Refactor instruction handlers to use single instruction per handler pattern

X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs

@@ -0,0 +1,72 @@
+namespace X86Disassembler.X86.Handlers;
+
+/// <summary>
+/// Factory for creating instruction handlers
+/// </summary>
+public class InstructionHandlerFactory
+{
+    private readonly byte[] _codeBuffer;
+    private readonly InstructionDecoder _decoder;
+    private readonly int _length;
+    private readonly List<IInstructionHandler> _handlers = new List<IInstructionHandler>();
+    
+    /// <summary>
+    /// Initializes a new instance of the InstructionHandlerFactory class
+    /// </summary>
+    /// <param name="codeBuffer">The buffer containing the code to decode</param>
+    /// <param name="decoder">The instruction decoder that owns this factory</param>
+    /// <param name="length">The length of the buffer</param>
+    public InstructionHandlerFactory(byte[] codeBuffer, InstructionDecoder decoder, int length)
+    {
+        _codeBuffer = codeBuffer;
+        _decoder = decoder;
+        _length = length;
+        
+        // Register all instruction handlers
+        RegisterHandlers();
+    }
+    
+    /// <summary>
+    /// Registers all instruction handlers
+    /// </summary>
+    private void RegisterHandlers()
+    {
+        // Register specific instruction handlers
+        _handlers.Add(new RetHandler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new RetImmHandler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new JmpRel32Handler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new JmpRel8Handler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new CallRel32Handler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new XorRegMemHandler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new TestRegMemHandler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new TestAlImmHandler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new TestEaxImmHandler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new FnstswHandler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new ConditionalJumpHandler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new TwoByteConditionalJumpHandler(_codeBuffer, _decoder, _length));
+        
+        // Register group handlers for instructions that share similar decoding logic
+        _handlers.Add(new Group1Handler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new Group3Handler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new FloatingPointHandler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new DataTransferHandler(_codeBuffer, _decoder, _length));
+    }
+    
+    /// <summary>
+    /// Gets a handler that can decode the given opcode
+    /// </summary>
+    /// <param name="opcode">The opcode to decode</param>
+    /// <returns>A handler that can decode the opcode, or null if no handler is found</returns>
+    public IInstructionHandler? GetHandler(byte opcode)
+    {
+        foreach (var handler in _handlers)
+        {
+            if (handler.CanHandle(opcode))
+            {
+                return handler;
+            }
+        }
+        
+        return null;
+    }
+}