Re: Inverted index to accelerate guix package search

[zimoun]

Hi,


On Tue, 14 Jan 2020 at 16:27, Giovanni Biscuolo <address@hidden> wrote:

> Pierre Neidhardt <address@hidden> writes:

> > By the way, what about using Xapian in Guix?

Xapian could be really cool!
However, the size of this dependency should be evaluated; then
optional feature or not.


> Actually I would love to search (tag?!?) for packages/services/machines
> (profiles?) the same way I query my email database with notmuch: it
> would give me a fourth dimension in "DevOps" :-)

Currently, you can output all the packages with 'guix search ""' and
index them using the Python API. It is not so nice but it should give
an idea about what to expose first to Guile.


> I cannot find Guile in Xapian bindings [1] but NotDeft [2] have some
> Emacs Lisp code to interact with Xapian

There is some work. IMHO.

If Guix goes to Xapian, all the Git history of all the packages should
be indexed. Today, it is really hard to find the right commit
corresponding to the right version -- the only solution I have is "git
log"+grep; not really friendly.

Some discussion spoke about using an external index, fetched for
example on the Guix Data Service. But I personally do not like to rely
on external service accessible through the network. However, note that
index all the packages of all the Guix history using
guile-git+fold-packages is not straightforward: resource consuming and
piece of well-thought data structures.

Well, now "guix time-machine" is here, Guix is lacking tools to browse
the history of all the packages.


Cheers,
simon