guix-play/guix/hg-download.scm
Holger Peters 521d33cdc6
guix: hg-download: Add hg-predicate.
`hg-predicate' acts for mercurial repositories as `git-predicate' acts
for git-repositories.

* guix/hg-download.scm (hg-predicate): New procedure.

Signed-off-by: Christopher Baines <mail@cbaines.net>
2020-11-14 10:27:00 +00:00

133 lines
4.9 KiB
Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2015, 2016, 2017, 2019 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 Ricardo Wurmus <rekado@elephly.net>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix hg-download)
#:use-module (guix gexp)
#:use-module (guix store)
#:use-module (guix monads)
#:use-module (guix records)
#:use-module (guix modules)
#:use-module (guix packages)
#:autoload (guix build-system gnu) (standard-packages)
#:use-module (ice-9 match)
#:use-module (ice-9 popen)
#:use-module (ice-9 rdelim)
#:export (hg-reference
hg-reference?
hg-reference-url
hg-reference-changeset
hg-reference-recursive?
hg-predicate
hg-fetch))
;;; Commentary:
;;;
;;; An <origin> method that fetches a specific changeset from a Mercurial
;;; repository. The repository URL and changeset ID are specified with a
;;; <hg-reference> object.
;;;
;;; Code:
(define-record-type* <hg-reference>
hg-reference make-hg-reference
hg-reference?
(url hg-reference-url)
(changeset hg-reference-changeset))
(define (hg-package)
"Return the default Mercurial package."
(let ((distro (resolve-interface '(gnu packages version-control))))
(module-ref distro 'mercurial)))
(define* (hg-fetch ref hash-algo hash
#:optional name
#:key (system (%current-system)) (guile (default-guile))
(hg (hg-package)))
"Return a fixed-output derivation that fetches REF, a <hg-reference>
object. The output is expected to have recursive hash HASH of type
HASH-ALGO (a symbol). Use NAME as the file name, or a generic name if #f."
(define guile-zlib
(module-ref (resolve-interface '(gnu packages guile)) 'guile-zlib))
(define modules
(delete '(guix config)
(source-module-closure '((guix build hg)
(guix build download-nar)))))
(define build
(with-imported-modules modules
(with-extensions (list guile-zlib)
#~(begin
(use-modules (guix build hg)
(guix build download-nar))
(or (hg-fetch '#$(hg-reference-url ref)
'#$(hg-reference-changeset ref)
#$output
#:hg-command (string-append #+hg "/bin/hg"))
(download-nar #$output))))))
(mlet %store-monad ((guile (package->derivation guile system)))
(gexp->derivation (or name "hg-checkout") build
#:leaked-env-vars '("http_proxy" "https_proxy"
"LC_ALL" "LC_MESSAGES" "LANG"
"COLUMNS")
#:system system
#:local-build? #t ;don't offload repo cloning
#:hash-algo hash-algo
#:hash hash
#:recursive? #t
#:guile-for-build guile)))
(define (hg-file-list directory)
"Evaluates to a list of files contained in the repository at path
@var{directory}"
(let* ((port (open-input-pipe (format #f "hg files --repository ~s" directory)))
(files (let loop ((files '()))
(let ((line (read-line port)))
(cond
((eof-object? line) files)
(else
(loop (cons line files))))))))
(close-pipe port)
(map canonicalize-path files)))
(define (should-select? path-list candidate)
"Returns #t in case that @var{candidate} is a file that is part of the given
@var{path-list}."
(let ((canon-candidate (canonicalize-path candidate)))
(let loop ((xs path-list))
(cond
((null? xs)
;; Directories are not part of `hg files', but `local-file' will not
;; recurse if we don't return #t for directories.
(equal? (array-ref (lstat candidate) 13) 'directory))
((string-contains candidate (car xs)) #t)
(else (loop (cdr xs)))))))
(define (hg-predicate directory)
"This procedure evaluates to a predicate that reports back whether a given
@var{file} - @var{stat} combination is part of the files tracked by
Mercurial."
(let ((files (hg-file-list directory)))
(lambda (file stat)
(should-select? files file))))
;;; hg-download.scm ends here