1 files changed, 112 insertions, 0 deletions
diff --git a/src/Ryujinx.Graphics.Vulkan/HashTableSlim.cs b/src/Ryujinx.Graphics.Vulkan/HashTableSlim.cs
new file mode 100644
index 00000000..e4ad3958
--- /dev/null
+++ b/src/Ryujinx.Graphics.Vulkan/HashTableSlim.cs
@@ -0,0 +1,112 @@
+using System;
+using System.Collections.Generic;
+
+namespace Ryujinx.Graphics.Vulkan
+{
+    interface IRefEquatable<T>
+    {
+        bool Equals(ref T other);
+    }
+
+    class HashTableSlim<K, V> where K : IRefEquatable<K>
+    {
+        private const int TotalBuckets = 16; // Must be power of 2
+        private const int TotalBucketsMask = TotalBuckets - 1;
+
+        private struct Entry
+        {
+            public int Hash;
+            public K Key;
+            public V Value;
+        }
+
+        private readonly Entry[][] _hashTable = new Entry[TotalBuckets][];
+
+        public IEnumerable<K> Keys
+        {
+            get
+            {
+                foreach (Entry[] bucket in _hashTable)
+                {
+                    if (bucket != null)
+                    {
+                        foreach (Entry entry in bucket)
+                        {
+                            yield return entry.Key;
+                        }
+                    }
+                }
+            }
+        }
+
+        public IEnumerable<V> Values
+        {
+            get
+            {
+                foreach (Entry[] bucket in _hashTable)
+                {
+                    if (bucket != null)
+                    {
+                        foreach (Entry entry in bucket)
+                        {
+                            yield return entry.Value;
+                        }
+                    }
+                }
+            }
+        }
+
+        public void Add(ref K key, V value)
+        {
+            var entry = new Entry()
+            {
+                Hash = key.GetHashCode(),
+                Key = key,
+                Value = value
+            };
+
+            int hashCode = key.GetHashCode();
+            int bucketIndex = hashCode & TotalBucketsMask;
+
+            var bucket = _hashTable[bucketIndex];
+            if (bucket != null)
+            {
+                int index = bucket.Length;
+
+                Array.Resize(ref _hashTable[bucketIndex], index + 1);
+
+                _hashTable[bucketIndex][index] = entry;
+            }
+            else
+            {
+                _hashTable[bucketIndex] = new Entry[]
+                {
+                    entry
+                };
+            }
+        }
+
+        public bool TryGetValue(ref K key, out V value)
+        {
+            int hashCode = key.GetHashCode();
+
+            var bucket = _hashTable[hashCode & TotalBucketsMask];
+            if (bucket != null)
+            {
+                for (int i = 0; i < bucket.Length; i++)
+                {
+                    ref var entry = ref bucket[i];
+
+                    if (entry.Hash == hashCode && entry.Key.Equals(ref key))
+                    {
+                        value = entry.Value;
+                        return true;
+                    }
+                }
+            }
+
+            value = default;
+            return false;
+        }
+    }
+}