xref: /titanic_41/usr/src/lib/libast/common/string/fmtscale.c (revision 8700009e2cc8cb186241e1fdd74973da1121ee4c)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                      by AT&T Knowledge Ventures                      *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #pragma prototyped
23 /*
24  * Glenn Fowler
25  * AT&T Research
26  *
27  * return number n scaled to metric multiples of k { 1000 1024 }
28  * return string length is at most 5 chars + terminating nul
29  */
30 
31 #include <ast.h>
32 #include <lclib.h>
33 
34 char*
35 fmtscale(register Sfulong_t n, int k)
36 {
37 	register Sfulong_t	m;
38 	int			r;
39 	int			z;
40 	const char*		u;
41 	char			suf[3];
42 	char*			s;
43 	char*			buf;
44 	Lc_numeric_t*		p = (Lc_numeric_t*)LCINFO(AST_LC_NUMERIC)->data;
45 
46 	static const char	scale[] = "bkMGTPE";
47 
48 	u = scale;
49 	if (n < 1000)
50 		r = 0;
51 	else
52 	{
53 		m = 0;
54 		while (n >= k && *(u + 1))
55 		{
56 			m = n;
57 			n /= k;
58 			u++;
59 		}
60 		if ((r = (10 * (m % k) + (k / 2)) / k) > 9)
61 		{
62 			r = 0;
63 			n++;
64 		}
65 		if (k == 1024 && n >= 1000)
66 		{
67 			n = 1;
68 			r = 0;
69 			u++;
70 		}
71 	}
72 	buf = fmtbuf(z = 8);
73 	s = suf;
74 	if (u > scale)
75 	{
76 		if (k == 1024)
77 		{
78 			*s++ = *u == 'k' ? 'K' : *u;
79 			*s++ = 'i';
80 		}
81 		else
82 			*s++ = *u;
83 	}
84 	*s = 0;
85 	if (n > 0 && n < 10)
86 		sfsprintf(buf, z, "%I*u%c%d%s", sizeof(n), n, p->decimal >= 0 ? p->decimal : '.', r, suf);
87 	else
88 	{
89 		if (r >= 5)
90 			n++;
91 		sfsprintf(buf, z, "%I*u%s", sizeof(n), n, suf);
92 	}
93 	return buf;
94 }
95