Question

I want to associate custom data to a Type, and retrieve that data in run-time, blazingly fast.

This is just my imagination, of my perfect world:

var myInfo = typeof(MyClass).GetMyInformation();

this would be very fast… of course this does not exist! If it did I would not be asking. hehe 😉

This is the way using custom attributes:

var myInfo = typeof(MyClass).GetCustomAttribute(“MyInformation”);

this is slow because it requires a lookup of the string “MyInformation”

This is a way using a Dictionary<Type, MyInformation>:

var myInfo = myInformationDictionary[typeof(MyClass)];

This is also slow because it is still a lookup of ‘typeof(MyClass)’.

I know that dictionary is very fast, but this is not enough… it is not as fast as calling a method. It is not even the same order of speed.

I am not saying I want it to be as fast as a method call. I want to associate information with a type and access it as fast as possible. I am asking whether there is a better way, or event a best way of doing it.

Any ideas??

Thanks!

EDIT:

The typeof(MyClass) I mentioned in all of previous snippets, are actualy variable… I don’t know that it is a specific MyClass type, it could be any type:

Type myType = typeFromSomewhere;

i.e. MyClass in this case just says that the class is made by me, and any other types that could come into this situation is also made by me… so it reads

typeof( One of My Own Classes, that I don’t know witch one is it, but it is mine for sure )

EDIT: CONCLUSION

Some performance results related to dictionaries:

Dic.buckets | Dic.Count | Dic.Key | Ops(x17)/s | Avg.Time | Min.Time | Max.Time
-----------------------------------------------------------------------------
     17519  |    12467  |   Type  |    1051538 |  0.95μs  |  0.86μs  |  0.42ms
       919  |      912  |   Type  |     814862 |  1.23μs  |  1.14μs  |  0.46ms
   1162687  |      912  |   Type  |    1126382 |  0.89μs  |  0.81μs  |  0.33ms
       919  |      912  |   Type  |     806992 |  1.24μs  |  1.16μs  |  0.21ms
        17  |       17  |   Type  |     872485 |  1.15μs  |  1.06μs  |  0.31ms
-----------------------------------------------------------------------------
     36353  |    18160  |  String |     227520 |  4.40μs  |  3.98μs  |  0.47ms
       919  |      911  |  String |     219159 |  4.57μs  |  4.14μs  |  0.29ms
   1162687  |      911  |  String |     236384 |  4.23μs  |  3.82μs  |  0.41ms
       919  |      911  |  String |     223042 |  4.49μs  |  4.10μs  |  0.43ms
        17  |       17  |  String |     229985 |  4.35μs  |  3.94μs  |  0.28ms

Interface Call:

ops(x17)/s: 2896001
Average: 0.35μs
Min: 0.34μs
Max: 1.20μs

Virtual Call:

ops(x17)/s: 3115254
Average: 0.32μs
Min: 0.32μs
Max: 0.65μs

I see that I have under-estimated Dictionaries!!! =)

It seems that Dictionary of Type to anything is 3x to 4x slower than a virtual method call.

This is not the case using Dictionary of strings. That ones are 10x to 12x slower than a virtual method call.

So I have prooved me wrong!

And, NO I AM NOT MAKING A MISSILE!!! someone has supposed this in a comment bellow =)

Thanks everybody.

Answer 1

Dictionary<Type,Object> works for me.