Unity FastReflection

Convert MethodInfo to Delegate to reduce the invoke cost.

How to use

1. Create a cached call with target & funcName & parameterTypes .

static CachedCallFactory.Create(object target,string func,System.Type[] arguementTypes) => BaseCachedCall

2. Call Invoke of BaseCachedCall

BaseCachedCall.Invoke(object[] args) => void

Examples:

public class TestObject{

    public void Run(){
    }
}

//....

var obj = new TestObject();
//Create a cached call of obj.Run(parameters)
var cachedCall = CachedCallFactory.Create(obj,"Run",new Type[]{});

//Invoke the method
cachedCall.Invoke(null);

Benchmark

Call instance void method 10000 times

CALL MODE	Directly	Delegate	CachedCall	Reflection
COST(ms)	0.121	0.144	0.193	22.191

CachedCall has simular performance with directly call and must faster than reflection.

IL2CPP AOT Issue

If you create a cachedCall with ValueType parameters, it may caused AOT Issue.

More Info: https://stackoverflow.com/questions/56183606/invoke-generic-method-via-reflection-in-c-sharp-il2cpp-on-ios

To resolve this issue, we must use CachedCallArguementsTypeRegister.EnsureCall to let compiler generate AOT code.

for example:

//These codes can be put anywhere of your project, alse no need to be ran. It is only for compiler.
private static void Register(){
    //Support create cachedCalls with one int paramster
    CachedCallArguementsTypeRegister.EnsureCall<int>();

    //Support create cachedCalls with bool & int parameters
    CachedCallArguementsTypeRegister.EnsureCall<bool,int>();
}