Ryujinx/Ryujinx.Graphics.Vulkan/HashTableSlim.cs

112 lines
2.8 KiB
C#

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;
}
}
}