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 | |