Re: [gentoo-portage-dev] handling config stuff in portage (for package compression, etc)

[Marius Mauch]

On Sat, 5 Nov 2005 20:58:57 -0600
Jason Pepas <cell@×××××××××××.edu> wrote:

> So, I have been going over how "class config" works in portage, but I
> am still unsure of where to fit in the changes I would need.
>
> I suppose I'll lay out the structure of what I had in mind and ask
> y'all for advice.
>
> Compression would be supported in a modular fashion.  The following
> config options would be supported for each type of compression:
>
> ZEXT - the compression filename extension
> TZEXT - the binary package filename extension
> ZCOMPRESS - the command used to compress a file
> ZDECOMPRESS - the command used to uncompress a file
> ZFILTER - command used to compress in a pipeline
> ZUNFILTER - command used to uncompress in a pipeline
> ZRECOMPRESS - should files already compressed using another method be
> uncompressed and then recompressed using the preferred method? (ie, if
> manpages are shipped as foo.1.gz and you want foo.1.bz2)

I really don't like this Z prefix, should rather be
PORTAGE_COMPRESS_{EXT,BINEXT,COMPRESSCOMMAND,...}
(avoid env namespace pollution a IMO a lot cleaner)

> For example, if Z="bzip2", a file would be sourced ("bzip2.sh"), which
> would contain the these settings:
>
> ZEXT="bz2"
> TZEXT="tbz2"
> ZCOMPRESS="bzip2"
> ZDECOMPRESS="bunzip2"
> ZFILTER="bzip2"
> ZUNFILTER="bunzip2"
> ZRECOMPRESS="no"

Why this indirection? Just for convienience or are there technical
reasons? If it's just convienience then you don't need this, just
utilize the "source" command in make.conf. Anyway, there is no place for
one-letter vars in make.*

> The following subsystems would "source" one of these files to get
> their settings:
>
> PKG_
> DOC_
> MAN_
> INFO_
>
> possibly others.
>
> So, if PKG_Z="bzip2", bzip2.sh would be read to set PKG_ZEXT,
> PKG_TZEXT, PKG_ZCOMPRESS, etc.

Why are those vars needed? Can't they be directly derived from the
global ones?

> As these module files are sourced, individual config options could be
> overridden via values in the environment.  For example, if I wanted
> gzip used across the board, but I wanted different levels of
> compression for man pages and packages, I could do this in make.conf:
>
> Z="gzip"
> PKG_ZCOMPRESS="gzip --best"
> MAN_ZCOMPRESS="gzip --fast"

Somehow this part looks like overengineering to me. Doesn't seem worth
to introduce 7*4=28 new vars just for this.

Marius

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