Fast forward-backward (write-read)

[Paul Rubin]

Paul Rubin <no.email at nospam.invalid> writes:
> Seeking backwards in files works, but the performance hit is
> significant.  There is also a performance hit to scanning pointers
> backwards in memory, due to cache misprediction.  If it's something
> you're just running a few times, seeking backwards the simplest
> approach. 

Oh yes, I should have mentioned, it may be simpler and perhaps a little
bit faster to use mmap rather than seeking.