Mailinglist Archive: zypp-devel (70 mails)

[Duncan Mac-Vicar Prett <dmacvicar@xxxxxxx>]

> Solver algorithms:
> ------------------
>
> - the solver allows arch changes from/to noarch without complaining.
>   good or bad?

good question. noarch is supposed to work, but I am not sure if this usecase 
really happens often. I can imagine a java package getting rid of some native 
extension, in this case the noarch package wll be the enhanced one by the 
package maintainer.

> - vendow changes are allowed from unknown to known. libzypp doesn't
>   allow that. Feature?

There are not known vendors, there are vendor changes, and current libzypp 
behaviour is not select a different vendor in a upgrade as candidate, unless 
it s a explicit user transaction.

> - arch changes are only considered if the name stays the same, so
>   a rename can install a different architecture.

bug?

> - same with vendor.

bug :-)
 
> - should prune_best_version_arch consider the arch or the vendor this
>   is about an installed package?

what does it do?

> - we disable conflicting rules when searching for a suggestion, should
>   we first extend them with arch changes/vendor changes/downgrades?
>   In what order?

I dont understand.

> - distupdate sets 'allowuninstall'. Should it only allow uninstall
>   for packages that do not have an update in the repositories?

No idea.
 
> - splitprovides don't work at all.
>
> - repo priorities should influence the order in which package rules
>   are fulfilled.

why?

I think repo priorities are no more than part of the policy to select a 
candidate. I think in tis aspect the solver should implement something 
flexible, like a callback passing candidates and context and returning the 
selected one, or giving each of them scores.

> - weak systemrules should be created for all installed packages, so
>   that they are available when the erase rule is disabled if a
>   suggestion is calculated.

what are weak system rules? a installed rpm recommends?

> - should we implement weak systemrules as weak rules?

??

> - prune_best_version_arch has a n^2 loop when looking at obsoletes.
>   Should we create an obsoletes index to speed that up?

ZYpp right now has indexes for all kind of requries, and that is why it needs 
all dependencies in the pool before solving, to build those.
 
> Code cleanup:
> -------------
> - move whatprovides/whatprovidesdata from pool to solver?
>   good: can implement installed(), though I don't know if we need

I wanted to implement each_installed() in the solver (ruby)

>   bad: need to allocate solver if we just want to look up a provides.
>        can't re-use whatprovides for multiple solver runs with different
>        solvers.

it can be in the pool and wrapped in the solver. The solver has access to the 
pool but not viceversa

> - implement unified idarray in pool, so that repos don't have to
>   come with their own idarrays? Would need memory for hash, but
>   unification would be a nice thing. Would also fix solver memory
>   leak with learned rules. Needs some hard numbers abour memory usage.

No idea here.

> - make bitmap macros inline functions?

it is ok as long as they are well documented and it the right header.
 
> - rename ID Macros to ID_, e.g. ARCH_NOARCH to ID_ARCH_NOARCH?

Everything that makes things explicit and intutive-> principe of least 
surprise -> is welcome.

> - support different streams than FILE in repo_ functions? Is it
>   enough that glibc supports FILE overloading, see the undocumented
>   fopencookie()?

For ruby bindings it was no problem to work with FILE. Still, I am thinking of 
the use case of an application server, where you want to load the repos once 
in memory and share them across requests. It is a valid use case (I already 
saw it), but I have no idea how to support this.

-- 
Duncan Mac-Vicar Prett  
Novell :: SUSE R&D, Maxfeldstr. 5, 90409 Nürnberg
GF: Markus Rex, HRB 16746 (AG Nürnberg)
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