gnu: Add xxhash.

* gnu/packages/digest.scm: New file
(xxhash): New public variable.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add new file.

gnu/local.mk

@@ -119,6 +119,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/packages/dejagnu.scm			\
   %D%/packages/dico.scm				\
   %D%/packages/dictionaries.scm			\
+  %D%/packages/digest.scm			\
   %D%/packages/direct-connect.scm		\
   %D%/packages/disk.scm				\
   %D%/packages/display-managers.scm		\

gnu/packages/digest.scm

@@ -0,0 +1,55 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2017 Tobias Geerinckx-Rice <me@tobias.gr>
+;;;
+;;; 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 digest)
+  #:use-module ((guix licenses) #:prefix license:)
+  #:use-module (guix packages)
+  #:use-module (guix download)
+  #:use-module (guix build-system gnu))
+
+(define-public xxhash
+  (package
+    (name "xxhash")
+    (version "0.6.4")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append "https://github.com/Cyan4973/xxHash/archive/v"
+                           version ".tar.gz"))
+       (file-name (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32 "08nv9h3jzg6y85ysy2dj3qvvfsdz0rwkk497a2366syz278wqw25"))))
+    (build-system gnu-build-system)
+    (arguments
+     `(#:make-flags
+       (list "CC=gcc"
+             "XXH_FORCE_MEMORY_ACCESS=1" ; improved performance with GCC
+             (string-append "prefix=" (assoc-ref %outputs "out")))
+       #:test-target "test"
+       #:phases
+       (modify-phases %standard-phases
+         (delete 'configure))))         ; no configure script
+    (home-page "https://cyan4973.github.io/xxHash/")
+    (synopsis "Extremely fast hash algorithm")
+    (description
+     "xxHash is an extremely fast non-cryptographic hash algorithm.  It works
+at speeds close to RAM limits, and comes in both 32- and 64-bit flavours.
+The code is highly portable, and hashes of the same length are identical on all
+platforms (both big and little endian).")
+    (license (list license:bsd-2        ; xxhash library (xxhash.[ch])
+                   license:gpl2+))))    ; xxhsum.c