Unify string interning and object reference tracking

Major refactor: merges string interning and object reference tracking (IId/Non-IId) into a unified position-based cache and footer in binary serialization. Wire format now uses cache indices for all references; hashcode/Id prefixes removed. Serialization and deserialization logic simplified, improving performance and maintainability. Legacy code paths and redundant dictionary lookups eliminated.

AyCode.Core/Serializers/AcSerializerContextBase.cs

@@ -83,54 +83,13 @@ public abstract class AcSerializerContextBase<TMetadata, TOptions>
 
     #endregion
 
-    #region Tracking API - int
+    #region Wrapper Iteration (for footer writing)
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryGetValue(TypeMetadataWrapper<TMetadata> wrapper, int refId, out object? instance)
-    {
-        return wrapper.TryGetValue(refId, out instance);
-    }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryGetValue(TypeMetadataWrapper<TMetadata> wrapper, long refId, out object? instance)
-    {
-        return wrapper.TryGetValue(refId, out instance);
-    }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryGetValue(TypeMetadataWrapper<TMetadata> wrapper, Guid refId, out object? instance)
-    {
-        return wrapper.TryGetValue(refId, out instance);
-    }
 
     /// <summary>
-    /// For deserialization: checks if an object with this Id was already seen.
+    /// Iterates all wrappers and collects InternEntry data for ID tracking footer.
-    /// If yes, returns the existing object. If no, stores this object and returns it.
-    /// Uses IdentityMap.TryGetOrAddValue - single Dictionary operation!
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public object TryGetOrStoreInt32(TypeMetadataWrapper<TMetadata> wrapper, object newObj, int id)
+    public Dictionary<Type, TypeMetadataWrapper<TMetadata>>.ValueCollection GetWrappers() => _wrappers.Values;
-    {
-        return id == 0 ? newObj : wrapper.TryGetOrStoreId(id, newObj);
-    }
-
-    /// <summary>
-    /// For deserialization: checks if an object with this Id was already seen (long version).
-    /// </summary>
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public object TryGetOrStoreLong(TypeMetadataWrapper<TMetadata> wrapper, object newObj, long id)
-    {
-        return id == 0 ? newObj : wrapper.TryGetOrStoreId(id, newObj);
-    }
-
-    /// <summary>
-    /// For deserialization: checks if an object with this Id was already seen (Guid version).
-    /// </summary>
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public object TryGetOrStoreGuid(TypeMetadataWrapper<TMetadata> wrapper, object newObj, Guid id)
-    {
-        return id == Guid.Empty ? newObj : wrapper.TryGetOrStoreId(id, newObj);
-    }
 
     #endregion
 

AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.BinaryDeserializationContext.cs

@@ -20,10 +20,11 @@ public static partial class AcBinaryDeserializer
         private List<string>? _propertyNames;
         private Dictionary<int, string>? _stringCache;
 
-        // Position-based string interning: flat int[] for cache-friendly access
+        // Position-based interning: flat int[] for cache-friendly access
         // Layout: [pos0, cacheIdx0, pos1, cacheIdx1, ...] - pairs sorted by position
+        // Shared for string interning AND IId object references
         private int[]? _dupData;                  // Footer data: (position, cacheIndex) pairs as flat int array
-        private string[]? _internStringCache;     // Cache for duplicated strings only
+        private object?[]? _internCache;          // Shared cache for interned strings AND IId objects
         private int _dupCheckIndex;               // Current index in _dupData (increments by 2)
         private int _nextDupPosition;             // Cached next dup position - avoids array access in hot path
         
@@ -76,9 +77,9 @@ public static partial class AcBinaryDeserializer
             _propertyNames = null;
             _stringCache = null;
 
-            // Position-based string interning fields
+            // Position-based interning fields (shared: string + IId)
             _dupData = null;
-            _internStringCache = null;
+            _internCache = null;
             _dupCheckIndex = 0;
             _nextDupPosition = int.MaxValue;
 
@@ -160,18 +161,19 @@ public static partial class AcBinaryDeserializer
                 }
             }
 
-            // Footer-based: read string intern indices from footer
+            // Footer-based: read intern indices from footer (string + IId)
             if (hasInternFooter && footerPosition > 0)
             {
-                ReadFooterStringIndices(footerPosition);
+                ReadFooterIndices(footerPosition);
             }
         }
         
         /// <summary>
-        /// Reads string intern footer: [dupCount][pos0][idx0][pos1][idx1]...
+        /// Reads intern footer: [dupCount][pos0][idx0][pos1][idx1]...
+        /// Shared for string interning AND IId object references.
         /// VarUInt format read into flat int[] for fast hot path access.
         /// </summary>
-        private void ReadFooterStringIndices(int footerPosition)
+        private void ReadFooterIndices(int footerPosition)
         {
             // Save current position (start of data)
             var dataPosition = _position;
@@ -184,7 +186,7 @@ public static partial class AcBinaryDeserializer
             if (dupCount == 0)
             {
                 _dupData = Array.Empty<int>();
-                _internStringCache = Array.Empty<string>();
+                _internCache = Array.Empty<object?>();
                 _nextDupPosition = int.MaxValue;
             }
             else
@@ -198,7 +200,7 @@ public static partial class AcBinaryDeserializer
                     _dupData[i * 2 + 1] = (int)ReadVarUInt();  // cacheIndex
                 }
 
-                _internStringCache = new string[dupCount];
+                _internCache = new object?[dupCount];
                 // Cache first dup position for ultra-fast hot path
                 _nextDupPosition = _dupData[0];
             }
@@ -555,14 +557,14 @@ public static partial class AcBinaryDeserializer
         }
 
         /// <summary>
-        /// Registers an interned string during body read (StringInternNew).
+        /// Registers an interned value (string or IId object) during body read.
         /// Uses position-based check for 100% reliable cache matching.
         /// Ultra-fast: single int comparison in hot path.
         /// </summary>
-        /// <param name="value">The string value read from stream</param>
+        /// <param name="value">The value read from stream (string or IId object)</param>
-        /// <param name="streamPosition">Stream position BEFORE reading the string (type code position)</param>
+        /// <param name="streamPosition">Stream position BEFORE reading the value (type code position)</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void RegisterInternedString(string value, int streamPosition)
+        public void RegisterInternedValue(object value, int streamPosition)
         {
             // Ultra-fast hot path: single int comparison
             if (streamPosition != _nextDupPosition)
@@ -572,7 +574,7 @@ public static partial class AcBinaryDeserializer
             // _dupData layout: [pos0, cacheIdx0, pos1, cacheIdx1, ...]
             var data = _dupData!;
             var idx = _dupCheckIndex;
-            _internStringCache![data[idx + 1]] = value;  // cacheIndex is at odd positions
+            _internCache![data[idx + 1]] = value;  // cacheIndex is at odd positions
 
             idx += 2;
             _dupCheckIndex = idx;
@@ -587,12 +589,7 @@ public static partial class AcBinaryDeserializer
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public string GetInternedString(int cacheIndex)
         {
-            //if (_internStringCache == null || cacheIndex >= _internStringCache.Length)
+            var result = _internCache![cacheIndex];
-            //{
-            //    throw new AcBinaryDeserializationException($"Invalid interned string cache index '{cacheIndex}'.", _position);
-            //}
-
-            var result = _internStringCache![cacheIndex];
             if (result == null)
             {
                 throw new AcBinaryDeserializationException(
@@ -600,6 +597,23 @@ public static partial class AcBinaryDeserializer
                     _position);
             }
 
+            return (string)result;
+        }
+
+        /// <summary>
+        /// Gets an interned object by cache index (ObjectRef type code).
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public object GetInternedObject(int cacheIndex)
+        {
+            var result = _internCache![cacheIndex];
+            if (result == null)
+            {
+                throw new AcBinaryDeserializationException(
+                    $"Interned object at cache index '{cacheIndex}' was not populated.",
+                    _position);
+            }
+
             return result;
         }
 
@@ -614,37 +628,6 @@ public static partial class AcBinaryDeserializer
             return _propertyNames[index];
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void RegisterObject(TypeMetadataWrapper<BinaryDeserializeTypeMetadata> wrapper, int refId, object instance)
-        {
-            if (refId == 0) throw new Exception("refId == 0");
-            ContextClass.TryGetOrStoreInt32(wrapper, instance, refId);
-            //if (refId <= 0)
-            //{
-            //    return;
-            //}
-
-            //_objectReferences ??= new Dictionary<int, object>(16);
-            //_objectReferences[refId] = instance;
-        }
-
-        //[MethodImpl(MethodImplOptions.AggressiveInlining)]
-        //public object? GetReferencedObject(TypeMetadataWrapper<BinaryDeserializeTypeMetadata> wrapper, int refId)
-        //{
-        //    //if (refId <= 0)
-        //    //{
-        //    //    return null;
-        //    //}
-
-        //    //if (_objectReferences == null || !_objectReferences.TryGetValue(refId, out var value))
-        //    //{
-        //    //    throw new AcBinaryDeserializationException($"Unknown object reference id '{refId}'.", _position);
-        //    //}
-
-
-        //    //return value;
-        //}
-
         private void EnsureAvailable(int length)
         {
             if (_position > _buffer.Length - length)
@@ -659,19 +642,5 @@ public static partial class AcBinaryDeserializer
             return ReadStringUtf8(byteLength);
         }
 
-        #region IId Reference Cache - Delegates to ContextClass
-
-        /// <summary>
-        /// After PopulateObject, checks if we should reuse an existing IId object.
-        /// Delegates to ContextClass which uses AcSerializerContextBase infrastructure.
-        /// Returns the object to use (either the new one or an existing cached one).
-        /// </summary>
-        //[MethodImpl(MethodImplOptions.AggressiveInlining)]
-        //public object GetOrRegisterIIdObject(object newObj, TypeMetadataWrapper<BinaryDeserializeTypeMetadata> wrapper)
-        //{
-        //    return ContextClass.GetOrRegisterIIdObject(newObj, wrapper);
-        //}
-
-        #endregion
     }
 }

AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.BinaryDeserializationContextClass.cs

@@ -1,6 +1,4 @@
 using System;
-using System.Collections.Generic;
-using System.Runtime.CompilerServices;
 
 namespace AyCode.Core.Serializers.Binaries;
 
@@ -28,26 +26,5 @@ public static partial class AcBinaryDeserializer
             Clear();
             base.Reset(options);
         }
-
-        /// <summary>
-        /// After PopulateObject, checks if we should reuse an existing IId object.
-        /// Uses the unified tracking from AcSerializerContextBase (IdentityMap).
-        /// Returns the object to use (either the new one or an existing cached one).
-        /// </summary>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public object GetOrRegisterIIdObject(object newObj, BinaryDeserializeTypeMetadata metadata)
-        {
-            if (!metadata.IsIId) return newObj;
-
-            var wrapper = GetWrapper(newObj.GetType());
-
-            return metadata.IdAccessorType switch
-            {
-                IdAccessorType.Int32 => TryGetOrStoreInt32(wrapper, newObj, metadata.GetIdInt32(newObj)),
-                IdAccessorType.Int64 => TryGetOrStoreLong(wrapper, newObj, metadata.GetIdInt64(newObj)),
-                IdAccessorType.Guid => TryGetOrStoreGuid(wrapper, newObj, metadata.GetIdGuid(newObj)),
-                _ => newObj
-            };
-        }
     }
 }

AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.CrossType.cs

@@ -214,30 +214,21 @@ public static partial class AcBinaryDeserializer
     /// </summary>
     private static object? ReadObjectWithMapping(ref BinaryDeserializationContext context, Type destType, int[] indexMapping, int depth)
     {
+        // Note: streamPosition captured before Object type code (already consumed by caller)
+        var streamPosition = context.Position - 1;
         var wrapper = context.ContextClass.GetWrapper(destType);
         var metadata = wrapper.Metadata;
 
-        // Handle reference ID if present
+        // Wire format: [Object][props...] - no refId prefix in new format
-        if (context.ContextClass.UseTypeReferenceHandling(metadata))
-        {
-            var refId = context.ReadVarInt();
-            if (context.ContextClass.TryGetValue(wrapper, refId, out var instance)) return instance;
-            
-            // New object with ID - will be registered below
-            instance = CreateInstance(destType, metadata);
-            if (instance != null && refId > 0)
-            {
-                context.RegisterObject(wrapper, refId, instance);
-            }
-
-            PopulateObjectWithMapping(ref context, instance!, destType, indexMapping, depth);
-            return instance;
-        }
-
-        // No reference handling
         var obj = CreateInstance(destType, metadata);
         if (obj != null)
         {
+            // Register in shared intern cache BEFORE populate (position-based sequential check)
+            if (context.ContextClass.UseTypeReferenceHandling(metadata))
+            {
+                context.RegisterInternedValue(obj, streamPosition);
+            }
+
             PopulateObjectWithMapping(ref context, obj, destType, indexMapping, depth);
         }
         return obj;
@@ -332,18 +323,16 @@ public static partial class AcBinaryDeserializer
             var existingObj = propInfo.GetValue(target);
             if (existingObj != null)
             {
+                var objStreamPos = context.Position; // position of Object type code
                 context.ReadByte(); // consume Object marker
 
-                // Handle ref ID if present
+                // Register in shared intern cache BEFORE populate (position-based sequential check)
                 if (context.ContextClass.UseTypeReferenceHandling(wrapper.Metadata))
                 {
-                    var refId = context.ReadVarInt();
+                    context.RegisterInternedValue(existingObj, objStreamPos);
-                    if (refId > 0)
-                    {
-                        context.RegisterObject(wrapper, refId, existingObj);
-                    }
                 }
 
+                // Wire format: [Object][props...] - no refId prefix in new format
                 PopulateObjectCore(ref context, existingObj, wrapper, nextDepth, skipDefaultWrite: false);
                 return;
             }

AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.Populate.cs

@@ -13,19 +13,8 @@ public static partial class AcBinaryDeserializer
 {
     #region Helper Methods
     
-    /// <summary>
+    // ReadAndRegisterHashcodeIfNeeded removed - new format uses position-based footer for all reference tracking.
-    /// Reads hashcode prefix and registers object for Non-IId types with RefHandling=All.
+    // No hashcode prefix in wire format anymore.
-    /// IId types have no prefix - their Id is in the properties.
-    /// Call this AFTER consuming the Object marker, BEFORE PopulateObjectCore.
-    /// </summary>
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static void ReadAndRegisterHashcodeIfNeeded(ref BinaryDeserializationContext context, TypeMetadataWrapper<BinaryDeserializeTypeMetadata> wrapper, object instance)
-    {
-        if (wrapper.Metadata.IsIId || !context.ContextClass.UseTypeReferenceHandling(wrapper.Metadata)) return;
-
-        var hashcode = context.ReadVarInt();
-        context.ContextClass.TryGetOrStoreInt32(wrapper, instance, hashcode);
-    }
     
     #endregion
 
@@ -39,9 +28,9 @@ public static partial class AcBinaryDeserializer
     /// Populate object with automatic mode detection from context.
     /// Uses IsMergeMode to determine merge behavior for IId collections.
     /// Wire format:
-    /// - IId types: [Object][props 0-tól...] - no refId prefix, Id is in props
+    /// - IId types: [Object][props 0-t<EFBFBD>l...] - no refId prefix, Id is in props
-    /// - Non-IId + All: [Object][hashcode][props 0-tól...] - hashcode prefix
+    /// - Non-IId + All: [Object][hashcode][props 0-t<EFBFBD>l...] - hashcode prefix
-    /// - Ref=Off: [Object][props 0-tól...] - no prefix
+    /// - Ref=Off: [Object][props 0-t<EFBFBD>l...] - no prefix
     /// </summary>
     private static void PopulateObject(ref BinaryDeserializationContext context, object target, Type targetType, int depth)
     {
@@ -51,8 +40,8 @@ public static partial class AcBinaryDeserializer
 
     /// <summary>
     /// Core populate logic shared by all populate paths.
-    /// Handles hashcode reading for Non-IId types internally.
     /// Wire format: All properties are written WITH type markers (including Id for IId types).
+    /// No hashcode prefix - position-based footer handles reference tracking.
     /// </summary>
     private static void PopulateObjectCore(
         ref BinaryDeserializationContext context,
@@ -61,9 +50,6 @@ public static partial class AcBinaryDeserializer
         int depth,
         bool skipDefaultWrite)
     {
-        // Handle hashcode for Non-IId types - ONE place for this logic!
-        ReadAndRegisterHashcodeIfNeeded(ref context, wrapper, target);
-        
         PopulateObjectProperties(ref context, target, wrapper.Metadata, depth, skipDefaultWrite);
     }
     

AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.cs

@@ -790,7 +790,7 @@ public static partial class AcBinaryDeserializer
         var length = (int)context.ReadVarUInt();
         if (length == 0) return string.Empty;
         var str = context.ReadStringUtf8(length);
-        context.RegisterInternedString(str, streamPosition);
+        context.RegisterInternedValue(str, streamPosition);
         return str;
     }
 
@@ -922,81 +922,14 @@ public static partial class AcBinaryDeserializer
     #region Object Reading
 
     /// <summary>
-    /// Reads an ObjectRef - looks up previously registered object.
+    /// Reads an ObjectRef - looks up previously registered object from shared intern cache.
-    /// Wire format:
+    /// Wire format: [ObjectRef][VarUInt cacheIndex]
-    /// - IId types: [ObjectRef][Id érték] - lookup by Id
-    /// - Non-IId types: [ObjectRef][hashcode] - lookup by hashcode
     /// </summary>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static object? ReadObjectRef(ref BinaryDeserializationContext context, Type targetType, int depth)
     {
-        var wrapper = context.ContextClass.GetWrapper(targetType);
+        var cacheIndex = (int)context.ReadVarUInt();
-        return ReadObjectRef(ref context, ref wrapper);
+        return context.GetInternedObject(cacheIndex);
-    }
-    
-    private static object? ReadObjectRef(ref BinaryDeserializationContext context, ref TypeMetadataWrapper<BinaryDeserializeTypeMetadata> wrapper)
-    {
-        var metadata = wrapper.Metadata;
-        
-        if (metadata.IsIId)
-        {
-            // IId: [ObjectRef][Id érték] - lookup by Id
-            return metadata.IdAccessorType switch
-            {
-                IdAccessorType.Int32 => ReadObjectRefInt32(ref context, ref wrapper),
-                IdAccessorType.Int64 => ReadObjectRefInt64(ref context, ref wrapper),
-                IdAccessorType.Guid => ReadObjectRefGuid(ref context, ref wrapper),
-                _ => throw new AcBinaryDeserializationException(
-                    $"IId type '{metadata.SourceType.Name}' must have valid IdAccessorType",
-                    context.Position, metadata.SourceType)
-            };
-        }
-        else
-        {
-            // Non-IId: [ObjectRef][hashcode] - lookup by hashcode (always Int32)
-            var hashcode = context.ReadVarInt();
-            if (wrapper.TryGetValueInt32(hashcode, out var instance))
-                return instance;
-            
-            throw new AcBinaryDeserializationException(
-                $"ObjectRef hashcode {hashcode} not found for type '{metadata.SourceType.Name}'",
-                context.Position, metadata.SourceType);
-        }
-    }
-    
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static object? ReadObjectRefInt32(ref BinaryDeserializationContext context, ref TypeMetadataWrapper<BinaryDeserializeTypeMetadata> wrapper)
-    {
-        var id = context.ReadVarInt();
-        if (wrapper.TryGetValueInt32(id, out var instance))
-            return instance;
-        
-        throw new AcBinaryDeserializationException(
-            $"ObjectRef Id {id} not found for type '{wrapper.Metadata.SourceType.Name}'",
-            context.Position, wrapper.Metadata.SourceType);
-    }
-    
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static object? ReadObjectRefInt64(ref BinaryDeserializationContext context, ref TypeMetadataWrapper<BinaryDeserializeTypeMetadata> wrapper)
-    {
-        var id = context.ReadVarLong();
-        if (wrapper.TryGetValueInt64(id, out var instance))
-            return instance;
-        
-        throw new AcBinaryDeserializationException(
-            $"ObjectRef Id {id} not found for type '{wrapper.Metadata.SourceType.Name}'",
-            context.Position, wrapper.Metadata.SourceType);
-    }
-    
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static object? ReadObjectRefGuid(ref BinaryDeserializationContext context, ref TypeMetadataWrapper<BinaryDeserializeTypeMetadata> wrapper)
-    {
-        var id = context.ReadGuidUnsafe();
-        if (wrapper.TryGetValueGuid(id, out var instance))
-            return instance;
-        
-        throw new AcBinaryDeserializationException(
-            $"ObjectRef Id {id} not found for type '{wrapper.Metadata.SourceType.Name}'",
-            context.Position, wrapper.Metadata.SourceType);
     }
 
     /// <summary>
@@ -1008,6 +941,9 @@ public static partial class AcBinaryDeserializer
     /// </summary>
     private static object? ReadObject(ref BinaryDeserializationContext context, Type targetType, int depth)
     {
+        // Capture stream position of the Object type code (already consumed)
+        var streamPosition = context.Position - 1;
+
         // Handle dictionary types
         if (IsDictionaryType(targetType, out var keyType, out var valueType))
         {
@@ -1017,51 +953,22 @@ public static partial class AcBinaryDeserializer
         var wrapper = context.ContextClass.GetWrapper(targetType);
         var metadata = wrapper.Metadata;
 
-        object? instance;
+        // Wire format: [Object][props...] - no hashcode prefix, no Id prefix
+        // Position-based footer handles all reference tracking
+        var instance = CreateInstance(targetType, metadata);
+        if (instance == null) return null;
 
+        // Register in shared intern cache BEFORE populate (position-based sequential check)
+        // Instance is populated in-place, so registering early is safe.
+        // Must happen before reading inner content (strings/objects) that may also need registration.
         if (context.ContextClass.UseTypeReferenceHandling(metadata))
         {
-            if (metadata.IsIId)
+            context.RegisterInternedValue(instance, streamPosition);
-            {
+        }
-                // IId: [Object][props 0-tól...]
-                // Create → Populate (Id beolvasódik) → Register by Id
-                instance = CreateInstance(targetType, metadata);
-                if (instance == null) return null;
 
         PopulateObject(ref context, instance, metadata, depth, skipDefaultWrite: true);
 
-                // Register by Id after populate - uses typed methods on wrapper
-                RegisterIIdInstance(context.ContextClass, wrapper, instance, metadata);
-            }
-            else
-            {
-                // Non-IId + All: [Object][hashcode][props 0-tól...]
-                var hashcode = context.ReadVarInt();
-                
-                // TryGetValue - if already exists, return (shouldn't happen for Object, only ObjectRef)
-                if (wrapper.TryGetValueInt32(hashcode, out instance))
-                    return instance;
-                
-                // Create + Register by hashcode (always Int32 for Non-IId)
-                instance = CreateInstance(targetType, metadata);
-                if (instance == null) return null;
-                wrapper.TryGetOrStoreInt32(hashcode, instance);
-                
-                // Populate
-                PopulateObject(ref context, instance, metadata, depth, skipDefaultWrite: true);
-            }
-        }
-        else
-        {
-            // Ref=Off: [Object][props 0-tól...]
-            instance = CreateInstance(targetType, metadata);
-            if (instance == null) return null;
-            
-            PopulateObject(ref context, instance, metadata, depth, skipDefaultWrite: true);
-        }
-        
         // ChainMode: Register/retrieve from chain tracker (separate from reference handling)
-        // Note: For ChainMode, we need IdGetter OR typed getters (IdAccessorType != None)
         if (context.IsChainMode && metadata.IsIId && metadata.IdType != null)
         {
             var id = GetIdBoxed(instance, metadata);
@@ -1424,7 +1331,7 @@ public static partial class AcBinaryDeserializer
         var byteLen = (int)context.ReadVarUInt();
         if (byteLen == 0) return;
         var str = context.ReadStringUtf8(byteLen);
-        context.RegisterInternedString(str, streamPosition);
+        context.RegisterInternedValue(str, streamPosition);
     }
 
     ///// <summary>
@@ -1447,18 +1354,8 @@ public static partial class AcBinaryDeserializer
 
     private static void SkipObject(ref BinaryDeserializationContext context, BinaryDeserializeTypeMetadata metaData)
     {
-        // Wire format:
+        // Wire format: [Object][props...] - no hashcode prefix in new format
-        // - IId: [Object][props 0-tól...] - no hashcode
-        // - Non-IId + All: [Object][hashcode][props 0-tól...] - hashcode present
-        if (context.ContextClass.UseTypeReferenceHandling(metaData) && !metaData.IsIId)
-        {
-            // Non-IId: skip hashcode
-            context.ReadVarInt();
-        }
-
         // NEW FORMAT: Can't skip without knowing property count!
-        // Need to read type metadata to know how many properties to skip
-        // For now, throw exception - SkipObject not supported with new format
         throw new NotSupportedException(
             "SkipObject is not supported with SKIP marker format. " +
             "Unable to determine property count without type metadata.");
@@ -1487,20 +1384,6 @@ public static partial class AcBinaryDeserializer
 
     #region IId Registration Helpers
 
-    /// <summary>
-    /// Registers an IId instance after populate - uses pre-bound delegate, NO SWITCH!
-    /// </summary>
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static void RegisterIIdInstance(
-        BinaryDeserializationContextClass contextClass,
-        TypeMetadataWrapper<BinaryDeserializeTypeMetadata> wrapper,
-        object instance,
-        BinaryDeserializeTypeMetadata metadata)
-    {
-        // Pre-bound delegate - no switch needed!
-        wrapper.RegisterById!(instance);
-    }
-    
     /// <summary>
     /// Gets Id as boxed object - only used for ChainMode (rare path).
     /// </summary>

AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs

@@ -122,6 +122,10 @@ public static partial class AcBinarySerializer
 
         // These properties delegate to Options for convenience
         public bool UseStringInterning => Options.UseStringInterning != StringInterningMode.None;
+        /// <summary>
+        /// True if we need footer position in header (string interning OR reference handling).
+        /// </summary>
+        public bool HasFooter => UseStringInterning || ReferenceHandling != ReferenceHandlingMode.None;
         public bool UseMetadata => Options.UseMetadata;
         public byte MinStringInternLength => Options.MinStringInternLength;
         public byte MaxStringInternLength => Options.MaxStringInternLength;
@@ -263,41 +267,99 @@ public static partial class AcBinarySerializer
         public int GetDupCount() => _nextCacheIndex;
 
         /// <summary>
-        /// Writes the footer with (position, cacheIndex) pairs sorted by position.
+        /// Writes the merged footer with (position, cacheIndex) pairs sorted by position.
+        /// Collects entries from string interning AND ID tracking (all wrappers).
         /// VarUInt format for compact size, deserializer reads into flat int[].
         /// </summary>
-        public void WriteInternedStringFooter()
+        public void WriteInternedFooter()
         {
-            if (_stringInternMap == null || _nextCacheIndex == 0) return;
+            if (_nextCacheIndex == 0) return;
 
-            // Collect entries with CacheIndex >= 0 (occurred more than once)
+            // Collect ALL entries with CacheIndex >= 0 (string + ID, all occurred more than once)
-            // We need to sort by StreamPosition for deserializer sequential access
             Span<(int Position, int CacheIndex)> entries = _nextCacheIndex <= 64
                 ? stackalloc (int, int)[_nextCacheIndex]
                 : new (int, int)[_nextCacheIndex];
 
             var idx = 0;
+
+            // 1. String intern entries
+            if (_stringInternMap != null)
+            {
                 var count = _stringInternMap.Count;
                 for (var i = 0; i < count; i++)
                 {
                     ref var entry = ref _stringInternMap.GetValueRefAt(i);
                     if (entry.CacheIndex >= 0)
-                {
                         entries[idx++] = (entry.StreamPosition, entry.CacheIndex);
                 }
             }
 
+            // 2. ID tracking entries from all wrappers
+            foreach (var wrapper in GetWrappers())
+            {
+                CollectInternEntries(wrapper.IdentityMapInt32, ref entries, ref idx);
+                CollectInternEntries(wrapper.IdentityMapInt64, ref entries, ref idx);
+                CollectInternEntries(wrapper.IdentityMapGuid, ref entries, ref idx);
+            }
+
             // Sort by StreamPosition (ascending) for deserializer sequential check
-            entries.Sort((a, b) => a.Position.CompareTo(b.Position));
+            var usedEntries = entries.Slice(0, idx);
+            usedEntries.Sort((a, b) => a.Position.CompareTo(b.Position));
 
             // Write pairs as VarUInt for compact size
-            for (var i = 0; i < _nextCacheIndex; i++)
+            for (var i = 0; i < idx; i++)
             {
-                WriteVarUInt((uint)entries[i].Position);
+                WriteVarUInt((uint)usedEntries[i].Position);
-                WriteVarUInt((uint)entries[i].CacheIndex);
+                WriteVarUInt((uint)usedEntries[i].CacheIndex);
             }
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static void CollectInternEntries<TKey>(IdentityMap<TKey, InternEntry>? map,
+            ref Span<(int Position, int CacheIndex)> entries, ref int idx) where TKey : notnull
+        {
+            if (map == null) return;
+            var count = map.Count;
+            for (var i = 0; i < count; i++)
+            {
+                ref var entry = ref map.GetValueRefAt(i);
+                if (entry.CacheIndex >= 0)
+                    entries[idx++] = (entry.StreamPosition, entry.CacheIndex);
+            }
+        }
+
+        #endregion
+
+        #region Object Reference Tracking (IId + Non-IId)
+
+        /// <summary>
+        /// Tries to track an IId object (Int32 Id). Uses shared _nextCacheIndex with string interning.
+        /// Returns true if first occurrence, false if already seen (cacheIndex assigned).
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public bool TryTrackObject(TypeMetadataWrapper<BinarySerializeTypeMetadata> wrapper, object obj, out int cacheIndex)
+        {
+            return TryTrack(wrapper, obj, _position, ref _nextCacheIndex, out cacheIndex);
+        }
+
+        /// <summary>
+        /// Tries to track an IId object (Int64 Id).
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public bool TryTrackObjectLong(TypeMetadataWrapper<BinarySerializeTypeMetadata> wrapper, object obj, out int cacheIndex)
+        {
+            return TryTrackLong(wrapper, obj, _position, ref _nextCacheIndex, out cacheIndex);
+        }
+
+        /// <summary>
+        /// Tries to track an IId object (Guid Id).
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public bool TryTrackObjectGuid(TypeMetadataWrapper<BinarySerializeTypeMetadata> wrapper, object obj, out int cacheIndex)
+        {
+            return TryTrackGuid(wrapper, obj, _position, ref _nextCacheIndex, out cacheIndex);
+        }
+
         #endregion
 
         #region Property Name Table
@@ -971,10 +1033,10 @@ public static partial class AcBinarySerializer
             // Header layout:
             // [0] version (1 byte)
             // [1] flags (1 byte)
-            // [2-5] footer position (4 bytes, only if UseStringInterning)
+            // [2-5] footer position (4 bytes, if string interning OR reference handling)
-            EnsureCapacity(UseStringInterning ? 6 : 2);
+            EnsureCapacity(HasFooter ? 6 : 2);
             _headerPosition = _position;
-            _position += UseStringInterning ? 6 : 2;
+            _position += HasFooter ? 6 : 2;
         }
 
         /// <summary>
@@ -991,7 +1053,7 @@ public static partial class AcBinarySerializer
         public void FinalizeHeaderSections()
         {
             var hasPropertyNames = UseMetadata && _propertyNameList is { Count: > 0 };
-            var dupCount = UseStringInterning ? GetDupCount() : 0;
+            var dupCount = GetDupCount(); // Shared counter: string intern + ID tracking
             var hasInternTable = dupCount > 0;
 
             // Calculate property names header size (strings go to footer now)
@@ -1008,7 +1070,7 @@ public static partial class AcBinarySerializer
             }
 
             // Write property names to header if needed
-            var headerPayloadStart = _headerPosition + (UseStringInterning ? 6 : 2);
+            var headerPayloadStart = _headerPosition + (HasFooter ? 6 : 2);
             if (hasPropertyNames)
             {
                 var headerPos = headerPayloadStart;
@@ -1020,12 +1082,13 @@ public static partial class AcBinarySerializer
                 }
             }
 
-            // Footer: write indices of strings that occurred more than once
+            // Footer: write merged intern entries (string + ID)
             var footerPosition = 0;
             if (hasInternTable)
             {
                 footerPosition = _position;
-                WriteFooterStringIndices(dupCount);
+                WriteVarUInt((uint)dupCount);
+                WriteInternedFooter();
             }
 
             // Write header
@@ -1037,36 +1100,21 @@ public static partial class AcBinarySerializer
                 flags |= BinaryTypeCode.HeaderFlag_RefHandling_OnlyId;
             else if (ReferenceHandling == ReferenceHandlingMode.All)
                 flags |= (byte)(BinaryTypeCode.HeaderFlag_RefHandling_OnlyId | BinaryTypeCode.HeaderFlag_RefHandling_All);
-            // Set footer position flag if string interning is enabled
+            // Set footer position flag if footer is needed (string interning OR ref handling)
-            if (UseStringInterning)
+            if (HasFooter)
                 flags |= BinaryTypeCode.HeaderFlag_HasFooterPosition;
 
             _buffer[_headerPosition] = AcBinarySerializerOptions.FormatVersion;
             _buffer[_headerPosition + 1] = flags;
 
-            // Always write footer position if string interning is enabled in options
+            // Write footer position if footer is needed
             // (even if there's no actual interned data - footer position will be 0)
-            if (UseStringInterning)
+            if (HasFooter)
             {
                 Unsafe.WriteUnaligned(ref _buffer[_headerPosition + 2], footerPosition);
             }
         }
 
-        /// <summary>
-        /// Writes the footer with total count (for verification) + dup count + indices.
-        /// Footer format: [totalStringCount][dupCount][dupIndex0][dupIndex1]...
-        /// </summary>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        /// <summary>
-        /// Writes footer: [dupCount][(position, cacheIndex), ...]
-        /// Position-based format for 100% reliable deserializer matching.
-        /// </summary>
-        private void WriteFooterStringIndices(int dupCount)
-        {
-            // Dup count + (position, cacheIndex) pairs
-            WriteVarUInt((uint)dupCount);
-            WriteInternedStringFooter();
-        }
 
         /// <summary>
         /// Writes UTF8 string at specific position, optimized for ASCII strings.

AyCode.Core/Serializers/Binaries/AcBinarySerializer.cs

@@ -846,15 +846,15 @@ public static partial class AcBinarySerializer
         {
             if (metadata.IsIId)
             {
-                // IId típus: track by Id, ObjectRef writes Id
+                // IId típus: track by Id, ObjectRef writes cacheIndex
                 switch (metadata.IdAccessorType)
                 {
                     case IdAccessorType.Int32:
-                        if (!context.TryTrack(wrapper, value, out int intId))
+                        if (!context.TryTrackObject(wrapper, value, out int cacheIndex32))
                         {
-                            // Already seen → ObjectRef + Id
+                            // Already seen → ObjectRef + cacheIndex
                             context.WriteByte(BinaryTypeCode.ObjectRef);
-                            context.WriteVarInt(intId);
+                            context.WriteVarUInt((uint)cacheIndex32);
                             return;
                         }
                         // First occurrence → Object (no extra data, Id in props)
@@ -862,20 +862,20 @@ public static partial class AcBinarySerializer
                         break;
 
                     case IdAccessorType.Int64:
-                        if (!context.TryTrack(wrapper, value, out long longId))
+                        if (!context.TryTrackObjectLong(wrapper, value, out int cacheIndex64))
                         {
                             context.WriteByte(BinaryTypeCode.ObjectRef);
-                            context.WriteVarLong(longId);
+                            context.WriteVarUInt((uint)cacheIndex64);
                             return;
                         }
                         context.WriteByte(BinaryTypeCode.Object);
                         break;
 
                     case IdAccessorType.Guid:
-                        if (!context.TryTrack(wrapper, value, out Guid guidId))
+                        if (!context.TryTrackObjectGuid(wrapper, value, out int cacheIndexGuid))
                         {
                             context.WriteByte(BinaryTypeCode.ObjectRef);
-                            context.WriteGuidBits(guidId);
+                            context.WriteVarUInt((uint)cacheIndexGuid);
                             return;
                         }
                         context.WriteByte(BinaryTypeCode.Object);
@@ -884,17 +884,16 @@ public static partial class AcBinarySerializer
             }
             else
             {
-                // Non-IId + RefHandling=All: track by hashcode (IdAccessorType=Int32, RefIdGetter=GetHashCode)
+                // Non-IId + RefHandling=All: track by hashcode
-                if (!context.TryTrack(wrapper, value, out int hashcode))
+                if (!context.TryTrackObject(wrapper, value, out int cacheIndexHash))
                 {
-                    // Already seen → ObjectRef + hashcode
+                    // Already seen → ObjectRef + cacheIndex
                     context.WriteByte(BinaryTypeCode.ObjectRef);
-                    context.WriteVarInt(hashcode);
+                    context.WriteVarUInt((uint)cacheIndexHash);
                     return;
                 }
-                // First occurrence → Object + hashcode + props
+                // First occurrence → Object (no extra prefix for Non-IId in new format)
                 context.WriteByte(BinaryTypeCode.Object);
-                context.WriteVarInt(hashcode);
             }
         }
         else

AyCode.Core/Serializers/IdentityMap.cs

@@ -59,16 +59,6 @@ public interface IIdentityMap
 /// <typeparam name="TValue">The value type</typeparam>
 public sealed class IdentityMap<TKey, TValue> : IIdentityMap where TKey : notnull
 {
-    private const bool _useSmallInt = false;
-
-    // Small int optimization (TKey = int only, 0-4095), 512 bytes (fits in L1 cache!)
-    private const int SmallBitmapSize = 64;
-    private const int SmallSize = 4096;
-
-    // Small int optimization (TKey = int only, 0-65535)
-    //private const int SmallBitmapSize = 1024;
-    //private const int SmallSize = SmallBitmapSize * 64;
-
     // Slot for hash table entries (generation needed for hash table validity)
     private struct HashSlot
     {
@@ -76,10 +66,6 @@ public sealed class IdentityMap<TKey, TValue> : IIdentityMap where TKey : notnul
         public int Next;           // next slot index in chain (-1 = end)
     }
 
-    // Small int storage - SIMPLE: bitmap for "seen?" + direct TValue[] for values
-    // Bitmap protects values - no generation needed, no value array clearing on Reset!
-    private ulong[]? _smallBitmap;          // Cache-friendly "seen?" check (512 bytes, cleared on Reset)
-
     // Hash table storage (for large ints and other types)
     private int[]? _buckets;           // bucket index → first entry index
     private HashSlot[]? _entries;      // hash table entries
@@ -97,32 +83,15 @@ public sealed class IdentityMap<TKey, TValue> : IIdentityMap where TKey : notnul
     private static readonly bool IsString = typeof(TKey) == typeof(string);
     private static readonly bool IsValueTypeValue = typeof(TValue).IsValueType;
 
+    /// <summary>
+    /// Number of entries in the hash table. Use with GetValueRefAt for iteration.
+    /// </summary>
+    public int Count => _count;
+
     public IdentityMap()
     {
     }
 
-    /// <summary>
-    /// Tries to add a key to tracking (serialization).
-    /// Returns true if first occurrence (key was added).
-    /// Returns false if already seen.
-    /// </summary>
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryAddKey(TKey key)
-    {
-        // Small int fast path
-        if (_useSmallInt && IsInt32)
-        {
-            var intKey = Unsafe.As<TKey, int>(ref key);
-            if ((uint)intKey < SmallSize)
-            {
-                return TryAddSmallInt(intKey);
-            }
-        }
-
-        // Hash table path
-        return TryAddHash(key, out _);
-    }
-
     /// <summary>
     /// Tries to add a key and returns slot index for ref access to value.
     /// Returns true if first occurrence (key was added).
@@ -135,32 +104,6 @@ public sealed class IdentityMap<TKey, TValue> : IIdentityMap where TKey : notnul
         return TryAddHash(key, out slotIndex);
     }
 
-    /// <summary>
-    /// Number of entries in the hash table. Use with GetValueRefAt for iteration.
-    /// </summary>
-    public int Count => _count;
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private bool TryAddSmallInt(int key)
-    {
-        // Lazy init - ONLY bitmap for tracking
-        if (_smallBitmap == null)
-        {
-            _smallBitmap = ArrayPool<ulong>.Shared.Rent(SmallBitmapSize);
-            Array.Clear(_smallBitmap, 0, SmallBitmapSize);
-        }
-
-        var wordIdx = key >> 6;
-        var bit = 1UL << (key & 63);
-
-        ref var word = ref _smallBitmap[wordIdx];
-        if ((word & bit) != 0)
-            return false;  // Already seen (bitmap is cleared on Reset)
-
-        word |= bit;
-        return true;
-    }
-
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static bool KeyEquals(TKey a, TKey b)
     {
@@ -297,96 +240,6 @@ public sealed class IdentityMap<TKey, TValue> : IIdentityMap where TKey : notnul
         _keys = newKeys;
     }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool HasKey(TKey key)
-    {
-        // Small int fast path - bitmap check is cache-friendly (512 bytes)
-        if (_useSmallInt && IsInt32)
-        {
-            var intKey = Unsafe.As<TKey, int>(ref key);
-            if ((uint)intKey < SmallSize && _smallBitmap != null)
-            {
-                var wordIdx = intKey >> 6;
-                var bit = 1UL << (intKey & 63);
-                return (_smallBitmap[wordIdx] & bit) != 0;
-            }
-        }
-
-        // Hash table path
-        if (_buckets == null) return false;
-
-        var hash = GetHashCode(key);
-        var bucketIdx = (hash & 0x7FFFFFFF) % _bucketsLength;
-
-        for (var i = _buckets[bucketIdx]; i >= 0; i = _entries![i].Next)
-        {
-            if (KeyEquals(_keys![i], key))
-                return true;
-        }
-        return false;
-    }
-
-    /// <summary>
-    /// Checks if key exists and returns existing value, or adds new key (deserialization).
-    /// Returns true if first occurrence (key was added, out = default).
-    /// Returns false if already seen (out = existing value).
-    /// </summary>
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryGetOrAddKey(TKey key, out TValue? existing)
-    {
-        if (!TryAddHash(key, out var slotIndex))
-        {
-            existing = _entries![slotIndex].Value;
-            return false;
-        }
-        existing = default;
-        return true;
-    }
-
-    /// <summary>
-    /// Gets existing value or adds new value for key (deserialization with value storage).
-    /// Returns the existing value if key was seen before, or stores and returns newValue.
-    /// </summary>
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public TValue TryGetOrAddValue(TKey key, TValue newValue)
-    {
-        if (!TryAddHash(key, out var slotIndex))
-        {
-            var existing = _entries![slotIndex].Value;
-            if (existing != null) return existing;
-        }
-        _entries![slotIndex].Value = newValue;
-        return newValue;
-    }
-
-    /// <summary>
-    /// Tries to get the value for a key.
-    /// Returns true if found, false if not.
-    /// </summary>
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryGetValue(TKey key, out TValue? value)
-    {
-        if (_buckets == null)
-        {
-            value = default;
-            return false;
-        }
-
-        var hash = GetHashCode(key);
-        var bucketIdx = (hash & 0x7FFFFFFF) % _bucketsLength;
-
-        for (var i = _buckets[bucketIdx]; i >= 0; i = _entries![i].Next)
-        {
-            if (KeyEquals(_keys![i], key))
-            {
-                value = _entries[i].Value;
-                return true;
-            }
-        }
-        value = default;
-        return false;
-    }
-
     /// <summary>
     /// Returns a reference to the value at the given slot index.
     /// Use with slotIndex from TryAdd for in-place value modification.
@@ -415,15 +268,8 @@ public sealed class IdentityMap<TKey, TValue> : IIdentityMap where TKey : notnul
     /// <param name="preRentBuckets">If true, pre-rent arrays at next capacity (useful for async Clear to shift work from hot path)</param>
     public void Reset(bool preRentBuckets = false)
     {
-        if (_smallBitmap != null)
+        if (_buckets == null) return;
-        {
-            Array.Clear(_smallBitmap, 0, SmallBitmapSize);
-            //ArrayPool<ulong>.Shared.Return(_smallBitmap);
-            //_smallBitmap = null;
-        }
 
-        if (_buckets != null)
-        {
         // Small arrays: keep and clear (faster than pool round-trip)
         if (_bucketsLength <= InitialHashCapacity * 5)
         {
@@ -478,6 +324,5 @@ public sealed class IdentityMap<TKey, TValue> : IIdentityMap where TKey : notnul
         _count = 0;
     }
 }
-}
 
 #endregion

AyCode.Core/Serializers/SerializationContextBase.cs

@@ -15,94 +15,42 @@ public abstract class SerializationContextBase<TMetadata, TOptions> : AcSerializ
     where TMetadata : TypeMetadataBase
     where TOptions : AcSerializerOptions
 {
-    private bool _useSmallInt = false;
-    private const int BitArraySize = 1024;
-    private const int MaxSmallId = BitArraySize * 64;
 
-    #region Id Extraction (to be implemented by derived sealed classes)
+    #region Tracking - InternEntry based (serializer side)
-
-    // Future: Abstract methods for Id extraction
-    // protected abstract int GetIdInt32Core(object obj, TMetadata metadata);
-    // protected abstract long GetIdInt64Core(object obj, TMetadata metadata);
-    // protected abstract Guid GetIdGuidCore(object obj, TMetadata metadata);
-
-    #endregion
-
-    #region Tracking (to be moved from AcSerializerContextBase)
 
     /// <summary>
     /// Tries to track an object with int RefId.
-    /// Use when wrapper.Metadata.IdAccessorType == Int32.
+    /// Returns true if first occurrence, false if already seen (cacheIndex assigned).
-    /// Returns true if first occurrence.
+    /// Uses shared nextCacheIndex counter (shared with string interning).
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryTrack(TypeMetadataWrapper<TMetadata> wrapper, object obj, out int refId)
+    public bool TryTrack(TypeMetadataWrapper<TMetadata> wrapper, object obj, int streamPosition, ref int nextCacheIndex, out int cacheIndex)
     {
         Debug.Assert(wrapper.Metadata.IdAccessorType == IdAccessorType.Int32);
-
+        var id = wrapper.RefIdGetterInt32!(obj);
-        // Use pre-cast getter - no cast overhead!
+        return wrapper.TryTrackInt32(id, streamPosition, ref nextCacheIndex, out cacheIndex);
-        refId = wrapper.RefIdGetterInt32!(obj);
-
-        // BitArray fast path for small positive IDs
-        return (_useSmallInt && refId is >= 0 and < MaxSmallId) ? TryTrackSmallId(wrapper, refId) : wrapper.TryAddKey(refId);
-    }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static bool TryTrackSmallId(TypeMetadataWrapper<TMetadata> wrapper, int id)
-    {
-        // Lazy init - but only once per type per serialization
-        var bitmap = wrapper.SmallIdBitmap ?? InitSmallIdBitmap(wrapper);
-
-        var idx = (uint)id;
-        var wordIdx = idx >> 6;
-        var bitIdx = (int)(idx & 63);
-
-        var mask = 1UL << bitIdx;
-        ref var word = ref bitmap[wordIdx];
-
-        if ((word & mask) != 0) return false;
-
-        word |= mask;
-        return true;
-    }
-    
-    [MethodImpl(MethodImplOptions.NoInlining)]
-    private static ulong[] InitSmallIdBitmap(TypeMetadataWrapper<TMetadata> wrapper)
-    {
-        wrapper.SmallIdBitmap = new ulong[BitArraySize];
-        return wrapper.SmallIdBitmap;
     }
 
     /// <summary>
     /// Tries to track an object with long RefId.
-    /// Use when wrapper.Metadata.IdAccessorType == Int64.
-    /// Returns true if first occurrence.
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryTrack(TypeMetadataWrapper<TMetadata> wrapper, object obj, out long refId)
+    public bool TryTrackLong(TypeMetadataWrapper<TMetadata> wrapper, object obj, int streamPosition, ref int nextCacheIndex, out int cacheIndex)
     {
         Debug.Assert(wrapper.Metadata.IdAccessorType == IdAccessorType.Int64);
-
+        var id = wrapper.RefIdGetterInt64!(obj);
-        // Use pre-cast getter - no cast overhead!
+        return wrapper.TryTrackInt64(id, streamPosition, ref nextCacheIndex, out cacheIndex);
-        refId = wrapper.RefIdGetterInt64!(obj);
-
-        return wrapper.TryAddKey(refId);
     }
 
     /// <summary>
     /// Tries to track an object with Guid RefId.
-    /// Use when wrapper.Metadata.IdAccessorType == Guid.
-    /// Returns true if first occurrence.
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryTrack(TypeMetadataWrapper<TMetadata> wrapper, object obj, out Guid refId)
+    public bool TryTrackGuid(TypeMetadataWrapper<TMetadata> wrapper, object obj, int streamPosition, ref int nextCacheIndex, out int cacheIndex)
     {
         Debug.Assert(wrapper.Metadata.IdAccessorType == IdAccessorType.Guid);
-
+        var id = wrapper.RefIdGetterGuid!(obj);
-        // Use pre-cast getter - no cast overhead!
+        return wrapper.TryTrackGuid(id, streamPosition, ref nextCacheIndex, out cacheIndex);
-        refId = wrapper.RefIdGetterGuid!(obj);
-
-        return wrapper.TryAddKey(refId);
     }
 
     #endregion

AyCode.Core/Serializers/TypeMetadataWrapper.cs

@@ -40,17 +40,17 @@ public sealed class TypeMetadataWrapper<TMetadata> where TMetadata : TypeMetadat
     /// <summary>
     /// Typed IdentityMap for Int32 IDs. Direct access, no type check.
     /// </summary>
-    internal IdentityMap<int, object?>? IdentityMapInt32;
+    internal IdentityMap<int, InternEntry>? IdentityMapInt32;
 
     /// <summary>
     /// Typed IdentityMap for Int64 IDs. Direct access, no type check.
     /// </summary>
-    internal IdentityMap<long, object?>? IdentityMapInt64;
+    internal IdentityMap<long, InternEntry>? IdentityMapInt64;
 
     /// <summary>
     /// Typed IdentityMap for Guid IDs. Direct access, no type check.
     /// </summary>
-    internal IdentityMap<Guid, object?>? IdentityMapGuid;
+    internal IdentityMap<Guid, InternEntry>? IdentityMapGuid;
 
     #endregion
 
@@ -68,11 +68,6 @@ public sealed class TypeMetadataWrapper<TMetadata> where TMetadata : TypeMetadat
     /// </summary>
     private static readonly Func<object, int> HashCodeGetter = RuntimeHelpers.GetHashCode;
     
-    /// <summary>
-    /// Pre-bound delegate to register instance by Id - NO SWITCH in hot path!
-    /// Set in constructor based on IdAccessorType. Method group conversion = no allocation.
-    /// </summary>
-    internal readonly Action<object>? RegisterById;
 
     /// <summary>
     /// Creates a new wrapper for the given metadata.
@@ -86,20 +81,17 @@ public sealed class TypeMetadataWrapper<TMetadata> where TMetadata : TypeMetadat
         // Use cached delegate from metadata for IId types, static fallback for non-IId
         var refIdGetter = metadata.TypedIdGetter ?? HashCodeGetter;
 
-        // Pre-cast typed getters AND set RegisterById delegate - avoids switch in every call
+        // Pre-cast typed getters based on IdAccessorType
         switch (metadata.IdAccessorType)
         {
             case IdAccessorType.Int32:
                 RefIdGetterInt32 = (Func<object, int>)refIdGetter;
-                RegisterById = RegisterByInt32Id;  // Method group - no allocation!
                 break;
             case IdAccessorType.Int64:
                 RefIdGetterInt64 = (Func<object, long>)refIdGetter;
-                RegisterById = RegisterByInt64Id;
                 break;
             case IdAccessorType.Guid:
                 RefIdGetterGuid = (Func<object, Guid>)refIdGetter;
-                RegisterById = RegisterByGuidId;
                 break;
         }
     }
@@ -126,165 +118,84 @@ public sealed class TypeMetadataWrapper<TMetadata> where TMetadata : TypeMetadat
         IdentityMapGuid?.Reset(preRentBuckets);
     }
 
-    #region Direct Int32 Operations - No type check, no generic overhead
+    #region Serializer: TryTrack by typed Id → InternEntry with slotIndex
 
     /// <summary>
-    /// Tries to get object by Int32 Id. Returns true if found.
+    /// Tries to track Int32 Id. Returns true if first occurrence.
-    /// Direct dictionary lookup - no generic type check!
+    /// On repeat: assigns CacheIndex from shared counter, returns cacheIndex.
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryGetValueInt32(int id, out object? instance)
+    public bool TryTrackInt32(int id, int streamPosition, ref int nextCacheIndex, out int cacheIndex)
     {
-        if (IdentityMapInt32 != null)
+        if (id == 0) { cacheIndex = -1; return true; } // Default Id - no tracking
-            return IdentityMapInt32.TryGetValue(id, out instance);
 
-        instance = null;
+        var map = IdentityMapInt32 ??= new IdentityMap<int, InternEntry>();
+        if (!map.TryAdd(id, out var slotIndex))
+        {
+            // 2+ occurrence: assign CacheIndex if first repeat
+            ref var entry = ref map.GetValueRef(slotIndex);
+            if (entry.CacheIndex < 0)
+                entry.CacheIndex = nextCacheIndex++;
+            cacheIndex = entry.CacheIndex;
             return false;
         }
 
-    /// <summary>
+        // 1st occurrence: store stream position
-    /// Gets existing object or stores new one by Int32 Id.
+        ref var newEntry = ref map.GetValueRef(slotIndex);
-    /// Direct dictionary access - no generic type check!
+        newEntry.StreamPosition = streamPosition;
-    /// </summary>
+        newEntry.CacheIndex = -1;
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        cacheIndex = -1;
-    public object TryGetOrStoreInt32(int id, object newObj)
+        return true;
-    {
-        if (id == 0) return newObj; // Default Id - no tracking
-        
-        var map = IdentityMapInt32 ??= new IdentityMap<int, object?>();
-        return map.TryGetOrAddValue(id, newObj);
     }
 
     /// <summary>
-    /// Registers IId instance by extracting its Int32 Id.
+    /// Tries to track Int64 Id. Returns true if first occurrence.
-    /// Combines Id getter + store in one call.
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public void RegisterByInt32Id(object instance)
+    public bool TryTrackInt64(long id, int streamPosition, ref int nextCacheIndex, out int cacheIndex)
     {
-        var id = RefIdGetterInt32!(instance);
+        if (id == 0) { cacheIndex = -1; return true; }
-        if (id == 0) return;
 
-        var map = IdentityMapInt32 ??= new IdentityMap<int, object?>();
+        var map = IdentityMapInt64 ??= new IdentityMap<long, InternEntry>();
-        map.TryGetOrAddValue(id, instance);
+        if (!map.TryAdd(id, out var slotIndex))
-    }
-    
-    #endregion
-
-    #region Direct Int64 Operations
-    
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryGetValueInt64(long id, out object? instance)
         {
-        if (IdentityMapInt64 != null)
+            ref var entry = ref map.GetValueRef(slotIndex);
-            return IdentityMapInt64.TryGetValue(id, out instance);
+            if (entry.CacheIndex < 0)
-        
+                entry.CacheIndex = nextCacheIndex++;
-        instance = null;
+            cacheIndex = entry.CacheIndex;
             return false;
         }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        ref var newEntry = ref map.GetValueRef(slotIndex);
-    public object TryGetOrStoreInt64(long id, object newObj)
+        newEntry.StreamPosition = streamPosition;
-    {
+        newEntry.CacheIndex = -1;
-        if (id == 0) return newObj;
+        cacheIndex = -1;
-        
+        return true;
-        var map = IdentityMapInt64 ??= new IdentityMap<long, object?>();
-        return map.TryGetOrAddValue(id, newObj);
     }
 
+    /// <summary>
+    /// Tries to track Guid Id. Returns true if first occurrence.
+    /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public void RegisterByInt64Id(object instance)
+    public bool TryTrackGuid(Guid id, int streamPosition, ref int nextCacheIndex, out int cacheIndex)
     {
-        var id = RefIdGetterInt64!(instance);
+        if (id == Guid.Empty) { cacheIndex = -1; return true; }
-        if (id == 0) return;
 
-        var map = IdentityMapInt64 ??= new IdentityMap<long, object?>();
+        var map = IdentityMapGuid ??= new IdentityMap<Guid, InternEntry>();
-        map.TryGetOrAddValue(id, instance);
+        if (!map.TryAdd(id, out var slotIndex))
-    }
-    
-    #endregion
-
-    #region Direct Guid Operations
-    
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryGetValueGuid(Guid id, out object? instance)
         {
-        if (IdentityMapGuid != null)
+            ref var entry = ref map.GetValueRef(slotIndex);
-            return IdentityMapGuid.TryGetValue(id, out instance);
+            if (entry.CacheIndex < 0)
-        
+                entry.CacheIndex = nextCacheIndex++;
-        instance = null;
+            cacheIndex = entry.CacheIndex;
             return false;
         }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        ref var newEntry = ref map.GetValueRef(slotIndex);
-    public object TryGetOrStoreGuid(Guid id, object newObj)
+        newEntry.StreamPosition = streamPosition;
-    {
+        newEntry.CacheIndex = -1;
-        if (id == Guid.Empty) return newObj;
+        cacheIndex = -1;
-        
+        return true;
-        var map = IdentityMapGuid ??= new IdentityMap<Guid, object?>();
-        return map.TryGetOrAddValue(id, newObj);
-    }
-    
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public void RegisterByGuidId(object instance)
-    {
-        var id = RefIdGetterGuid!(instance);
-        if (id == Guid.Empty) return;
-        
-        var map = IdentityMapGuid ??= new IdentityMap<Guid, object?>();
-        map.TryGetOrAddValue(id, instance);
-    }
-    
-    #endregion
-
-    #region Legacy Generic Methods (for backward compatibility)
-    
-    /// <summary>
-    /// Gets or creates the typed IdentityMap for tracking.
-    /// SLOW PATH - use typed methods (TryGetValueInt32, etc.) instead!
-    /// </summary>
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public IdentityMap<TId, object?> GetOrCreateIdentityMap<TId>() where TId : notnull
-    {
-        // Route to typed fields based on TId
-        if (typeof(TId) == typeof(int))
-        {
-            var map = IdentityMapInt32 ??= new IdentityMap<int, object?>();
-            return Unsafe.As<IdentityMap<int, object?>, IdentityMap<TId, object?>>(ref map);
-        }
-        if (typeof(TId) == typeof(long))
-        {
-            var map = IdentityMapInt64 ??= new IdentityMap<long, object?>();
-            return Unsafe.As<IdentityMap<long, object?>, IdentityMap<TId, object?>>(ref map);
-        }
-        if (typeof(TId) == typeof(Guid))
-        {
-            var map = IdentityMapGuid ??= new IdentityMap<Guid, object?>();
-            return Unsafe.As<IdentityMap<Guid, object?>, IdentityMap<TId, object?>>(ref map);
-        }
-
-        throw new NotSupportedException($"Id type {typeof(TId)} is not supported");
-    }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryAddKey<TId>(TId key) where TId : struct
-    {
-        var map = GetOrCreateIdentityMap<TId>();
-        return map.TryAddKey(key);
-    }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool TryGetValue<TId>(TId refId, out object? instance) where TId : struct
-    {
-        var map = GetOrCreateIdentityMap<TId>();
-        return map.TryGetValue(refId, out instance);
-    }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public object TryGetOrStoreId<TId>(TId id, object newObj) where TId : struct
-    {
-        var map = GetOrCreateIdentityMap<TId>();
-        return map.TryGetOrAddValue(id, newObj);
     }
 
     #endregion