriteLine($"{directory}/{zipPath} -> /{zipPath}");
             pass.InjectFileFromDisk(zipPath, file);
         }

Robust.Server/BaseServer.cs

@@ -28,6 +28,7 @@ using Robust.Shared.Localization;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
+using Robust.Shared.Player;
 using Robust.Shared.Profiling;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
@@ -659,10 +660,14 @@ namespace Robust.Server
             {
                 // Write down exception log
                 var logPath = _config.GetCVar(CVars.LogPath);
-                var relPath = PathHelpers.ExecutableRelativeFile(logPath);
-                Directory.CreateDirectory(relPath);
-                var pathToWrite = Path.Combine(relPath,
+                if (!Path.IsPathRooted(logPath))
+                {
+                    logPath = PathHelpers.ExecutableRelativeFile(logPath);
+                }
+
+                var pathToWrite = Path.Combine(logPath,
                     "Runtime-" + DateTime.Now.ToString("yyyy-MM-dd-THH-mm-ss") + ".txt");
+                Directory.CreateDirectory(logPath);
                 File.WriteAllText(pathToWrite, _runtimeLog.Display(), EncodingHelpers.UTF8);
             }
 

Robust.Server/Console/Commands/PlayerCommands.cs

@@ -21,7 +21,7 @@ namespace Robust.Server.Console.Commands
 
             var sb = new StringBuilder();
 
-            var players = _players.ServerSessions;
+            var players = _players.Sessions;
             sb.AppendLine($"{"Player Name",20} {"Status",12} {"Playing Time",14} {"Ping",9} {"IP EndPoint",20}");
             sb.AppendLine("-------------------------------------------------------------------------------");
 
@@ -50,8 +50,8 @@ namespace Robust.Server.Console.Commands
         {
             if (args.Length < 1)
             {
-                var player = shell.Player as IPlayerSession;
-                var toKickPlayer = player ?? _players.ServerSessions.FirstOrDefault();
+                var player = shell.Player;
+                var toKickPlayer = player ?? _players.Sessions.FirstOrDefault();
                 if (toKickPlayer == null)
                 {
                     shell.WriteLine("You need to provide a player to kick.");
@@ -79,7 +79,7 @@ namespace Robust.Server.Console.Commands
         {
             if (args.Length == 1)
             {
-                var options = _players.ServerSessions.OrderBy(c => c.Name).Select(c => c.Name).ToArray();
+                var options = _players.Sessions.OrderBy(c => c.Name).Select(c => c.Name).ToArray();
 
                 return CompletionResult.FromHintOptions(options, "<PlayerIndex>");
             }

Robust.Server/Console/Commands/ProfileEntitySpawningCommand.cs

@@ -43,6 +43,7 @@ public sealed class ProfileEntitySpawningCommand : IConsoleCommand
 
         GC.Collect();
 
+        Span<EntityUid> ents = stackalloc EntityUid[amount];
         var stopwatch = new Stopwatch();
         stopwatch.Start();
 
@@ -50,12 +51,17 @@ public sealed class ProfileEntitySpawningCommand : IConsoleCommand
 
         for (var i = 0; i < amount; i++)
         {
-            _entities.SpawnEntity(prototype, MapCoordinates.Nullspace);
+            ents[i] = _entities.SpawnEntity(prototype, MapCoordinates.Nullspace);
         }
 
         MeasureProfiler.SaveData();
 
         shell.WriteLine($"Server: Profiled spawning {amount} entities in {stopwatch.Elapsed.TotalMilliseconds:N3} ms");
+
+        foreach (var ent in ents)
+        {
+            _entities.DeleteEntity(ent);
+        }
     }
 }
 #endif

Robust.Server/Console/Commands/ViewSubscriberCommand.cs

@@ -1,9 +1,8 @@
 using Robust.Server.GameObjects;
-using Robust.Server.Player;
 using Robust.Shared.Console;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 
 namespace Robust.Server.Console.Commands
 {
@@ -17,7 +16,7 @@ namespace Robust.Server.Console.Commands
         {
             var session = shell.Player;
 
-            if (session is not IPlayerSession playerSession)
+            if (session is not { } playerSession)
             {
                 shell.WriteError($"Unable to find {nameof(ICommonSession)} for shell");
                 return;
@@ -54,7 +53,7 @@ namespace Robust.Server.Console.Commands
             {
                 var session = shell.Player;
 
-                if (session is not IPlayerSession playerSession)
+                if (session is not { } playerSession)
                 {
                     shell.WriteError($"Unable to find {nameof(ICommonSession)} for shell");
                     return;

Robust.Server/Console/ConGroupController.cs

@@ -1,6 +1,4 @@
-using Robust.Server.Player;
-using Robust.Shared.Map;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Toolshed;
 using Robust.Shared.Toolshed.Errors;
 
@@ -10,27 +8,27 @@ namespace Robust.Server.Console
     {
         public IConGroupControllerImplementation? Implementation { get; set; }
 
-        public bool CanCommand(IPlayerSession session, string cmdName)
+        public bool CanCommand(ICommonSession session, string cmdName)
         {
             return Implementation?.CanCommand(session, cmdName) ?? false;
         }
 
-        public bool CanAdminPlace(IPlayerSession session)
+        public bool CanAdminPlace(ICommonSession session)
         {
             return Implementation?.CanAdminPlace(session) ?? false;
         }
 
-        public bool CanScript(IPlayerSession session)
+        public bool CanScript(ICommonSession session)
         {
             return Implementation?.CanScript(session) ?? false;
         }
 
-        public bool CanAdminMenu(IPlayerSession session)
+        public bool CanAdminMenu(ICommonSession session)
         {
             return Implementation?.CanAdminMenu(session) ?? false;
         }
 
-        public bool CanAdminReloadPrototypes(IPlayerSession session)
+        public bool CanAdminReloadPrototypes(ICommonSession session)
         {
             return Implementation?.CanAdminReloadPrototypes(session) ?? false;
         }

Robust.Server/Console/IConGroupControllerImplementation.cs

@@ -1,14 +1,14 @@
-using Robust.Server.Player;
+using Robust.Shared.Player;
 using Robust.Shared.Toolshed;
 
 namespace Robust.Server.Console
 {
     public interface IConGroupControllerImplementation : IPermissionController
     {
-        bool CanCommand(IPlayerSession session, string cmdName);
-        bool CanAdminPlace(IPlayerSession session);
-        bool CanScript(IPlayerSession session);
-        bool CanAdminMenu(IPlayerSession session);
-        bool CanAdminReloadPrototypes(IPlayerSession session);
+        bool CanCommand(ICommonSession session, string cmdName);
+        bool CanAdminPlace(ICommonSession session);
+        bool CanScript(ICommonSession session);
+        bool CanAdminMenu(ICommonSession session);
+        bool CanAdminReloadPrototypes(ICommonSession session);
     }
 }

Robust.Server/Console/ServerConsoleHost.cs

@@ -7,7 +7,7 @@ using Robust.Shared.Console;
 using Robust.Shared.IoC;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Toolshed;
 using Robust.Shared.Toolshed.Syntax;
 using Robust.Shared.Utility;
@@ -41,7 +41,7 @@ namespace Robust.Server.Console
 
             var msg = new MsgConCmd();
             msg.Text = command;
-            NetManager.ServerSendMessage(msg, ((IPlayerSession)session).ConnectedClient);
+            NetManager.ServerSendMessage(msg, session.Channel);
         }
 
         /// <inheritdoc />
@@ -49,18 +49,12 @@ namespace Robust.Server.Console
         {
             var msg = new FormattedMessage();
             msg.AddText(text);
-            if (session is IPlayerSession playerSession)
-                OutputText(playerSession, msg, false);
-            else
-                OutputText(null, msg, false);
+            OutputText(session, msg, false);
         }
 
         public override void WriteLine(ICommonSession? session, FormattedMessage msg)
         {
-            if (session is IPlayerSession playerSession)
-                OutputText(playerSession, msg, false);
-            else
-                OutputText(null, msg, false);
+            OutputText(session, msg, false);
         }
 
         /// <inheritdoc />
@@ -68,10 +62,7 @@ namespace Robust.Server.Console
         {
             var msg = new FormattedMessage();
             msg.AddText(text);
-            if (session is IPlayerSession playerSession)
-                OutputText(playerSession, msg, true);
-            else
-                OutputText(null, msg, true);
+            OutputText(session, msg, true);
         }
 
         public bool IsCmdServer(IConsoleCommand cmd) => true;
@@ -155,7 +146,7 @@ namespace Robust.Server.Console
 
         private bool ShellCanExecute(IConsoleShell shell, string cmdName)
         {
-            return shell.Player == null || _groupController.CanCommand((IPlayerSession)shell.Player, cmdName);
+            return shell.Player == null || _groupController.CanCommand(shell.Player, cmdName);
         }
 
         private void HandleRegistrationRequest(INetChannel senderConnection)
@@ -213,7 +204,7 @@ namespace Robust.Server.Console
             ExecuteCommand(session, text);
         }
 
-        private void OutputText(IPlayerSession? session, FormattedMessage text, bool error)
+        private void OutputText(ICommonSession? session, FormattedMessage text, bool error)
         {
             if (session != null)
             {

Robust.Server/GameObjects/Components/Actor/ActorComponent.cs

@@ -1,13 +0,0 @@
-using Robust.Server.Player;
-using Robust.Shared.GameObjects;
-using Robust.Shared.ViewVariables;
-
-namespace Robust.Server.GameObjects
-{
-    [RegisterComponent]
-    public sealed partial class ActorComponent : Component
-    {
-        [ViewVariables]
-        public IPlayerSession PlayerSession { get; internal set; } = default!;
-    }
-}

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

@@ -1,12 +1,12 @@
 using System.Collections.Generic;
-using Robust.Server.Player;
 using Robust.Shared.GameObjects;
+using Robust.Shared.Player;
 
 namespace Robust.Server.GameObjects
 {
     [RegisterComponent]
     internal sealed partial class ViewSubscriberComponent : Component
     {
-        internal readonly HashSet<IPlayerSession> SubscribedSessions = new();
+        internal readonly HashSet<ICommonSession> SubscribedSessions = new();
     }
 }

Robust.Server/GameObjects/EntitySystems/ActorSystem.cs

@@ -1,175 +0,0 @@
-using System.Diagnostics.CodeAnalysis;
-using JetBrains.Annotations;
-using Robust.Server.Player;
-using Robust.Shared.GameObjects;
-using Robust.Shared.IoC;
-using Robust.Shared.Network;
-using Robust.Shared.Utility;
-
-namespace Robust.Server.GameObjects
-{
-    /// <summary>
-    ///     System that handles players being attached/detached from entities.
-    /// </summary>
-    [UsedImplicitly]
-    public sealed class ActorSystem : EntitySystem
-    {
-        [Dependency] private readonly IPlayerManager _playerManager = default!;
-
-        public override void Initialize()
-        {
-            base.Initialize();
-
-            SubscribeLocalEvent<ActorComponent, ComponentShutdown>(OnActorShutdown);
-        }
-
-        /// <summary>
-        ///     Attaches a player session to an entity, optionally kicking any sessions already attached to it.
-        /// </summary>
-        /// <param name="uid">The entity to attach the player to</param>
-        /// <param name="player">The player to attach to the entity</param>
-        /// <param name="force">Whether to kick any existing players from the entity</param>
-        /// <returns>Whether the attach succeeded, or not.</returns>
-        public bool Attach(EntityUid? uid, IPlayerSession player, bool force = false)
-        {
-            return Attach(uid, player, false, out _);
-        }
-
-        /// <summary>
-        ///     Attaches a player session to an entity, optionally kicking any sessions already attached to it.
-        /// </summary>
-        /// <param name="entity">The entity to attach the player to</param>
-        /// <param name="player">The player to attach to the entity</param>
-        /// <param name="force">Whether to kick any existing players from the entity</param>
-        /// <param name="forceKicked">The player that was forcefully kicked, or null.</param>
-        /// <returns>Whether the attach succeeded, or not.</returns>
-        public bool Attach(EntityUid? entity, IPlayerSession player, bool force, out IPlayerSession? forceKicked)
-        {
-            // Null by default.
-            forceKicked = null;
-
-            if (player.AttachedEntity == entity)
-                return true;
-
-            if (entity is not { } uid)
-                return Detach(player);
-
-            // Cannot attach to a deleted, nonexisting or terminating entity.
-            if (!TryComp(uid, out MetaDataComponent? meta) || meta.EntityLifeStage > EntityLifeStage.MapInitialized)
-            {
-                return false;
-            }
-
-            // Check if there was a player attached to the entity already...
-            if (EntityManager.TryGetComponent(uid, out ActorComponent? actor))
-            {
-                // If we're not forcing the attach, this fails.
-                if (!force)
-                    return false;
-
-                // Set the event's force-kicked session before detaching it.
-                forceKicked = actor.PlayerSession;
-                Detach(uid, actor);
-            }
-
-            // Detach from the currently attached entity.
-            if (!Detach(player))
-                return false;
-
-            // We add the actor component.
-            actor = EntityManager.AddComponent<ActorComponent>(uid);
-            EntityManager.EnsureComponent<EyeComponent>(uid);
-            actor.PlayerSession = player;
-            player.SetAttachedEntity(uid);
-
-            // The player is fully attached now, raise an event!
-            RaiseLocalEvent(uid, new PlayerAttachedEvent(uid, player, forceKicked), true);
-            DebugTools.Assert(player.AttachedEntity == entity);
-            return true;
-        }
-
-        /// <summary>
-        ///     Detaches an attached session from the entity, if any.
-        /// </summary>
-        /// <param name="entity">The entity player sessions will be detached from.</param>
-        /// <returns>Whether any player session was detached.</returns>
-        public bool Detach(EntityUid uid, ActorComponent? actor = null)
-        {
-            if (!Resolve(uid, ref actor, false))
-                return false;
-
-            RemComp(uid, actor);
-            return true;
-        }
-
-        /// <summary>
-        ///     Detaches this player from its attached entity, if any.
-        /// </summary>
-        /// <param name="player">The player session that will be detached from any attached entities.</param>
-        /// <returns>Whether the player is now detached from any entities.
-        /// This returns true if the player wasn't attached to any entity.</returns>
-        public bool Detach(IPlayerSession player)
-        {
-            var uid = player.AttachedEntity;
-            return uid == null || Detach(uid.Value);
-        }
-
-        private void OnActorShutdown(EntityUid entity, ActorComponent component, ComponentShutdown args)
-        {
-            component.PlayerSession.SetAttachedEntity(null);
-
-            // The player is fully detached now that the component has shut down.
-            RaiseLocalEvent(entity, new PlayerDetachedEvent(entity, component.PlayerSession), true);
-        }
-
-        public bool TryGetActorFromUserId(NetUserId? userId, [NotNullWhen(true)] out IPlayerSession? actor, [MaybeNullWhen(true)] out EntityUid? actorEntity)
-        {
-            actor = null;
-            actorEntity = null;
-            if (userId != null)
-            {
-                if (!_playerManager.TryGetSessionById(userId.Value, out actor))
-                    return false;
-                actorEntity = actor.AttachedEntity;
-            }
-
-            return actor != null;
-        }
-    }
-
-    /// <summary>
-    ///     Event for when a player has been attached to an entity.
-    /// </summary>
-    public sealed class PlayerAttachedEvent : EntityEventArgs
-    {
-        public EntityUid Entity { get; }
-        public IPlayerSession Player { get; }
-
-        /// <summary>
-        ///     The player session that was forcefully kicked from the entity, if any.
-        /// </summary>
-        public IPlayerSession? Kicked { get; }
-
-        public PlayerAttachedEvent(EntityUid entity, IPlayerSession player, IPlayerSession? kicked = null)
-        {
-            Entity = entity;
-            Player = player;
-            Kicked = kicked;
-        }
-    }
-
-    /// <summary>
-    ///     Event for when a player has been detached from an entity.
-    /// </summary>
-    public sealed class PlayerDetachedEvent : EntityEventArgs
-    {
-        public EntityUid Entity { get; }
-        public IPlayerSession Player { get; }
-
-        public PlayerDetachedEvent(EntityUid entity, IPlayerSession player)
-        {
-            Entity = entity;
-            Player = player;
-        }
-    }
-}

Robust.Server/GameObjects/EntitySystems/AudioSystem.cs

@@ -6,7 +6,6 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
 using Robust.Shared.Player;
-using Robust.Shared.Players;
 
 namespace Robust.Server.GameObjects;
 [UsedImplicitly]

Robust.Server/GameObjects/EntitySystems/EyeSystem.cs

@@ -1,5 +1,4 @@
 using Robust.Shared.GameObjects;
-using Robust.Shared.GameStates;
 
 namespace Robust.Server.GameObjects;
 

Robust.Server/GameObjects/EntitySystems/InputSystem.cs

@@ -5,6 +5,7 @@ using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Input;
 using Robust.Shared.IoC;
+using Robust.Shared.Player;
 
 namespace Robust.Server.GameObjects
 {
@@ -15,10 +16,10 @@ namespace Robust.Server.GameObjects
     {
         [Dependency] private readonly IPlayerManager _playerManager = default!;
 
-        private readonly Dictionary<IPlayerSession, IPlayerCommandStates> _playerInputs = new();
+        private readonly Dictionary<ICommonSession, IPlayerCommandStates> _playerInputs = new();
 
 
-        private readonly Dictionary<IPlayerSession, uint> _lastProcessedInputCmd = new();
+        private readonly Dictionary<ICommonSession, uint> _lastProcessedInputCmd = new();
 
         /// <inheritdoc />
         public override void Initialize()
@@ -48,7 +49,7 @@ namespace Robust.Server.GameObjects
             if (!Enum.IsDefined(typeof(BoundKeyState), msg.State))
                 return;
 
-            var session = (IPlayerSession) eventArgs.SenderSession;
+            var session = eventArgs.SenderSession;
 
             if (_lastProcessedInputCmd[session] < msg.InputSequence)
                 _lastProcessedInputCmd[session] = msg.InputSequence;
@@ -65,12 +66,12 @@ namespace Robust.Server.GameObjects
             }
         }
 
-        public IPlayerCommandStates GetInputStates(IPlayerSession session)
+        public IPlayerCommandStates GetInputStates(ICommonSession session)
         {
             return _playerInputs[session];
         }
 
-        public uint GetLastInputCommand(IPlayerSession session)
+        public uint GetLastInputCommand(ICommonSession session)
         {
             return _lastProcessedInputCmd[session];
         }

Robust.Server/GameObjects/EntitySystems/MapLoaderSystem.cs

@@ -5,6 +5,9 @@ using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Numerics;
+using Arch.Core;
+using Arch.Core.Utils;
+using Collections.Pooled;
 using Robust.Server.Maps;
 using Robust.Shared.ContentPack;
 using Robust.Shared.GameObjects;
@@ -154,10 +157,11 @@ public sealed class MapLoaderSystem : EntitySystem
             var sw = new Stopwatch();
             sw.Start();
             result = Deserialize(data);
-            _logLoader.Debug($"Loaded map in {sw.Elapsed}");
 
-            var mapEnt = _mapManager.GetMapEntityId(mapId);
+            _logLoader.Info($"Loaded map {resPath} in {sw.Elapsed}");
             var xformQuery = _serverEntityManager.GetEntityQuery<TransformComponent>();
+            var mapEnt = _mapManager.GetMapEntityId(mapId);
+
             var rootEnts = new List<EntityUid>();
             // aeoeoeieioe content
 
@@ -174,6 +178,8 @@ public sealed class MapLoaderSystem : EntitySystem
                 }
             }
 
+            // EntityManager.CleanupArch();
+
             rootUids = rootEnts;
         }
 
@@ -290,6 +296,9 @@ public sealed class MapLoaderSystem : EntitySystem
 
         ReadGrids(data);
 
+        // grids prior to engine v175 might've been serialized with empty chunks which now throw debug asserts.
+        RemoveEmptyChunks(data);
+
         // Then, go hierarchically in order and do the entity things.
         StartupEntities(data);
 
@@ -305,6 +314,25 @@ public sealed class MapLoaderSystem : EntitySystem
         return true;
     }
 
+    private void RemoveEmptyChunks(MapData data)
+    {
+        var gridQuery = _serverEntityManager.GetEntityQuery<MapGridComponent>();
+        foreach (var uid in data.EntitiesToDeserialize.Keys)
+        {
+            if (!gridQuery.TryGetComponent(uid, out var gridComp))
+                continue;
+
+            foreach (var (index, chunk) in gridComp.Chunks)
+            {
+                if (chunk.FilledTiles > 0)
+                    continue;
+
+                Log.Warning($"Encountered empty chunk while deserializing map. Grid: {ToPrettyString(uid)}. Chunk index: {index}");
+                gridComp.Chunks.Remove(index);
+            }
+        }
+    }
+
     private bool VerifyEntitiesExist(MapData data, BeforeEntityReadEvent ev)
     {
         _stopwatch.Restart();
@@ -406,6 +434,10 @@ public sealed class MapLoaderSystem : EntitySystem
         if (data.Version >= 4)
         {
             var metaEntities = data.RootMappingNode.Get<SequenceDataNode>("entities");
+            using var mapSaveCompType = new PooledSet<Type>()
+            {
+                typeof(MapSaveIdComponent)
+            };
 
             foreach (var metaDef in metaEntities.Cast<MappingDataNode>())
             {
@@ -425,9 +457,30 @@ public sealed class MapLoaderSystem : EntitySystem
 
                 var entities = (SequenceDataNode) metaDef["entities"];
                 EntityPrototype? proto = null;
+                var count = entities.Count;
+                var entTotal = data.Entities.Count + count;
+                data.Entities.EnsureCapacity(entTotal);
+                data.UidEntityMap.EnsureCapacity(entTotal);
+                data.EntitiesToDeserialize.EnsureCapacity(entTotal);
 
                 if (type != null)
-                    _prototypeManager.TryIndex(type, out proto);
+                {
+                    if (_prototypeManager.TryIndex(type, out proto) && count > 1)
+                    {
+                        ComponentType[] compTypes;
+
+                        if (data.Options.StoreMapUids)
+                        {
+                            compTypes = EntityManager.GetComponentType(proto, mapSaveCompType);
+                        }
+                        else
+                        {
+                            compTypes = EntityManager.GetComponentType(proto);
+                        }
+
+                        EntityManager.Reserve(compTypes, count);
+                    }
+                }
 
                 foreach (var entityDef in entities.Cast<MappingDataNode>())
                 {
@@ -442,6 +495,7 @@ public sealed class MapLoaderSystem : EntitySystem
                     {
                         deletedPrototypeUids.Add(entity);
                     }
+                    // TODO: Move this elsewhere?
                     else if (data.Options.StoreMapUids)
                     {
                         var comp = _serverEntityManager.AddComponent<MapSaveIdComponent>(entity);
@@ -550,6 +604,7 @@ public sealed class MapLoaderSystem : EntitySystem
             _context.CurrentlyIgnoredComponents = missingComponentList.Cast<ValueDataNode>().Select(x => x.Value).ToHashSet();
 
         _serverEntityManager.FinishEntityLoad(uid, meta.EntityPrototype, _context);
+
         if (_context.CurrentlyIgnoredComponents.Count > 0)
             meta.LastComponentRemoved = _timing.CurTick;
     }

Robust.Server/GameObjects/EntitySystems/MapSystem.cs

@@ -24,11 +24,6 @@ namespace Robust.Server.GameObjects
             _cfg.OnValueChanged(CVars.GameDeleteEmptyGrids, SetGridDeletion, true);
         }
 
-        protected override void OnMapAdd(EntityUid uid, MapComponent component, ComponentAdd args)
-        {
-            EnsureComp<PhysicsMapComponent>(uid);
-        }
-
         private void SetGridDeletion(bool value)
         {
             _deleteEmptyGrids = value;
@@ -66,9 +61,8 @@ namespace Robust.Server.GameObjects
 
         private void HandleGridEmpty(EntityUid uid, MapGridComponent component, EmptyGridEvent args)
         {
-            if (!_deleteEmptyGrids) return;
-            if (!EntityManager.EntityExists(uid)) return;
-            if (EntityManager.GetComponent<MetaDataComponent>(uid).EntityLifeStage >= EntityLifeStage.Terminating) return;
+            if (!_deleteEmptyGrids || TerminatingOrDeleted(uid) || HasComp<MapComponent>(uid))
+                return;
 
             MapManager.DeleteGrid(args.GridId);
         }

Robust.Server/GameObjects/EntitySystems/ServerMetaDataSystem.cs

@@ -1,6 +1,7 @@
 using Robust.Server.GameStates;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
+using Robust.Shared.Player;
 
 namespace Robust.Server.GameObjects;
 

Robust.Server/GameObjects/EntitySystems/UserInterfaceSystem.cs

@@ -1,13 +1,12 @@
 using System;
 using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using JetBrains.Annotations;
 using Robust.Server.Player;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Utility;
 
 namespace Robust.Server.GameObjects
@@ -21,8 +20,6 @@ namespace Robust.Server.GameObjects
 
         private readonly List<ICommonSession> _sessionCache = new();
 
-        private readonly Dictionary<ICommonSession, List<PlayerBoundUserInterface>> _openInterfaces = new();
-
         /// <inheritdoc />
         public override void Initialize()
         {
@@ -46,7 +43,7 @@ namespace Robust.Server.GameObjects
             if (args.NewStatus != SessionStatus.Disconnected)
                 return;
 
-            if (!_openInterfaces.TryGetValue(args.Session, out var buis))
+            if (!OpenInterfaces.TryGetValue(args.Session, out var buis))
                 return;
 
             foreach (var bui in buis.ToArray())
@@ -92,7 +89,7 @@ namespace Robust.Server.GameObjects
         /// <summary>
         ///     Verify that the subscribed clients are still in range of the interface.
         /// </summary>
-        private void CheckRange(EntityUid uid, Shared.GameObjects.ActiveUserInterfaceComponent activeUis, PlayerBoundUserInterface ui, TransformComponent transform, EntityQuery<TransformComponent> query)
+        private void CheckRange(EntityUid uid, ActiveUserInterfaceComponent activeUis, PlayerBoundUserInterface ui, TransformComponent transform, EntityQuery<TransformComponent> query)
         {
             if (ui.InteractionRange <= 0)
                 return;
@@ -139,11 +136,6 @@ namespace Robust.Server.GameObjects
             }
         }
 
-        private void ActivateInterface(PlayerBoundUserInterface ui)
-        {
-            EnsureComp<ActiveUserInterfaceComponent>(ui.Owner).Interfaces.Add(ui);
-        }
-
         #region Get BUI
 
         public bool HasUi(EntityUid uid, Enum uiKey, UserInterfaceComponent? ui = null)
@@ -168,20 +160,14 @@ namespace Robust.Server.GameObjects
                 ? bui
                 : null;
         }
-        public bool TryGetUi(EntityUid uid, Enum uiKey, [NotNullWhen(true)] out PlayerBoundUserInterface? bui, UserInterfaceComponent? ui = null)
-        {
-            bui = null;
-
-            return Resolve(uid, ref ui, false) && ui.Interfaces.TryGetValue(uiKey, out bui);
-        }
 
         /// <summary>
         ///     Return UIs a session has open.
         ///     Null if empty.
-        /// <summary>
+        /// </summary>
         public List<PlayerBoundUserInterface>? GetAllUIsForSession(ICommonSession session)
         {
-            _openInterfaces.TryGetValue(session, out var value);
+            OpenInterfaces.TryGetValue(session, out var value);
             return value;
         }
         #endregion
@@ -194,7 +180,7 @@ namespace Robust.Server.GameObjects
             return bui.SubscribedSessions.Count > 0;
         }
 
-        public bool SessionHasOpenUi(EntityUid uid, Enum uiKey, IPlayerSession session, UserInterfaceComponent? ui = null)
+        public bool SessionHasOpenUi(EntityUid uid, Enum uiKey, ICommonSession session, UserInterfaceComponent? ui = null)
         {
             if (!TryGetUi(uid, uiKey, out var bui, ui))
                 return false;
@@ -218,7 +204,7 @@ namespace Robust.Server.GameObjects
         public bool TrySetUiState(EntityUid uid,
             Enum uiKey,
             BoundUserInterfaceState state,
-            IPlayerSession? session = null,
+            ICommonSession? session = null,
             UserInterfaceComponent? ui = null,
             bool clearOverrides = true)
         {
@@ -259,94 +245,14 @@ namespace Robust.Server.GameObjects
             bui.StateDirty = true;
         }
 
-        /// <summary>
-        ///     Switches between closed and open for a specific client.
-        /// </summary>
-        public bool TryToggleUi(EntityUid uid, Enum uiKey, ICommonSession session, UserInterfaceComponent? ui = null)
-        {
-            if (!TryGetUi(uid, uiKey, out var bui, ui))
-                return false;
-
-            ToggleUi(bui, session);
-            return true;
-        }
-
-        /// <summary>
-        ///     Switches between closed and open for a specific client.
-        /// </summary>
-        public void ToggleUi(PlayerBoundUserInterface bui, ICommonSession session)
-        {
-            if (bui._subscribedSessions.Contains(session))
-                CloseUi(bui, session);
-            else
-                OpenUi(bui, session);
-        }
-
-        #region Open
-
-        public bool TryOpen(EntityUid uid, Enum uiKey, IPlayerSession session, UserInterfaceComponent? ui = null)
-        {
-            if (!TryGetUi(uid, uiKey, out var bui, ui))
-                return false;
-
-            return OpenUi(bui, session);
-        }
-
-        /// <summary>
-        ///     Opens this interface for a specific client.
-        /// </summary>
-        public bool OpenUi(PlayerBoundUserInterface bui, ICommonSession session)
-        {
-            if (session.Status == SessionStatus.Connecting || session.Status == SessionStatus.Disconnected)
-                return false;
-
-            if (!bui._subscribedSessions.Add(session))
-                return false;
-
-            _openInterfaces.GetOrNew(session).Add(bui);
-            RaiseLocalEvent(bui.Owner, new BoundUIOpenedEvent(bui.UiKey, bui.Owner, session));
-
-            RaiseNetworkEvent(new BoundUIWrapMessage(GetNetEntity(bui.Owner), new OpenBoundInterfaceMessage(), bui.UiKey), session.ConnectedClient);
-
-            // Fun fact, clients needs to have BUIs open before they can receive the state.....
-            if (bui.LastStateMsg != null)
-                RaiseNetworkEvent(bui.LastStateMsg, session.ConnectedClient);
-
-            ActivateInterface(bui);
-            return true;
-        }
-
-        #endregion
-
         #region Close
-        public bool TryClose(EntityUid uid, Enum uiKey, IPlayerSession session, UserInterfaceComponent? ui = null)
-        {
-            if (!TryGetUi(uid, uiKey, out var bui, ui))
-                return false;
-
-            return CloseUi(bui, session);
-        }
-
-        /// <summary>
-        ///     Close this interface for a specific client.
-        /// </summary>
-        public bool CloseUi(PlayerBoundUserInterface bui, ICommonSession session, ActiveUserInterfaceComponent? activeUis = null)
-        {
-            if (!bui._subscribedSessions.Remove(session))
-                return false;
-
-            RaiseNetworkEvent(new BoundUIWrapMessage(GetNetEntity(bui.Owner), new CloseBoundInterfaceMessage(), bui.UiKey), session.ConnectedClient);
-            CloseShared(bui, session, activeUis);
-            return true;
-        }
-
         protected override void CloseShared(PlayerBoundUserInterface bui, ICommonSession session, ActiveUserInterfaceComponent? activeUis = null)
         {
             var owner = bui.Owner;
             bui._subscribedSessions.Remove(session);
             bui.PlayerStateOverrides.Remove(session);
 
-            if (_openInterfaces.TryGetValue(session, out var buis))
+            if (OpenInterfaces.TryGetValue(session, out var buis))
                 buis.Remove(bui);
 
             RaiseLocalEvent(owner, new BoundUIClosedEvent(bui.UiKey, owner, session));

Robust.Server/GameObjects/EntitySystems/ViewSubscriberSystem.cs

@@ -1,5 +1,5 @@
-using Robust.Server.Player;
 using Robust.Shared.GameObjects;
+using Robust.Shared.Player;
 
 namespace Robust.Server.GameObjects
 {
@@ -18,7 +18,7 @@ namespace Robust.Server.GameObjects
         /// <summary>
         ///     Subscribes the session to get PVS updates from the point of view of the specified entity.
         /// </summary>
-        public void AddViewSubscriber(EntityUid uid, IPlayerSession session)
+        public void AddViewSubscriber(EntityUid uid, ICommonSession session)
         {
             // If the entity doesn't have the component, it will be added.
             var viewSubscriber = EntityManager.EnsureComponent<ViewSubscriberComponent>(uid);
@@ -27,7 +27,7 @@ namespace Robust.Server.GameObjects
                 return; // Already subscribed, do nothing else.
 
             viewSubscriber.SubscribedSessions.Add(session);
-            session.AddViewSubscription(uid);
+            session.ViewSubscriptions.Add(uid);
 
             RaiseLocalEvent(uid, new ViewSubscriberAddedEvent(uid, session), true);
         }
@@ -35,7 +35,7 @@ namespace Robust.Server.GameObjects
         /// <summary>
         ///     Unsubscribes the session from getting PVS updates from the point of view of the specified entity.
         /// </summary>
-        public void RemoveViewSubscriber(EntityUid uid, IPlayerSession session)
+        public void RemoveViewSubscriber(EntityUid uid, ICommonSession session)
         {
             if(!EntityManager.TryGetComponent(uid, out ViewSubscriberComponent? viewSubscriber))
                 return; // Entity didn't have any subscriptions, do nothing.
@@ -43,7 +43,7 @@ namespace Robust.Server.GameObjects
             if (!viewSubscriber.SubscribedSessions.Remove(session))
                 return; // Session wasn't subscribed, do nothing.
 
-            session.RemoveViewSubscription(uid);
+            session.ViewSubscriptions.Remove(uid);
             RaiseLocalEvent(uid, new ViewSubscriberRemovedEvent(uid, session), true);
         }
 
@@ -51,7 +51,7 @@ namespace Robust.Server.GameObjects
         {
             foreach (var session in component.SubscribedSessions)
             {
-                session.RemoveViewSubscription(uid);
+                session.ViewSubscriptions.Remove(uid);
             }
         }
     }
@@ -62,9 +62,9 @@ namespace Robust.Server.GameObjects
     public sealed class ViewSubscriberAddedEvent : EntityEventArgs
     {
         public EntityUid View { get; }
-        public IPlayerSession Subscriber { get; }
+        public ICommonSession Subscriber { get; }
 
-        public ViewSubscriberAddedEvent(EntityUid view, IPlayerSession subscriber)
+        public ViewSubscriberAddedEvent(EntityUid view, ICommonSession subscriber)
         {
             View = view;
             Subscriber = subscriber;
@@ -78,9 +78,9 @@ namespace Robust.Server.GameObjects
     public sealed class ViewSubscriberRemovedEvent : EntityEventArgs
     {
         public EntityUid View { get; }
-        public IPlayerSession Subscriber { get; }
+        public ICommonSession Subscriber { get; }
 
-        public ViewSubscriberRemovedEvent(EntityUid view, IPlayerSession subscriber)
+        public ViewSubscriberRemovedEvent(EntityUid view, ICommonSession subscriber)
         {
             View = view;
             Subscriber = subscriber;

Robust.Server/GameObjects/IServerEntityNetworkManager.cs

@@ -1,12 +1,10 @@
-using System.Collections.Generic;
-using Robust.Server.Player;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Timing;
+using Robust.Shared.Player;
 
 namespace Robust.Server.GameObjects
 {
     public interface IServerEntityNetworkManager : IEntityNetworkManager
     {
-        uint GetLastMessageSequence(IPlayerSession session);
+        uint GetLastMessageSequence(ICommonSession session);
     }
 }

Robust.Server/GameObjects/ServerEntityManager.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
 using JetBrains.Annotations;
 using Prometheus;
 using Robust.Server.Player;
@@ -15,6 +14,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
+using Robust.Shared.Player;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Replays;
 using Robust.Shared.Timing;
@@ -26,7 +26,7 @@ namespace Robust.Server.GameObjects
     /// Manager for entities -- controls things like template loading and instantiation
     /// </summary>
     [UsedImplicitly] // DI Container
-    public sealed class ServerEntityManager : EntityManager, IServerEntityManagerInternal
+    public sealed partial class ServerEntityManager : EntityManager, IServerEntityManagerInternal
     {
         private static readonly Gauge EntitiesCount = Metrics.CreateGauge(
             "robust_entities_count",
@@ -62,7 +62,7 @@ namespace Robust.Server.GameObjects
 
         EntityUid IServerEntityManagerInternal.AllocEntity(EntityPrototype? prototype)
         {
-            return AllocEntity(prototype, out _);
+            return AllocEntity(prototype, out _, out _);
         }
 
         void IServerEntityManagerInternal.FinishEntityLoad(EntityUid entity, IEntityLoadContext? context)
@@ -85,15 +85,15 @@ namespace Robust.Server.GameObjects
             StartEntity(entity);
         }
 
-        private protected override EntityUid CreateEntity(string? prototypeName, out MetaDataComponent metadata, IEntityLoadContext? context = null)
+        private protected override EntityUid CreateEntity(string? prototypeName, out MetaDataComponent metadata, out TransformComponent xform, IEntityLoadContext? context = null)
         {
             if (prototypeName == null)
-                return base.CreateEntity(prototypeName, out metadata, context);
+                return base.CreateEntity(prototypeName, out metadata, out xform, context);
 
             if (!PrototypeManager.TryIndex<EntityPrototype>(prototypeName, out var prototype))
                 throw new EntityCreationException($"Attempted to spawn an entity with an invalid prototype: {prototypeName}");
 
-            var entity = base.CreateEntity(prototype, out metadata, context);
+            var entity = base.CreateEntity(prototype, out metadata, out xform, context);
 
             // At this point in time, all data configure on the entity *should* be purely from the prototype.
             // As such, we can reset the modified ticks to Zero,
@@ -131,7 +131,7 @@ namespace Robust.Server.GameObjects
 
         private readonly PriorityQueue<MsgEntity> _queue = new(new MessageSequenceComparer());
 
-        private readonly Dictionary<IPlayerSession, uint> _lastProcessedSequencesCmd =
+        private readonly Dictionary<ICommonSession, uint> _lastProcessedSequencesCmd =
             new();
 
         private bool _logLateMsgs;
@@ -159,10 +159,10 @@ namespace Robust.Server.GameObjects
 
             base.TickUpdate(frameTime, noPredictions, histogram);
 
-            EntitiesCount.Set(Entities.Count);
+            EntitiesCount.Set(EntityCount);
         }
 
-        public uint GetLastMessageSequence(IPlayerSession session)
+        public uint GetLastMessageSequence(ICommonSession session)
         {
             return _lastProcessedSequencesCmd[session];
         }

Robust.Server/GameStates/IServerGameStateManager.cs

@@ -1,6 +1,6 @@
 using System;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Timing;
 
 namespace Robust.Server.GameStates

Robust.Server/GameStates/PvsCollection.cs

@@ -8,7 +8,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 

Robust.Server/GameStates/PvsOverrideSystem.cs

@@ -1,5 +1,5 @@
 using Robust.Shared.GameObjects;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 
 namespace Robust.Server.GameStates;
 

Robust.Server/GameStates/PvsSystem.Ack.cs

@@ -1,7 +1,7 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 

Robust.Server/GameStates/PvsSystem.Dirty.cs

@@ -1,8 +1,8 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using Robust.Server.Player;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
+using Robust.Shared.Player;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -68,7 +68,7 @@ namespace Robust.Server.GameStates
             return true;
         }
 
-        public void CleanupDirty(IEnumerable<IPlayerSession> sessions)
+        public void CleanupDirty(IEnumerable<ICommonSession> sessions)
         {
             if (!CullingEnabled)
             {

Robust.Server/GameStates/PvsSystem.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Numerics;
 using System.Runtime.InteropServices;
@@ -15,7 +16,7 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.Map;
 using Robust.Shared.Map.Components;
 using Robust.Shared.Maths;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Threading;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
@@ -35,10 +36,16 @@ internal sealed partial class PvsSystem : EntitySystem
     public const float ChunkSize = 8;
 
     // TODO make this a cvar. Make it in terms of seconds and tie it to tick rate?
+    // Main issue is that I CBF figuring out the logic for handling it changing mid-game.
     public const int DirtyBufferSize = 20;
     // Note: If a client has ping higher than TickBuffer / TickRate, then the server will treat every entity as if it
     // had entered PVS for the first time. Note that due to the PVS budget, this buffer is easily overwhelmed.
 
+    /// <summary>
+    /// See <see cref="CVars.NetForceAckThreshold"/>.
+    /// </summary>
+    public int ForceAckThreshold { get; private set; }
+
     /// <summary>
     /// Maximum number of pooled objects
     /// </summary>
@@ -139,6 +146,7 @@ internal sealed partial class PvsSystem : EntitySystem
 
         _configManager.OnValueChanged(CVars.NetPVS, SetPvs, true);
         _configManager.OnValueChanged(CVars.NetMaxUpdateRange, OnViewsizeChanged, true);
+        _configManager.OnValueChanged(CVars.NetForceAckThreshold, OnForceAckChanged, true);
 
         _serverGameStateManager.ClientAck += OnClientAck;
         _serverGameStateManager.ClientRequestFull += OnClientRequestFull;
@@ -156,6 +164,7 @@ internal sealed partial class PvsSystem : EntitySystem
 
         _configManager.UnsubValueChanged(CVars.NetPVS, SetPvs);
         _configManager.UnsubValueChanged(CVars.NetMaxUpdateRange, OnViewsizeChanged);
+        _configManager.UnsubValueChanged(CVars.NetForceAckThreshold, OnForceAckChanged);
 
         _serverGameStateManager.ClientAck -= OnClientAck;
         _serverGameStateManager.ClientRequestFull -= OnClientRequestFull;
@@ -199,7 +208,7 @@ internal sealed partial class PvsSystem : EntitySystem
         // return last acked to pool, but only if it is not still in the OverflowDictionary.
         if (sessionData.LastAcked != null && !sessionData.SentEntities.ContainsKey(sessionData.LastAcked.Value.Tick))
         {
-            DebugTools.Assert(sessionData.SentEntities.Values.Contains(sessionData.LastAcked.Value.Data));
+            DebugTools.Assert(!sessionData.SentEntities.Values.Contains(sessionData.LastAcked.Value.Data));
             _visSetPool.Return(sessionData.LastAcked.Value.Data);
         }
 
@@ -212,6 +221,11 @@ internal sealed partial class PvsSystem : EntitySystem
         _viewSize = obj * 2;
     }
 
+    private void OnForceAckChanged(int value)
+    {
+        ForceAckThreshold = value;
+    }
+
     private void SetPvs(bool value)
     {
         _seenAllEnts.Clear();
@@ -258,6 +272,7 @@ internal sealed partial class PvsSystem : EntitySystem
         {
             sessionData.LastSeenAt.Remove(metadata.NetEntity);
             sessionData.LastLeftView.Remove(metadata.NetEntity);
+
             if (sessionData.SentEntities.TryGetValue(previousTick, out var ents))
                 ents.Remove(metadata.NetEntity);
         }
@@ -420,10 +435,15 @@ internal sealed partial class PvsSystem : EntitySystem
 
     #endregion
 
-    public (List<(int, IChunkIndexLocation)> , HashSet<int>[], EntityUid[][] viewers) GetChunks(IPlayerSession[] sessions)
+    public List<(int, IChunkIndexLocation)> GetChunks(
+        ICommonSession[] sessions,
+        ref HashSet<int>[] playerChunks,
+        ref EntityUid[][] viewerEntities)
     {
-        var playerChunks = new HashSet<int>[sessions.Length];
-        var viewerEntities = new EntityUid[sessions.Length][];
+        // Pass these in to avoid allocating new ones every tick, 99% of the time sessions length is going to be the same size.
+        // These values will get overridden here and the old values have already been returned to the pool by this point.
+        Array.Resize(ref playerChunks, sessions.Length);
+        Array.Resize(ref viewerEntities, sessions.Length);
 
         _chunkList.Clear();
         // Keep track of the index of each chunk we use for a faster index lookup.
@@ -446,8 +466,8 @@ internal sealed partial class PvsSystem : EntitySystem
             var session = sessions[i];
             playerChunks[i] = _playerChunkPool.Get();
 
-            var viewers = GetSessionViewers(session);
-            viewerEntities[i] = viewers;
+            ref var viewers = ref viewerEntities[i];
+            GetSessionViewers(session, ref viewers);
 
             for (var j = 0; j < viewers.Length; j++)
             {
@@ -539,7 +559,7 @@ internal sealed partial class PvsSystem : EntitySystem
             }
         }
 
-        return (_chunkList, playerChunks, viewerEntities);
+        return _chunkList;
     }
 
     public void RegisterNewPreviousChunkTrees(
@@ -556,23 +576,20 @@ internal sealed partial class PvsSystem : EntitySystem
             _reusedTrees.Add(chunks[i]);
         }
 
-        var previousIndices = _previousTrees.Keys.ToArray();
-        for (var i = 0; i < previousIndices.Length; i++)
+        foreach (var (index, chunk) in _previousTrees)
         {
-            var index = previousIndices[i];
             // ReSharper disable once InconsistentlySynchronizedField
-            if (_reusedTrees.Contains(index)) continue;
-            var chunk = _previousTrees[index];
-            if (chunk.HasValue)
+            if (_reusedTrees.Contains(index))
+                continue;
+
+            if (chunk != null)
             {
                 _chunkCachePool.Return(chunk.Value.metadata);
                 _treePool.Return(chunk.Value.tree);
             }
 
             if (!chunks.Contains(index))
-            {
                 _previousTrees.Remove(index);
-            }
         }
 
         _previousTrees.EnsureCapacity(chunks.Count);
@@ -689,7 +706,7 @@ internal sealed partial class PvsSystem : EntitySystem
     }
 
     internal (List<EntityState>? updates, List<NetEntity>? deletions, List<NetEntity>? leftPvs, GameTick fromTick)
-        CalculateEntityStates(IPlayerSession session,
+        CalculateEntityStates(ICommonSession session,
             GameTick fromTick,
             GameTick toTick,
             (Dictionary<NetEntity, MetaDataComponent> metadata, RobustTree<NetEntity> tree)?[] chunks,
@@ -697,8 +714,8 @@ internal sealed partial class PvsSystem : EntitySystem
             EntityUid[] viewers)
     {
         DebugTools.Assert(session.Status == SessionStatus.InGame);
-        var newEntityBudget = _netConfigManager.GetClientCVar(session.ConnectedClient, CVars.NetPVSEntityBudget);
-        var enteredEntityBudget = _netConfigManager.GetClientCVar(session.ConnectedClient, CVars.NetPVSEntityEnterBudget);
+        var newEntityBudget = _netConfigManager.GetClientCVar(session.Channel, CVars.NetPVSEntityBudget);
+        var enteredEntityBudget = _netConfigManager.GetClientCVar(session.Channel, CVars.NetPVSEntityEnterBudget);
         var newEntityCount = 0;
         var enteredEntityCount = 0;
         var sessionData = PlayerData[session];
@@ -875,7 +892,7 @@ internal sealed partial class PvsSystem : EntitySystem
             return null;
 
         var tick = _gameTiming.CurTick;
-        var minSize = Math.Max(0, lastSent.Count - lastSent.Count);
+        var minSize = Math.Max(0, lastSent.Count - visibleEnts.Count);
         var leftView = new List<NetEntity>(minSize);
 
         foreach (var netEntity in lastSent.Keys)
@@ -1300,30 +1317,44 @@ Transform last modified: {Transform(uid).LastModifiedTick}");
         return entState;
     }
 
-    private EntityUid[] GetSessionViewers(ICommonSession session)
+    private void GetSessionViewers(ICommonSession session, [NotNull] ref EntityUid[]? viewers)
     {
-        if (session.Status != SessionStatus.InGame || session is not IPlayerSession sess)
-            return Array.Empty<EntityUid>();
+        if (session.Status != SessionStatus.InGame)
+        {
+            viewers = Array.Empty<EntityUid>();
+            return;
+        }
 
         // Fast path
-        if (sess.ViewSubscriptionCount == 0)
+        if (session.ViewSubscriptions.Count == 0)
         {
             if (session.AttachedEntity == null)
-                return Array.Empty<EntityUid>();
+            {
+                viewers = Array.Empty<EntityUid>();
+                return;
+            }
 
-            return new[] { session.AttachedEntity.Value };
+            Array.Resize(ref viewers, 1);
+            viewers[0] = session.AttachedEntity.Value;
+            return;
         }
 
-        var viewers = new HashSet<EntityUid>();
-        if (session.AttachedEntity != null)
-            viewers.Add(session.AttachedEntity.Value);
-
-        foreach (var uid in sess.ViewSubscriptions)
+        int i = 0;
+        if (session.AttachedEntity is { } local)
         {
-            viewers.Add(uid);
+            DebugTools.Assert(!session.ViewSubscriptions.Contains(local));
+            Array.Resize(ref viewers, session.ViewSubscriptions.Count + 1);
+            viewers[i++] = local;
+        }
+        else
+        {
+            Array.Resize(ref viewers, session.ViewSubscriptions.Count);
         }
 
-        return viewers.ToArray();
+        foreach (var ent in session.ViewSubscriptions)
+        {
+            viewers[i++] = ent;
+        }
     }
 
     // Read Safe
@@ -1412,7 +1443,7 @@ Transform last modified: {Transform(uid).LastModifiedTick}");
 [ByRefEvent]
 public struct ExpandPvsEvent
 {
-    public readonly IPlayerSession Session;
+    public readonly ICommonSession Session;
 
     /// <summary>
     /// List of entities that will get added to this session's PVS set.
@@ -1425,7 +1456,7 @@ public struct ExpandPvsEvent
     /// </summary>
     public List<EntityUid>? RecursiveEntities;
 
-    public ExpandPvsEvent(IPlayerSession session)
+    public ExpandPvsEvent(ICommonSession session)
     {
         Session = session;
     }

Robust.Server/GameStates/ServerGameStateManager.cs

@@ -26,7 +26,7 @@ using Prometheus;
 using Robust.Server.Replays;
 using Robust.Shared.Console;
 using Robust.Shared.Map.Components;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 
 namespace Robust.Server.GameStates
 {
@@ -37,6 +37,9 @@ namespace Robust.Server.GameStates
         // Mapping of net UID of clients -> last known acked state.
         private GameTick _lastOldestAck = GameTick.Zero;
 
+        private HashSet<int>[] _playerChunks = Array.Empty<HashSet<int>>();
+        private EntityUid[][] _viewerEntities = Array.Empty<EntityUid[]>();
+
         private PvsSystem _pvs = default!;
 
         [Dependency] private readonly EntityManager _entityManager = default!;
@@ -168,7 +171,7 @@ Oldest acked clients: {string.Join(", ", players)}
         /// <inheritdoc />
         public void SendGameStateUpdate()
         {
-            var players = _playerManager.ServerSessions.Where(o => o.Status == SessionStatus.InGame).ToArray();
+            var players = _playerManager.Sessions.Where(o => o.Status == SessionStatus.InGame).ToArray();
 
             // Update entity positions in PVS chunks/collections
             // TODO disable processing if culling is disabled? Need to check if toggling PVS breaks anything.
@@ -224,7 +227,7 @@ Oldest acked clients: {string.Join(", ", players)}
             _pvs.CullDeletionHistory(oldestAck);
         }
 
-        private GameTick SendStates(IPlayerSession[] players, PvsData? pvsData)
+        private GameTick SendStates(ICommonSession[] players, PvsData? pvsData)
         {
             var inputSystem = _systemManager.GetEntitySystem<InputSystem>();
             var opts = new ParallelOptions {MaxDegreeOfParallelism = _parallelMgr.ParallelProcessCount};
@@ -265,9 +268,9 @@ Oldest acked clients: {string.Join(", ", players)}
             public (Dictionary<NetEntity, MetaDataComponent> metadata, RobustTree<NetEntity> tree)?[] ChunkCache;
         }
 
-        private PvsData? GetPVSData(IPlayerSession[] players)
+        private PvsData? GetPVSData(ICommonSession[] players)
         {
-            var (chunks, playerChunks, viewerEntities) = _pvs.GetChunks(players);
+            var chunks= _pvs.GetChunks(players, ref _playerChunks, ref _viewerEntities);
             const int ChunkBatchSize = 2;
             var chunksCount = chunks.Count;
             var chunkBatches = (int)MathF.Ceiling((float)chunksCount / ChunkBatchSize);
@@ -310,8 +313,8 @@ Oldest acked clients: {string.Join(", ", players)}
             ArrayPool<bool>.Shared.Return(reuse);
             return new PvsData()
             {
-                PlayerChunks = playerChunks,
-                ViewerEntities = viewerEntities,
+                PlayerChunks = _playerChunks,
+                ViewerEntities = _viewerEntities,
                 ChunkCache = chunkCache,
             };
         }
@@ -319,11 +322,11 @@ Oldest acked clients: {string.Join(", ", players)}
         private void SendStateUpdate(int i,
             PvsThreadResources resources,
             InputSystem inputSystem,
-            IPlayerSession session,
+            ICommonSession session,
             PvsData? pvsData,
             ref uint oldestAckValue)
         {
-            var channel = session.ConnectedClient;
+            var channel = session.Channel;
             var sessionData = _pvs.PlayerData[session];
             var lastAck = sessionData.LastReceivedAck;
             List<NetEntity>? leftPvs = null;
@@ -347,7 +350,7 @@ Oldest acked clients: {string.Join(", ", players)}
                 (entStates, deletions, fromTick) = _pvs.GetAllEntityStates(session, lastAck, _gameTiming.CurTick);
             }
 
-            var playerStates = _playerManager.GetPlayerStates(lastAck);
+            var playerStates = _playerManager.GetPlayerStates(fromTick);
 
             // lastAck varies with each client based on lag and such, we can't just make 1 global state and send it to everyone
             var lastInputCommand = inputSystem.GetLastInputCommand(session);
@@ -368,11 +371,25 @@ Oldest acked clients: {string.Join(", ", players)}
             stateUpdateMessage.State = state;
             stateUpdateMessage.CompressionContext = resources.CompressionContext;
 
-            _networkManager.ServerSendMessage(stateUpdateMessage, channel);
-
             // If the state is too big we let Lidgren send it reliably. This is to avoid a situation where a state is so
             // large that it (or part of it) consistently gets dropped. When we send reliably, we immediately update the
             // ack so that the next state will not also be huge.
+            //
+            // We also do this if the client's last ack is too old. This helps prevent things like the entity deletion
+            // history from becoming too bloated if a bad client fails to send acks for whatever reason.
+
+            if (_gameTiming.CurTick.Value > lastAck.Value + _pvs.ForceAckThreshold)
+            {
+                stateUpdateMessage.ForceSendReliably = true;
+#if FULL_RELEASE
+                var connectedTime = (DateTime.UtcNow - session.ConnectedTime).TotalMinutes;
+                if (lastAck > GameTick.Zero && connectedTime > 1)
+                    _logger.Warning($"Client {session} exceeded ack-tick threshold. Last ack: {lastAck}. Cur tick: {_gameTiming.CurTick}. Connect time: {connectedTime} minutes");
+#endif
+            }
+
+            _networkManager.ServerSendMessage(stateUpdateMessage, channel);
+
             if (stateUpdateMessage.ShouldSendReliably())
             {
                 sessionData.LastReceivedAck = _gameTiming.CurTick;

Robust.Server/Maps/MapChunkSerializer.cs

@@ -12,6 +12,7 @@ using Robust.Shared.Serialization.Markdown.Mapping;
 using Robust.Shared.Serialization.Markdown.Validation;
 using Robust.Shared.Serialization.Markdown.Value;
 using Robust.Shared.Serialization.TypeSerializers.Interfaces;
+using Robust.Shared.Utility;
 
 namespace Robust.Server.Maps;
 
@@ -93,6 +94,7 @@ internal sealed class MapChunkSerializer : ITypeSerializer<MapChunk, MappingData
         IDependencyCollection dependencies, bool alwaysWrite = false,
         ISerializationContext? context = null)
     {
+        DebugTools.Assert(value.FilledTiles > 0, "Attempting to write an empty chunk");
         var root = new MappingDataNode();
         var ind = new ValueDataNode($"{value.X},{value.Y}");
         root.Add("ind", ind);

Robust.Server/Physics/GridFixtureSystem.cs

@@ -3,7 +3,6 @@ using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Numerics;
 using Robust.Server.Console;
-using Robust.Server.Player;
 using Robust.Shared;
 using Robust.Shared.Collections;
 using Robust.Shared.Configuration;
@@ -15,7 +14,7 @@ using Robust.Shared.Map.Components;
 using Robust.Shared.Maths;
 using Robust.Shared.Physics.Components;
 using Robust.Shared.Physics.Systems;
-using Robust.Shared.Players;
+using Robust.Shared.Player;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -92,9 +91,7 @@ namespace Robust.Server.Physics
 
         private void OnDebugRequest(RequestGridNodesMessage msg, EntitySessionEventArgs args)
         {
-            var pSession = (PlayerSession) args.SenderSession;
-
-            if (!_conGroup.CanCommand(pSession, ShowGridNodesCommand)) return;
+            if (!_conGroup.CanCommand(args.SenderSession, ShowGridNodesCommand)) return;
 
             AddDebugSubscriber(args.SenderSession);
         }

Robust.Server/Placement/PlacementManager.cs

@@ -15,6 +15,7 @@ using Robust.Shared.Maths;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
 using Robust.Shared.Placement;
+using Robust.Shared.Player;
 using Robust.Shared.Prototypes;
 
 namespace Robust.Server.Placement
@@ -30,6 +31,10 @@ namespace Robust.Server.Placement
         [Dependency] private readonly IMapManager _mapManager = default!;
         [Dependency] private readonly ILogManager _logManager = default!;
 
+        private EntityLookupSystem _lookup => _entityManager.System<EntityLookupSystem>();
+        private SharedMapSystem _maps => _entityManager.System<SharedMapSystem>();
+        private SharedTransformSystem _xformSystem => _entityManager.System<SharedTransformSystem>();
+
         //TO-DO: Expand for multiple permission per mob?
         //       Add support for multi-use placeables (tiles etc.).
         public List<PlacementInformation> BuildPermissions { get; set; } = new();
@@ -44,6 +49,7 @@ namespace Robust.Server.Placement
 
         public void Initialize()
         {
+            // Someday PlacementManagerSystem my beloved.
             _sawmill = _logManager.GetSawmill("placement");
 
             _networkManager.RegisterNetMessage<MsgPlacement>(HandleNetMessage);
@@ -142,7 +148,7 @@ namespace Robust.Server.Placement
                     if (_entityManager.TryGetComponent<MapGridComponent>(gridUid, out var grid))
                     {
                         var replacementQuery = _entityManager.GetEntityQuery<PlacementReplacementComponent>();
-                        var anc = grid.GetAnchoredEntitiesEnumerator(grid.LocalToTile(coordinates));
+                        var anc = _maps.GetAnchoredEntitiesEnumerator(gridUid.Value, grid, _maps.LocalToTile(gridUid.Value, grid, coordinates));
                         var toDelete = new ValueList<EntityUid>();
 
                         while (anc.MoveNext(out var ent))
@@ -185,14 +191,11 @@ namespace Robust.Server.Placement
 
             MapGridComponent? grid;
 
-            _mapManager.TryGetGrid(coordinates.EntityId, out grid);
-
-            if (grid == null)
-                _mapManager.TryFindGridAt(coordinates.ToMap(_entityManager), out _, out grid);
-
-            if (grid != null)  // stick to existing grid
+            EntityUid gridId = coordinates.EntityId;
+            if (_entityManager.TryGetComponent(coordinates.EntityId, out grid)
+                || _mapManager.TryFindGridAt(coordinates.ToMap(_entityManager, _xformSystem), out gridId, out grid))
             {
-                grid.SetTile(coordinates, new Tile(tileType));
+                _maps.SetTile(gridId, grid, coordinates, new Tile(tileType));
 
                 var placementEraseEvent = new PlacementTileEvent(tileType, coordinates, placingUserId);
                 _entityManager.EventBus.RaiseEvent(EventSource.Local, placementEraseEvent);
@@ -201,9 +204,9 @@ namespace Robust.Server.Placement
             {
                 var newGrid = _mapManager.CreateGridEntity(coordinates.GetMapId(_entityManager));
                 var newGridXform = _entityManager.GetComponent<TransformComponent>(newGrid);
-                newGridXform.WorldPosition = coordinates.Position - newGrid.Comp.TileSizeHalfVector; // assume bottom left tile origin
+                _xformSystem.SetWorldPosition(newGridXform, coordinates.Position - newGrid.Comp.TileSizeHalfVector); // assume bottom left tile origin
                 var tilePos = newGrid.Comp.WorldToTile(coordinates.Position);
-                newGrid.Comp.SetTile(tilePos, new Tile(tileType));
+                _maps.SetTile(newGrid.Owner, newGrid.Comp, tilePos, new Tile(tileType));
 
                 var placementEraseEvent = new PlacementTileEvent(tileType, coordinates, placingUserId);
                 _entityManager.EventBus.RaiseEvent(EventSource.Local, placementEraseEvent);
@@ -227,11 +230,16 @@ namespace Robust.Server.Placement
         {
             EntityCoordinates start = _entityManager.GetCoordinates(msg.NetCoordinates);
             Vector2 rectSize = msg.RectSize;
-            foreach (EntityUid entity in EntitySystem.Get<EntityLookupSystem>().GetEntitiesIntersecting(start.GetMapId(_entityManager),
+            foreach (var entity in _lookup.GetEntitiesIntersecting(start.GetMapId(_entityManager),
                 new Box2(start.Position, start.Position + rectSize)))
             {
-                if (_entityManager.Deleted(entity) || _entityManager.HasComponent<MapGridComponent>(entity) || _entityManager.HasComponent<ActorComponent>(entity))
+                if (_entityManager.Deleted(entity) ||
+                    _entityManager.HasComponent<MapGridComponent>(entity) ||
+                    _entityManager.HasComponent<ActorComponent>(entity))
+                {
                     continue;
+                }
+
                 var placementEraseEvent = new PlacementEntityEvent(entity, _entityManager.GetComponent<TransformComponent>(entity).Coordinates, PlacementEventAction.Erase, msg.MsgChannel.UserId);
                 _entityManager.EventBus.RaiseEvent(EventSource.Local, placementEraseEvent);
                 _entityManager.DeleteEntity(entity);
@@ -243,19 +251,19 @@ namespace Robust.Server.Placement
         /// </summary>
         public void SendPlacementBegin(EntityUid mob, int range, string objectType, string alignOption)
         {
-            if (!_entityManager.TryGetComponent<ActorComponent?>(mob, out var actor))
+            if (!_entityManager.TryGetComponent(mob, out ActorComponent? actor))
                 return;
 
-            var playerConnection = actor.PlayerSession.ConnectedClient;
-            if (playerConnection == null)
-                return;
+            var playerConnection = actor.PlayerSession.Channel;
 
-            var message = new MsgPlacement();
-            message.PlaceType = PlacementManagerMessage.StartPlacement;
-            message.Range = range;
-            message.IsTile = false;
-            message.ObjType = objectType;
-            message.AlignOption = alignOption;
+            var message = new MsgPlacement
+            {
+                PlaceType = PlacementManagerMessage.StartPlacement,
+                Range = range,
+                IsTile = false,
+                ObjType = objectType,
+                AlignOption = alignOption
+            };
             _networkManager.ServerSendMessage(message, playerConnection);
         }
 
@@ -264,19 +272,19 @@ namespace Robust.Server.Placement
         /// </summary>
         public void SendPlacementBeginTile(EntityUid mob, int range, string tileType, string alignOption)
         {
-            if (!_entityManager.TryGetComponent<ActorComponent?>(mob, out var actor))
+            if (!_entityManager.TryGetComponent(mob, out ActorComponent? actor))
                 return;
 
-            var playerConnection = actor.PlayerSession.ConnectedClient;
-            if (playerConnection == null)
-                return;
+            var playerConnection = actor.PlayerSession.Channel;
 
-            var message = new MsgPlacement();
-            message.PlaceType = PlacementManagerMessage.StartPlacement;
-            message.Range = range;
-            message.IsTile = true;
-            message.ObjType = tileType;
-            message.AlignOption = alignOption;
+            var message = new MsgPlacement
+            {
+                PlaceType = PlacementManagerMessage.StartPlacement,
+                Range = range,
+                IsTile = true,
+                ObjType = tileType,
+                AlignOption = alignOption
+            };
             _networkManager.ServerSendMessage(message, playerConnection);
         }
 
@@ -285,15 +293,15 @@ namespace Robust.Server.Placement
         /// </summary>
         public void SendPlacementCancel(EntityUid mob)
         {
-            if (!_entityManager.TryGetComponent<ActorComponent?>(mob, out var actor))
+            if (!_entityManager.TryGetComponent(mob, out ActorComponent? actor))
                 return;
 
-            var playerConnection = actor.PlayerSession.ConnectedClient;
-            if (playerConnection == null)
-                return;
+            var playerConnection = actor.PlayerSession.Channel;
 
-            var message = new MsgPlacement();
-            message.PlaceType = PlacementManagerMessage.CancelPlacement;
+            var message = new MsgPlacement
+            {
+                PlaceType = PlacementManagerMessage.CancelPlacement
+            };
             _networkManager.ServerSendMessage(message, playerConnection);
         }
 

Robust.Server/Player/IPlayerManager.cs

@@ -1,88 +1,12 @@
-using System;
-using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
-using Robust.Shared.Enums;
-using Robust.Shared.GameStates;
 using Robust.Shared.Input;
-using Robust.Shared.Map;
-using Robust.Shared.Network;
 using Robust.Shared.Player;
-using Robust.Shared.Players;
-using Robust.Shared.Timing;
 
-namespace Robust.Server.Player
+namespace Robust.Server.Player;
+
+/// <summary>
+///     Manages each players session when connected to the server.
+/// </summary>
+public interface IPlayerManager : ISharedPlayerManager
 {
-    /// <summary>
-    ///     Manages each players session when connected to the server.
-    /// </summary>
-    public interface IPlayerManager : ISharedPlayerManager
-    {
-        BoundKeyMap KeyMap { get; }
-
-        /// <summary>
-        /// Same as the common sessions, but the server version.
-        /// </summary>
-        IEnumerable<IPlayerSession> ServerSessions { get; }
-
-        /// <summary>
-        ///     Raised when the <see cref="SessionStatus" /> of a <see cref="IPlayerSession" /> is changed.
-        /// </summary>
-        event EventHandler<SessionStatusEventArgs> PlayerStatusChanged;
-
-        /// <summary>
-        ///     Initializes the manager.
-        /// </summary>
-        /// <param name="maxPlayers">Maximum number of players that can connect to this server at one time.</param>
-        void Initialize(int maxPlayers);
-
-        void Shutdown();
-
-        bool TryGetSessionByUsername(string username, [NotNullWhen(true)] out IPlayerSession? session);
-
-        /// <summary>
-        ///     Returns the client session of the networkId.
-        /// </summary>
-        /// <returns></returns>
-        IPlayerSession GetSessionByUserId(NetUserId index);
-
-        IPlayerSession GetSessionByChannel(INetChannel channel);
-
-        bool TryGetSessionByChannel(INetChannel channel, [NotNullWhen(true)] out IPlayerSession? session);
-
-        bool TryGetSessionById(NetUserId userId, [NotNullWhen(true)] out IPlayerSession? session);
-
-        /// <summary>
-        ///     Checks to see if a PlayerIndex is a valid session.
-        /// </summary>
-        bool ValidSessionId(NetUserId index);
-
-        IPlayerData GetPlayerData(NetUserId userId);
-        bool TryGetPlayerData(NetUserId userId, [NotNullWhen(true)] out IPlayerData? data);
-        bool TryGetPlayerDataByUsername(string userName, [NotNullWhen(true)] out IPlayerData? data);
-        bool HasPlayerData(NetUserId userId);
-
-        /// <summary>
-        ///     Tries to get the user ID of the user with the specified username.
-        /// </summary>
-        /// <remarks>
-        ///     This only works if this user has already connected once before during this server run.
-        ///     It does still work if the user has since disconnected.
-        /// </remarks>
-        bool TryGetUserId(string userName, out NetUserId userId);
-
-        IEnumerable<IPlayerData> GetAllPlayerData();
-
-
-        [Obsolete]
-        void DetachAll();
-        [Obsolete("Use player Filter or Inline me!")]
-        List<IPlayerSession> GetPlayersInRange(MapCoordinates worldPos, int range);
-        [Obsolete("Use player Filter or Inline me!")]
-        List<IPlayerSession> GetPlayersInRange(EntityCoordinates worldPos, int range);
-        [Obsolete("Use player Filter or Inline me!")]
-        List<IPlayerSession> GetPlayersBy(Func<IPlayerSession, bool> predicate);
-        [Obsolete("Use player Filter or Inline me!")]
-        List<IPlayerSession> GetAllPlayers();
-        List<PlayerState>? GetPlayerStates(GameTick fromTick);
-    }
-}
+    BoundKeyMap KeyMap { get; }
+}

Robust.Server/Player/IPlayerSession.cs

@@ -1,77 +0,0 @@
-using System;
-using System.Collections.Generic;
-using Robust.Server.GameObjects;
-using Robust.Shared.GameObjects;
-using Robust.Shared.Network;
-using Robust.Shared.Player;
-using Robust.Shared.Players;
-
-namespace Robust.Server.Player
-{
-    public interface IPlayerSession : ICommonSession
-    {
-        DateTime ConnectedTime { get; }
-
-        event EventHandler<SessionStatusEventArgs> PlayerStatusChanged;
-
-        void JoinGame();
-
-        LoginType AuthType { get; }
-
-        /// <summary>
-        ///     Attaches this player to an entity.
-        ///     NOTE: The content pack almost certainly has an alternative for this.
-        ///     Do not call this directly for most content code.
-        /// </summary>
-        /// <param name="entity">The entity to attach to.</param>
-        [Obsolete("Use ActorSystem.Attach() instead.")]
-        void AttachToEntity(EntityUid? entity);
-
-        /// <summary>
-        ///     Attaches this player to an entity.
-        ///     NOTE: The content pack almost certainly has an alternative for this.
-        ///     Do not call this directly for most content code.
-        /// </summary>
-        /// <param name="uid">The entity to attach to.</param>
-        [Obsolete("Use ActorSystem.Attach() instead.")]
-        void AttachToEntity(EntityUid uid);
-
-        /// <summary>
-        ///     Detaches this player from an entity.
-        ///     NOTE: The content pack almost certainly has an alternative for this.
-        ///     Do not call this directly for most content code.
-        /// </summary>
-        [Obsolete("Use ActorSystem.Detach() instead.")]
-        void DetachFromEntity();
-        void OnConnect();
-        void OnDisconnect();
-
-        IReadOnlySet<EntityUid> ViewSubscriptions { get; }
-
-        int ViewSubscriptionCount { get; }
-
-        /// <summary>
-        ///     Persistent data for this player.
-        /// </summary>
-        IPlayerData Data { get; }
-
-        /// <summary>
-        ///     Internal method to set <see cref="ICommonSession.AttachedEntity"/> and update the player's status.
-        ///     Do NOT use this unless you know what you're doing, you probably want <see cref="AttachToEntity"/>
-        ///     and <see cref="DetachFromEntity"/> instead.
-        /// </summary>
-        internal void SetAttachedEntity(EntityUid? entity);
-
-        /// <summary>
-        ///     Internal method to add an entity Uid to <see cref="ViewSubscriptions"/>.
-        ///     Do NOT use this outside of <see cref="ViewSubscriberSystem"/>.
-        /// </summary>
-        internal void AddViewSubscription(EntityUid eye);
-
-        /// <summary>
-        ///     Internal method to remove an entity Uid from <see cref="ViewSubscriptions"/>.
-        ///     Do NOT use this outside of <see cref="ViewSubscriberSystem"/>.
-        /// </summary>
-        internal void RemoveViewSubscription(EntityUid eye);
-    }
-}

Robust.Server/Player/PlayerData.cs

@@ -1,24 +0,0 @@
-using Robust.Shared.Network;
-using Robust.Shared.Player;
-using Robust.Shared.ViewVariables;
-
-namespace Robust.Server.Player
-{
-    sealed class PlayerData : IPlayerData
-    {
-        public PlayerData(NetUserId userId, string userName)
-        {
-            UserId = userId;
-            UserName = userName;
-        }
-
-        [ViewVariables]
-        public NetUserId UserId { get; }
-
-        [ViewVariables]
-        public string UserName { get; }
-
-        [ViewVariables]
-        public object? ContentDataUncast { get; set; }
-    }
-}

Robust.Server/Player/PlayerManager.cs

@@ -2,7 +2,6 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
-using System.Threading;
 using System.Threading.Tasks;
 using Prometheus;
 using Robust.Server.Configuration;
@@ -12,22 +11,19 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.Input;
 using Robust.Shared.IoC;
-using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
 using Robust.Shared.Player;
-using Robust.Shared.Players;
 using Robust.Shared.Reflection;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
-using Robust.Shared.ViewVariables;
 
 namespace Robust.Server.Player
 {
     /// <summary>
     ///     This class will manage connected player sessions.
     /// </summary>
-    public sealed class PlayerManager : IPlayerManager
+    internal sealed class PlayerManager : SharedPlayerManager, IPlayerManager
     {
         private static readonly Gauge PlayerCountMetric = Metrics
             .CreateGauge("robust_player_count", "Number of players on the server.");
@@ -41,79 +37,13 @@ namespace Robust.Server.Player
 
         public BoundKeyMap KeyMap { get; private set; } = default!;
 
-        private GameTick _lastStateUpdate;
-
-        private readonly ReaderWriterLockSlim _sessionsLock = new();
-
-        /// <summary>
-        ///     Active sessions of connected clients to the server.
-        /// </summary>
-        [ViewVariables]
-        private readonly Dictionary<NetUserId, PlayerSession> _sessions = new();
-
-        [ViewVariables]
-        private readonly Dictionary<NetUserId, PlayerData> _playerData = new();
-
-        [ViewVariables]
-        private readonly Dictionary<string, NetUserId> _userIdMap = new();
-
         /// <inheritdoc />
-        public IEnumerable<ICommonSession> NetworkedSessions => Sessions;
-
-        /// <inheritdoc />
-        public IEnumerable<ICommonSession> Sessions
-        {
-            get
-            {
-                _sessionsLock.EnterReadLock();
-                try
-                {
-                    return _sessions.Values;
-                }
-                finally
-                {
-                    _sessionsLock.ExitReadLock();
-                }
-            }
-        }
-
-        public IEnumerable<IPlayerSession> ServerSessions => Sessions.Cast<IPlayerSession>();
-
-        /// <inheritdoc />
-        [ViewVariables]
-        public int PlayerCount
-        {
-            get
-            {
-                _sessionsLock.EnterReadLock();
-                try
-                {
-                    return _sessions.Count;
-                }
-                finally
-                {
-                    _sessionsLock.ExitReadLock();
-                }
-            }
-        }
-
-        /// <inheritdoc />
-        [ViewVariables]
-        public int MaxPlayers { get; private set; } = 32;
-
-        public ICommonSession? LocalSession => null;
-
-        /// <inheritdoc />
-        public event EventHandler<SessionStatusEventArgs>? PlayerStatusChanged;
-
-        /// <inheritdoc />
-        public void Initialize(int maxPlayers)
+        public override void Initialize(int maxPlayers)
         {
+            base.Initialize(maxPlayers);
             KeyMap = new BoundKeyMap(_reflectionManager);
             KeyMap.PopulateKeyFunctionsMap();
 
-            MaxPlayers = maxPlayers;
-
             _network.RegisterNetMessage<MsgPlayerListReq>(HandlePlayerListReq);
             _network.RegisterNetMessage<MsgPlayerList>();
             _network.RegisterNetMessage<MsgSyncTimeBase>();
@@ -123,8 +53,9 @@ namespace Robust.Server.Player
             _network.Disconnect += EndSession;
         }
 
-        public void Shutdown()
+        public override void Shutdown()
         {
+            base.Shutdown();
             KeyMap = default!;
 
             _network.Connecting -= OnConnecting;
@@ -132,250 +63,6 @@ namespace Robust.Server.Player
             _network.Disconnect -= EndSession;
         }
 
-        public bool TryGetSessionByUsername(string username, [NotNullWhen(true)] out IPlayerSession? session)
-        {
-            if (!_userIdMap.TryGetValue(username, out var userId))
-            {
-                session = null;
-                return false;
-            }
-
-            _sessionsLock.EnterReadLock();
-            try
-            {
-                if (_sessions.TryGetValue(userId, out var iSession))
-                {
-                    session = iSession;
-                    return true;
-                }
-            }
-            finally
-            {
-                _sessionsLock.ExitReadLock();
-            }
-
-
-            session = null;
-            return false;
-        }
-
-        IPlayerSession IPlayerManager.GetSessionByChannel(INetChannel channel) => GetSessionByChannel(channel);
-        public bool TryGetSessionByChannel(INetChannel channel, [NotNullWhen(true)] out IPlayerSession? session)
-        {
-            _sessionsLock.EnterReadLock();
-            try
-            {
-                // Should only be one session per client. Returns that session, in theory.
-                if (_sessions.TryGetValue(channel.UserId, out var concrete))
-                {
-                    session = concrete;
-                    return true;
-                }
-
-                session = null;
-                return false;
-            }
-            finally
-            {
-                _sessionsLock.ExitReadLock();
-            }
-        }
-
-        private PlayerSession GetSessionByChannel(INetChannel channel)
-        {
-            _sessionsLock.EnterReadLock();
-            try
-            {
-                // Should only be one session per client. Returns that session, in theory.
-                return _sessions[channel.UserId];
-            }
-            finally
-            {
-                _sessionsLock.ExitReadLock();
-            }
-        }
-
-        /// <inheritdoc />
-        public IPlayerSession GetSessionByUserId(NetUserId index)
-        {
-            _sessionsLock.EnterReadLock();
-            try
-            {
-                return _sessions[index];
-            }
-            finally
-            {
-                _sessionsLock.ExitReadLock();
-            }
-        }
-
-        public bool ValidSessionId(NetUserId index)
-        {
-            _sessionsLock.EnterReadLock();
-            try
-            {
-                return _sessions.ContainsKey(index);
-            }
-            finally
-            {
-                _sessionsLock.ExitReadLock();
-            }
-        }
-
-        public bool TryGetSessionById(NetUserId userId, [NotNullWhen(true)] out IPlayerSession? session)
-        {
-            _sessionsLock.EnterReadLock();
-            try
-            {
-                if (_sessions.TryGetValue(userId, out var playerSession))
-                {
-                    session = playerSession;
-                    return true;
-                }
-            }
-            finally
-            {
-                _sessionsLock.ExitReadLock();
-            }
-            session = default;
-            return false;
-        }
-
-        /// <summary>
-        ///     Causes all sessions to switch from the lobby to the the game.
-        /// </summary>
-        [Obsolete]
-        public void SendJoinGameToAll()
-        {
-            _sessionsLock.EnterReadLock();
-            try
-            {
-                foreach (var s in _sessions.Values)
-                {
-                    s.JoinGame();
-                }
-            }
-            finally
-            {
-                _sessionsLock.ExitReadLock();
-            }
-        }
-
-        public bool TryGetUserId(string userName, out NetUserId userId)
-        {
-            return _userIdMap.TryGetValue(userName, out userId);
-        }
-
-        public IEnumerable<IPlayerData> GetAllPlayerData()
-        {
-            return _playerData.Values;
-        }
-
-        /// <summary>
-        ///     Causes all sessions to detach from their entity.
-        /// </summary>
-        [Obsolete]
-        public void DetachAll()
-        {
-            _sessionsLock.EnterReadLock();
-            try
-            {
-                foreach (var s in _sessions.Values)
-                {
-                    s.DetachFromEntity();
-                }
-            }
-            finally
-            {
-                _sessionsLock.ExitReadLock();
-            }
-        }
-
-        /// <summary>
-        ///     Gets all players inside of a circle.
-        /// </summary>
-        /// <param name="worldPos">Position of the circle in world-space.</param>
-        /// <param name="range">Radius of the circle in world units.</param>
-        /// <returns></returns>
-        [Obsolete("Use player Filter or Inline me!")]
-        public List<IPlayerSession> GetPlayersInRange(MapCoordinates worldPos, int range)
-        {
-            return Filter.Empty()
-                .AddInRange(worldPos, range)
-                .Recipients
-                .Cast<IPlayerSession>()
-                .ToList();
-        }
-
-        /// <summary>
-        ///     Gets all players inside of a circle.
-        /// </summary>
-        /// <param name="worldPos">Position of the circle in world-space.</param>
-        /// <param name="range">Radius of the circle in world units.</param>
-        /// <returns></returns>
-        [Obsolete("Use player Filter or Inline me!")]
-        public List<IPlayerSession> GetPlayersInRange(EntityCoordinates worldPos, int range)
-        {
-            return Filter.Empty()
-                .AddInRange(worldPos.ToMap(_entityManager), range)
-                .Recipients
-                .Cast<IPlayerSession>()
-                .ToList();
-        }
-
-        [Obsolete("Use player Filter or Inline me!")]
-        public List<IPlayerSession> GetPlayersBy(Func<IPlayerSession, bool> predicate)
-        {
-            return Filter.Empty()
-                .AddWhere((session => predicate((IPlayerSession)session)))
-                .Recipients
-                .Cast<IPlayerSession>()
-                .ToList();
-        }
-
-        /// <summary>
-        ///     Gets all players in the server.
-        /// </summary>
-        /// <returns></returns>
-        [Obsolete("Use player Filter or Inline me!")]
-        public List<IPlayerSession> GetAllPlayers()
-        {
-            return ServerSessions.ToList();
-        }
-
-        /// <summary>
-        ///     Gets all player states in the server.
-        /// </summary>
-        /// <param name="fromTick"></param>
-        /// <returns></returns>
-        public List<PlayerState>? GetPlayerStates(GameTick fromTick)
-        {
-            if (_lastStateUpdate < fromTick)
-            {
-                return null;
-            }
-
-            _sessionsLock.EnterReadLock();
-            try
-            {
-#if FULL_RELEASE
-                return _sessions.Values
-                    .Select(s => s.PlayerState)
-                    .ToList();
-#else
-                // Integration tests need to clone data before "sending" it to the client. Otherwise they reference the
-                // same object.
-                return _sessions.Values
-                    .Select(s => s.PlayerState.Clone())
-                    .ToList();
-#endif
-            }
-            finally
-            {
-                _sessionsLock.ExitReadLock();
-            }
-        }
-
         private Task OnConnecting(NetConnectingArgs args)
         {
             if (PlayerCount >= _baseServer.MaxPlayers)
@@ -393,30 +80,8 @@ namespace Robust.Server.Player
         /// <param name="args"></param>
         private void NewSession(object? sender, NetChannelArgs args)
         {
-            if (!_playerData.TryGetValue(args.Channel.UserId, out var data))
-            {
-                data = new PlayerData(args.Channel.UserId, args.Channel.UserName);
-                _playerData.Add(args.Channel.UserId, data);
-            }
-
-            _userIdMap[args.Channel.UserName] = args.Channel.UserId;
-
-            var session = new PlayerSession(this, args.Channel, data);
-
-            session.PlayerStatusChanged += (_, sessionArgs) => OnPlayerStatusChanged(session, sessionArgs.OldStatus, sessionArgs.NewStatus);
-
-            _sessionsLock.EnterWriteLock();
-            try
-            {
-                _sessions.Add(args.Channel.UserId, session);
-            }
-            finally
-            {
-                _sessionsLock.ExitWriteLock();
-            }
-
+            CreateAndAddSession(args.Channel);
             PlayerCountMetric.Set(PlayerCount);
-
             // Synchronize base time.
             var msgTimeBase = new MsgSyncTimeBase();
             (msgTimeBase.Time, msgTimeBase.Tick) = _timing.TimeBase;
@@ -425,11 +90,6 @@ namespace Robust.Server.Player
             _cfg.SyncConnectingClient(args.Channel);
         }
 
-        private void OnPlayerStatusChanged(IPlayerSession session, SessionStatus oldStatus, SessionStatus newStatus)
-        {
-            PlayerStatusChanged?.Invoke(this, new SessionStatusEventArgs(session, oldStatus, newStatus));
-        }
-
         /// <summary>
         ///     Ends a clients session, and disconnects them.
         /// </summary>
@@ -441,20 +101,18 @@ namespace Robust.Server.Player
             }
 
             // make sure nothing got messed up during the life of the session
-            DebugTools.Assert(session.ConnectedClient == args.Channel);
+            DebugTools.Assert(session.Channel == args.Channel);
 
-            //Detach the entity and (don't)delete it.
-            session.OnDisconnect();
-            _sessionsLock.EnterWriteLock();
-            try
+            SetStatus(session, SessionStatus.Disconnected);
+            SetAttachedEntity(session, null, out _, true);
+
+            var viewSys = EntManager.System<ViewSubscriberSystem>();
+            foreach (var eye in session.ViewSubscriptions.ToArray())
             {
-                _sessions.Remove(session.UserId);
-            }
-            finally
-            {
-                _sessionsLock.ExitWriteLock();
+                viewSys.RemoveViewSubscriber(eye, session);
             }
 
+            RemoveSession(session.UserId);
             PlayerCountMetric.Set(PlayerCount);
             Dirty();
         }
@@ -469,17 +127,18 @@ namespace Robust.Server.Player
             // This is done before the packet is built, so that the client
             // can see themselves Connected.
             var session = GetSessionByChannel(channel);
-            session.OnConnect();
+            session.ConnectedTime = DateTime.UtcNow;
+            SetStatus(session, SessionStatus.Connected);
 
-            var list = new List<PlayerState>();
+            var list = new List<SessionState>();
             foreach (var client in players)
             {
-                var info = new PlayerState
+                var info = new SessionState
                 {
                     UserId = client.UserId,
                     Name = client.Name,
                     Status = client.Status,
-                    Ping = client.ConnectedClient.Ping
+                    Ping = client.Channel!.Ping
                 };
                 list.Add(info);
             }
@@ -489,46 +148,7 @@ namespace Robust.Server.Player
             channel.SendMessage(netMsg);
         }
 
-        public void Dirty()
-        {
-            _lastStateUpdate = _timing.CurTick;
-        }
-
-        public IPlayerData GetPlayerData(NetUserId userId)
-        {
-            return _playerData[userId];
-        }
-
-        public bool TryGetPlayerData(NetUserId userId, [NotNullWhen(true)] out IPlayerData? data)
-        {
-            if (_playerData.TryGetValue(userId, out var playerData))
-            {
-                data = playerData;
-                return true;
-            }
-            data = default;
-            return false;
-        }
-
-        public bool TryGetPlayerDataByUsername(string userName, [NotNullWhen(true)] out IPlayerData? data)
-        {
-            if (!_userIdMap.TryGetValue(userName, out var userId))
-            {
-                data = null;
-                return false;
-            }
-
-            // PlayerData is initialized together with the _userIdMap so we can trust that it'll be present.
-            data = _playerData[userId];
-            return true;
-        }
-
-        public bool HasPlayerData(NetUserId userId)
-        {
-            return _playerData.ContainsKey(userId);
-        }
-
-        public bool TryGetSessionByEntity(EntityUid uid, [NotNullWhen(true)] out ICommonSession? session)
+        public override bool TryGetSessionByEntity(EntityUid uid, [NotNullWhen(true)] out ICommonSession? session)
         {
             if (!_entityManager.TryGetComponent(uid, out ActorComponent? actor))
             {
@@ -540,18 +160,4 @@ namespace Robust.Server.Player
             return true;
         }
     }
-
-    public sealed class SessionStatusEventArgs : EventArgs
-    {
-        public SessionStatusEventArgs(IPlayerSession session, SessionStatus oldStatus, SessionStatus newStatus)
-        {
-            Session = session;
-            OldStatus = oldStatus;
-            NewStatus = newStatus;
-        }
-
-        public IPlayerSession Session { get; }
-        public SessionStatus OldStatus { get; }
-        public SessionStatus NewStatus { get; }
-    }
 }

Robust.Server/Player/PlayerSession.cs

@@ -1,224 +0,0 @@
-using System;
-using System.Collections.Generic;
-using Robust.Server.GameObjects;
-using Robust.Shared.Enums;
-using Robust.Shared.GameObjects;
-using Robust.Shared.GameStates;
-using Robust.Shared.IoC;
-using Robust.Shared.Log;
-using Robust.Shared.Network;
-using Robust.Shared.Player;
-using Robust.Shared.Players;
-using Robust.Shared.ViewVariables;
-
-namespace Robust.Server.Player
-{
-    /// <summary>
-    /// This is the session of a connected client.
-    /// </summary>
-    internal sealed class PlayerSession : IPlayerSession
-    {
-        private readonly PlayerManager _playerManager;
-        public readonly PlayerState PlayerState;
-        private readonly HashSet<EntityUid> _viewSubscriptions = new();
-
-        public PlayerSession(PlayerManager playerManager, INetChannel client, PlayerData data)
-        {
-            _playerManager = playerManager;
-            UserId = client.UserId;
-            Name = client.UserName;
-            _data = data;
-
-            PlayerState = new PlayerState
-            {
-                UserId = client.UserId,
-            };
-
-            ConnectedClient = client;
-
-            UpdatePlayerState();
-        }
-
-        [ViewVariables] public IReadOnlySet<EntityUid> ViewSubscriptions => _viewSubscriptions;
-        public int ViewSubscriptionCount => _viewSubscriptions.Count;
-
-        [ViewVariables] public INetChannel ConnectedClient { get; }
-
-        /// <inheritdoc />
-        [ViewVariables] public EntityUid? AttachedEntity { get; set; }
-
-        private SessionStatus _status = SessionStatus.Connecting;
-
-        [ViewVariables]
-        internal string Name { get; set; }
-
-        /// <inheritdoc />
-        string ICommonSession.Name
-        {
-            get => this.Name;
-            set => this.Name = value;
-        }
-
-        [ViewVariables]
-        internal short Ping
-        {
-            get => ConnectedClient.Ping;
-            set => throw new NotSupportedException();
-        }
-
-        short ICommonSession.Ping
-        {
-            get => this.Ping;
-            set => this.Ping = value;
-        }
-
-        [ViewVariables]
-        internal SessionStatus Status
-        {
-            get => _status;
-            set
-            {
-                if (_status == value)
-                    return;
-
-                var old = _status;
-                _status = value;
-                UpdatePlayerState();
-
-                PlayerStatusChanged?.Invoke(this, new SessionStatusEventArgs(this, old, value));
-            }
-        }
-
-        /// <inheritdoc />
-        SessionStatus ICommonSession.Status
-        {
-            get => this.Status;
-            set => this.Status = value;
-        }
-
-        /// <inheritdoc />
-        public DateTime ConnectedTime { get; private set; }
-
-        [ViewVariables(VVAccess.ReadWrite)]
-        public int VisibilityMask { get; set; } = 1;
-
-        /// <inheritdoc />
-        [ViewVariables]
-        public NetUserId UserId { get; }
-
-        private readonly PlayerData _data;
-
-        [ViewVariables] public IPlayerData Data => _data;
-
-        /// <inheritdoc />
-        public event EventHandler<SessionStatusEventArgs>? PlayerStatusChanged;
-
-        /// <inheritdoc />
-        [Obsolete("Use ActorSystem.Attach() instead.")]
-        public void AttachToEntity(EntityUid? entity)
-        {
-            EntitySystem.Get<ActorSystem>().Attach(entity, this);
-        }
-
-        /// <inheritdoc />
-        [Obsolete("Use ActorSystem.Attach() instead.")]
-        public void AttachToEntity(EntityUid uid)
-        {
-            EntitySystem.Get<ActorSystem>().Attach(uid, this);
-        }
-
-        /// <inheritdoc />
-        [Obsolete("Use ActorSystem.Detach() instead.")]
-        public void DetachFromEntity()
-        {
-            if (AttachedEntity == null)
-                return;
-
-            if (IoCManager.Resolve<IEntityManager>().Deleted(AttachedEntity!.Value))
-            {
-                Logger.Error($"Player \"{this}\" was attached to an entity that was deleted. THIS SHOULD NEVER HAPPEN, BUT DOES.");
-                // We can't contact ActorSystem because trying to fire an entity event would crash.
-                // Work around it.
-                AttachedEntity = null;
-                UpdatePlayerState();
-                return;
-            }
-
-            EntitySystem.Get<ActorSystem>().Detach(AttachedEntity.Value);
-        }
-
-        /// <inheritdoc />
-        public void OnConnect()
-        {
-            ConnectedTime = DateTime.UtcNow;
-            Status = SessionStatus.Connected;
-            UpdatePlayerState();
-        }
-
-        /// <inheritdoc />
-        public void OnDisconnect()
-        {
-            Status = SessionStatus.Disconnected;
-
-            UnsubscribeAllViews();
-            DetachFromEntity();
-            UpdatePlayerState();
-        }
-
-        /// <summary>
-        ///     Causes the session to switch from the lobby to the game.
-        /// </summary>
-        public void JoinGame()
-        {
-            if (ConnectedClient == null || Status == SessionStatus.InGame)
-                return;
-
-            Status = SessionStatus.InGame;
-            UpdatePlayerState();
-        }
-
-        public LoginType AuthType => ConnectedClient.AuthType;
-
-        /// <inheritdoc />
-        void IPlayerSession.SetAttachedEntity(EntityUid? entity)
-        {
-            AttachedEntity = entity;
-            UpdatePlayerState();
-        }
-
-        void IPlayerSession.AddViewSubscription(EntityUid eye)
-        {
-            _viewSubscriptions.Add(eye);
-        }
-
-        void IPlayerSession.RemoveViewSubscription(EntityUid eye)
-        {
-            _viewSubscriptions.Remove(eye);
-        }
-
-        private void UnsubscribeAllViews()
-        {
-            var viewSubscriberSystem = EntitySystem.Get<ViewSubscriberSystem>();
-
-            foreach (var eye in _viewSubscriptions)
-            {
-                viewSubscriberSystem.RemoveViewSubscriber(eye, this);
-            }
-        }
-
-        private void UpdatePlayerState()
-        {
-            PlayerState.Status = Status;
-            PlayerState.Name = Name;
-            PlayerState.ControlledEntity = IoCManager.Resolve<IEntityManager>().GetNetEntity(AttachedEntity);
-
-            _playerManager.Dirty();
-        }
-
-        /// <inheritdoc />
-        public override string ToString()
-        {
-            return Name;
-        }
-    }
-}

Robust.Server/Robust.Server.csproj

@@ -22,7 +22,7 @@
     <PackageReference Include="Microsoft.Extensions.Primitives" Version="6.0.0" />
     <PackageReference Include="prometheus-net.DotNetRuntime" Version="4.2.2" />
     <PackageReference Include="TerraFX.Interop.Windows" Version="10.0.20348-rc2" PrivateAssets="compile" />
-    <PackageReference Include="Microsoft.Extensions.ObjectPool" Version="6.0.2" PrivateAssets="compile" />
+    <PackageReference Include="Microsoft.Extensions.ObjectPool" Version="7.0.0" PrivateAssets="compile" />
     <PackageReference Include="SpaceWizards.Sodium" Version="0.2.1" PrivateAssets="compile" />
     <PackageReference Include="SharpZstd.Interop" Version="1.5.2-beta2" PrivateAssets="compile" />
     <PackageReference Condition="'$(FullRelease)' != 'True'" Include="JetBrains.Profiler.Api" Version="1.2.0" />

Robust.Server/Scripting/ScriptHost.cs

@@ -1,9 +1,9 @@
-using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Text;
+using System.Threading.Tasks;
 using JetBrains.Annotations;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Completion;
@@ -20,6 +20,7 @@ using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
+using Robust.Shared.Player;
 using Robust.Shared.Reflection;
 using Robust.Shared.Scripting;
 using Robust.Shared.Utility;
@@ -38,7 +39,7 @@ namespace Robust.Server.Scripting
         [Dependency] private readonly IDependencyCollection _dependencyCollection = default!;
         [Dependency] private readonly ILogManager _logManager = default!;
 
-        readonly Dictionary<IPlayerSession, Dictionary<int, ScriptInstance>> _instances =
+        readonly Dictionary<ICommonSession, Dictionary<int, ScriptInstance>> _instances =
             new();
 
         private ISawmill _sawmill = default!;
@@ -294,9 +295,9 @@ namespace Robust.Server.Scripting
                 loader: TextLoader.From(TextAndVersion.Create(SourceText.From(message.Code), VersionStamp.Create()))
             ));
 
-            var results = await CompletionService
-                .GetService(document)
-                .GetCompletionsAsync(document, message.Cursor);
+            var results = await (CompletionService
+                .GetService(document)?
+                .GetCompletionsAsync(document, message.Cursor) ?? Task.FromResult<CompletionList?>(null));
 
             if (results is not null)
             {