[arch-general] About Arch pkg compress format

[Dimitrios Apostolou]

Hi,

On Tue, 2008-05-20 at 10:14 +0200, Jan de Groot wrote:
> Pacman itself is ready for .tar.bz2 package files. The whole issue
> with .bz2 files is that compression and decompression times increase a
> lot without giving the same amount of size reduction back. We've done
> some recent tests with LZMA, which compresses just as good as bzip2 at
> the lowest compression rate, but does it at the same speed as gzip. 

About LZMA I should add that when using higher (actually the default)
compression rate, compression is much better than bzip2 but takes more
time/memory. Decompression however, which is what really matters in a
packaging format, is kept fast and lightweight.

> The
> downside is that LZMA is not supported by libarchive, and won't be
> supported officially either, because libarchive is BSD licensed and LZMA
> is GPL licensed.

Can't this problem be circumvented by spawning the lzma command line
utility, and piping all data to it? I understand that this perhaps
negates the purpose of libarchive, but the overhead should be small.


Thanks, 
Dimitris