Soenneker.Reflection.Cache

The fastest .NET Reflection cache

Why?

System.Reflection is slow. If you need to call Reflection code repeatedly, this library can drastically speed up subsequent calls. It's thread-safe and supports concurrency.

Installation

dotnet add package Soenneker.Reflection.Cache

This cache can either be added to DI like so:

public void ConfigureServices(IServiceCollection services)
{
    services.AddReflectionCacheAsSingleton(); // or AddReflectionCacheAsScoped()
}

and you could access it like:

public class MyService
{
    private readonly IReflectionCache _cache;

    public MyService(IReflectionCache cache)
    {
        _cache = cache;
    }
}

or you can instantiate it manually:

var cache = new ReflectionCache(threadSafe: true); // can be disabled for extra speed

Usage

var type1 = Type.GetType("System.String"); // <-- regular Reflection
var type2 = cache.GetType("System.String"); // <-- cached Reflection
bool areEqual = type1 == type2; // true

Keep in mind:

cache.GetType("System.String"); // <-- as slow as regular Reflection
cache.GetType("System.String"); // <-- very fast because the first call was cached

⚠️ Important ⚠️

Be mindful of the "cache chain". Use the Cached methods and types until you need to get the final Reflection type you need from the cache.

There are two methods for most operations like this:

Type typeofString = cache.GetType("System.String"); // <-- caches, stops the cache chain
CachedType type = cache.GetCachedType("System.String"); // <-- caches, continues the cache chain

Scenario: Retrieving parameters from a method

✅ Good:

CachedType cachedType = cache.GetCachedType("System.String");
CachedMethod cachedMethodInfo = cachedType.GetCachedMethod("Intern");
ParameterInfo?[] parameters = cachedMethodInfo.GetParameters(); // < -- parameters are now cached

❌ Bad:

CachedType cachedType = cache.GetCachedType("System.String");
MethodInfo methodInfo = cachedType.GetMethod("Intern"); // <-- uh oh, a non-cached Reflection type
ParameterInfo?[] parameters = methodInfo.GetParameters(); // <-- not cached, repeat calls are slow

Tips

• Almost all of the Cached methods (e.g. GetCachedParameters() vs GetParameters() are faster due to the final preparation needed to match the System.Reflection methods.
• Work with the Cached objects instead of Reflection objects if possible. They're faster to retrieve and allow for more efficient downstream chaining.
• Thread safety can be disabled for more speed. It's enabled by default.
• Consider if caching is even necessary for your use case. If you're only calling Reflection once, it may not be worth it.
• Caching isn't free. Be thoughtful of your memory footprint and where/when you dispose of the cache.

Notes

• A cache removal mechanism is needing to be built yet.
• Many Reflection functionalities are not yet implemented, and could benefit from caching.
• If you see something that could be improved (performance or allocation), please open an issue or PR.

---

Benchmarks (.NET 9.0)

GetType() 5,772% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetType_string_NoCache	1,022.30 ns	9.462 ns	8.851 ns	baseline
GetType_string_Cache	17.52 ns	0.303 ns	0.283 ns	58.38x faster	1.12x
GetType_string_threadSafe_Cache	24.73 ns	0.139 ns	0.116 ns	41.29x faster	0.33x
GetCachedType_type_Cache	12.21 ns	0.234 ns	0.218 ns	83.76x faster	1.74x
GetCachedType_type_ThreadSafe_Cache	19.01 ns	0.067 ns	0.052 ns	53.73x faster	0.47x

GetMethods() 24,842% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetMethods_NoCache	256.526 ns	1.4587 ns	1.2180 ns	baseline
GetMethods_Cache	1.030 ns	0.0412 ns	0.0385 ns	249.428x faster	10.30x

GetMethod() 37% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetMethod_NoCache	23.06 ns	0.234 ns	0.208 ns	baseline
GetMethod_Cache	16.77 ns	0.079 ns	0.070 ns	1.37x faster	0.01x

GetMembers() 83,924% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetMembers_NoCache	550.2334 ns	4.1411 ns	3.8736 ns	baseline
GetMembers_Cache	0.6579 ns	0.0515 ns	0.0481 ns	840.247x faster	58.17x
GetMembers_ThreadSafe_Cache	0.7273 ns	0.0307 ns	0.0287 ns	757.728x faster	31.76x

GetMember() 1,043% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetMember_NoCache	136.57 ns	1.353 ns	1.266 ns	baseline
GetMember_Cache	11.95 ns	0.091 ns	0.081 ns	11.43x faster	0.12x

GetProperties() 8,960% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetProperties_NoCache	58.5363 ns	0.3463 ns	0.3070 ns	baseline
GetProperties_Cache	0.6502 ns	0.0370 ns	0.0328 ns	90.25x faster	4.59x
GetProperties_ThreadSafe_Cache	0.7169 ns	0.0129 ns	0.0108 ns	81.72x faster	1.36x

GetProperty() 57% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetProperty_NoCache	25.61 ns	0.382 ns	0.357 ns	baseline
GetProperty_Cache	16.23 ns	0.074 ns	0.062 ns	1.57x faster	0.01x

GetFields() 419% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetFields_NoCache	48.941 ns	0.9092 ns	0.8505 ns	baseline
GetFields_Cache	1.141 ns	0.0512 ns	0.0479 ns	42.95x faster	1.32x
GetFields_ThreadSafe_Cache	1.178 ns	0.0144 ns	0.0128 ns	41.56x faster	0.79x

GetInterfaces() 1,439% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetInterfaces_NoCache	13.1880 ns	0.1197 ns	0.0999 ns	baseline
GetInterfaces_Cache	0.8649 ns	0.0469 ns	0.0439 ns	15.39x faster	0.58x

GetInterface() 144% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetInterface_NoCache	32.84 ns	0.411 ns	0.364 ns	baseline
GetInterface_Cache	13.47 ns	0.227 ns	0.212 ns	2.44x faster	0.05x

GetConstructors() 4,054% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetConstructors_NoCache	38.4477 ns	0.2020 ns	0.1687 ns	baseline
GetConstructors_Cache	0.9280 ns	0.0109 ns	0.0102 ns	41.54x faster	0.36x
GetConstructors_ThreadSafe_Cache	1.0120 ns	0.0689 ns	0.0645 ns	38.39x faster	2.42x

GetConstructor() 601% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetConstructor_NoCache	18.16 ns	0.298 ns	0.278 ns	baseline
GetConstructor_NoCache_Parameters	127.18 ns	1.592 ns	1.489 ns	7.01x slower	0.16x
GetConstructor_Cache	10.36 ns	0.057 ns	0.048 ns	1.76x faster	0.03x
GetConstructor_Cache_Parameters	21.12 ns	0.366 ns	0.342 ns	1.16x slower	0.02x

Activator.CreateInstance(params) vs cachedConstructor.CreateInstance(params) 242% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
Activator_Create_with_parameters	325.58 ns	1.713 ns	1.431 ns	baseline
Cache_CreateInstance_with_parameters	95.61 ns	1.943 ns	1.908 ns	3.42x faster	0.07x

GetCustomAttributes() 1,658% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetAttributes_NoCache	2,560.76 ns	6.740 ns	6.305 ns	baseline
GetAttributes_Cache	15.35 ns	0.287 ns	0.268 ns	166.858x faster	2.97x

GetGenericTypeDefinition() 499% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetGenericTypeDefinition_NoCache	1.8759 ns	0.0481 ns	0.0450 ns	baseline
GetGenericTypeDefinition_Cache	0.3159 ns	0.0313 ns	0.0293 ns	5.99x faster	0.58x

IsAssignableFrom() 51% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
IsAssignableFrom_NoCache	9.355 ns	0.1357 ns	0.1270 ns	baseline
IsAssignableFrom_Cache	6.198 ns	0.0794 ns	0.0742 ns	1.51x faster	0.04x

MakeGenericType() 1,485% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
MakeGenericType_NoCache	158.56 ns	0.900 ns	0.842 ns	baseline
MakeGenericType_Cache	10.01 ns	0.216 ns	0.202 ns	15.85x faster	0.31x

GetElementType() 1,847% faster

Method	Mean	Error	StdDev	Ratio	RatioSD
GetElementType_NoCache	4.9175 ns	0.0442 ns	0.0369 ns	baseline
GetElementType_Cache	0.2585 ns	0.0204 ns	0.0191 ns	19.47x faster	1.06x

Properties on Type (e.g. typeof(string).IsNullable)

Method	Mean	Error	StdDev	Median
IsAbstract_NoCache	2.4277 ns	0.0319 ns	0.0299 ns	2.4152 ns
IsAbstract_Cache	0.0000 ns	0.0000 ns	0.0000 ns	0.0000 ns
IsInterface_NoCache	0.7720 ns	0.0219 ns	0.0194 ns	0.7662 ns
IsInterface_Cache	0.0045 ns	0.0076 ns	0.0071 ns	0.0000 ns
IsGenericType_NoCache	0.8707 ns	0.0281 ns	0.0262 ns	0.8732 ns
IsGenericType_Cache	0.2667 ns	0.0195 ns	0.0182 ns	0.2651 ns
IsEnum_NoCache	0.5322 ns	0.0242 ns	0.0227 ns	0.5291 ns
IsEnum_Cache	0.2612 ns	0.0251 ns	0.0235 ns	0.2526 ns
IsNullable_NoCache	1.4296 ns	0.0297 ns	0.0278 ns	1.4305 ns
IsNullable_Cache	0.2312 ns	0.0077 ns	0.0065 ns	0.2278 ns
IsByRef_NoCache	1.8439 ns	0.0332 ns	0.0310 ns	1.8410 ns
IsByRef_Cache	0.0012 ns	0.0025 ns	0.0022 ns	0.0000 ns
IsArray_NoCache	2.2914 ns	0.0484 ns	0.0452 ns	2.2652 ns
IsArray_Cache	0.0060 ns	0.0102 ns	0.0096 ns	0.0000 ns

Notes:

• These benchmarks are built over iterations. The first operation is going to be as slow as the Reflection it sits in front of.
• Many of these are based off of a test class TestType which is located in the test library.