2 files changed, 62 insertions, 0 deletions
diff --git a/lib/hash-pjw.c b/lib/hash-pjw.c
new file mode 100644
index 0000000000..141b08b51f
--- /dev/null
+++ b/lib/hash-pjw.c
@@ -0,0 +1,42 @@
+/* hash-pjw.c -- compute a hash value from a NUL-terminated string.
+   Copyright 2001 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 2, 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "hash-pjw.h"
+
+/* A hash function for NUL-terminated char* strings using
+   the method described in Aho, Sethi, & Ullman, p 436. */
+
+unsigned int
+hash_pjw (const void *x, unsigned int tablesize)
+{
+  const char *s = x;
+  unsigned int h = 0;
+  unsigned int g;
+
+  while (*s != 0)
+    {
+      h = (h << 4) + *s++;
+      if ((g = h & (unsigned int) 0xf0000000) != 0)
+        h = (h ^ (g >> 24)) ^ g;
+    }
+
+  return (h % tablesize);
+}
diff --git a/lib/hash-pjw.h b/lib/hash-pjw.h
new file mode 100644
index 0000000000..efcda115ae
--- /dev/null
+++ b/lib/hash-pjw.h
@@ -0,0 +1,20 @@
+/* hash-pjw.h -- declaration for a simple hash function
+   Copyright 2001 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 2, 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; see the file COPYING.
+   If not, write to the Free Software Foundation,
+   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+unsigned int
+hash_pjw (const void *x, unsigned int tablesize);