d2 file input performance

[Christian Köstlin]

Hi guys,


i started the thread: 
http://stackoverflow.com/questions/7202710/fastest-way-of-reading-bytes-in-d2 
on stackoverflow, because i ran into kind of a problem.

i wanted to read data from a file (or even better from a stream, but 
lets stay with file), byte-by-byte. the whole thing was part of my 
protobuf implementation for d2, and there you have to look at each byte 
to read out the varints. i was very proud of my implementation until i
benchmarked it first against java (ok ... i was a little slower than 
java) and then against c++ (ok ... this was a complete different game).

after some optimizing i got better, but was still way slower than c++. 
so i started some small microbenchmarks regarding fileio: 
https://github.com/gizmomogwai/performance in c++, java and d2.

could you help me improve on the d2 performance? i am sure, that i am 
missing something fundamental, because i thing it should be at least 
possible be equal or better than java.

thanks in advance

christian