source: MondoRescue/branches/3.2/mindi-busybox/libbb/human_readable.c@ 3232

Last change on this file since 3232 was 2725, checked in by Bruno Cornec, 13 years ago
  • Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3
File size: 5.2 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * June 30, 2001 Manuel Novoa III
4 *
5 * All-integer version (hey, not everyone has floating point) of
6 * make_human_readable_str, modified from similar code I had written
7 * for busybox several months ago.
8 *
9 * Notes:
10 * 1) I'm using an unsigned long long to hold the product size * block_size,
11 * as df (which calls this routine) could request a representation of a
12 * partition size in bytes > max of unsigned long. If long longs aren't
13 * available, it would be possible to do what's needed using polynomial
14 * representations (say, powers of 1024) and manipulating coefficients.
15 * The base ten "bytes" output could be handled similarly.
16 *
17 * 2) This routine always outputs a decimal point and a tenths digit when
18 * display_unit != 0. Hence, it isn't uncommon for the returned string
19 * to have a length of 5 or 6.
20 *
21 * It might be nice to add a flag to indicate no decimal digits in
22 * that case. This could be either an additional parameter, or a
23 * special value of display_unit. Such a flag would also be nice for du.
24 *
25 * Some code to omit the decimal point and tenths digit is sketched out
26 * and "#if 0"'d below.
27 *
28 * Licensed under GPLv2, see file LICENSE in this source tree.
29 */
30
31#include "libbb.h"
32
33const char* FAST_FUNC make_human_readable_str(unsigned long long val,
34 unsigned long block_size, unsigned long display_unit)
35{
36 static const char unit_chars[] ALIGN1 = {
37 '\0', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'
38 };
39
40 static char *str;
41
42 unsigned frac; /* 0..9 - the fractional digit */
43 const char *u;
44 const char *fmt;
45
46 if (val == 0)
47 return "0";
48
49 fmt = "%llu";
50 if (block_size > 1)
51 val *= block_size;
52 frac = 0;
53 u = unit_chars;
54
55 if (display_unit) {
56 val += display_unit/2; /* Deal with rounding */
57 val /= display_unit; /* Don't combine with the line above! */
58 /* will just print it as ulonglong (below) */
59 } else {
60 while ((val >= 1024)
61 /* && (u < unit_chars + sizeof(unit_chars) - 1) - always true */
62 ) {
63 fmt = "%llu.%u%c";
64 u++;
65 frac = (((unsigned)val % 1024) * 10 + 1024/2) / 1024;
66 val /= 1024;
67 }
68 if (frac >= 10) { /* we need to round up here */
69 ++val;
70 frac = 0;
71 }
72#if 1
73 /* If block_size is 0, dont print fractional part */
74 if (block_size == 0) {
75 if (frac >= 5) {
76 ++val;
77 }
78 fmt = "%llu%*c";
79 frac = 1;
80 }
81#endif
82 }
83
84 if (!str) {
85 /* sufficient for any width of val */
86 str = xmalloc(sizeof(val)*3 + 2 + 3);
87 }
88 sprintf(str, fmt, val, frac, *u);
89 return str;
90}
91
92
93/* vda's implementations of the similar idea */
94
95/* Convert unsigned long long value into compact 5-char representation.
96 * String is not terminated (buf[5] is untouched) */
97void FAST_FUNC smart_ulltoa5(unsigned long long ul, char buf[5], const char *scale)
98{
99 const char *fmt;
100 char c;
101 unsigned v, u, idx = 0;
102
103 if (ul > 99999) { // do not scale if 99999 or less
104 ul *= 10;
105 do {
106 ul /= 1024;
107 idx++;
108 } while (ul >= 100000);
109 }
110 v = ul; // ullong divisions are expensive, avoid them
111
112 fmt = " 123456789";
113 u = v / 10;
114 v = v % 10;
115 if (!idx) {
116 // 99999 or less: use "12345" format
117 // u is value/10, v is last digit
118 c = buf[0] = " 123456789"[u/1000];
119 if (c != ' ') fmt = "0123456789";
120 c = buf[1] = fmt[u/100%10];
121 if (c != ' ') fmt = "0123456789";
122 c = buf[2] = fmt[u/10%10];
123 if (c != ' ') fmt = "0123456789";
124 buf[3] = fmt[u%10];
125 buf[4] = "0123456789"[v];
126 } else {
127 // value has been scaled into 0..9999.9 range
128 // u is value, v is 1/10ths (allows for 92.1M format)
129 if (u >= 100) {
130 // value is >= 100: use "1234M', " 123M" formats
131 c = buf[0] = " 123456789"[u/1000];
132 if (c != ' ') fmt = "0123456789";
133 c = buf[1] = fmt[u/100%10];
134 if (c != ' ') fmt = "0123456789";
135 v = u % 10;
136 u = u / 10;
137 buf[2] = fmt[u%10];
138 } else {
139 // value is < 100: use "92.1M" format
140 c = buf[0] = " 123456789"[u/10];
141 if (c != ' ') fmt = "0123456789";
142 buf[1] = fmt[u%10];
143 buf[2] = '.';
144 }
145 buf[3] = "0123456789"[v];
146 buf[4] = scale[idx]; /* typically scale = " kmgt..." */
147 }
148}
149
150/* Convert unsigned long long value into compact 4-char
151 * representation. Examples: "1234", "1.2k", " 27M", "123T"
152 * String is not terminated (buf[4] is untouched) */
153void FAST_FUNC smart_ulltoa4(unsigned long long ul, char buf[4], const char *scale)
154{
155 const char *fmt;
156 char c;
157 unsigned v, u, idx = 0;
158
159 if (ul > 9999) { // do not scale if 9999 or less
160 ul *= 10;
161 do {
162 ul /= 1024;
163 idx++;
164 } while (ul >= 10000);
165 }
166 v = ul; // ullong divisions are expensive, avoid them
167
168 fmt = " 123456789";
169 u = v / 10;
170 v = v % 10;
171 if (!idx) {
172 // 9999 or less: use "1234" format
173 // u is value/10, v is last digit
174 c = buf[0] = " 123456789"[u/100];
175 if (c != ' ') fmt = "0123456789";
176 c = buf[1] = fmt[u/10%10];
177 if (c != ' ') fmt = "0123456789";
178 buf[2] = fmt[u%10];
179 buf[3] = "0123456789"[v];
180 } else {
181 // u is value, v is 1/10ths (allows for 9.2M format)
182 if (u >= 10) {
183 // value is >= 10: use "123M', " 12M" formats
184 c = buf[0] = " 123456789"[u/100];
185 if (c != ' ') fmt = "0123456789";
186 v = u % 10;
187 u = u / 10;
188 buf[1] = fmt[u%10];
189 } else {
190 // value is < 10: use "9.2M" format
191 buf[0] = "0123456789"[u];
192 buf[1] = '.';
193 }
194 buf[2] = "0123456789"[v];
195 buf[3] = scale[idx]; /* typically scale = " kmgt..." */
196 }
197}
Note: See TracBrowser for help on using the repository browser.