From 15f90aed29d3a40277694630bdaa896005d8d351 Mon Sep 17 00:00:00 2001
From: Youmu Liu <105042599+Nitload-NSI@users.noreply.github.com>
Date: Thu, 21 May 2026 19:40:00 +0800
Subject: [PATCH] L4 is now a burden

---
 .../HighPerformance/Memory/L4.CacheLine.cs    | 32 +++++++++++++
 .../HighPerformance/Memory/L4.Prefetch.cs     |  5 ---
 StgSharp.Common/HighPerformance/Memory/L4.cs  | 45 ++-----------------
 3 files changed, 36 insertions(+), 46 deletions(-)

diff --git a/StgSharp.Common/HighPerformance/Memory/L4.CacheLine.cs b/StgSharp.Common/HighPerformance/Memory/L4.CacheLine.cs
index c42466d9..f33c74bd 100644
--- a/StgSharp.Common/HighPerformance/Memory/L4.CacheLine.cs
+++ b/StgSharp.Common/HighPerformance/Memory/L4.CacheLine.cs
@@ -119,5 +119,37 @@ namespace StgSharp.HighPerformance.Memory
             #endregion
         }
 
+        [StructLayout(LayoutKind.Sequential)]
+        public unsafe ref struct Handle : IDisposable
+        {
+
+            private CacheLineMetadata* _head;
+            private nuint _handle;
+
+            private Handle(
+                    nuint handle,
+                    CacheLineMetadata* cacheRefCount
+            )
+            {
+                _handle = handle;
+                _head = cacheRefCount;
+            }
+
+            [Obsolete("You should not create a CacheLineHandle instance outside a L4", true)]
+            public Handle() { }
+
+            public readonly nuint Address => _handle;
+
+            public void Dispose()
+            {
+                if (_handle == 0) {
+                    return;
+                }
+                _handle = 0;
+                _ = Interlocked.Decrement(ref _head->RefCount);
+            }
+
+        }
+
     }
 }
diff --git a/StgSharp.Common/HighPerformance/Memory/L4.Prefetch.cs b/StgSharp.Common/HighPerformance/Memory/L4.Prefetch.cs
index 357ff251..b218708a 100644
--- a/StgSharp.Common/HighPerformance/Memory/L4.Prefetch.cs
+++ b/StgSharp.Common/HighPerformance/Memory/L4.Prefetch.cs
@@ -33,16 +33,11 @@ namespace StgSharp.HighPerformance.Memory
     public unsafe partial class L4
     {
 
-        public const int MaxActivateCacheLineCount = 1024;
-
         private partial void Prefetch()
         {
             if (CurrentPredict is null) {
                 return;
             }
-            if (_activeCount > MaxActivateCacheLineCount) {
-                throw new OverflowException("Too many activated cache line in external reference.");
-            }
             IL4Predict predict = CurrentPredict;
             int predictIndex = CurrentPredictIndex;
             Span<CacheLineDescription> span = new(_prediction, PredictionCount);
diff --git a/StgSharp.Common/HighPerformance/Memory/L4.cs b/StgSharp.Common/HighPerformance/Memory/L4.cs
index 4e2d14b7..3c93616b 100644
--- a/StgSharp.Common/HighPerformance/Memory/L4.cs
+++ b/StgSharp.Common/HighPerformance/Memory/L4.cs
@@ -59,7 +59,6 @@ namespace StgSharp.HighPerformance.Memory
         private readonly CacheLineDescription* _prediction;
         private bool _disposed;
         private bool _exhausted;
-        private int _activeCount;
 
         private int _aheadCount;
 
@@ -123,7 +122,7 @@ namespace StgSharp.HighPerformance.Memory
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void ContinueOnce(
-                    L4CacheLine line
+                    Handle line
         )
         {
             if (line.Address > 0) {
@@ -157,8 +156,8 @@ namespace StgSharp.HighPerformance.Memory
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public L4CacheLine Map(
-                           ref CacheLineDescription prediction
+        public Handle Map(
+                      ref CacheLineDescription prediction
         )
         {
             if ((_aheadCount < PredictionLeastAhead) && !_exhausted)
@@ -188,10 +187,9 @@ namespace StgSharp.HighPerformance.Memory
                     if (Interlocked.Increment(ref entry->RefCount) > 0)
                     {
                         (*_predictCount)[entry->Id] = 0;
-                        _ = Interlocked.Increment(ref _activeCount);
                         _ = Interlocked.Decrement(ref _aheadCount);
                         _ = Interlocked.Decrement(ref (*_mapCount)[entry->Id]);
-                        return new L4CacheLine((nuint)entry->Position, ref _activeCount, ref entry->RefCount);
+                        return new Handle((nuint)entry->Position, ref entry->RefCount);
                     } else
                     {
                         _ = Interlocked.Decrement(ref entry->RefCount);
@@ -204,39 +202,4 @@ namespace StgSharp.HighPerformance.Memory
         private partial void Prefetch();
 
     }
-
-    public ref struct L4CacheLine : IDisposable
-    {
-
-        private ref int _activeCount;
-        private ref int _refCount;
-        private nuint _handle;
-
-        internal L4CacheLine(
-                 nuint handle,
-                 ref int activeCount,
-                 ref int cacheRefCount
-        )
-        {
-            _handle = handle;
-            _refCount = ref cacheRefCount;
-            _activeCount = ref activeCount;
-        }
-
-        [Obsolete("You should not create a CacheLineHandle instance outside a L4", true)]
-        public L4CacheLine() { }
-
-        public readonly nuint Address => _handle;
-
-        public void Dispose()
-        {
-            if (_handle == 0) {
-                return;
-            }
-            _handle = 0;
-            _ = Interlocked.Decrement(ref _activeCount);
-            _ = Interlocked.Decrement(ref _refCount);
-        }
-
-    }
 }