Re: [gentoo-portage-dev] Package compression header for binhosts

[Ned Ludd <solar@gentoo.org>]

On Mon, 2010-05-31 at 22:16 -0700, Brian Harring wrote:
> On Mon, May 31, 2010 at 08:32:34PM -0700, Zac Medico wrote:
> > Hi,
> > 
> > In order to support alternative compression types for binhost
> > packages, I was thinking about adding support for a header field in
> > the Packages index file. For example, a header line like
> > "PACKAGE_EXTENSION: txz" could be used to indicate that clients
> > should download files with txz extensions instead of tbz2
> > extensions. I'm planning to add support for both tgz [1] and txz
> > extensions.
> > 
> > [1] http://bugs.gentoo.org/show_bug.cgi?id=142579
> 
> 1) requires a version header bump

Agreed. But there were some other pending changes for "VERSION: 1"

Any planned changes to the format should be documented on
https://bugs.gentoo.org/show_bug.cgi?id=263994


> 2) a header alone isn't useful unless it's specifiable per cpv entry; 
> thus it must be inheritable

Per CPV entries is going to bloat the format and make me carry around a
more data on a per pkg basis then I'd want to. How about we run with
zac's idea but use tools to convert a full repo over to $EXTENTION
This should keep the portage code fast as well as it checks for invalid
binpkgs all the time. Having to have portage process a ton of ever
growing extentions is just going to be slow.

> 3) PACKAGE_EXTENSION is overly verbose and unclear it's specifying 
> the compressor too; it's intention is for compression, state it as 
> such (I mention this in light of URI's existance where 
> PACKAGE_EXTENSION would only be a hint of compressor)
> 
> Re: #1, there is a decent set of optimizations I'm kicking around in 
> pkgcore for the next version- a discussion should probably be started 
> there.
> 
> Offhand, having a compression specific header (a simple enumeration 
> of known compressors) and a DEFAULT_URI that is python string 

No go bro. The 'Packages' format should be independent of python.

> interpolation  assembled (for example, 
> DEFAULT_URI="%(host)s/%(category)s/%(pf)s.txz") seems wiser.  Via 
> doing what I'm suggesting, it would be possible to do binpkg 
> repository 'views' w/out having to map each binpkg into the url space 
> for it.
> 
> ~harring

-- 
Ned Ludd <solar@gentoo.org>
Gentoo Linux