Refactor folder structure

src/Runtime/Ghost.Entities/SharedComponent.cs

@@ -0,0 +1,176 @@
+#if false
+using Misaki.HighPerformance.LowLevel.Buffer;
+using Misaki.HighPerformance.LowLevel.Collections;
+using Misaki.HighPerformance.LowLevel.Utilities;
+
+namespace Ghost.Entities;
+
+public interface ISharedComponent
+{
+}
+
+internal unsafe sealed class SharedComponentStore : IDisposable
+{
+    private struct EntryInfo
+    {
+        public int RefCount;
+        public int HashCode;
+        public int Version;
+        public int NextFree; // free-list linkage (index)
+    }
+
+    private struct TypeStore : IDisposable
+    {
+        public int TypeSize;
+        public UnsafeList<byte> Data;         // raw bytes, stride = TypeSize
+        public UnsafeList<EntryInfo> Infos;   // parallel to Data entries (Entry 0 reserved)
+        public UnsafeHashMap<long, int> HashLookup; // (hashKey) -> entryIndex
+        public int FreeListHead; // head index, 0 means none (we'll use Infos[0].NextFree too if you prefer)
+        public int VersionCounter;
+
+        public void Dispose()
+        {
+            Data.Dispose();
+            Infos.Dispose();
+            HashLookup.Dispose();
+        }
+    }
+
+    private readonly UnsafeHashMap<int, TypeStore> _perType; // componentTypeId -> TypeStore
+
+    public SharedComponentStore(int initialCapacity = 16)
+    {
+        _perType = new UnsafeHashMap<int, TypeStore>(initialCapacity, Allocator.Persistent);
+    }
+
+    public void Dispose()
+    {
+        foreach (var kvp in _perType)
+        {
+            kvp.Value.Dispose();
+        }
+
+        _perType.Dispose();
+    }
+
+    public int InsertOrGet(int componentTypeId, int typeSize, void* data, int hashCode)
+    {
+        // Reserve index 0 for "default"
+        if (data == null)
+        {
+            return 0;
+        }
+
+        ref var store = ref GetOrCreateTypeStore(componentTypeId, typeSize);
+
+        // Combine (typeId, hash) into a single key; collisions handled by memcmp below.
+        var key = ((long)componentTypeId << 32) ^ (uint)hashCode;
+
+        if (store.HashLookup.TryGetValue(key, out var existingIndex))
+        {
+            var existingPtr = (byte*)store.Data.GetUnsafePtr() + (existingIndex * store.TypeSize);
+            if (new Span<byte>(existingPtr, store.TypeSize).SequenceEqual(new Span<byte>(data, store.TypeSize)))
+            {
+                ((EntryInfo*)store.Infos.GetUnsafePtr())[existingIndex].RefCount++;
+                return existingIndex;
+            }
+            // If collision: fall through to insert (you may want a secondary structure).
+        }
+
+        int index = AllocateEntry(ref store);
+
+        var dst = (byte*)store.Data.GetUnsafePtr() + (index * store.TypeSize);
+        MemoryUtility.MemCpy(dst, data, (nuint)store.TypeSize);
+
+        store.Infos[index] = new EntryInfo
+        {
+            RefCount = 1,
+            HashCode = hashCode,
+            Version = ++store.VersionCounter,
+            NextFree = -1
+        };
+
+        store.HashLookup[key] = index;
+        return index;
+    }
+
+    public void AddRef(int componentTypeId, int index)
+    {
+        if (index == 0) return;
+        ref var store = ref _perType[componentTypeId];
+        store.Infos[index].RefCount++;
+    }
+
+    public void Release(int componentTypeId, int index)
+    {
+        if (index == 0) return;
+        ref var store = ref _perType.GetValueByKey(componentTypeId);
+
+        ref var info = ref store.Infos.Ptr[index];
+        info.RefCount--;
+        if (info.RefCount > 0) return;
+
+        // Remove from hash lookup (best-effort; collisions require more robust handling)
+        long key = ((long)componentTypeId << 32) ^ (uint)info.HashCode;
+        store.HashLookup.Remove(key);
+
+        // Push to free-list
+        info.NextFree = store.FreeListHead;
+        store.FreeListHead = index;
+    }
+
+    public void* GetDataPtr(int componentTypeId, int index)
+    {
+        if (index == 0) return null;
+        ref var store = ref _perType.GetValueByKey(componentTypeId);
+        return (byte*)store.Data.Ptr + (index * store.TypeSize);
+    }
+
+    private ref TypeStore GetOrCreateTypeStore(int componentTypeId, int typeSize)
+    {
+        if (_perType.TryGetValue(componentTypeId, out var existing))
+        {
+            // UnsafeHashMap returns by value in some implementations; you may need a different pattern here.
+            // Adjust to your container API (e.g., TryGetValueRef).
+        }
+
+        var store = new TypeStore
+        {
+            TypeSize = typeSize,
+            Data = new UnsafeList<byte>(typeSize * 16, Allocator.Persistent),
+            Infos = new UnsafeList<EntryInfo>(16, Allocator.Persistent),
+            HashLookup = new UnsafeHashMap<long, int>(16, Allocator.Persistent),
+            FreeListHead = 0,
+            VersionCounter = 0
+        };
+
+        // Create reserved default entry at index 0
+        store.Data.Resize(typeSize); // one element worth of bytes
+        store.Infos.Add(new EntryInfo { RefCount = int.MaxValue, HashCode = 0, Version = 0, NextFree = -1 });
+
+        _perType.Add(componentTypeId, store);
+        // NOTE: returning a ref requires a "get ref" API; adjust to your UnsafeHashMap capabilities.
+        return ref _perType.GetValueByKey(componentTypeId);
+    }
+
+    private static int AllocateEntry(ref TypeStore store)
+    {
+        if (store.FreeListHead != 0)
+        {
+            int idx = store.FreeListHead;
+            store.FreeListHead = store.Infos[idx].NextFree;
+            store.Infos[idx].NextFree = -1;
+            return idx;
+        }
+
+        int newIndex = store.Infos.Count;
+        store.Infos.Add(default);
+
+        int newByteCount = (newIndex + 1) * store.TypeSize;
+        store.Data.Resize(newByteCount);
+
+        return newIndex;
+    }
+}
+
+#endif