[Python-Dev] Zip format

Greg Stein gstein@lyra.org
Sat, 11 Dec 1999 03:26:59 -0800 (PST)


On Fri, 10 Dec 1999, Andrew M. Kuchling wrote:
> M.-A. Lemburg writes:
> >There were issues with zlib 1.0.4 and later ones. Also, many
> >Linux distributions don't have the zlib header files installed.
> 
> For example, on RH6.0, zlib.h and zlib.a are in zlib-devel.XXX.rpm,
> and zlib.XXX.rpm only contains libz.so.  On the other hand, anyone
> who's compiling Python should really have the various -devel RPMs

Exactly. The distro's *have* the headers -- it all depends on what you
installed. I happen to have the headers on my system (because I installed
zlib-devel, as AMK mentions).

> installed.  I'd argue against including it, because it might cause odd
> versioning problems.  For example, what if I have PIL compiled against
> zlib1.1.2 (zlib is used for writing PNGs) and the Python binary
> includes zlib1.1.3?  There might be hard-to-debug problems
> caused by calling the wrong symbol.

I totally agree.

>...
> Just received Guido's email suggesting skipping compression in
> archives; not a bad idea.  You'd use less CPU, but might do
> more I/O because you're reading more sectors off disk.  There
> probably isn't much need for compression when the archive is on-disk;
> Java needed it because of applets.

There are all kinds of things that we can do here. Consider mmap'ing the
archive into a shared memory segment, used by all the Python processes on
the system... woo! :-)

IMO, the standard distro can use zip files, and just bail if they are
compressed, but Python cannot load zlib. Obvious failure with an obvious
remedy. No big deal.

As Guido also mentions, an installer can just bring along zlib if they
want to use a compressed archive. i.e. their choice.

Cheers,
-g

-- 
Greg Stein, http://www.lyra.org/