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
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
Notes
Consider if caching is even necessary for your use case. If you're only calling Reflection once, it may not be worth it.
Be thoughtful of your memory footprint and where/when you dispose of the cache.
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 8.0)
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
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.
These are based off of a test class TestType which is located in the test library.
Outliers have been removed in cases BenchmarkDotnet deems necessary.
Soenneker.Reflection.Cache