Re: More diff performance notes

> Humor me --- why are we comparing ourselves with diff | gzip? Why
> aren't we comparing ourselves with diff -ae?

We are comparing ourselves to diff -ae | gzip; I'm just not always
clear that I use those options. Not sure if that was the source of
any confusion or not.

It would be somewhat unfair to compare ourselves to diff -ae without
gzip because diff doesn't compress its output and we do. And because
it would be about as easy to "just use diff and gzip" as it would to
"just use diff", if we can't get better performance using more
advanced algorithms.

(While I'm here, I have determined that I just about match diff+gzip
on the .elc data set if I change the svndiff encoding so that new data
immediately follows "copy from new data" instructions instead of being
stored in a separate part of the window. The average encoded bytes
per instruction drops to 2.48 in the binary case and 2.80 in the text
case.)
Received on Sat Oct 21 14:36:10 2006