1 files changed, 47 insertions, 0 deletions
diff --git a/src/hash.c b/src/hash.c
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index 0000000..064deab
--- /dev/null
+++ b/src/hash.c
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+/* hash.c - The gdbm hash function. */
+
+/* This file is part of GDBM, the GNU data base manager.
+   Copyright (C) 1990, 1991, 1993, 2007  Free Software Foundation, Inc.
+
+   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 3, or (at your option)
+   any later version.
+
+   This program 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 Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Include system configuration before all else. */
+#include "autoconf.h"
+
+#include "gdbmdefs.h"
+
+
+/* This hash function computes a 31 bit value.  The value is used to index
+   the hash directory using the top n bits.  It is also used in a hash bucket
+   to find the home position of the element by taking the value modulo the
+   bucket hash table size. */
+
+int
+_gdbm_hash (datum key)
+{
+  unsigned int value;	/* Used to compute the hash value.  */
+  int   index;		/* Used to cycle through random values. */
+
+
+  /* Set the initial value from key. */
+  value = 0x238F13AF * key.dsize;
+  for (index = 0; index < key.dsize; index++)
+    value = (value + (key.dptr[index] << (index*5 % 24))) & 0x7FFFFFFF;
+
+  value = (1103515243 * value + 12345) & 0x7FFFFFFF;  
+
+  /* Return the value. */
+  return((int) value);
+}