探索一下 Enum 优化
探索一下 Enum 优化
SV.Enums主要是探索如何让 enum 更高效
其中涉及的优化手段并非完全自创
很多内容参考于以下项目
主要优化手段
其实主要全是 空间换时间，大量缓存
封装入口方法以及 source-generators 生成
不过本项目尝试了封装入口方法、ModuleInitializer、source-generators 来避免对使用影响（其实更主要是尝试如何避免使用interceptors）
public static class Enums<T> where T : struct, Enum
{
public static bool IsFlags => CheckInfo().IsFlags;
public static bool IsEmpty => CheckInfo().IsEmpty;
internal static IEnumInfo<T> Info;
[MethodImpl(Enums.Optimization)]
internal static IEnumInfo<T> CheckInfo()
{
if (Info == null)
{
Info = new EnumInfo<T>();
}
return Info;
}
public static T Parse(string name, bool ignoreCase)
{
if (CheckInfo().TryParse(name, ignoreCase, out var result))
return result;
throw new ArgumentException($"Specified value '{name}' is not defined.", nameof(name));
}
这样做主要就可以利用 source-generators 生成enum 处理代码，
并通过 ModuleInitializer 在运行时启用生成的enum代码
如下为生成enum 代码示例
internal class EnumInfoAD125120120540FC9AA056E2DD394A7C : EnumBase<global::Benchmark.Fruits2>
{
public override bool IsDefined(string name)
{
return name switch
{
nameof(global::Benchmark.Fruits2.Apple) => true,
nameof(global::Benchmark.Fruits2.Lemon) => true,
nameof(global::Benchmark.Fruits2.Melon) => true,
nameof(global::Benchmark.Fruits2.Banana) => true,
_ => false,
};
}
public override string? GetName(global::Benchmark.Fruits2 t)
{
switch (t)
{
case global::Benchmark.Fruits2.Apple: return nameof(global::Benchmark.Fruits2.Apple);
case global::Benchmark.Fruits2.Lemon: return nameof(global::Benchmark.Fruits2.Lemon);
case global::Benchmark.Fruits2.Melon: return nameof(global::Benchmark.Fruits2.Melon);
case global::Benchmark.Fruits2.Banana: return nameof(global::Benchmark.Fruits2.Banana);
default:
return null;
}
}
protected override bool TryParseCase(in ReadOnlySpan<char> name, out global::Benchmark.Fruits2 result)
{
switch (name)
{
case ReadOnlySpan<char> current when current.Equals(nameof(global::Benchmark.Fruits2.Apple).AsSpan(), global::System.StringComparison.Ordinal):
result = global::Benchmark.Fruits2.Apple;
return true;
case ReadOnlySpan<char> current when current.Equals(nameof(global::Benchmark.Fruits2.Lemon).AsSpan(), global::System.StringComparison.Ordinal):
result = global::Benchmark.Fruits2.Lemon;
return true;
case ReadOnlySpan<char> current when current.Equals(nameof(global::Benchmark.Fruits2.Melon).AsSpan(), global::System.StringComparison.Ordinal):
result = global::Benchmark.Fruits2.Melon;
return true;
case ReadOnlySpan<char> current when current.Equals(nameof(global::Benchmark.Fruits2.Banana).AsSpan(), global::System.StringComparison.Ordinal):
result = global::Benchmark.Fruits2.Banana;
return true;
default:
result = default;
return false;
}
}
protected override bool TryParseIgnoreCase(in ReadOnlySpan<char> name, out global::Benchmark.Fruits2 result)
{
switch (name)
{
case ReadOnlySpan<char> current when current.Equals(nameof(global::Benchmark.Fruits2.Apple).AsSpan(), global::System.StringComparison.OrdinalIgnoreCase):
result = global::Benchmark.Fruits2.Apple;
return true;
case ReadOnlySpan<char> current when current.Equals(nameof(global::Benchmark.Fruits2.Lemon).AsSpan(), global::System.StringComparison.OrdinalIgnoreCase):
result = global::Benchmark.Fruits2.Lemon;
return true;
case ReadOnlySpan<char> current when current.Equals(nameof(global::Benchmark.Fruits2.Melon).AsSpan(), global::System.StringComparison.OrdinalIgnoreCase):
result = global::Benchmark.Fruits2.Melon;
return true;
case ReadOnlySpan<char> current when current.Equals(nameof(global::Benchmark.Fruits2.Banana).AsSpan(), global::System.StringComparison.OrdinalIgnoreCase):
result = global::Benchmark.Fruits2.Banana;
return true;
default:
result = default;
return false;
}
}
}
internal static partial class EnumsF1029F0E5915401BBDD8559E2B5289B1
{
[ModuleInitializer]
internal static void Init4771B8A4BD2E4761973279D81E61089C()
{
global::SV.Enums.SetEnumInfo<global::Benchmark.Fruits2>(new EnumInfoAD125120120540FC9AA056E2DD394A7C());
}
}
不过这样封装入口，存在一定性能损失
空间换时间
当然如果不使用 source-generators， 对应功能也有默认实现
部分代码如下， 大部分东西都内存缓存了
public class EnumInfo<T> : IEnumInfo<T> where T : struct, Enum
{
private readonly string[] names;
private readonly T[] values;
private readonly (string Name, T Value)[] members;
private readonly FastReadOnlyDictionary<string, T> membersByName;
private readonly FastReadOnlyDictionary<T, (string Name, EnumMemberAttribute Member, FastReadOnlyDictionary<int, string> Labels)> namesByMember;
private readonly Type underlyingType;
private readonly TypeCode underlyingTypeCode;
public bool IsFlags { get; private set; }
public bool IsEmpty => values.Length == 0;
public EnumInfo() : base()
{
var t = typeof(T);
names = Enum.GetNames(t);
members = names.Select(i => (i, (T)Enum.Parse(t, i))).ToArray();
values = members.Select(i => i.Value).ToArray();
membersByName = members.ToFastReadOnlyDictionary(i => i.Name, i => i.Value);
namesByMember = membersByName.AsEnumerable().DistinctBy(i => i.Value).ToFastReadOnlyDictionary(i => i.Value, i =>
{
var fieldInfo = t.GetField(i.Key)!;
return (i.Key, fieldInfo.GetCustomAttribute<EnumMemberAttribute>(), fieldInfo.GetCustomAttributes<LabelAttribute>().DistinctBy(i => i.Index).ToFastReadOnlyDictionary(x => x.Index, x => x.Value));
});
underlyingType = Enum.GetUnderlyingType(t);
underlyingTypeCode = Type.GetTypeCode(underlyingType);
IsFlags = t.IsDefined(typeof(FlagsAttribute), true);
}
[MethodImpl(Enums.Optimization)]
public bool TryParseIgnoreCase(in ReadOnlySpan<char> name, out T result)
{
foreach (var member in members.AsSpan())
{
if (name.Equals(member.Name.AsSpan(), StringComparison.OrdinalIgnoreCase))
{
result = member.Value;
return true;
}
}
result = default;
return false;
}
enum 转换方法
同时提供一些 不用拆箱装箱的 enum 转换方法，里面移除了类型检查的逻辑，所以理论只能保证正常使用不会有问题
public static T ToEnum(int value)
public static T ToEnum(byte value)
public static T ToEnum(Int16 value)
public static T ToEnum(Int64 value)
...
性能测试
简单做下性能测试， 部分代码如下
public enum Fruits
{
Apple,
Lemon,
Melon,
Banana,
Lemon1,
Melon2,
Banana3,
Lemon11,
Melon21,
Banana31,
Lemon12,
Melon22,
Banana32,
Lemon13,
Melon23,
Banana33,
Lemon131,
Melon231,
Banana331,
Lemon14,
Melon24,
Banana34,
}
[MemoryDiagnoser, Orderer(summaryOrderPolicy: SummaryOrderPolicy.FastestToSlowest), GroupBenchmarksBy(BenchmarkLogicalGroupRule.ByCategory), CategoriesColumn]
public class EnumBenchmarks
{
private readonly EnumInfo<Fruits> test;
public EnumBenchmarks()
{
test = new EnumInfo<Fruits>();
}
[Benchmark(Baseline = true), BenchmarkCategory("IgnoreCase")]
public Fruits ParseIgnoreCase()
{
return Enum.Parse<Fruits>("melon", true);
}
[Benchmark, BenchmarkCategory("IgnoreCase")]
public Fruits FastEnumParseIgnoreCase()
{
return FastEnum.Parse<Fruits>("melon", true);
}
[Benchmark, BenchmarkCategory("IgnoreCase")]
public Fruits SVEnumsParseIgnoreCase()
{
Enums<Fruits>.TryParse("melon", true, out var v);
return v;
}
[Benchmark, BenchmarkCategory("IgnoreCase")]
public Fruits EnumInfoParseIgnoreCase()
{
test.TryParse("melon", true, out var v);
return v;
}
[Benchmark(Baseline = true)]
public Fruits Parse()
{
return Enum.Parse<Fruits>("Melon", false);
}
[Benchmark]
public Fruits FastEnumParse()
{
return FastEnum.Parse<Fruits>("Melon", false);
}
[Benchmark]
public Fruits SVEnumsParse()
{
Enums<Fruits>.TryParse("Melon", out var v);
return v;
}
[Benchmark]
public Fruits EnumInfoParse()
{
test.TryParse("Melon", false, out var v);
return v;
}
...
[MemoryDiagnoser, Orderer(summaryOrderPolicy: SummaryOrderPolicy.FastestToSlowest), GroupBenchmarksBy(BenchmarkLogicalGroupRule.ByCategory), CategoriesColumn]
public class ToEnumBenchmarks
{
private readonly EnumInfo<Fruits> test;
public ToEnumBenchmarks()
{
test = new EnumInfo<Fruits>();
//Enums.SetEnumInfo<Fruits>(new TestIEnumInfo());
}
[Benchmark(Baseline = true), BenchmarkCategory("ToEnumInt")]
public Fruits ToEnumInt()
{
return (Fruits)Enum.ToObject(typeof(Fruits), 11);
}
[Benchmark, BenchmarkCategory("ToEnumInt")]
public Fruits SVEnumsToEnumInt()
{
return Enums<Fruits>.ToEnum(11);
}
[Benchmark, BenchmarkCategory("ToEnumInt")]
public Fruits ToEnumIntByte()
{
return (Fruits)Enum.ToObject(typeof(Fruits), (byte)11);
}
[Benchmark, BenchmarkCategory("ToEnumInt")]
public Fruits SVEnumsToEnumIntByte()
{
return Enums<Fruits>.ToEnum((byte)11);
}
[Benchmark, BenchmarkCategory("ToEnumInt")]
public Fruits ToEnumIntObject()
{
return (Fruits)Enum.ToObject(typeof(Fruits), (object)11);
}
[Benchmark, BenchmarkCategory("ToEnumInt")]
public Fruits SVEnumsToEnumIntObject()
{
return Enums<Fruits>.ToEnum((object)11);
}
}
结果如下
BenchmarkDotNet v0.14.0, Windows 10 (10.0.19045.4651/22H2/2022Update)
Intel Core i7-10700 CPU 2.90GHz, 1 CPU, 16 logical and 8 physical cores
.NET SDK 9.0.100-preview.5.24307.3
[Host] : .NET 8.0.6 (8.0.624.26715), X64 RyuJIT AVX2
DefaultJob : .NET 8.0.6 (8.0.624.26715), X64 RyuJIT AVX2
| Method | Mean | Error | StdDev | Median | Ratio | RatioSD | Gen0 | Allocated | Alloc Ratio |
|---|---|---|---|---|---|---|---|---|---|
| SVEnumsToEnumInt | 0.9796 ns | 0.0062 ns | 0.0055 ns | 0.9781 ns | 0.02 | 0.00 | - | - | 0.00 |
| SVEnumsToEnumIntByte | 1.0990 ns | 0.0089 ns | 0.0074 ns | 1.0966 ns | 0.03 | 0.00 | - | - | 0.00 |
| SVEnumsToEnumIntObject | 5.1211 ns | 0.0842 ns | 0.0746 ns | 5.1295 ns | 0.12 | 0.00 | 0.0029 | 24 B | 1.00 |
| ToEnumIntByte | 40.9720 ns | 0.2100 ns | 0.1861 ns | 40.9065 ns | 1.00 | 0.03 | 0.0029 | 24 B | 1.00 |
| ToEnumInt | 41.1962 ns | 0.8452 ns | 1.4122 ns | 40.4985 ns | 1.00 | 0.05 | 0.0029 | 24 B | 1.00 |
| ToEnumIntObject | 48.2590 ns | 0.4380 ns | 0.3882 ns | 48.0802 ns | 1.17 | 0.04 | 0.0057 | 48 B | 2.00 |
| Method | Categories | Mean | Error | StdDev | Ratio | RatioSD | Gen0 | Gen1 | Allocated | Alloc Ratio |
|---|---|---|---|---|---|---|---|---|---|---|
| SVEnumsParse | 2.8382 ns | 0.0508 ns | 0.0450 ns | 0.12 | 0.00 | - | - | - | NA | |
| FastEnumParse | 6.9671 ns | 0.0437 ns | 0.0388 ns | 0.28 | 0.00 | - | - | - | NA | |
| EnumInfoParse | 7.1513 ns | 0.1049 ns | 0.0930 ns | 0.29 | 0.00 | - | - | - | NA | |
| Parse | 24.5338 ns | 0.0548 ns | 0.0485 ns | 1.00 | 0.00 | - | - | - | NA | |
| FastEnumGetName | GetName | 0.8608 ns | 0.0175 ns | 0.0155 ns | 0.32 | 0.01 | - | - | - | NA |
| EnumInfoGetName | GetName | 1.4291 ns | 0.0147 ns | 0.0130 ns | 0.54 | 0.01 | - | - | - | NA |
| SVEnumsGetName | GetName | 1.6210 ns | 0.0148 ns | 0.0131 ns | 0.61 | 0.01 | - | - | - | NA |
| GetName | GetName | 2.6512 ns | 0.0150 ns | 0.0125 ns | 1.00 | 0.01 | - | - | - | NA |
| SVEnumsGetNames | GetNames | 0.2539 ns | 0.0061 ns | 0.0051 ns | 0.01 | 0.00 | - | - | - | 0.00 |
| FastEnumGetNames | GetNames | 0.6874 ns | 0.0195 ns | 0.0163 ns | 0.03 | 0.00 | - | - | - | 0.00 |
| GetNames | GetNames | 21.0463 ns | 0.4645 ns | 0.5162 ns | 1.00 | 0.03 | 0.0239 | 0.0001 | 200 B | 1.00 |
| SVEnumsGetValues | GetValues | 0.3022 ns | 0.0296 ns | 0.0277 ns | 0.009 | 0.00 | - | - | - | 0.00 |
| FastEnumGetValues | GetValues | 0.6683 ns | 0.0098 ns | 0.0082 ns | 0.021 | 0.00 | - | - | - | 0.00 |
| GetValues | GetValues | 32.5145 ns | 0.6732 ns | 0.5968 ns | 1.000 | 0.03 | 0.0134 | - | 112 B | 1.00 |
| SVEnumsParseIgnoreCase | IgnoreCase | 3.0465 ns | 0.0680 ns | 0.0727 ns | 0.12 | 0.00 | - | - | - | NA |
| EnumInfoParseIgnoreCase | IgnoreCase | 10.1299 ns | 0.1660 ns | 0.1472 ns | 0.42 | 0.01 | - | - | - | NA |
| FastEnumParseIgnoreCase | IgnoreCase | 10.3531 ns | 0.0807 ns | 0.0674 ns | 0.42 | 0.00 | - | - | - | NA |
| ParseIgnoreCase | IgnoreCase | 24.3767 ns | 0.1270 ns | 0.1060 ns | 1.00 | 0.01 | - | - | - | NA |
| SVEnumsIsDefinedName | IsDefinedName | 2.7188 ns | 0.0111 ns | 0.0098 ns | 0.11 | 0.00 | - | - | - | NA |
| EnumInfoIsDefinedName | IsDefinedName | 6.6075 ns | 0.0190 ns | 0.0148 ns | 0.26 | 0.00 | - | - | - | NA |
| FastEnumIsDefinedName | IsDefinedName | 6.7011 ns | 0.0388 ns | 0.0303 ns | 0.26 | 0.00 | - | - | - | NA |
| IsDefinedName | IsDefinedName | 25.3131 ns | 0.2064 ns | 0.1829 ns | 1.00 | 0.01 | - | - | - | NA |
