[cups.development] [RFE] STR #3369: lzma is more efficient than gzip for ppd files

[Jérôme Bouat]

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[STR New]

On my Ubuntu karmic Linux distribution, the /usr/share/ppd directory uses a
lot of disk space.

All the ppd files are currently compressed by using gzip.

I think that using lzma would decrease the used disk space as well as
improve the decompression speed.

Below is a comparaison for the file
/usr/share/ppd/openprinting/KONICA_MINOLTA/KO1050UX.ppd.gz:
-----
j at j-desktop:~$ du KO1050UX.ppd*
256 KO1050UX.ppd
24 KO1050UX.ppd.gz
16 KO1050UX.ppd.lzma
j at j-desktop:~$ time { for i in {0..999} ; do unlzma -c KO1050UX.ppd.lzma
>/dev/null ; done }

real 0m18.765s
user 0m7.060s
sys 0m11.560s
j at j-desktop:~$ time { for i in {0..999} ; do gunzip -c KO1050UX.ppd.gz
>/dev/null ; done }

real 0m23.183s
user 0m6.840s
sys 0m16.170s
j at j-desktop:~$
-----

I posted a feature request to my Linux distribution here:
https://bugs.launchpad.net/ubuntu/+source/foomatic-db/+bug/446245

Unfortunately I was told that those ppd files couldn't be compressed with
lzma because cups was able to read only the gzip compression format.

Link: http://www.cups.org/str.php?L3369
Version:  -feature