DRY out multiple hash functions.

[pazpar2-moved-to-github.git] / src / jenkins_hash.c

diff --git a/src/jenkins_hash.c b/src/jenkins_hash.c
new file mode 100644 (file)
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+++ b/src/jenkins_hash.c
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+/* This file is part of Pazpar2.
+   Copyright (C) 2006-2009 Index Data
+
+Pazpar2 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, or (at your option) any later
+version.
+
+Pazpar2 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 this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+/** \file 
+    \brief Jenkins hash function
+*/
+
+#if HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "jenkins_hash.h"
+
+// Jenkins one-at-a-time hash (from wikipedia)
+unsigned int jenkins_hash(const unsigned char *key)
+{
+    unsigned int hash = 0;
+
+    while (*key)
+    {
+        hash += *(key++);
+        hash += (hash << 10);
+        hash ^= (hash >> 6);
+    }
+    hash += (hash << 3);
+    hash ^= (hash >> 11);
+    hash += (hash << 15);
+    return hash;
+}
+
+/*
+ * Local variables:
+ * c-basic-offset: 4
+ * c-file-style: "Stroustrup"
+ * indent-tabs-mode: nil
+ * End:
+ * vim: shiftwidth=4 tabstop=8 expandtab
+ */
+