guix-devel/tests/store-deduplication.scm

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
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;;; under the terms of the GNU General Public License as published by
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;;; your option) any later version.
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;;; GNU General Public License for more details.
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(define-module (test-store-deduplication)
  #:use-module (guix tests)
  #:use-module (guix store deduplication)
  #:use-module (gcrypt hash)
  #:use-module ((guix utils) #:select (call-with-temporary-directory))
  #:use-module (guix build utils)
  #:use-module (rnrs bytevectors)
  #:use-module (ice-9 binary-ports)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-64))

(test-begin "store-deduplication")

(test-equal "deduplicate"
  (cons* #t #f                                    ;inode comparisons
         2 (make-list 5 6))                       ;'nlink' values

  (call-with-temporary-directory
   (lambda (store)
     (let ((data      (string->utf8 "Hello, world!"))
           (identical (map (lambda (n)
                             (string-append store "/" (number->string n)
                                            "/a/b/c"))
                           (iota 5)))
           (unique    (string-append store "/unique")))
       (for-each (lambda (file)
                   (mkdir-p (dirname file))
                   (call-with-output-file file
                     (lambda (port)
                       (put-bytevector port data))))
                 identical)
       ;; Make the parent of IDENTICAL read-only.  This should not prevent
       ;; deduplication for inserting its hard link.
       (chmod (dirname (second identical)) #o544)

       (call-with-output-file unique
         (lambda (port)
           (put-bytevector port (string->utf8 "This is unique."))))

       (deduplicate store (nar-sha256 store) #:store store)

       ;; (system (string-append "ls -lRia " store))
       (cons* (apply = (map (compose stat:ino stat) identical))
              (= (stat:ino (stat unique))
                 (stat:ino (stat (car identical))))
              (stat:nlink (stat unique))
              (map (compose stat:nlink stat) identical))))))

(test-end "store-deduplication")