Re: Outreachy - Guix Data Service: questions about improving the data for derivation comparisons.

[Luciana Lima Brito <lubrito@posteo.net>]

On Thu, 22 Apr 2021 21:08:08 +0100
Christopher Baines <mail@cbaines.net> wrote:

> I'm not quite sure what you mean by empty fields in the JSON here?

I mean now it appears like this in the json

hash-alg:	{}

Before, it was entirely omitted.
 
> It sounds like you're roughly on the right track, do share what
> changes you're making and then I can have a look.

This is the part I've changed on comparison.scm in the function
derivation-outputs-differences-data:

 (map (match-lambda
         ((output-name path hash-algorithm hash recursive
                       derivation_ids)
          (let ((parsed-derivation-ids
                 (map string->number
                      (parse-postgresql-array-string derivation_ids))))
            (list output-name
                  path
                  (if (string? hash-algorithm)
                          hash-algorithm
                          '())
                  (if (string? hash)
                      hash
                      '())
                  (string=? recursive "t")
                  (append (if (memq base-derivation-id
                                    parsed-derivation-ids)
                              '(base)
                              '())
                          (if (memq target-derivation-id
                                    parsed-derivation-ids)
                              '(target)
                              '()))))))
       (exec-query conn query))

Basically, I moved the hash-algorithm, hash, and recursive tests from
controller.scm here. I spent more time familiarizing with this part of
the code and the dataset. I don't have anything ready for the idea I
told you in the last email because I'm not so sure if that is the way
to go, but I can make some experiments in this regard.

-- 
Best Regards,

Luciana Lima Brito
MSc. in Computer Science