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 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 * If block_size is also 0, no decimal digits are printed.
22 *
23 * Licensed under GPLv2, see file LICENSE in this source tree.
24 */
25 #include "libbb.h"
26
make_human_readable_str(unsigned long long val,unsigned long block_size,unsigned long display_unit)27 const char* FAST_FUNC make_human_readable_str(unsigned long long val,
28 unsigned long block_size, unsigned long display_unit)
29 {
30 static const char unit_chars[] ALIGN1 = {
31 '\0', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'
32 };
33
34 unsigned frac; /* 0..9 - the fractional digit */
35 const char *u;
36 const char *fmt;
37
38 if (val == 0)
39 return "0";
40
41 fmt = "%llu";
42 if (block_size > 1)
43 val *= block_size;
44 frac = 0;
45 u = unit_chars;
46
47 if (display_unit) {
48 val += display_unit/2; /* Deal with rounding */
49 val /= display_unit; /* Don't combine with the line above! */
50 /* will just print it as ulonglong (below) */
51 } else {
52 while ((val >= 1024)
53 /* && (u < unit_chars + sizeof(unit_chars) - 1) - always true */
54 ) {
55 fmt = "%llu.%u%c";
56 u++;
57 frac = (((unsigned)val % 1024) * 10 + 1024/2) / 1024;
58 val /= 1024;
59 }
60 if (frac >= 10) { /* we need to round up here */
61 ++val;
62 frac = 0;
63 }
64 #if 1
65 /* If block_size is 0, dont print fractional part */
66 if (block_size == 0) {
67 if (frac >= 5) {
68 ++val;
69 }
70 fmt = "%llu%*c";
71 frac = 1;
72 }
73 #endif
74 }
75
76 return auto_string(xasprintf(fmt, val, frac, *u));
77 }
78
79
80 /* vda's implementations of the similar idea */
81
82 /* Convert unsigned long long value into compact 5-char representation.
83 * String is not terminated (buf[5] is untouched) */
smart_ulltoa5(unsigned long long ul,char buf[5],const char * scale)84 char* FAST_FUNC smart_ulltoa5(unsigned long long ul, char buf[5], const char *scale)
85 {
86 const char *fmt;
87 char c;
88 unsigned v, u, idx = 0;
89
90 if (ul > 99999) { // do not scale if 99999 or less
91 ul *= 10;
92 do {
93 ul /= 1024;
94 idx++;
95 } while (ul >= 100000);
96 }
97 v = ul; // ullong divisions are expensive, avoid them
98
99 fmt = " 123456789";
100 u = v / 10;
101 v = v % 10;
102 if (!idx) {
103 // 99999 or less: use "12345" format
104 // u is value/10, v is last digit
105 c = buf[0] = " 123456789"[u/1000];
106 if (c != ' ') fmt = "0123456789";
107 c = buf[1] = fmt[u/100%10];
108 if (c != ' ') fmt = "0123456789";
109 c = buf[2] = fmt[u/10%10];
110 if (c != ' ') fmt = "0123456789";
111 buf[3] = fmt[u%10];
112 buf[4] = "0123456789"[v];
113 } else {
114 // value has been scaled into 0..9999.9 range
115 // u is value, v is 1/10ths (allows for 92.1M format)
116 if (u >= 100) {
117 // value is >= 100: use "1234M', " 123M" formats
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 v = u % 10;
123 u = u / 10;
124 buf[2] = fmt[u%10];
125 } else {
126 // value is < 100: use "92.1M" format
127 c = buf[0] = " 123456789"[u/10];
128 if (c != ' ') fmt = "0123456789";
129 buf[1] = fmt[u%10];
130 buf[2] = '.';
131 }
132 buf[3] = "0123456789"[v];
133 buf[4] = scale[idx]; /* typically scale = " kmgt..." */
134 }
135 return buf + 5;
136 }
137
138 /* Convert unsigned long long value into compact 4-char
139 * representation. Examples: "1234", "1.2k", " 27M", "123T"
140 * String is not terminated (buf[4] is untouched) */
smart_ulltoa4(unsigned long long ul,char buf[4],const char * scale)141 char* FAST_FUNC smart_ulltoa4(unsigned long long ul, char buf[4], const char *scale)
142 {
143 const char *fmt;
144 char c;
145 unsigned v, u, idx = 0;
146
147 if (ul > 9999) { // do not scale if 9999 or less
148 ul *= 10;
149 do {
150 ul /= 1024;
151 idx++;
152 } while (ul >= 10000);
153 }
154 v = ul; // ullong divisions are expensive, avoid them
155
156 fmt = " 123456789";
157 u = v / 10;
158 v = v % 10;
159 if (!idx) {
160 // 9999 or less: use "1234" format
161 // u is value/10, v is last digit
162 c = buf[0] = " 123456789"[u/100];
163 if (c != ' ') fmt = "0123456789";
164 c = buf[1] = fmt[u/10%10];
165 if (c != ' ') fmt = "0123456789";
166 buf[2] = fmt[u%10];
167 buf[3] = "0123456789"[v];
168 } else {
169 // u is value, v is 1/10ths (allows for 9.2M format)
170 if (u >= 10) {
171 // value is >= 10: use "123M', " 12M" formats
172 c = buf[0] = " 123456789"[u/100];
173 if (c != ' ') fmt = "0123456789";
174 v = u % 10;
175 u = u / 10;
176 buf[1] = fmt[u%10];
177 } else {
178 // value is < 10: use "9.2M" format
179 buf[0] = "0123456789"[u];
180 buf[1] = '.';
181 }
182 buf[2] = "0123456789"[v];
183 buf[3] = scale[idx]; /* typically scale = " kmgt..." */
184 }
185 return buf + 4;
186 }
187