| 1 | /* $NetBSD: subr_humanize.c,v 1.1 2009/10/02 15:48:41 pooka Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 1997, 1998, 1999, 2002, 2007, 2008 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Luke Mewburn. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | #include <sys/cdefs.h> |
| 33 | __KERNEL_RCSID(0, "$NetBSD: subr_humanize.c,v 1.1 2009/10/02 15:48:41 pooka Exp $" ); |
| 34 | |
| 35 | #include <sys/types.h> |
| 36 | #include <sys/systm.h> |
| 37 | |
| 38 | /* |
| 39 | * snprintf() `bytes' into `buf', reformatting it so that the number, |
| 40 | * plus a possible `x' + suffix extension) fits into len bytes (including |
| 41 | * the terminating NUL). |
| 42 | * Returns the number of bytes stored in buf, or -1 if there was a problem. |
| 43 | * E.g, given a len of 9 and a suffix of `B': |
| 44 | * bytes result |
| 45 | * ----- ------ |
| 46 | * 99999 `99999 B' |
| 47 | * 100000 `97 kB' |
| 48 | * 66715648 `65152 kB' |
| 49 | * 252215296 `240 MB' |
| 50 | */ |
| 51 | int |
| 52 | humanize_number(char *buf, size_t len, uint64_t bytes, const char *suffix, |
| 53 | int divisor) |
| 54 | { |
| 55 | /* prefixes are: (none), kilo, Mega, Giga, Tera, Peta, Exa */ |
| 56 | const char *prefixes; |
| 57 | int r; |
| 58 | uint64_t umax; |
| 59 | size_t i, suffixlen; |
| 60 | |
| 61 | if (buf == NULL || suffix == NULL) |
| 62 | return (-1); |
| 63 | if (len > 0) |
| 64 | buf[0] = '\0'; |
| 65 | suffixlen = strlen(suffix); |
| 66 | /* check if enough room for `x y' + suffix + `\0' */ |
| 67 | if (len < 4 + suffixlen) |
| 68 | return (-1); |
| 69 | |
| 70 | if (divisor == 1024) { |
| 71 | /* |
| 72 | * binary multiplies |
| 73 | * XXX IEC 60027-2 recommends Ki, Mi, Gi... |
| 74 | */ |
| 75 | prefixes = " KMGTPE" ; |
| 76 | } else |
| 77 | prefixes = " kMGTPE" ; /* SI for decimal multiplies */ |
| 78 | |
| 79 | umax = 1; |
| 80 | for (i = 0; i < len - suffixlen - 3; i++) { |
| 81 | umax *= 10; |
| 82 | if (umax > bytes) |
| 83 | break; |
| 84 | } |
| 85 | for (i = 0; bytes >= umax && prefixes[i + 1]; i++) |
| 86 | bytes /= divisor; |
| 87 | |
| 88 | r = snprintf(buf, len, "%qu%s%c%s" , (unsigned long long)bytes, |
| 89 | i == 0 ? "" : " " , prefixes[i], suffix); |
| 90 | |
| 91 | return (r); |
| 92 | } |
| 93 | |
| 94 | int |
| 95 | format_bytes(char *buf, size_t len, uint64_t bytes) |
| 96 | { |
| 97 | int rv; |
| 98 | size_t nlen; |
| 99 | |
| 100 | rv = humanize_number(buf, len, bytes, "B" , 1024); |
| 101 | if (rv != -1) { |
| 102 | /* nuke the trailing ` B' if it exists */ |
| 103 | nlen = strlen(buf) - 2; |
| 104 | if (strcmp(&buf[nlen], " B" ) == 0) |
| 105 | buf[nlen] = '\0'; |
| 106 | } |
| 107 | return (rv); |
| 108 | } |
| 109 | |