Add (guix store deduplication).

* guix/store/database.scm (register-path): Add #:deduplicate? and call
'deduplicate' when it's true.
(counting-wrapper-port, nar-sha256): Move to...
* guix/store/deduplication.scm: ... here.  New file.
* tests/store-deduplication.scm: New file.
* Makefile.am (STORE_MODULES): Add deduplication.scm.
(SCM_TESTS) [HAVE_GUILE_SQLITE3]: Add store-deduplication.scm.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

1 files changed, 64 insertions, 0 deletions

diff --git a/tests/store-deduplication.scm b/tests/store-deduplication.scm
new file mode 100644
index 0000000000..04817a193a
--- /dev/null
+++ b/tests/store-deduplication.scm
@@ -0,0 +1,64 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2018 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 (test-store-deduplication)
+  #:use-module (guix tests)
+  #:use-module (guix store deduplication)
+  #:use-module (guix 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)))
+                           (iota 5)))
+           (unique    (string-append store "/unique")))
+       (for-each (lambda (file)
+                   (call-with-output-file file
+                     (lambda (port)
+                       (put-bytevector port data))))
+                 identical)
+       (call-with-output-file unique
+         (lambda (port)
+           (put-bytevector port (string->utf8 "This is unique."))))
+
+       (for-each (lambda (file)
+                   (deduplicate file (sha256 data) #:store store))
+                 identical)
+       (deduplicate unique (nar-sha256 unique) #: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")