xref: /dragonfly/lib/libtcplay/humanize.c (revision 15640dd4f52cd004b858c5b1d94340663e1d39af)
1 /*
2  * Copyright (c) 2011 Alex Hornung <alex@alexhornung.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  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in
13  *    the documentation and/or other materials provided with the
14  *    distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
19  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
20  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
22  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <string.h>
31 #include <stdlib.h>
32 #include <stdio.h>
33 #include <inttypes.h>
34 #include <ctype.h>
35 #include <errno.h>
36 
37 #include "humanize.h"
38 
39 static const char prefixes[] = " KMGTPE";
40 int
_humanize_number(char * buf,size_t bufsz,uint64_t num)41 _humanize_number(char *buf, size_t bufsz, uint64_t num)
42 {
43           const char *prefixp;
44           int ret;
45           uint64_t i, d;
46 
47           prefixp = prefixes;
48           i = num;
49           d = 0;
50 
51           while ((i > 1024) && (*prefixp != '\0')) {
52                     d = (i % 1024)/10;
53                     i /= 1024;
54                     ++prefixp;
55           }
56 
57           if (d > 0)
58                     ret = snprintf(buf, bufsz, "%"PRIu64".%"PRIu64" %c",
59                         i, d, *prefixp);
60           else
61                     ret = snprintf(buf, bufsz, "%"PRIu64" %c", i, *prefixp);
62 
63 
64           if ((ret < 0) || ((size_t)ret >= bufsz)) {
65                     errno = ENOMEM;
66                     return -1;
67           } else {
68                     return 0;
69           }
70 }
71 
72 int
_dehumanize_number(const char * buf,uint64_t * dest)73 _dehumanize_number(const char *buf, uint64_t *dest)
74 {
75           char *endptr;
76           uint64_t n, n_check, d;
77           uint64_t multiplier;
78           size_t len;
79 
80           if (*buf == '\0') {
81                     errno = EINVAL;
82                     return -1;
83           }
84 
85           len = strlen(buf);
86           if (tolower(buf[len-1]) == 'b')
87                     --len;
88 
89           multiplier = 1;
90 
91           switch (tolower(buf[len-1])) {
92           case 'y':
93                     multiplier *= 1024;
94                     /* FALLTHROUGH */
95           case 'z':
96                     multiplier *= 1024;
97                     /* FALLTHROUGH */
98           case 'e':
99                     multiplier *= 1024;
100                     /* FALLTHROUGH */
101           case 'p':
102                     multiplier *= 1024;
103                     /* FALLTHROUGH */
104           case 't':
105                     multiplier *= 1024;
106                     /* FALLTHROUGH */
107           case 'g':
108                     multiplier *= 1024;
109                     /* FALLTHROUGH */
110           case 'm':
111                     multiplier *= 1024;
112                     /* FALLTHROUGH */
113           case 'k':
114                     multiplier *= 1024;
115                     break;
116           default:
117                     /*
118                      * only set error if string ends in a character that
119                      * is not a valid unit.
120                      */
121                     if (isalpha(buf[len-1])) {
122                               errno = EINVAL;
123                               return -1;
124                     }
125           }
126 
127           d = 0;
128           n = n_check = strtoull(buf, &endptr, 10);
129           if (endptr) {
130                     if ((*endptr != '.') && (*endptr != '\0') &&
131                         (*endptr != ' ') && (endptr != &buf[len-1])) {
132                               errno = EINVAL;
133                               return -1;
134                     }
135 
136                     if (*endptr == '.') {
137                               d = strtoull(endptr+1, &endptr, 10);
138                               if (endptr && (*endptr != '\0') &&
139                                   (*endptr != ' ') &&
140                                   (endptr != &buf[len-1])) {
141                                         errno = EINVAL;
142                                         return -1;
143                               }
144                     }
145           }
146 
147           if (d != 0) {
148                     while (d < 100)
149                               d *= 10;
150 
151                     while (d > 1000)
152                               d /= 10;
153           }
154 
155           d *= (multiplier/1024);
156           n *= multiplier;
157 
158           if ((uint64_t)(n/multiplier) != n_check) {
159                     errno = ERANGE;
160                     return -1;
161           }
162 
163           n += d;
164           *dest = n;
165 
166           return 0;
167 }
168 
169 #ifdef __TEST_HUMANIZE__
170 
171 #include <assert.h>
main(int argc,char * argv[])172 int main(int argc, char *argv[])
173 {
174           char buf[1024];
175           uint64_t n, out;
176           int err;
177 
178           if (argc < 3)
179                     return -1;
180 
181           n = strtoull(argv[1], NULL, 10);
182 
183           err = _humanize_number(buf, 1024, n);
184           assert(err == 0);
185 
186           err = _dehumanize_number(buf, &out);
187           assert(err == 0);
188 
189           printf("Converting: %"PRIu64" => %s => %"PRIu64"\n", n, buf, out);
190 
191           err = _dehumanize_number(argv[2], &out);
192           assert (err == 0);
193 
194           printf("Converting: %s => %"PRIu64"\n", argv[2], out);
195 
196           return 0;
197 }
198 
199 #endif
200