Bug#590163: Changes in foomatic-db
OdyX, you are partially wrong.
The OpenPrinting database, available through the OpenPrinting web site
ot through the foomatic-db package, provides two types of data:
1. XML files from which the pages of the OpenPrinting web site and also
PPD files, the so-called Foomatic PPDs are generated. On the local
system the foomatic-db-engine package generates the PPDs. The link
/usr/lib/cups/driver/foomatic makes CUPS auto-generating the PPDs
on-the-fly, so that they are available in printer setup tools and also
if one creates a print queue on the command line as I showed in my
previous posting.
2. Ready-made PPD files. Many PPD files are available as physical PPDs.
These files are provided by printer manufacturers, mainly for PostScript
printers and some also for PCL printers.
If you install foomatic-db from upstream, (2) causes a much higher disk
occupation than (1), even if each PPD file is individually gzipped.
The former foomatic-filters-ppds package contained all Foomatic PPDs
from (1) pre-built as ready-made PPDs and the PPDs of (2) plus the
foomatic-filters package. So this was a one-package solution without
need of generating PPDs, so mainly for easy use with CUPS 1.1.x (no PPD
generator support) or non-CUPS spoolers. foomatic-db-engine was not
needed. So this package was a major disk space killer, so completely
unsuitable for live CDs or CUPS installations on routers.
The foomatic-db source package builds three binary packages:
1. foomatic-db: This package contains the XML data of the OpenPrinting
database, no PPD files.
2. openprinting-ppds and openprinting-ppds-extra: These two packages
contain all manufacturer-supplied physical PPDs, and no PPDs generated
from Foomatic XML data. The splitting into two packages was done to be
able to ship the most important PPDs on the Ubuntu Desktop CD without
occupying to much of the CD space with PPD files. These packages DO NOT
contain any PPD files which is generated from the Foomatic XML data of (1).
The change we have done is to replace the PPDs which are present as
physical files in the openprinting-ppds and openprinting-ppds-extra
packages by one single highly (but losslessly) compressed file from
which CUPS automatically extracts the PPDs needed. The compressed PPDs
are in the files
/usr/lib/cups/driver/openprinting-ppds
/usr/lib/cups/driver/openprinting-ppds-extra
This leads to the following savings (on Ubuntu Maverick):
Binary Package *.deb file installed system
------------------------------------------------------------
openprinting-ppds ~4 MB ~5 MB
openprinting-ppds-extra ~18 MB ~28 MB
Compression is by a factor of 10 better than file-by-file gzip compression.
See also
http://pypi.python.org/pypi/pyppd
https://bugs.launchpad.net/bugs/493282
hplip-data ballooned by 2.5 MB in lucid
https://bugs.launchpad.net/bugs/446245
lzma more efficient than gzip
Till
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