Imported Upstream version 93u+upstream

1 files changed, 165 insertions, 0 deletions

diff --git a/src/lib/libast/misc/recfmt.c b/src/lib/libast/misc/recfmt.c
new file mode 100644
index 0000000..09c3220
--- /dev/null
+++ b/src/lib/libast/misc/recfmt.c
@@ -0,0 +1,165 @@
+/***********************************************************************
+*                                                                      *
+*               This software is part of the ast package               *
+*          Copyright (c) 1985-2011 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>                  *
+*                  David Korn <dgk@research.att.com>                   *
+*                   Phong Vo <kpv@research.att.com>                    *
+*                                                                      *
+***********************************************************************/
+#pragma prototyped
+
+/*
+ * determine record format by sampling data in <buf,size>
+ * total is the total file size, <=0 if not available
+ * return r:
+ *	-1				could not determine
+ *	RECTYPE(r)==REC_fixed		fixed length REC_F_SIZE(r)
+ *	RECTYPE(r)==REC_delimited	variable length delimiter=REC_D_DELIMITER(r)
+ *	RECTYPE(r)==REC_variable	variable length
+ */
+
+#include <recfmt.h>
+
+typedef struct
+{
+	unsigned int	rep[4 * 1024];
+	unsigned int	hit[UCHAR_MAX + 1];
+} Sample_t;
+
+Recfmt_t
+recfmt(const void* buf, size_t size, off_t total)
+{
+	register unsigned char*		s;
+	register unsigned char*		t;
+	register Sample_t*		q;
+	register unsigned int*		h;
+	register unsigned int		i;
+	unsigned int			j;
+	unsigned int			k;
+	unsigned int			n;
+	unsigned int			m;
+	unsigned int			x;
+	unsigned long			f;
+	unsigned long			g;
+
+	static unsigned char		terminators[] = { '\n', 0x15, 0x25 };
+
+	/*
+	 * check for V format
+	 */
+
+	s = (unsigned char*)buf;
+	t = s + size;
+	while ((k = (t - s)) >= 4 && !s[2] && !s[3])
+	{
+		if ((i = (s[0]<<8)|s[1]) > k)
+			break;
+		s += i;
+	}
+	if (!k || size > 2 * k)
+		return REC_V_TYPE(4, 0, 2, 0, 1);
+	s = (unsigned char*)buf;
+
+	/*
+	 * check for terminated records
+	 */
+
+	for (i = 0; i < elementsof(terminators); i++)
+		if ((t = (unsigned char*)memchr((void*)s, k = terminators[i], size / 2)) && (n = t - s + 1) > 1 && (total <= 0 || !(total % n)))
+		{
+			for (j = n - 1; j < size; j += n)
+				if (s[j] != k)
+				{
+					n = 0;
+					break;
+				}
+			if (n)
+				return REC_D_TYPE(terminators[i]);
+		}
+
+	/*
+	 * check fixed length record frequencies
+	 */
+
+	if (!(q = newof(0, Sample_t, 1, 0)))
+		return REC_N_TYPE();
+	x = 0;
+	for (i = 0; i < size; i++)
+	{
+		h = q->hit + s[i];
+		m = i - *h;
+		*h = i;
+		if (m < elementsof(q->rep))
+		{
+			if (m > x)
+				x = m;
+			q->rep[m]++;
+		}
+	}
+	n = 0;
+	m = 0;
+	f = ~0;
+	for (i = x; i > 1; i--)
+	{
+		if ((total <= 0 || !(total % i)) && q->rep[i] > q->rep[n])
+		{
+			m++;
+			g = 0;
+			for (j = i; j < size - i; j += i)
+				for (k = 0; k < i; k++)
+					if (s[j + k] != s[j + k - i])
+						g++;
+			g = (((g * 100) / i) * 100) / q->rep[i];
+			if (g <= f)
+			{
+				f = g;
+				n = i;
+			}
+		}
+	}
+	if (m <= 1 && n <= 2 && total > 1 && total < 256)
+	{
+		n = 0;
+		for (i = 0; i < size; i++)
+			for (j = 0; j < elementsof(terminators); j++)
+				if (s[i] == terminators[j])
+					n++;
+		n = n ? 0 : total;
+	}
+	free(q);
+	return n ? REC_F_TYPE(n) : REC_N_TYPE();
+}
+
+#if MAIN
+
+main()
+{
+	void*	s;
+	size_t	size;
+	off_t	total;
+
+	if (!(s = sfreserve(sfstdin, SF_UNBOUND, 0)))
+	{
+		sfprintf(sfstderr, "read error\n");
+		return 1;
+	}
+	size = sfvalue(sfstdin);
+	total = sfsize(sfstdin);
+	sfprintf(sfstdout, "%d\n", recfmt(s, size, total));
+	return 0;
+}
+
+#endif