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
31/*
32 * Return B_TRUE if "str" is a number string, B_FALSE otherwise.
33 * Works for integer and floating point numbers.
34 */
35boolean_t
36zfs_isnumber(const char *str)
37{
38	for (; *str; str++)
39		if (!(isdigit(*str) || (*str == '.')))
40			return (B_FALSE);
41
42	return (B_TRUE);
43}
44
45/*
46 * Convert a number to an appropriately human-readable output.
47 */
48void
49zfs_nicenum_format(uint64_t num, char *buf, size_t buflen,
50    enum zfs_nicenum_format format)
51{
52	uint64_t n = num;
53	int index = 0;
54	const char *u;
55	const char *units[3][7] = {
56	    [ZFS_NICENUM_1024] = {"", "K", "M", "G", "T", "P", "E"},
57	    [ZFS_NICENUM_BYTES] = {"B", "K", "M", "G", "T", "P", "E"},
58	    [ZFS_NICENUM_TIME] = {"ns", "us", "ms", "s", "?", "?", "?"}
59	};
60
61	const int units_len[] = {[ZFS_NICENUM_1024] = 6,
62	    [ZFS_NICENUM_BYTES] = 6,
63	    [ZFS_NICENUM_TIME] = 4};
64
65	const int k_unit[] = {	[ZFS_NICENUM_1024] = 1024,
66	    [ZFS_NICENUM_BYTES] = 1024,
67	    [ZFS_NICENUM_TIME] = 1000};
68
69	double val;
70
71	if (format == ZFS_NICENUM_RAW) {
72		(void) snprintf(buf, buflen, "%llu", (u_longlong_t)num);
73		return;
74	} else if (format == ZFS_NICENUM_RAWTIME && num > 0) {
75		(void) snprintf(buf, buflen, "%llu", (u_longlong_t)num);
76		return;
77	} else if (format == ZFS_NICENUM_RAWTIME && num == 0) {
78		(void) snprintf(buf, buflen, "%s", "-");
79		return;
80	}
81
82	while (n >= k_unit[format] && index < units_len[format]) {
83		n /= k_unit[format];
84		index++;
85	}
86
87	u = units[format][index];
88
89	/* Don't print zero latencies since they're invalid */
90	if ((format == ZFS_NICENUM_TIME) && (num == 0)) {
91		(void) snprintf(buf, buflen, "-");
92	} else if ((index == 0) || ((num %
93	    (uint64_t)powl(k_unit[format], index)) == 0)) {
94		/*
95		 * If this is an even multiple of the base, always display
96		 * without any decimal precision.
97		 */
98		(void) snprintf(buf, buflen, "%llu%s", (u_longlong_t)n, u);
99
100	} else {
101		/*
102		 * We want to choose a precision that reflects the best choice
103		 * for fitting in 5 characters.  This can get rather tricky when
104		 * we have numbers that are very close to an order of magnitude.
105		 * For example, when displaying 10239 (which is really 9.999K),
106		 * we want only a single place of precision for 10.0K.  We could
107		 * develop some complex heuristics for this, but it's much
108		 * easier just to try each combination in turn.
109		 */
110		int i;
111		for (i = 2; i >= 0; i--) {
112			val = (double)num /
113			    (uint64_t)powl(k_unit[format], index);
114
115			/*
116			 * Don't print floating point values for time.  Note,
117			 * we use floor() instead of round() here, since
118			 * round can result in undesirable results.  For
119			 * example, if "num" is in the range of
120			 * 999500-999999, it will print out "1000us".  This
121			 * doesn't happen if we use floor().
122			 */
123			if (format == ZFS_NICENUM_TIME) {
124				if (snprintf(buf, buflen, "%d%s",
125				    (unsigned int) floor(val), u) <= 5)
126					break;
127
128			} else {
129				if (snprintf(buf, buflen, "%.*f%s", i,
130				    val, u) <= 5)
131					break;
132			}
133		}
134	}
135}
136
137/*
138 * Convert a number to an appropriately human-readable output.
139 */
140void
141zfs_nicenum(uint64_t num, char *buf, size_t buflen)
142{
143	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_1024);
144}
145
146/*
147 * Convert a time to an appropriately human-readable output.
148 * @num:	Time in nanoseconds
149 */
150void
151zfs_nicetime(uint64_t num, char *buf, size_t buflen)
152{
153	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_TIME);
154}
155
156/*
157 * Print out a raw number with correct column spacing
158 */
159void
160zfs_niceraw(uint64_t num, char *buf, size_t buflen)
161{
162	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_RAW);
163}
164
165/*
166 * Convert a number of bytes to an appropriately human-readable output.
167 */
168void
169zfs_nicebytes(uint64_t num, char *buf, size_t buflen)
170{
171	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_BYTES);
172}
173