Add humanize_number.c from NetBSD HEAD, verbatim.

--HG-- extra : convert_revision : 021f8a0ed63b28d735682365fe34dbe666c30835
2008-12-22 06:55:54 +01:00 · 2008-12-22 06:55:54 +01:00 · ce5d9faac3
commit ce5d9faac3
parent b303ff28a6
1 changed files with 147 additions and 0 deletions
--- a/lib/humanize_number.c
+++ b/lib/humanize_number.c
@ -0,0 +1,147 @@
+/*	$NetBSD: humanize_number.c,v 1.14 2008/04/28 20:22:59 martin Exp $	*/
+
+/*
+ * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
+ * NASA Ames Research Center, by Luke Mewburn and by Tomas Svensson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: humanize_number.c,v 1.14 2008/04/28 20:22:59 martin Exp $");
+#endif /* LIBC_SCCS and not lint */
+
+#include "namespace.h"
+#include <assert.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <locale.h>
+
+int
+humanize_number(char *buf, size_t len, int64_t bytes,
+    const char *suffix, int scale, int flags)
+{
+	const char *prefixes, *sep;
+	int	b, i, r, maxscale, s1, s2, sign;
+	int64_t	divisor, max;
+	size_t	baselen;
+
+	_DIAGASSERT(buf != NULL);
+	_DIAGASSERT(suffix != NULL);
+	_DIAGASSERT(scale >= 0);
+
+	if (flags & HN_DIVISOR_1000) {
+		/* SI for decimal multiplies */
+		divisor = 1000;
+		if (flags & HN_B)
+			prefixes = "B\0k\0M\0G\0T\0P\0E";
+		else
+			prefixes = "\0\0k\0M\0G\0T\0P\0E";
+	} else {
+		/*
+		 * binary multiplies
+		 * XXX IEC 60027-2 recommends Ki, Mi, Gi...
+		 */
+		divisor = 1024;
+		if (flags & HN_B)
+			prefixes = "B\0K\0M\0G\0T\0P\0E";
+		else
+			prefixes = "\0\0K\0M\0G\0T\0P\0E";
+	}
+
+#define	SCALE2PREFIX(scale)	(&prefixes[(scale) << 1])
+	maxscale = 7;
+
+	if (scale >= maxscale &&
+	    (scale & (HN_AUTOSCALE | HN_GETSCALE)) == 0)
+		return (-1);
+
+	if (buf == NULL || suffix == NULL)
+		return (-1);
+
+	if (len > 0)
+		buf[0] = '\0';
+	if (bytes < 0) {
+		sign = -1;
+		bytes *= -100;
+		baselen = 3;		/* sign, digit, prefix */
+	} else {
+		sign = 1;
+		bytes *= 100;
+		baselen = 2;		/* digit, prefix */
+	}
+	if (flags & HN_NOSPACE)
+		sep = "";
+	else {
+		sep = " ";
+		baselen++;
+	}
+	baselen += strlen(suffix);
+
+	/* Check if enough room for `x y' + suffix + `\0' */
+	if (len < baselen + 1)
+		return (-1);
+
+	if (scale & (HN_AUTOSCALE | HN_GETSCALE)) {
+		/* See if there is additional columns can be used. */
+		for (max = 100, i = len - baselen; i-- > 0;)
+			max *= 10;
+
+		/*
+		 * Divide the number until it fits the given column.
+		 * If there will be an overflow by the rounding below,
+		 * divide once more.
+		 */
+		for (i = 0; bytes >= max - 50 && i < maxscale; i++)
+			bytes /= divisor;
+
+		if (scale & HN_GETSCALE)
+			return (i);
+	} else
+		for (i = 0; i < scale && i < maxscale; i++)
+			bytes /= divisor;
+
+	/* If a value <= 9.9 after rounding and ... */
+	if (bytes < 995 && i > 0 && flags & HN_DECIMAL) {
+		/* baselen + \0 + .N */
+		if (len < baselen + 1 + 2)
+			return (-1);
+		b = ((int)bytes + 5) / 10;
+		s1 = b / 10;
+		s2 = b % 10;
+		r = snprintf(buf, len, "%d%s%d%s%s%s",
+		    sign * s1, localeconv()->decimal_point, s2,
+		    sep, SCALE2PREFIX(i), suffix);
+	} else
+		r = snprintf(buf, len, "%" PRId64 "%s%s%s",
+		    sign * ((bytes + 50) / 100),
+		    sep, SCALE2PREFIX(i), suffix);
+
+	return (r);
+}