patches welcome! On Fri, Oct 3, 2008 at 5:30 PM, Ayende Rahien <[EMAIL PROTECTED]> wrote: > The problem is with the guarantees that the method does. > This is a valid implementation for random number generator: > http://xkcd.com/221/ > > A UUID isn't going to be duplicated, because it is unique to the machine and > time it was generated, and there is care taken to ensure that even if you > have two thread creating the a guid on the same micro second, you'll get two > different guids. > There is no such guarantees for random numbers. > > On Sat, Oct 4, 2008 at 3:06 AM, Paul Davis <[EMAIL PROTECTED]>wrote: > >> Ayende, >> >> Perhaps I'm missing something, but I don't see the problem. >> >> I suppose you could technically claim that we're not setting the >> version bits properly but that seems rather not important given that >> we have the revision protection. Also unless I'm mistaken this would >> only be a problem if someone is using an external UUID generation >> scheme that happens to be extremely not random. Which while possible, >> would still send up red flags on constant collisions on document >> creation. >> >> Paul >> >> On Fri, Oct 3, 2008 at 7:49 PM, Ayende Rahien <[EMAIL PROTECTED]> wrote: >> > Looking at the method implementation, it looks like there might be a >> problem >> > here. >> > >> > new_uuid() -> >> > list_to_binary(to_hex(crypto:rand_bytes(16))). >> > >> > In particular, we aren't actually guaranteed to have a unique value. >> > You can read more about what needs to be done to get unique guids: here: >> > http://blogs.msdn.com/oldnewthing/archive/2008/06/27/8659071.aspx >> > >> >
-- Chris Anderson http://jchris.mfdz.com
