Why do you have to care about all that? Just pick a random number and start incrementing++ from there. I don't see how this would yield any more collisions than a PRNG? Just because you move across the ID space sequentially instead of in an obfuscated pattern doesn't really mean there's a higher chance of picking the same ID twice?
(My argument here, really, is that using a PRNG at all sounds pretty crazy for ID generation, if you don't take steps to prevent or detect collisions)
(My argument here, really, is that using a PRNG at all sounds pretty crazy for ID generation, if you don't take steps to prevent or detect collisions)