117 lines
4.4 KiB
Scheme
117 lines
4.4 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
|
|
;;; Copyright © 2012 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 union)
|
|
#:use-module (ice-9 ftw)
|
|
#:use-module (ice-9 match)
|
|
#:use-module (srfi srfi-1)
|
|
#:use-module (srfi srfi-26)
|
|
#:export (tree-union
|
|
union-build))
|
|
|
|
;;; Commentary:
|
|
;;;
|
|
;;; Build a directory that is the union of a set of directories, using
|
|
;;; symbolic links.
|
|
;;;
|
|
;;; Code:
|
|
|
|
(define (tree-union trees)
|
|
"Return a tree that is the union of the trees listed in TREES. Each
|
|
tree has the form (PARENT LEAVES ...) or just LEAF, where each leaf is
|
|
itself a tree. "
|
|
(let loop ((trees trees))
|
|
(match trees
|
|
(() ; nothing left
|
|
'())
|
|
(_
|
|
(let ((dirs (filter pair? trees))
|
|
(leaves (remove pair? trees)))
|
|
`(,@leaves
|
|
,@(fold (lambda (dir result)
|
|
(cons `(,dir
|
|
,@(loop
|
|
(concatenate
|
|
(filter-map (match-lambda
|
|
((head children ...)
|
|
(and (equal? head dir)
|
|
children)))
|
|
dirs))))
|
|
result))
|
|
'()
|
|
(delete-duplicates (map car dirs)))))))))
|
|
|
|
(define* (union-build output directories)
|
|
"Build in the OUTPUT directory a symlink tree that is the union of all
|
|
the DIRECTORIES."
|
|
(define (file-tree dir)
|
|
;; Return the contents of DIR as a tree.
|
|
(match (file-system-fold (const #t)
|
|
(lambda (file stat result) ; leaf
|
|
(match result
|
|
(((siblings ...) rest ...)
|
|
`((,file ,@siblings) ,@rest))))
|
|
(lambda (dir stat result) ; down
|
|
`(() ,@result))
|
|
(lambda (dir stat result) ; up
|
|
(match result
|
|
(((leaves ...) (siblings ...) rest ...)
|
|
`(((,(basename dir) ,@leaves) ,@siblings)
|
|
,@rest))))
|
|
(const #f) ; skip
|
|
(lambda (file stat errno result)
|
|
(format (current-error-port) "union-build: ~a: ~a~%"
|
|
file (strerror errno)))
|
|
'(())
|
|
dir)
|
|
(((tree)) tree)
|
|
(() #f)))
|
|
|
|
(define tree-leaves
|
|
;; Return the leaves of the given tree.
|
|
(match-lambda
|
|
(((? string?) leaves ...)
|
|
leaves)))
|
|
|
|
(setvbuf (current-output-port) _IOLBF)
|
|
(setvbuf (current-error-port) _IOLBF)
|
|
|
|
(mkdir output)
|
|
(let loop ((tree (tree-union (append-map (compose tree-leaves file-tree)
|
|
directories)))
|
|
(dir '()))
|
|
(match tree
|
|
((? string?)
|
|
;; A leaf: create a symlink.
|
|
(let* ((dir (string-join dir "/"))
|
|
(target (string-append output "/" dir "/" (basename tree))))
|
|
(format (current-error-port) "`~a' ~~> `~a'~%"
|
|
tree target)
|
|
(symlink tree target)))
|
|
(((? string? subdir) leaves ...)
|
|
;; A sub-directory: create it in OUTPUT, and iterate over LEAVES.
|
|
(let ((dir (string-join dir "/")))
|
|
(mkdir (string-append output "/" dir "/" subdir)))
|
|
(for-each (cute loop <> `(,@dir ,subdir))
|
|
leaves))
|
|
((leaves ...)
|
|
;; A series of leaves: iterate over them.
|
|
(for-each (cut loop <> dir) leaves)))))
|
|
|
|
;;; union.scm ends here
|