Replace murmurhashneutral2 with xxHash (XXH64)

XXH64 is significantly faster than murmurhashneutral2 (on 64-bit
systems, which one can assume ccache almost always is running on these
days). This of course doesn’t matter for keys in hash tables, but it
opens up for using it as a checksumming algorithm for cached data as
well.

1 files changed, 39 insertions, 7 deletions

diff --git a/LICENSE.adoc b/LICENSE.adoc
index e10ae208..35ef1096 100644
--- a/LICENSE.adoc
+++ b/LICENSE.adoc
@@ -413,13 +413,6 @@ This Autoconf M4 snippet comes from http://www.python.org[Python] 2.6's
 -------------------------------------------------------------------------------
 
 
-src/murmurhashneutral2.[hc]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-This fast hash implementation is released to the public domain by Austin
-Appleby. See http://murmurhash.googlepages.com.
-
-
 src/minitrace.[hc]
 ~~~~~~~~~~~~~~~~~~
 
@@ -474,6 +467,45 @@ http://www.jhweiss.de/software/snprintf.html and has the following license:
   modified) versions of this file, nor is leaving this notice intact mandatory.
 -------------------------------------------------------------------------------
 
+src/xxhash.[hc]
+~~~~~~~~~~~~~~~
+
+xxHash - Extremely Fast Hash algorithm. Copied from xxHash v0.6.5 downloaded
+from <https://github.com/Cyan4973/xxHash/releases>.
+
+-------------------------------------------------------------------------------
+   Copyright (C) 2012-2016, Yann Collet.
+
+   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are
+   met:
+
+       * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+       * Redistributions in binary form must reproduce the above
+   copyright notice, this list of conditions and the following disclaimer
+   in the documentation and/or other materials provided with the
+   distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+   You can contact the author at :
+   - xxHash source repository : https://github.com/Cyan4973/xxHash
+-------------------------------------------------------------------------------
+
+
 src/zlib/*.[hc]
 ~~~~~~~~~~~~~~~