I forgot to comment on the actual patch...
Nikita Karetnikov <nik...@karetnikov.org> skribis:
> +(define (fold-values f acc seen lst)
Use ‘fold2’ from (guix utils) instead.
> +(define (derivations-to-prefetch store drv)
> + "Return the list of fixed-output derivations that DRV depends on, directly
> +or indirectly."
> + (define (unique-derivations acc seen lst)
> + ;; Return two values: the list of unique fixed-output derivations and the
> + ;; list of seen derivations.
> + (fold-values (lambda (acc seen drv-input)
> + (let ((drv* (call-with-input-file (derivation-input-path
> drv-input)
> + read-derivation)))
> + (cond ((fixed-output-derivation? drv*)
> + (values (lset-adjoin equal? acc drv*)
> + seen))
> + ((member drv* seen)
> + (values acc seen))
> + (else
> + (unique-derivations acc
> + (cons drv* seen)
> + (derivation-inputs drv*))))))
> + acc
> + seen
> + lst))
> +
> + (identity ; discard the second value
> + (unique-derivations '() '() (derivation-inputs drv))))
Can’t it be simplified along these lines:
--8<---------------cut here---------------start------------->8---
scheme@(guile-user)> (define (derivation-input->derivation input)
(call-with-input-file (derivation-input-path input)
read-derivation))
scheme@(guile-user)> (filter fixed-output-derivation?
(map derivation-input->derivation
(derivation-prerequisites $6)))
$10 = (#<derivation
/gnu/store/slmkaqybzszjxbl78ymp1dn9c79m9kmy-linux-libre-3.3.8-gnu.tar.xz.drv =>
/gnu/store/zgh2nvvxkwvmijchf4gyrqb4cq11znvd-linux-libre-3.3.8-gnu.tar.xz
3cbc2d0> #<derivation /gnu/store/c41c2g3g54ipwf5ja3wip5wc...
--8<---------------cut here---------------end--------------->8---
> +;; XXX: remove me.
> +(define specification->package+output
> + (@@ (guix scripts package) specification->package+output))
I think ‘specification->package’ from (guix scripts build) should be
used instead (it can be exported from there), because the output part of
the specification isn’t needed here: it would make no sense to type
guix prefetch glibc:debug
because the source of glibc:debug is the same as that of glibc.
> + (let ((opts (parse-options))
> + (store (open-connection)))
> + (map (lambda (package)
> + (format #t "Prefetching the derivations for '~a':~%"
> + (package-name package))
> +
> + (build-derivations
> + store
> + (map (lambda (drv)
> + ;; (format #t " ~a~%" (derivation-file-name drv))
> + (format #t " ~a~%" drv)
> + drv)
> + (derivations-to-prefetch
> + store
> + (package-derivation store package)))))
> +
> + (delete-duplicates
> + (filter-map (match-lambda
> + (('argument . value)
> + (identity ; discard the second value
> + ;; Check that all VALUEs in the list are valid
> + ;; packages before calling
> 'derivations-to-prefetch'.
> + ;; If VALUE is not a valid package,
> + ;; 'specification->package+output' will raise an
> + ;; error.
> + (specification->package+output value)))
> + (_ #f))
> + (reverse opts))))))
It should be a single ‘build-derivations’ call, to allow for
parallelism.
Thanks!
Ludo’.
