;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013 Nikita Karetnikov <nikita@karetnikov.org>
;;; Copyright © 2017 Eric Bavier <bavier@member.fsf.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 (gnu packages wdiff)
  #:use-module (guix licenses)
  #:use-module (guix packages)
  #:use-module (guix download)
  #:use-module (guix build-system gnu)
  #:use-module (gnu packages texinfo)
  #:use-module (gnu packages screen)
  #:use-module (gnu packages base))

(define-public wdiff
  (package
    (name "wdiff")
    (version "1.2.2")
    (source
     (origin
      (method url-fetch)
      (uri (string-append "mirror://gnu/wdiff/wdiff-"
                          version ".tar.gz"))
      (sha256
       (base32
        "0sxgg0ms5lhi4aqqvz1rj4s77yi9wymfm3l3gbjfd1qchy66kzrl"))))
    (build-system gnu-build-system)
    (arguments
     `(#:phases (modify-phases %standard-phases
                  (add-before 'check 'fix-sh
                    (lambda _
                      (substitute* "tests/testsuite"
                        (("#! /bin/sh")
                         (string-append "#!" (which "sh")))))))))
    (native-inputs
     (list which
           ;; For some reason wdiff.info gets rebuilt.
           texinfo))
    (home-page "https://www.gnu.org/software/wdiff/")
    (synopsis "Word difference finder")
    (description
     "GNU Wdiff is a front-end to the diff program from Diffutils that
allows you to compare files on a word-by-word basis, where a word is anything
between whitespace.")
    (license gpl3+)))
4d6c61e4b552e07&amp;showmsg=1'>root</a>/<a href='/guix/log/nix?id=f9c3a6dd2a50ae5b0d02b88054d6c61e4b552e07&amp;showmsg=1'>nix</a>/<a href='/guix/log/nix/libstore?id=f9c3a6dd2a50ae5b0d02b88054d6c61e4b552e07&amp;showmsg=1'>libstore</a>/<a href='/guix/log/nix/libstore/gc.cc?id=f9c3a6dd2a50ae5b0d02b88054d6c61e4b552e07&amp;showmsg=1'>gc.cc</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/nix/libstore/gc.cc?id=f9c3a6dd2a50ae5b0d02b88054d6c61e4b552e07'>Collapse</a>)</th><th class='left'>Author</th></tr>
<tr class='logheader'><td><span title='2021-11-16 14:34:28 +0100'>2021-11-16</span></td><td class='logsubject'><a href='/guix/commit/nix/libstore/gc.cc?id=472a0e82a52a3d5d841e1dfad6b13e26082a5750'>daemon: Do not deduplicate files smaller than 8 KiB.</a></td><td>Ludovic Courtès</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
Files smaller than 8 KiB typically represent ~70% of the entries in
/gnu/store/.links but only contribute to ~4% of the space savings
afforded by deduplication.

Not considering these files for deduplication speeds up file insertion
in the store and, more importantly, leaves 'removeUnusedLinks' with
fewer entries to traverse, thereby speeding it up proportionally.

Partly fixes &lt;https://issues.guix.gnu.org/24937&gt;.

* config-daemon.ac: Remove symlink hard link check and CAN_LINK_SYMLINK
definition.
* guix/store/deduplication.scm (%deduplication-minimum-size): New
variable.
(deduplicate)[loop]: Do not recurse when FILE's size is below
%DEDUPLICATION-MINIMUM-SIZE.
(dump-port): New procedure.
(dump-file/deduplicate)[hash]: Turn into...
[dump-and-compute-hash]: ... this thunk.
Call 'deduplicate' only when SIZE is greater than
%DEDUPLICATION-MINIMUM-SIZE; otherwise call 'dump-port'.
* nix/libstore/gc.cc (LocalStore::removeUnusedLinks): Drop files where
st.st_size &lt; deduplicationMinSize.
* nix/libstore/local-store.hh (deduplicationMinSize): New declaration.
* nix/libstore/optimise-store.cc (deduplicationMinSize): New variable.
(LocalStore::optimisePath_): Return when PATH is a symlink or smaller
than 'deduplicationMinSize'.
* tests/derivations.scm ("identical files are deduplicated"): Produce
files bigger than %DEDUPLICATION-MINIMUM-SIZE.
* tests/nar.scm ("restore-file-set with directories (signed, valid)"):
Likewise.
* tests/store-deduplication.scm ("deduplicate, below %deduplication-minimum-size"):
New test.
("deduplicate", "deduplicate, ENOSPC"): Produce files bigger than
%DEDUPLICATION-MINIMUM-SIZE.
* tests/store.scm ("substitute, deduplication"): Likewise.


</td></tr>