If it's via HTTP you might have a header which is named Content-Length (or something like that, I'm posting from memory)
Do you have a question, or are you just promoting your library?
I think you are mis-interpreting the response. The quote from Joshua Block (via Ashish R Garg) is trying to say that the same locks should be used for both read and writes. Or more likely, but hard to tell, as there isn't enough context, that the programmer shouldn't forget to lock the read operation, just because that thread isn't changing anything.
the reader writer lock may not have any (or very little) benefits.
Secondly, why would you want to do that, I mean separating Read and Write locks doesnt make any sense.