Re: [gentoo-dev] [pre-GLEP r3] Gentoo binary package container format

[Roy Bamford]

On 2018.11.30 17:06, Michał Górny wrote:
> On Mon, 2018-11-26 at 21:43 +0000, Roy Bamford wrote:
> > On 2018.11.26 18:58, Michał Górny wrote:
> > > Here's the newest version.
> > >
> > > Changes:
> > >
> > > - added explicit notion of parent directory (missing in previous
> GLEP
> > > but present in implementation),
> > >
> > > - explicitly named GNU tar format with list of permitted
> extensions,
> > >
> > > - changed volume label to 'gpkg-1.txt' file to improve
> portability;
> > > made
> > > it explicit version identifier as well,
> > >
> > > - added info on other package formats to rationale.
> > >
> >
> > [snip]
> >
> > The image archive stores all the files to be installed by the binary
> > package.  It should be included as the last of the files in the
> binary
> > package container.
> >
> > [snip]
> > >
> > > --
> > > Best regards,
> > > Michał Górny
> > >
> >
> > Its a nit today but that says that any future extensions, none
> > yet planned, should be placed before the image archive.
>
> Yes.
>
> > The specification needs to avoid the use of relative references.
> >
>
> I don't understand.  Could you be more specific what you expect
> instead?
>
> --
> Best regards,
> Michał Górny
>

Michał,

Enumerate the elements, in the preferred order, which you have 
already done. The is no need, in a specification that is intended
to be easily extensible to specify that any element should be last.
That constrains extensions.

To build on an example extension given earlier. Suppose an 
extension came along to add the ebuild, required eclasses and 
sources. The present wording says that they should be included 
before image archive.

Implementations may be capable of working with partial 
downloads, why force the download of elements that may not be
required to get the payload.

The overhead of the presently define elements is small compared
to the image and its useful to be able check the metadata to
determine if the image is really what is required. 

image 'last' works with the presently defined elements but may 
not be so good in the years to come.

Its a subtle difference between 'last', which means always at 
the end, no mater what, and 'fifth' which is last today but
might not be in the future.
 
-- 
Regards,

Roy Bamford
(Neddyseagoon) a member of
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