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 * 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 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 * 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 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 * 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