1 files changed, 136 insertions, 0 deletions
diff --git a/src/Ryujinx.Cpu/LightningJit/Cache/CacheMemoryAllocator.cs b/src/Ryujinx.Cpu/LightningJit/Cache/CacheMemoryAllocator.cs
new file mode 100644
index 00000000..8ba3a6dc
--- /dev/null
+++ b/src/Ryujinx.Cpu/LightningJit/Cache/CacheMemoryAllocator.cs
@@ -0,0 +1,136 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+
+namespace Ryujinx.Cpu.LightningJit.Cache
+{
+    class CacheMemoryAllocator
+    {
+        private readonly struct MemoryBlock : IComparable<MemoryBlock>
+        {
+            public int Offset { get; }
+            public int Size { get; }
+
+            public MemoryBlock(int offset, int size)
+            {
+                Offset = offset;
+                Size = size;
+            }
+
+            public int CompareTo([AllowNull] MemoryBlock other)
+            {
+                return Offset.CompareTo(other.Offset);
+            }
+        }
+
+        private readonly List<MemoryBlock> _blocks = new();
+
+        public CacheMemoryAllocator(int capacity)
+        {
+            _blocks.Add(new MemoryBlock(0, capacity));
+        }
+
+        public int Allocate(int size)
+        {
+            for (int i = 0; i < _blocks.Count; i++)
+            {
+                MemoryBlock block = _blocks[i];
+
+                if (block.Size > size)
+                {
+                    _blocks[i] = new(block.Offset + size, block.Size - size);
+                    return block.Offset;
+                }
+                else if (block.Size == size)
+                {
+                    _blocks.RemoveAt(i);
+                    return block.Offset;
+                }
+            }
+
+            // We don't have enough free memory to perform the allocation.
+            return -1;
+        }
+
+        public void ForceAllocation(int offset, int size)
+        {
+            int index = _blocks.BinarySearch(new(offset, size));
+
+            if (index < 0)
+            {
+                index = ~index;
+            }
+
+            int endOffset = offset + size;
+
+            MemoryBlock block = _blocks[index];
+
+            Debug.Assert(block.Offset <= offset && block.Offset + block.Size >= endOffset);
+
+            if (offset > block.Offset && endOffset < block.Offset + block.Size)
+            {
+                _blocks[index] = new(block.Offset, offset - block.Offset);
+                _blocks.Insert(index + 1, new(endOffset, (block.Offset + block.Size) - endOffset));
+            }
+            else if (offset > block.Offset)
+            {
+                _blocks[index] = new(block.Offset, offset - block.Offset);
+            }
+            else if (endOffset < block.Offset + block.Size)
+            {
+                _blocks[index] = new(endOffset, (block.Offset + block.Size) - endOffset);
+            }
+            else
+            {
+                _blocks.RemoveAt(index);
+            }
+        }
+
+        public void Free(int offset, int size)
+        {
+            Insert(new MemoryBlock(offset, size));
+        }
+
+        private void Insert(MemoryBlock block)
+        {
+            int index = _blocks.BinarySearch(block);
+
+            if (index < 0)
+            {
+                index = ~index;
+            }
+
+            if (index < _blocks.Count)
+            {
+                MemoryBlock next = _blocks[index];
+
+                int endOffs = block.Offset + block.Size;
+
+                if (next.Offset == endOffs)
+                {
+                    block = new MemoryBlock(block.Offset, block.Size + next.Size);
+                    _blocks.RemoveAt(index);
+                }
+            }
+
+            if (index > 0)
+            {
+                MemoryBlock prev = _blocks[index - 1];
+
+                if (prev.Offset + prev.Size == block.Offset)
+                {
+                    block = new MemoryBlock(block.Offset - prev.Size, block.Size + prev.Size);
+                    _blocks.RemoveAt(--index);
+                }
+            }
+
+            _blocks.Insert(index, block);
+        }
+
+        public void Clear()
+        {
+            _blocks.Clear();
+        }
+    }
+}