| Re: [p2-dev] Projector weight function |
Here is a non final copy of the article
Attachment:
lash2010.pdf
Description: Adobe PDF document
On 2011-07-20, at 5:26 PM, Langhuth, Eckart wrote: > Hi Daniel, > > thanks for reply. > Just for clarification. I do not assume the current behavior as a bug. > But I failed to find information regarding the objective function definition used. > So I raised the question here really out of curiosity. > Unfortunately the provided documentation link does not work for me. (404) > > The reported Tycho problem should be fixed in Tycho anyway. > 0.0.0 versions used in the feature.xml should be strictly resolved to the latest available version. > > Best regards, > Eckart > > On Behalf Of Daniel Le Berre > Sent: Mittwoch, 20. Juli 2011 15:44 > > Hi Eckart, > > Thanks for the bug report. We will take a closer look at your particular case. > > The way the objective function is defined in p2 is described here: > http://www.cril.univ-artois.fr/spip/publications/lash2010.pdf > > The behavior you observe might be expectable. > > Suppose that you have package x version 1 and x version 2 > > Version 1 has no dependencies and version 2 has dependencies on y z u and v. > > Suppose we have a minimal penalty of 1 for installing a package (to avoid installing a non necessary package). > > In that case, if the penalty for installing an "old" package for x1 is 4 for instance, then the solver prefers to install x1 for a penalty of 4 instead of x2 for a penalty of 5 (1 for each x2, y,,z, u, v). > > Note that with a bigger penalty for old versions, we could still install x2. > > I will check in your bug report if this is really what happens in your case. > > Cheers, > > Daniel > Le 20 juil. 2011 à 13:22, Langhuth, Eckart a écrit : > >> Hi, >> >> As requested I created a p2 bug for this issue >> https://bugs.eclipse.org/bugs/show_bug.cgi?id=352560 >> >> Best regards, >> Eckart >> >> From: p2-dev-bounces@xxxxxxxxxxx [mailto:p2-dev-bounces@xxxxxxxxxxx] On Behalf Of Pascal Rapicault >> Sent: Montag, 18. Juli 2011 18:52 >> To: P2 developer discussions >> Subject: Re: [p2-dev] Projector weight function >> >> For a new install (which is the case in a tycho build), the intent is for the resolver to return the highest version available. >> For addition on top of an install or update, the algorithm is a bit more complex but should favour the highest version of the things being in the transitive closure of what is being changed. >> >> Could you please open a bug (https://bugs.eclipse.org/bugs/enter_bug.cgi?product=Equinox) with the necessary IUs to recreate the problem. >> >> Thx >> >> On 2011-07-14, at 4:46 PM, Langhuth, Eckart wrote: >> >> >> Hi, >> >> while investigating a problem resulting in bug >> https://bugs.eclipse.org/bugs/show_bug.cgi?id=352081 >> I stumbled over the behavior of org.eclipse.equinox.internal.p2.director.Projector. >> >> Out of curiosity. Is there a description of the weight function used to determine a solution? >> In my example a feature includes a single plugin without a version constraint. (0.0.0) >> The search scope contains two version of the required plugin. >> The solution provided by the projector contains the plugin with the smaller version. >> My assumption would have been to prefer a solution with latest plugin version. >> The difference I see is that the higher version plugin defines more dependencies. >> Is it intended to prefer a small installation over a new one? >> >> Best regards, >> Eckart >> _______________________________________________ >> p2-dev mailing list >> p2-dev@xxxxxxxxxxx >> https://dev.eclipse.org/mailman/listinfo/p2-dev >> >> _______________________________________________ >> p2-dev mailing list >> p2-dev@xxxxxxxxxxx >> https://dev.eclipse.org/mailman/listinfo/p2-dev > > _______________________________________________ > p2-dev mailing list > p2-dev@xxxxxxxxxxx > https://dev.eclipse.org/mailman/listinfo/p2-dev > _______________________________________________ > p2-dev mailing list > p2-dev@xxxxxxxxxxx > https://dev.eclipse.org/mailman/listinfo/p2-dev