Re: Inverted index to accelerate guix package search

[zimoun]

Hi Pierre,

On Wed, 15 Jan 2020 at 10:12, Pierre Neidhardt <address@hidden> wrote:

> > What about the "build time" size? Other said, all one needs to build
> > to have xapian, i.e., the size of the full bag: starting from the
> > bootstrap seed and having Guix+Xapian (vs. Guix alone).
>
> As shows with guix graph?
>
> This yields a small graph:
> --8<---------------cut here---------------start------------->8---
> guix graph --type=bag-emerged xapian | dot -Tpdf > dag.pdf
> --8<---------------cut here---------------end--------------->8---
>
> This yields a big graph:
> --8<---------------cut here---------------start------------->8---
> guix graph --type=bag xapian | dot -Tpdf > dag.pdf
> --8<---------------cut here---------------end--------------->8---
>
> I don't know how it compares to other packages.

I do not know neither. But I guess that Xapian does not add extra
dependencies then itself.


I do not know if this filter is correct.

--8<---------------cut here---------------start------------->8---
guixdot=/tmp/guix.dot

guix graph --type=bag guix > $guixdot

for what in `guix graph --type=bag xapian | grep '@' | cut -d'[' -f1`;
do
    grep '@' $guixdot | grep $what > /dev/null
    if [ $? -eq 0 ]
    then
        echo "OK -- $what"
    else
        echo "KO -- $what"
    fi
done
--8<---------------cut here---------------end--------------->8---

Roughly, it compares the '/gnu/store'  hashes of the nodes. And all
the nodes of Xapian are already in the graph of Guix, except Xapian
itself. So there is not extra cost (really low). I mean if I
understand well.


Well, guile-xapian bindings is the blocking point.
Any taker? ;-)


All the best,
simon