xdelta files for security patches

Colin Percival colin.percival at wadham.ox.ac.uk
Wed May 14 01:07:30 PDT 2003


At 00:35 13/05/2003 +0100, I wrote:
>   Using some form of binary diffs is on my todo list for FreeBSD Update 
> (security/freebsd-update), but it's not a matter of critical 
> importance.  Right now updating from 4.7-RELEASE to the latest binaries 
> takes around 30 MB, depending upon which install set you chose (nocrypt, 
> crypt, kerberos4, kerberos5); good binary diffs would probably reduce 
> this to around 5 MB.
>   That said, I'm not sure if I would choose xdelta.

   Of course, when I wrote this, I had no idea that I was about to write a 
binary diff/patch utility in 12 hours.  In doing so, I've lost quite a bit 
of respect for xdelta; ok, my code is about five times slower and has a 
larger memory footprint, but it produces diffs 35% smaller and weighs in at 
a massive 281 lines (in contrast to the thousands of lines of code in xdelta).
   I'll be adding this into FreeBSD Update in the near future.  If anyone 
wants the code for other purposes, feel free to contact me.

Colin Percival




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