My patch add a new option to your script.
The option is HARDLINK
If it is true, a new directory ($BACKUPDIR/md5sum) will be populate with files like the follow example:
1ee297259f10a01ba155b321d50c8193 is "DATABASE_week.41.2007-10-13.sql" md5sum
A new function store do the hack.
Calls to compression compression functions are replaced by store function.
if HARDLINK is not set, store is like compression
Thanks for automysqlbackup