key64_t? ino64_t?

Corinna Vinschen
Wed May 14 13:33:00 GMT 2003

On Wed, May 14, 2003 at 07:09:24PM +1000, Robert Collins wrote:
> Aliasing isn't bad. However: we *must* prevent clashes. Probability has
> nothing to do with it. I can't comment on the Linux implementation: I
> haven't reviewed it.

My Linux man page tells me:

   Of  course  no  guarantee  can be given that the resulting
   key_t is unique. Typically, a best effort attempt combines
   the  given  proj_id  byte, the lower 16 bits of the i-node
   number, and the lower 8 bits of the device number  into  a
   32-bit  result.  Collisions may easily happen, for example
   between files on /dev/hda1 and files on /dev/sda1.

So Chuck's implementation is a multiple better than the Linux one
without the need to involve trees or tries.


Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Developer                      
Red Hat, Inc.

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