1 /* $NetBSD: convtbl.c,v 1.2 2016/08/02 17:53:46 scole Exp $ */
2
3 /*
4 * Copyright (c) 2003, Trent Nelson, <trent@arpa.com>.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $FreeBSD: releng/10.1/usr.bin/systat/convtbl.c 175387 2008-01-16 19:27:43Z delphij $
31 */
32
33 #include <sys/cdefs.h>
34 #ifndef lint
35 __RCSID("$NetBSD: convtbl.c,v 1.2 2016/08/02 17:53:46 scole Exp $");
36 #endif /* not lint */
37
38 #include <sys/types.h>
39
40 #include <stdlib.h>
41 #include <string.h>
42
43 #include "convtbl.h"
44
45 #define BIT (8)
46 #define BITS (1)
47 #define KILOBIT (1000LL)
48 #define MEGABIT (KILOBIT * 1000)
49 #define GIGABIT (MEGABIT * 1000)
50 #define TERABIT (GIGABIT * 1000)
51
52 #define BYTE (1)
53 #define BYTES (1)
54 #define KILOBYTE (1024LL)
55 #define MEGABYTE (KILOBYTE * 1024)
56 #define GIGABYTE (MEGABYTE * 1024)
57 #define TERABYTE (GIGABYTE * 1024)
58
59 struct convtbl {
60 uintmax_t mul;
61 uintmax_t scale;
62 const char *str;
63 const char *name;
64 };
65
66 static struct convtbl convtbl[] = {
67 /* mul, scale, str, name */
68 [SC_BYTE] = { BYTE, BYTES, "B", "byte" },
69 [SC_KILOBYTE] = { BYTE, KILOBYTE, "KB", "kbyte" },
70 [SC_MEGABYTE] = { BYTE, MEGABYTE, "MB", "mbyte" },
71 [SC_GIGABYTE] = { BYTE, GIGABYTE, "GB", "gbyte" },
72 [SC_TERABYTE] = { BYTE, TERABYTE, "TB", "tbyte" },
73
74 [SC_BIT] = { BIT, BITS, "b", "bit" },
75 [SC_KILOBIT] = { BIT, KILOBIT, "Kb", "kbit" },
76 [SC_MEGABIT] = { BIT, MEGABIT, "Mb", "mbit" },
77 [SC_GIGABIT] = { BIT, GIGABIT, "Gb", "gbit" },
78 [SC_TERABIT] = { BIT, TERABIT, "Tb", "tbit" },
79
80 [SC_AUTO] = { 0, 0, "", "auto" }
81 };
82
83 static
84 struct convtbl *
get_tbl_ptr(const uintmax_t size,const int scale)85 get_tbl_ptr(const uintmax_t size, const int scale)
86 {
87 uintmax_t tmp;
88 int idx;
89
90 /* If our index is out of range, default to auto-scaling. */
91 idx = scale < SC_AUTO ? scale : SC_AUTO;
92
93 if (idx == SC_AUTO)
94 /*
95 * Simple but elegant algorithm. Count how many times
96 * we can shift our size value right by a factor of ten,
97 * incrementing an index each time. We then use the
98 * index as the array index into the conversion table.
99 */
100 for (tmp = size, idx = SC_KILOBYTE;
101 tmp >= MEGABYTE && idx < SC_BIT - 1;
102 tmp >>= 10, idx++);
103
104 return (&convtbl[idx]);
105 }
106
107 double
convert(const uintmax_t size,const int scale)108 convert(const uintmax_t size, const int scale)
109 {
110 struct convtbl *tp;
111
112 tp = get_tbl_ptr(size, scale);
113 return ((double)size * tp->mul / tp->scale);
114
115 }
116
117 const char *
get_string(const uintmax_t size,const int scale)118 get_string(const uintmax_t size, const int scale)
119 {
120 struct convtbl *tp;
121
122 tp = get_tbl_ptr(size, scale);
123 return (tp->str);
124 }
125
126 int
get_scale(const char * name)127 get_scale(const char *name)
128 {
129 int i;
130
131 for (i = 0; i <= SC_AUTO; i++)
132 if (strcmp(convtbl[i].name, name) == 0)
133 return (i);
134 return (-1);
135 }
136
137 const char *
get_helplist(void)138 get_helplist(void)
139 {
140 int i;
141 size_t len;
142 static char *buf;
143
144 if (buf == NULL) {
145 len = 0;
146 for (i = 0; i <= SC_AUTO; i++)
147 len += strlen(convtbl[i].name) + 2;
148 if ((buf = malloc(len)) != NULL) {
149 buf[0] = '\0';
150 for (i = 0; i <= SC_AUTO; i++) {
151 strcat(buf, convtbl[i].name);
152 if (i < SC_AUTO)
153 strcat(buf, ", ");
154 }
155 } else
156 return ("");
157 }
158 return (buf);
159 }
160