From 1d7829593e7cc59f319f133407bf4edac10cfc7e Mon Sep 17 00:00:00 2001
From: Ottermandias <nickroederspam+git1@gmail.com>
Date: Fri, 1 Jul 2022 16:20:09 +0200
Subject: [PATCH] Add IncRef mode and debug DecRef check.

---
 .../Interop/Loader/ResourceLoader.Debug.cs    | 22 +++++++++++--
 .../Loader/ResourceLoader.Replacement.cs      | 33 +++++++++++--------
 Penumbra/Interop/Loader/ResourceLoader.cs     |  7 ++++
 3 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/Penumbra/Interop/Loader/ResourceLoader.Debug.cs b/Penumbra/Interop/Loader/ResourceLoader.Debug.cs
index ce95d523..6258dc13 100644
--- a/Penumbra/Interop/Loader/ResourceLoader.Debug.cs
+++ b/Penumbra/Interop/Loader/ResourceLoader.Debug.cs
@@ -14,6 +14,10 @@ namespace Penumbra.Interop.Loader;
 
 public unsafe partial class ResourceLoader
 {
+    // If in debug mode, this logs any resource at refcount 0 that gets decremented again, and skips the decrement instead.
+    private delegate byte                       ResourceHandleDecRef( ResourceHandle* handle );
+    private readonly Hook<ResourceHandleDecRef> _decRefHook;
+
     public delegate IntPtr ResourceHandleDestructor( ResourceHandle* handle );
 
     [Signature( "48 89 5C 24 ?? 57 48 83 EC ?? 48 8D 05 ?? ?? ?? ?? 48 8B D9 48 89 01 B8",
@@ -24,8 +28,8 @@ public unsafe partial class ResourceLoader
     {
         if( handle != null )
         {
-            PluginLog.Information( "[ResourceLoader] Destructing Resource Handle {Path:l} at 0x{Address:X} (Refcount {Refcount}) .", handle->FileName,
-                ( ulong )handle, handle->RefCount );
+            PluginLog.Information( "[ResourceLoader] Destructing Resource Handle {Path:l} at 0x{Address:X} (Refcount {Refcount}) .",
+                handle->FileName, ( ulong )handle, handle->RefCount );
         }
 
         return ResourceHandleDestructorHook!.Original( handle );
@@ -54,11 +58,13 @@ public unsafe partial class ResourceLoader
 
     public void EnableDebug()
     {
+        _decRefHook?.Enable();
         ResourceLoaded += AddModifiedDebugInfo;
     }
 
     public void DisableDebug()
     {
+        _decRefHook?.Disable();
         ResourceLoaded -= AddModifiedDebugInfo;
     }
 
@@ -207,6 +213,18 @@ public unsafe partial class ResourceLoader
         }
     }
 
+    // Prevent resource management weirdness.
+    private byte ResourceHandleDecRefDetour( ResourceHandle* handle )
+    {
+        if( handle->RefCount != 0 )
+        {
+            return _decRefHook!.Original( handle );
+        }
+
+        PluginLog.Error( $"Caught decrease of Reference Counter for {handle->FileName} at 0x{( ulong )handle:X} below 0." );
+        return 1;
+    }
+
     // Logging functions for EnableFullLogging.
     private static void LogPath( Utf8GamePath path, bool synchronous )
         => PluginLog.Information( $"[ResourceLoader] Requested {path} {( synchronous ? "synchronously." : "asynchronously." )}" );
diff --git a/Penumbra/Interop/Loader/ResourceLoader.Replacement.cs b/Penumbra/Interop/Loader/ResourceLoader.Replacement.cs
index eac70a20..0c9f6c7b 100644
--- a/Penumbra/Interop/Loader/ResourceLoader.Replacement.cs
+++ b/Penumbra/Interop/Loader/ResourceLoader.Replacement.cs
@@ -84,18 +84,6 @@ public unsafe partial class ResourceLoader
 
         ResourceRequested?.Invoke( gamePath, isSync );
 
-        // Force metadata tables to load synchronously and not be able to be replaced.
-        switch( *resourceType )
-        {
-            case ResourceType.Eqp:
-            case ResourceType.Gmp:
-            case ResourceType.Eqdp:
-            case ResourceType.Cmp:
-            case ResourceType.Est:
-                PluginLog.Verbose( "Forced resource {gamePath} to be loaded synchronously.", gamePath );
-                return CallOriginalHandler( true, resourceManager, categoryId, resourceType, resourceHash, path, pGetResParams, isUnk );
-        }
-
         // If no replacements are being made, we still want to be able to trigger the event.
         var (resolvedPath, data) = ResolvePath( gamePath, *categoryId, *resourceType, *resourceHash );
         PathResolved?.Invoke( gamePath, *resourceType, resolvedPath, data );
@@ -126,7 +114,7 @@ public unsafe partial class ResourceLoader
     // Try all resolve path subscribers or use the default replacer.
     private (FullPath?, object?) ResolvePath( Utf8GamePath path, ResourceCategory category, ResourceType resourceType, int resourceHash )
     {
-        if( !DoReplacements )
+        if( !DoReplacements || IsInIncRef )
         {
             return ( null, null );
         }
@@ -259,7 +247,7 @@ public unsafe partial class ResourceLoader
         ResourceHandleDestructorHook?.Dispose();
     }
 
-    private int ComputeHash( Utf8String path, GetResourceParameters* pGetResParams )
+    private static int ComputeHash( Utf8String path, GetResourceParameters* pGetResParams )
     {
         if( pGetResParams == null || !pGetResParams->IsPartialRead )
         {
@@ -276,4 +264,21 @@ public unsafe partial class ResourceLoader
             Utf8String.FromStringUnsafe( pGetResParams->SegmentLength.ToString( "x" ), true )
         ).Crc32;
     }
+
+
+    // A resource with ref count 0 that gets incremented goes through GetResourceAsync again.
+    // This means, that if the path determined from that is different than the resources path,
+    // a different resource gets loaded or incremented, while the IncRef'd resource stays at 0.
+    // This causes some problems and is hopefully prevented with this.
+    public bool IsInIncRef { get; private set; } = false;
+    private readonly Hook< ResourceHandleDestructor > _incRefHook;
+
+    private IntPtr ResourceHandleIncRefDetour( ResourceHandle* handle )
+    {
+        var tmp = IsInIncRef;
+        IsInIncRef = true;
+        var ret = _incRefHook.Original( handle );
+        IsInIncRef = tmp;
+        return ret;
+    }
 }
\ No newline at end of file
diff --git a/Penumbra/Interop/Loader/ResourceLoader.cs b/Penumbra/Interop/Loader/ResourceLoader.cs
index bc575d2e..f36b90c5 100644
--- a/Penumbra/Interop/Loader/ResourceLoader.cs
+++ b/Penumbra/Interop/Loader/ResourceLoader.cs
@@ -1,4 +1,5 @@
 using System;
+using Dalamud.Hooking;
 using Dalamud.Utility.Signatures;
 using FFXIVClientStructs.FFXIV.Client.System.Resource;
 using Penumbra.GameData.ByteString;
@@ -82,6 +83,7 @@ public unsafe partial class ResourceLoader : IDisposable
         ReadSqPackHook.Enable();
         GetResourceSyncHook.Enable();
         GetResourceAsyncHook.Enable();
+        _incRefHook.Enable();
     }
 
     public void DisableHooks()
@@ -95,11 +97,16 @@ public unsafe partial class ResourceLoader : IDisposable
         ReadSqPackHook.Disable();
         GetResourceSyncHook.Disable();
         GetResourceAsyncHook.Disable();
+        _incRefHook.Disable();
     }
 
     public ResourceLoader( Penumbra _ )
     {
         SignatureHelper.Initialise( this );
+        _decRefHook = new Hook< ResourceHandleDecRef >( ( IntPtr )FFXIVClientStructs.FFXIV.Client.System.Resource.Handle.ResourceHandle.fpDecRef,
+            ResourceHandleDecRefDetour );
+        _incRefHook = new Hook< ResourceHandleDestructor >(
+            ( IntPtr )FFXIVClientStructs.FFXIV.Client.System.Resource.Handle.ResourceHandle.fpIncRef, ResourceHandleIncRefDetour );
     }
 
     // Event fired whenever a resource is requested.