[Rpm-metadata] adding more information to repo metadata

Jeff Johnson n3npq at mac.com
Mon Oct 3 16:36:59 UTC 2005


On Oct 3, 2005, at 6:25 AM, Florian La Roche wrote:

> I've added the below text to http://people.redhat.com/laroche/pyrpm/ 
> README.html
> Adding the "flag" part of dependencies also as integer into the  
> repodata would
> make it more complete and useful for new tasks.
>
> greetings,
>
> Florian La Roche
>
>
>
> Notes about the Repo-Metadata
> -----------------------------
>
> The following things should be noted about the repo metadata. yum  
> is using
> the repodata only within the resolver part, then downloads the rpm  
> headers
> and passes all the headers on to rpmlib to verify again if the  
> resolver
> of rpmlib is ok as well as doing e.g. the installation ordering part
> within rpmlib. If the repodata would be more complete, more steps  
> could
> be done only based on the repodata being available:
>
>  - Even if no epoch is specified, the metadata still specifies this  
> as "0".
>    For most code paths this is no problem as for all comparisons of  
> version
>    data, a missing epoch is the same as a "0" epoch. This should  
> not be
>    a huge problem and would be only a cleanup item for the repodata.

This is purely a representational issue since
     Missing Epoch: and Epoch:0 are to be treated identically.

>  - For dependency information the `flag` part is only partially  
> copied into
>    the repodata. Just adding the `flag` information as integer  
> would make
>    sure all information is present in any case. Extending the  
> repodata to
>    have `intflag` added alongside the old information would be good.

Only those bits whose values are guaranteed were exposed in rpm- 
metadata.
Furthermore, the values were mapped into a different representation.

Exposing internal rpmlib values as an integer is simply stupid.
\
>  - Repo data adds a "pre" flag if the RPMSENSE_PREREQ flag is set.  
> That
>    information is actually not complete to identify install prereq and
>    we need the more complete flag information as requested above to
>    be able todo correct installation ordering based on repodata.

RPMSENSE_PREREQ is not needed for any purpose (yes there is
a difference in handling loops) since all Requires: used as tsort  
relations.

Define "need" please. I know of no case where any additional information
to qualify dependencies is necessary or desirable.

>  - There is a fixed regex string which specifies the filelist  
> information
>    for the primary.xml file. In addition also all files are listed if
>    they appear in any file requires from the same repository. This  
> means that
>    you need to download the full filelist once you work on more  
> than one
>    repository and you have file requirements outside of the fixed  
> regex list.
>    (Detecting the need for full filelists could be done per-repo to  
> give
>    a quite good detection algorithm.) Only possible path for this  
> is to
>    identify problems for several repos where the full filelists  
> need to be
>    downloaded and to add such a requirement into that repo or  
> otherwise
>    add a command line option to add such additional requirements  
> (which
>    should then get also written into the repodata).
>

I have suggested several times that repos generate file lists self- 
consistently
within a repo, rather than using a rule based on paths.

The suggestion was deemed too much work.

73 de Jeff




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