Imported Upstream version 93u+upstream

1 files changed, 113 insertions, 0 deletions

diff --git a/src/lib/libsum/sum-prng.c b/src/lib/libsum/sum-prng.c
new file mode 100644
index 0000000..8a85e47
--- /dev/null
+++ b/src/lib/libsum/sum-prng.c
@@ -0,0 +1,113 @@
+/***********************************************************************
+*                                                                      *
+*               This software is part of the ast package               *
+*          Copyright (c) 1996-2011 AT&T Intellectual Property          *
+*                      and is licensed under the                       *
+*                 Eclipse Public License, Version 1.0                  *
+*                    by AT&T Intellectual Property                     *
+*                                                                      *
+*                A copy of the License is available at                 *
+*          http://www.eclipse.org/org/documents/epl-v10.html           *
+*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
+*                                                                      *
+*              Information and Software Systems Research               *
+*                            AT&T Research                             *
+*                           Florham Park NJ                            *
+*                                                                      *
+*                 Glenn Fowler <gsf@research.att.com>                  *
+*                                                                      *
+***********************************************************************/
+#pragma prototyped
+
+/*
+ * prng
+ */
+
+#include <fnv.h>
+
+#define prng_description \
+	"32 bit PRNG (pseudo random number generator) hash."
+#define prng_options	"\
+[+mpy?The 32 bit PRNG multiplier.]:[number:=0x01000193]\
+[+add?The 32 bit PRNG addend.]:[number:=0]\
+[+init?The PRNG initial value. 0xffffffff is used if \anumber\a is omitted.]:?[number:=0x811c9dc5]\
+"
+#define prng_match	"prng"
+#define prng_done	long_done
+#define prng_print	long_print
+#define prng_data	long_data
+#define prng_scale	0
+
+typedef uint32_t Prngnum_t;
+
+typedef struct Prng_s
+{
+	_SUM_PUBLIC_
+	_SUM_PRIVATE_
+	_INTEGRAL_PRIVATE_
+	Prngnum_t		init;
+	Prngnum_t		mpy;
+	Prngnum_t		add;
+} Prng_t;
+
+static Sum_t*
+prng_open(const Method_t* method, const char* name)
+{
+	register Prng_t*	sum;
+	register const char*	s;
+	register const char*	t;
+	register const char*	v;
+	register int		i;
+
+	if (sum = newof(0, Prng_t, 1, 0))
+	{
+		sum->method = (Method_t*)method;
+		sum->name = name;
+	}
+	s = name;
+	while (*(t = s))
+	{
+		for (t = s, v = 0; *s && *s != '-'; s++)
+			if (*s == '=' && !v)
+				v = s;
+		i = (v ? v : s) - t;
+		if (isdigit(*t) || v && strneq(t, "mpy", i) && (t = v + 1))
+			sum->mpy = strtoul(t, NiL, 0);
+		else if (strneq(t, "add", i))
+			sum->add = v ? strtoul(v + 1, NiL, 0) : ~sum->add;
+		else if (strneq(t, "init", i))
+			sum->init = v ? strtoul(v + 1, NiL, 0) : ~sum->init;
+		if (*s == '-')
+			s++;
+	}
+	if (!sum->mpy)
+	{
+		sum->mpy = FNV_MULT;
+		if (!sum->init)
+			sum->init = FNV_INIT;
+	}
+	return (Sum_t*)sum;
+}
+
+static int
+prng_init(Sum_t* p)
+{
+	Prng_t*		sum = (Prng_t*)p;
+
+	sum->sum = sum->init;
+	return 0;
+}
+
+static int
+prng_block(Sum_t* p, const void* s, size_t n)
+{
+	Prng_t*			sum = (Prng_t*)p;
+	register Prngnum_t	c = sum->sum;
+	register unsigned char*	b = (unsigned char*)s;
+	register unsigned char*	e = b + n;
+
+	while (b < e)
+		c = c * sum->mpy + sum->add + *b++;
+	sum->sum = c;
+	return 0;
+}