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path: root/ARMeilleure/Translation/Cache/CacheMemoryAllocator.cs
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Diffstat (limited to 'ARMeilleure/Translation/Cache/CacheMemoryAllocator.cs')
-rw-r--r--ARMeilleure/Translation/Cache/CacheMemoryAllocator.cs96
1 files changed, 96 insertions, 0 deletions
diff --git a/ARMeilleure/Translation/Cache/CacheMemoryAllocator.cs b/ARMeilleure/Translation/Cache/CacheMemoryAllocator.cs
new file mode 100644
index 00000000..3111e886
--- /dev/null
+++ b/ARMeilleure/Translation/Cache/CacheMemoryAllocator.cs
@@ -0,0 +1,96 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+
+namespace ARMeilleure.Translation.Cache
+{
+ class CacheMemoryAllocator
+ {
+ private 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 List<MemoryBlock>();
+
+ 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 MemoryBlock(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 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);
+ }
+ }
+}