xref: /freebsd/sys/contrib/openzfs/lib/libzutil/zutil_nicenum.c (revision 3332f1b444d4a73238e9f59cca27bfc95fe936bd)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 #include <ctype.h>
27 #include <math.h>
28 #include <stdio.h>
29 #include <libzutil.h>
30 #include <string.h>
31 
32 /*
33  * Return B_TRUE if "str" is a number string, B_FALSE otherwise.
34  * Works for integer and floating point numbers.
35  */
36 boolean_t
37 zfs_isnumber(const char *str)
38 {
39 	if (!*str)
40 		return (B_FALSE);
41 
42 	for (; *str; str++)
43 		if (!(isdigit(*str) || (*str == '.')))
44 			return (B_FALSE);
45 
46 	/*
47 	 * Numbers should not end with a period ("." ".." or "5." are
48 	 * not valid)
49 	 */
50 	if (str[strlen(str) - 1] == '.') {
51 		return (B_FALSE);
52 	}
53 
54 	return (B_TRUE);
55 }
56 
57 /*
58  * Convert a number to an appropriately human-readable output.
59  */
60 void
61 zfs_nicenum_format(uint64_t num, char *buf, size_t buflen,
62     enum zfs_nicenum_format format)
63 {
64 	uint64_t n = num;
65 	int index = 0;
66 	const char *u;
67 	const char *units[3][7] = {
68 	    [ZFS_NICENUM_1024] = {"", "K", "M", "G", "T", "P", "E"},
69 	    [ZFS_NICENUM_BYTES] = {"B", "K", "M", "G", "T", "P", "E"},
70 	    [ZFS_NICENUM_TIME] = {"ns", "us", "ms", "s", "?", "?", "?"}
71 	};
72 
73 	const int units_len[] = {[ZFS_NICENUM_1024] = 6,
74 	    [ZFS_NICENUM_BYTES] = 6,
75 	    [ZFS_NICENUM_TIME] = 4};
76 
77 	const int k_unit[] = {	[ZFS_NICENUM_1024] = 1024,
78 	    [ZFS_NICENUM_BYTES] = 1024,
79 	    [ZFS_NICENUM_TIME] = 1000};
80 
81 	double val;
82 
83 	if (format == ZFS_NICENUM_RAW) {
84 		snprintf(buf, buflen, "%llu", (u_longlong_t)num);
85 		return;
86 	} else if (format == ZFS_NICENUM_RAWTIME && num > 0) {
87 		snprintf(buf, buflen, "%llu", (u_longlong_t)num);
88 		return;
89 	} else if (format == ZFS_NICENUM_RAWTIME && num == 0) {
90 		snprintf(buf, buflen, "%s", "-");
91 		return;
92 	}
93 
94 	while (n >= k_unit[format] && index < units_len[format]) {
95 		n /= k_unit[format];
96 		index++;
97 	}
98 
99 	u = units[format][index];
100 
101 	/* Don't print zero latencies since they're invalid */
102 	if ((format == ZFS_NICENUM_TIME) && (num == 0)) {
103 		(void) snprintf(buf, buflen, "-");
104 	} else if ((index == 0) || ((num %
105 	    (uint64_t)powl(k_unit[format], index)) == 0)) {
106 		/*
107 		 * If this is an even multiple of the base, always display
108 		 * without any decimal precision.
109 		 */
110 		(void) snprintf(buf, buflen, "%llu%s", (u_longlong_t)n, u);
111 
112 	} else {
113 		/*
114 		 * We want to choose a precision that reflects the best choice
115 		 * for fitting in 5 characters.  This can get rather tricky when
116 		 * we have numbers that are very close to an order of magnitude.
117 		 * For example, when displaying 10239 (which is really 9.999K),
118 		 * we want only a single place of precision for 10.0K.  We could
119 		 * develop some complex heuristics for this, but it's much
120 		 * easier just to try each combination in turn.
121 		 */
122 		int i;
123 		for (i = 2; i >= 0; i--) {
124 			val = (double)num /
125 			    (uint64_t)powl(k_unit[format], index);
126 
127 			/*
128 			 * Don't print floating point values for time.  Note,
129 			 * we use floor() instead of round() here, since
130 			 * round can result in undesirable results.  For
131 			 * example, if "num" is in the range of
132 			 * 999500-999999, it will print out "1000us".  This
133 			 * doesn't happen if we use floor().
134 			 */
135 			if (format == ZFS_NICENUM_TIME) {
136 				if (snprintf(buf, buflen, "%d%s",
137 				    (unsigned int) floor(val), u) <= 5)
138 					break;
139 
140 			} else {
141 				if (snprintf(buf, buflen, "%.*f%s", i,
142 				    val, u) <= 5)
143 					break;
144 			}
145 		}
146 	}
147 }
148 
149 /*
150  * Convert a number to an appropriately human-readable output.
151  */
152 void
153 zfs_nicenum(uint64_t num, char *buf, size_t buflen)
154 {
155 	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_1024);
156 }
157 
158 /*
159  * Convert a time to an appropriately human-readable output.
160  * @num:	Time in nanoseconds
161  */
162 void
163 zfs_nicetime(uint64_t num, char *buf, size_t buflen)
164 {
165 	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_TIME);
166 }
167 
168 /*
169  * Print out a raw number with correct column spacing
170  */
171 void
172 zfs_niceraw(uint64_t num, char *buf, size_t buflen)
173 {
174 	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_RAW);
175 }
176 
177 /*
178  * Convert a number of bytes to an appropriately human-readable output.
179  */
180 void
181 zfs_nicebytes(uint64_t num, char *buf, size_t buflen)
182 {
183 	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_BYTES);
184 }
185