Add Bob Jenkins' lookup3 32-bit and 64-bit hashes to pluginlib.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21155 a1c6a512-1295-4272-9138-f99709370657

apps/plugins/lib/jhash.h

@@ -0,0 +1,67 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* Copyright (C) 2009 by Andrew Mahone
+*
+* jhash.c headers
+*
+* This program 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 2
+* of the License, or (at your option) any later version.
+*
+* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+* KIND, either express or implied.
+*
+****************************************************************************/
+
+#ifndef _LIB_JHASH_H_
+#define _LIB_JHASH_H_
+#include <inttypes.h>     /* defines uint32_t etc */
+#include <sys/types.h>
+#include <plugin.h>
+
+/*
+hashw() -- hash an array of uint32_t into a 32-bit value
+  k:       pointer to the key, an array of uint32_t
+  length:  number of elements in the key
+  initval: an initialization value
+  returns the 32-bit hash
+*/
+uint32_t hashw(const uint32_t *k, size_t length, uint32_t  initval);
+
+/*
+hashw() -- hash an array of uint32_t into two 32-bit values
+(*pc) will be the same as the return value from hashword().
+  k:      pointer to the key, an array of uint32_t
+  length: number of elements in the key
+  pc, pb: pointers to primary and secondary initial values, also used to store
+          the hash results.
+*/
+void hashw2 (const uint32_t *k, size_t length, uint32_t *pc, uint32_t *pb);
+
+/*
+hashs() -- hash an array of bytes into a 32-bit value
+  k:       pointer to the key, an array of bytes
+  length:  number of elements in the key
+  initval: an initialization value
+  returns the 32-bit hash
+*/
+uint32_t hashs( const void *key, size_t length, uint32_t initval);
+
+/*
+hashs2() -- hash an array of bytes into two 32-bit values
+  k:       pointer to the key, an array of bytes
+  length: number of elements in the key
+  pc, pb: pointers to primary and secondary initial values, also used to store
+          the hash results.
+*/
+void hashs2(const void *key, size_t length, uint32_t *pc, uint32_t *pb);
+#endif
+