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 1.1 2003/01/04 22:07:24 phk Exp $ 29 * $DragonFly: src/usr.bin/systat/convtbl.c,v 1.1 2003/11/08 09:30:32 asmodai Exp $ 30 */ 31 32 #include <sys/types.h> 33 #include <unistd.h> 34 #include "convtbl.h" 35 36 struct convtbl convtbl[] = { 37 /* mul, scale, str */ 38 { BYTE, BYTES, "bytes" }, /* SC_BYTE (0) */ 39 { BYTE, KILO, "KB" }, /* SC_KILOBYTE (1) */ 40 { BYTE, MEGA, "MB" }, /* SC_MEGABYTE (2) */ 41 { BYTE, GIGA, "GB" }, /* SC_GIGABYTE (3) */ 42 43 { BIT, BITS, "b" }, /* SC_BITS (4) */ 44 { BIT, KILO, "Kb" }, /* SC_KILOBITS (5) */ 45 { BIT, MEGA, "Mb" }, /* SC_MEGABITS (6) */ 46 { BIT, GIGA, "Gb" }, /* SC_GIGABITS (7) */ 47 48 { 0, 0, "" } /* SC_AUTO (8) */ 49 50 }; 51 52 53 static __inline__ 54 struct convtbl * 55 get_tbl_ptr(const u_long size, const u_int scale) 56 { 57 struct convtbl *tbl_ptr = NULL; 58 u_long tmp = 0; 59 u_int index = scale; 60 61 /* If our index is out of range, default to auto-scaling. */ 62 if (index > SC_AUTO) 63 index = SC_AUTO; 64 65 if (index == SC_AUTO) 66 /* 67 * Simple but elegant algorithm. Count how many times 68 * we can shift our size value right by a factor of ten, 69 * incrementing an index each time. We then use the 70 * index as the array index into the conversion table. 71 */ 72 for (tmp = size, index = SC_KILOBYTE; 73 tmp >= MEGA && index <= SC_GIGABYTE; 74 tmp >>= 10, index++); 75 76 tbl_ptr = &convtbl[index]; 77 return tbl_ptr; 78 } 79 80 double 81 convert(const u_long size, const u_int scale) 82 { 83 struct convtbl *tp = NULL; 84 85 tp = get_tbl_ptr(size, scale); 86 87 return ((double)size * tp->mul / tp->scale); 88 89 } 90 91 char * 92 get_string(const u_long size, const u_int scale) 93 { 94 struct convtbl *tp = NULL; 95 96 tp = get_tbl_ptr(size, scale); 97 98 return tp->str; 99 } 100