Contents of /trunk/mkinitrd-magellan/busybox/libbb/human_readable.c
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Sun May 30 11:32:42 2010 UTC (14 years, 3 months ago) by niro
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Sun May 30 11:32:42 2010 UTC (14 years, 3 months ago) by niro
File MIME type: text/plain
File size: 5355 byte(s)
-updated to busybox-1.16.1 and enabled blkid/uuid support in default config
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 tarball for details. |
29 | */ |
30 | |
31 | #include "libbb.h" |
32 | |
33 | const 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) */ |
97 | void FAST_FUNC smart_ulltoa5(unsigned long long ul, char buf[6], 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) */ |
153 | void FAST_FUNC smart_ulltoa4(unsigned long long ul, char buf[5], 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 | } |