Re: 02/09: guix: store: Make register-items transactional, register drv outputs

["Ludovic Courtès" <ludo@gnu.org>]

Hi reepca!

Caleb Ristvedt <caleb.ristvedt@cune.org> skribis:

> Changes made, though I'm not quite sure about this part:
>
>> Could you add a test in tests/store-database.scm for this bit?
>>
>>> +        (when (derivation-path? real-file-name)
>>> +          (register-derivation-outputs))
>
> Should that be a separate test or an extension of "register-path"?
> Currently I'm doing the latter. And it looks ugly.

It’s part of ‘register-path’, so it’s a test of ‘register-path’, sure.
If you think it’s nicer to test it separately, you can write a separate
test.

>> Could you send updated patches?
>
> From 5ae8c31826f06f4ad0b52a4d7b0cd6c4abc64a20 Mon Sep 17 00:00:00 2001
> From: Caleb Ristvedt <caleb.ristvedt@cune.org>
> Date: Wed, 30 Jan 2019 17:03:38 -0600
> Subject: [PATCH 1/2] guix: store: Make register-items transactional.
>
> * guix/store/database.scm (SQLITE_BUSY, register-output-sql): new variables
>   (add-references): don't try finalizing after each use, only after all the
>   uses (otherwise a finalized statement would be used if #:cache? was #f).
>   (call-with-transaction): New procedure.
>   (register-items): Use call-with-transaction to prevent broken intermediate
>   states from being visible.
>
> * .dir-locals.el (call-with-transaction): indent it.

I applied this one (I updated the copyright year for you and tweaked the
commit log.)

> From adba9061739cd9afff9d404f871f66ce36147dd2 Mon Sep 17 00:00:00 2001
> From: Caleb Ristvedt <caleb.ristvedt@cune.org>
> Date: Wed, 13 Feb 2019 02:19:42 -0600
> Subject: [PATCH 2/2] guix: store: Register derivation outputs.
>
> * guix/store/database.scm (register-output-sql, derivation-outputs-sql): new
>   variables.
>   (registered-derivation-outputs): new procedure.
>   ((guix derivations), (guix store)): used for <derivation> and
>   derivation-path?, respectively.
>   (register-items): if item is a derivation, also register its outputs.
>
> * tests/store-database.scm (register-path): first register a dummy derivation
>   for the test file, and check that its outputs are registered in the
>   DerivationOutputs table and are equal to what was specified in the dummy
>   derivation.
> ---
>  guix/store/database.scm  | 41 ++++++++++++++++++++++++++++++++++++++++
>  tests/store-database.scm | 30 ++++++++++++++++++++++++++++-
>  2 files changed, 70 insertions(+), 1 deletion(-)
>
> diff --git a/guix/store/database.scm b/guix/store/database.scm
> index af7f82b049..b89d81d770 100644
> --- a/guix/store/database.scm
> +++ b/guix/store/database.scm
> @@ -21,6 +21,8 @@
>    #:use-module (sqlite3)
>    #:use-module (guix config)
>    #:use-module (guix serialization)
> +  #:use-module (guix derivations)
> +  #:use-module (guix store)

A problem is that we should not pull in these two modules here, because
they are conceptually at a higher level (they have to do with talking to
a separate daemon process.)

So perhaps a first step would be to re-arrange things, probably along
these lines:

  • Move the .drv parsing code and the <derivation> record type from
    (guix derivations) to, say, (guix store derivations).

  • Re-export all these bindings from (guix derivations).

  • Move ‘store-path?’, ‘derivation-path?’ & co. (everything below line
    1745 in guix/store.scm) to, say, (guix store files).  Re-export
    appropriately so the API remains unchanged.

At this point, (guix store …) modules won’t have to use (guix store) and
(guix derivations) at all.

How does that sound?

Thanks,
Ludo’.