1 /*
2 * Copyright (c) 2003, Trent Nelson, <trent@arpa.com>.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD: src/usr.bin/systat/convtbl.c,v 1.13 2008/01/16 19:27:42 delphij Exp $
29 */
30
31 #include <sys/types.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include "convtbl.h"
35
36 #define KILO (1000LL)
37 #define MEGA (KILO * 1000)
38 #define GIGA (MEGA * 1000)
39 #define TERA (GIGA * 1000)
40
41 #define BYTE (1)
42 #define BIT (8)
43
44 struct convtbl {
45 uintmax_t mul;
46 uintmax_t scale;
47 const char *str;
48 const char *name;
49 };
50
51 static struct convtbl convtbl[] = {
52 /* mul, scale, str, name */
53 [SC_BYTE] = { BYTE, 1, "B", "byte" },
54 [SC_KILOBYTE] = { BYTE, KILO, "KB", "kbyte" },
55 [SC_MEGABYTE] = { BYTE, MEGA, "MB", "mbyte" },
56 [SC_GIGABYTE] = { BYTE, GIGA, "GB", "gbyte" },
57 [SC_TERABYTE] = { BYTE, TERA, "TB", "tbyte" },
58 [SC_AUTOBYTE] = { BYTE, 0, "", "autobyte" },
59
60 [SC_BIT] = { BIT, 1, "b", "bit" },
61 [SC_KILOBIT] = { BIT, KILO, "Kb", "kbit" },
62 [SC_MEGABIT] = { BIT, MEGA, "Mb", "mbit" },
63 [SC_GIGABIT] = { BIT, GIGA, "Gb", "gbit" },
64 [SC_TERABIT] = { BIT, TERA, "Tb", "tbit" },
65 [SC_AUTOBIT] = { BIT, 0, "", "autobit" },
66
67 [SC_AUTO] = { 0, 0, "", "auto" }
68 };
69
70 static
71 struct convtbl *
get_tbl_ptr(const uintmax_t size,const int scale)72 get_tbl_ptr(const uintmax_t size, const int scale)
73 {
74 uintmax_t tmp;
75 int disp_bits, idx;
76
77 /* If our index is out of range, default to auto-scaling in bits. */
78 idx = scale < SC_AUTOBIT ? scale : SC_AUTOBIT;
79 disp_bits = idx > SC_AUTOBYTE;
80
81 if (idx == SC_AUTOBYTE || idx == SC_AUTOBIT)
82 /*
83 * Simple but elegant algorithm. Count how many times
84 * we can divide our size value by 1000,
85 * incrementing an index each time. We then use the
86 * index as the array index into the conversion table.
87 */
88 for (tmp = size, idx = disp_bits ? SC_BIT : SC_BYTE;
89 tmp >= 1000 / (disp_bits ? BIT : BYTE) &&
90 idx < (disp_bits ? SC_AUTOBIT : SC_AUTOBYTE) - 1;
91 tmp /= 1000, idx++);
92
93 return (&convtbl[idx]);
94 }
95
96 double
convert(const uintmax_t size,const int scale)97 convert(const uintmax_t size, const int scale)
98 {
99 struct convtbl *tp;
100
101 tp = get_tbl_ptr(size, scale);
102 return ((double)size * tp->mul / tp->scale);
103
104 }
105
106 const char *
get_string(const uintmax_t size,const int scale)107 get_string(const uintmax_t size, const int scale)
108 {
109 struct convtbl *tp;
110
111 tp = get_tbl_ptr(size, scale);
112 return (tp->str);
113 }
114
115 int
get_scale(const char * name)116 get_scale(const char *name)
117 {
118 int i;
119
120 for (i = 0; i <= SC_AUTO; i++)
121 if (strcmp(convtbl[i].name, name) == 0)
122 return (i);
123 return (-1);
124 }
125
126 const char *
get_helplist(void)127 get_helplist(void)
128 {
129 int i;
130 size_t len;
131 static char *buf;
132
133 if (buf == NULL) {
134 len = 0;
135 for (i = 0; i <= SC_AUTO; i++)
136 len += strlen(convtbl[i].name) + 2;
137 if ((buf = malloc(len)) != NULL) {
138 buf[0] = '\0';
139 for (i = 0; i <= SC_AUTO; i++) {
140 strcat(buf, convtbl[i].name);
141 if (i < SC_AUTO)
142 strcat(buf, ", ");
143 }
144 } else
145 return ("");
146 }
147 return (buf);
148 }
149