Revert optimization for RendererBase to use a plain type for the dict…

…ionary key (xoofx#632)

src/Markdig/Renderers/RendererBase.cs

@@ -19,20 +19,7 @@ namespace Markdig.Renderers
  /// <seealso cref="IMarkdownRenderer" />
  public abstract class RendererBase : IMarkdownRenderer
  {
- private readonly struct KeyWrapper : IEquatable<KeyWrapper>
- {
- public readonly IntPtr Key;
-
- public KeyWrapper(IntPtr key) => Key = key;
-
- public bool Equals(KeyWrapper other) => Key == other.Key;
-
- public override int GetHashCode() => Key.GetHashCode();
-
- public override bool Equals(object? obj) => throw new NotImplementedException();
- }
-
- private readonly Dictionary<KeyWrapper, IMarkdownObjectRenderer?> _renderersPerType = new();
+ private readonly Dictionary<Type, IMarkdownObjectRenderer?> _renderersPerType = new();
  internal int _childrenDepth = 0;
 
  /// <summary>
@@ -42,13 +29,11 @@ public abstract class RendererBase : IMarkdownRenderer
 
  private IMarkdownObjectRenderer? GetRendererInstance(MarkdownObject obj)
  {
- KeyWrapper key = GetKeyForType(obj);
- Type objectType = obj.GetType();
-
+ var key = obj.GetType();
  for (int i = 0; i < ObjectRenderers.Count; i++)
  {
  var renderer = ObjectRenderers[i];
- if (renderer.Accept(this, objectType))
+ if (renderer.Accept(this, key))
  {
  _renderersPerType[key] = renderer;
  return renderer;
@@ -156,7 +141,7 @@ public void Write(MarkdownObject obj)
  // Calls before writing an object
  ObjectWriteBefore?.Invoke(this, obj);
 
- if (!_renderersPerType.TryGetValue(GetKeyForType(obj), out IMarkdownObjectRenderer? renderer))
+ if (!_renderersPerType.TryGetValue(obj.GetType(), out IMarkdownObjectRenderer? renderer))
  {
  renderer = GetRendererInstance(obj);
  }
@@ -177,55 +162,5 @@ public void Write(MarkdownObject obj)
  // Calls after writing an object
  ObjectWriteAfter?.Invoke(this, obj);
  }
-
- [MethodImpl(MethodImplOptions.AggressiveInlining)]
- private static KeyWrapper GetKeyForType(MarkdownObject obj)
- {
-#if NET
- if (s_canUseMethodTablePointer)
- {
- IntPtr methodTablePtr = Unsafe.Add(ref Unsafe.As<RawData>(obj).Data, -1);
- return new KeyWrapper(methodTablePtr);
- }
-#endif
-
- IntPtr typeHandle = Type.GetTypeHandle(obj).Value;
- return new KeyWrapper(typeHandle);
- }
-
-#if NET
- private sealed class RawData
- {
- public IntPtr Data;
- }
-
- private static readonly bool s_canUseMethodTablePointer = GetCanUseMethodTablePointer();
-
- private static bool GetCanUseMethodTablePointer()
- {
- if (RuntimeInformation.OSArchitecture == Architecture.Wasm)
- {
- return false;
- }
-
- var obj1 = new LiteralInline();
- var obj2 = new ParagraphBlock();
- var obj3 = new LiteralInline();
- IntPtr ptr1 = Unsafe.Add(ref Unsafe.As<RawData>(obj1).Data, -1);
- IntPtr ptr2 = Unsafe.Add(ref Unsafe.As<RawData>(obj2).Data, -1);
- IntPtr ptr3 = Unsafe.Add(ref Unsafe.As<RawData>(obj3).Data, -1);
- GC.KeepAlive(obj1);
- GC.KeepAlive(obj2);
- GC.KeepAlive(obj3);
-
- if (ptr1 == ptr2 || ptr1 != ptr3)
- {
- Debug.Fail("This platform doesn't support the MT pointer optimization");
- return false;
- }
-
- return true;
- }
-#endif
  }
 }