Reference a big DLL for a single method

Question

I want to use a single method from a big Class library-dll in C#.

Are there any drawbacks of performance or anything else?
Should I "read" the method code with reflection tool and copy-paste it to my project?

Update: The hard disk space isn't an issue. My application is web app.

Answer 1

Are there any drawbacks of performance or anything else?

The only one that is actually important is the size of your distributable, if it matters to you. (Users downloading a 30 MB file instead of a 2 MB one). Performance differences will be negligible. Assembly binding and verifying the Strong Name (if it's signed) hash may take longer, but unlikely to be noticeable to a user.

Should I "read" the method code with reflection tool and copy-paste it to my project?

Probably not; most licensing terms prohibit reverse engineering and/or only partial distribution. Check the license, if any, to see if you can even do it first.

Answer 2

No, leave that up to the JIT compiler. It is already selective about what IL actually gets turned into machine code, it only compiles what actually executes. You'll lose a bit of virtual memory address space but that doesn't cost anything, it's virtual. You don't pay for what you don't use.