[cdac] Pass a delegate into Target

src/native/managed/cdacreader/src/Entrypoints.cs

@@ -15,7 +15,7 @@ internal static class Entrypoints
     private static unsafe int Init(ulong descriptor, delegate* unmanaged<ulong, byte*, uint, void*, int> readFromTarget, void* readContext, IntPtr* handle)
     {
         // TODO: [cdac] Better error code/details
-        if (!Target.TryCreate(descriptor, readFromTarget, readContext, out Target? target))
+        if (!Target.TryCreate(descriptor, (address, buffer, bufferLength) => readFromTarget(address, buffer, bufferLength, readContext), out Target? target))
             return -1;
 
         GCHandle gcHandle = GCHandle.Alloc(target);

src/native/managed/cdacreader/src/Target.cs

@@ -81,9 +81,11 @@ private readonly struct Configuration
     internal Contracts.Registry Contracts { get; }
     internal DataCache ProcessedData { get; }
 
-    public static bool TryCreate(ulong contractDescriptor, delegate* unmanaged<ulong, byte*, uint, void*, int> readFromTarget, void* readContext, out Target? target)
+    public delegate int ReadFromTargetDelegate(ulong address, byte* buffer, uint bytesToRead);
+
+    public static bool TryCreate(ulong contractDescriptor, ReadFromTargetDelegate readFromTarget, out Target? target)
     {
-        Reader reader = new Reader(readFromTarget, readContext);
+        Reader reader = new Reader(readFromTarget);
         if (TryReadContractDescriptor(contractDescriptor, reader, out Configuration config, out ContractDescriptorParser.ContractDescriptor? descriptor, out TargetPointer[] pointerData))
         {
             target = new Target(config, descriptor!, pointerData, reader);
@@ -418,26 +420,17 @@ public bool TryGet<T>(ulong address, [NotNullWhen(true)] out T? data)
         }
     }
 
-    private sealed class Reader
+    private struct Reader(Target.ReadFromTargetDelegate readFromTarget)
     {
-        private readonly delegate* unmanaged<ulong, byte*, uint, void*, int> _readFromTarget;
-        private readonly void* _context;
-
-        public Reader(delegate* unmanaged<ulong, byte*, uint, void*, int> readFromTarget, void* context)
-        {
-            _readFromTarget = readFromTarget;
-            _context = context;
-        }
-
         public int ReadFromTarget(ulong address, Span<byte> buffer)
         {
             fixed (byte* bufferPtr = buffer)
             {
-                return _readFromTarget(address, bufferPtr, (uint)buffer.Length, _context);
+                return readFromTarget(address, bufferPtr, (uint)buffer.Length);
             }
         }
 
         public int ReadFromTarget(ulong address, byte* buffer, uint bytesToRead)
-            => _readFromTarget(address, buffer, bytesToRead, _context);
+            => readFromTarget(address, buffer, bytesToRead);
     }
 }

src/native/managed/cdacreader/tests/MockMemorySpace.cs

@@ -159,11 +159,10 @@ public static ReadContext CreateContext(ReadOnlySpan<byte> descriptor, ReadOnlyS
 
     public static bool TryCreateTarget(ReadContext* context, out Target? target)
     {
-        return Target.TryCreate(ContractDescriptorAddr, &ReadFromTarget, context, out target);
+        return Target.TryCreate(ContractDescriptorAddr, (address, buffer, length) => ReadFromTarget(address, buffer, length, context), out target);
     }
 
-    [UnmanagedCallersOnly]
-    private static int ReadFromTarget(ulong address, byte* buffer, uint length, void* context)
+    private static int ReadFromTarget(ulong address, byte* buffer, uint length, ReadContext* context)
     {
         ReadContext* readContext = (ReadContext*)context;
         var span = new Span<byte>(buffer, (int)length);