guix-devel/guix/build/store-copy.scm

103 lines
3.7 KiB
Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2017 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 build store-copy)
#:use-module (guix build utils)
#:use-module (srfi srfi-1)
#:use-module (ice-9 rdelim)
#:use-module (ice-9 ftw)
#:export (read-reference-graph
closure-size
populate-store))
;;; Commentary:
;;;
;;; This module provides the tools to copy store items and their dependencies
;;; to another store. It relies on the availability of "reference graph"
;;; files as produced by 'gexp->derivation' et al. with the
;;; #:references-graphs parameter.
;;;
;;; Code:
(define (read-reference-graph port)
"Return a list of store paths from the reference graph at PORT.
The data at PORT is the format produced by #:references-graphs."
(let loop ((line (read-line port))
(result '()))
(cond ((eof-object? line)
(delete-duplicates result))
((string-prefix? "/" line)
(loop (read-line port)
(cons line result)))
(else
(loop (read-line port)
result)))))
(define (file-size file)
"Return the size of bytes of FILE, entering it if FILE is a directory."
(file-system-fold (const #t)
(lambda (file stat result) ;leaf
(+ (stat:size stat) result))
(lambda (directory stat result) ;down
(+ (stat:size stat) result))
(lambda (directory stat result) ;up
result)
(lambda (file stat result) ;skip
result)
(lambda (file stat errno result)
(format (current-error-port)
"file-size: ~a: ~a~%" file
(strerror errno))
result)
0
file
lstat))
(define (closure-size reference-graphs)
"Return an estimate of the size of the closure described by
REFERENCE-GRAPHS, a list of reference-graph files."
(define (graph-from-file file)
(call-with-input-file file read-reference-graph))
(define items
(delete-duplicates (append-map graph-from-file reference-graphs)))
(reduce + 0 (map file-size items)))
(define* (populate-store reference-graphs target)
"Populate the store under directory TARGET with the items specified in
REFERENCE-GRAPHS, a list of reference-graph files."
(define store
(string-append target (%store-directory)))
(define (things-to-copy)
;; Return the list of store files to copy to the image.
(define (graph-from-file file)
(call-with-input-file file read-reference-graph))
(delete-duplicates (append-map graph-from-file reference-graphs)))
(mkdir-p store)
(chmod store #o1775)
(for-each (lambda (thing)
(copy-recursively thing
(string-append target thing)))
(things-to-copy)))
;;; store-copy.scm ends here