Net.Like.Xue.Tokyo/Assets/Plugins/Animancer/Internal/Editor/ConversionCache.cs

102 lines
3.6 KiB
C#

// Animancer // https://kybernetik.com.au/animancer // Copyright 2018-2023 Kybernetik //
#if UNITY_EDITOR
//#define ANIMANCER_LOG_CONVERSION_CACHE
using System;
using System.Collections.Generic;
using UnityEngine;
namespace Animancer.Editor
{
/// <summary>[Editor-Only]
/// A simple system for converting objects and storing the results so they can be reused to minimise the need for
/// garbage collection, particularly for string construction.
/// </summary>
/// <remarks>This class doesn't use any Editor-Only functionality, but it's unlikely to be useful at runtime.</remarks>
/// https://kybernetik.com.au/animancer/api/Animancer.Editor/ConversionCache_2
///
public class ConversionCache<TKey, TValue>
{
/************************************************************************************************************************/
private class CachedValue
{
public int lastFrameAccessed;
public TValue value;
}
/************************************************************************************************************************/
private readonly Dictionary<TKey, CachedValue>
Cache = new Dictionary<TKey, CachedValue>();
private readonly List<TKey>
Keys = new List<TKey>();
private readonly Func<TKey, TValue>
Converter;
private int _LastCleanupFrame;
/************************************************************************************************************************/
/// <summary>
/// Creates a new <see cref="ConversionCache{TKey, TValue}"/> which uses the specified delegate to convert values.
/// </summary>
public ConversionCache(Func<TKey, TValue> converter) => Converter = converter;
/************************************************************************************************************************/
/// <summary>
/// If a value has already been cached for the specified `key`, return it. Otherwise create a new one using
/// the delegate provided in the constructor and cache it.
/// <para></para>
/// If the `key` is <c>null</c>, this method returns the default <typeparamref name="TValue"/>.
/// </summary>
/// <remarks>This method also periodically removes values that have not been used recently.</remarks>
public TValue Convert(TKey key)
{
if (key == null)
return default;
CachedValue cached;
// The next time a value is retrieved after at least 100 frames, clear out any old ones.
var frame = Time.frameCount;
if (_LastCleanupFrame + 100 < frame)
{
for (int i = Keys.Count - 1; i >= 0; i--)
{
var checkKey = Keys[i];
if (!Cache.TryGetValue(checkKey, out cached) ||
cached.lastFrameAccessed <= _LastCleanupFrame)
{
Cache.Remove(checkKey);
Keys.RemoveAt(i);
}
}
_LastCleanupFrame = frame;
}
if (!Cache.TryGetValue(key, out cached))
{
Cache.Add(key, cached = new CachedValue { value = Converter(key) });
Keys.Add(key);
}
cached.lastFrameAccessed = frame;
return cached.value;
}
/************************************************************************************************************************/
}
}
#endif