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
26 #include "libbb.h"
27
make_human_readable_str(unsigned long long val,unsigned long block_size,unsigned long display_unit)28 const char* FAST_FUNC make_human_readable_str(unsigned long long val,
29 unsigned long block_size, unsigned long display_unit)
30 {
31 static const char unit_chars[] ALIGN1 = {
32 '\0', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'
33 };
34
35 unsigned frac; /* 0..9 - the fractional digit */
36 const char *u;
37 const char *fmt;
38
39 if (val == 0)
40 return "0";
41
42 fmt = "%llu";
43 if (block_size > 1)
44 val *= block_size;
45 frac = 0;
46 u = unit_chars;
47
48 if (display_unit) {
49 val += display_unit/2; /* Deal with rounding */
50 val /= display_unit; /* Don't combine with the line above! */
51 /* will just print it as ulonglong (below) */
52 } else {
53 while ((val >= 1024)
54 /* && (u < unit_chars + sizeof(unit_chars) - 1) - always true */
55 ) {
56 fmt = "%llu.%u%c";
57 u++;
58 frac = (((unsigned)val % 1024) * 10 + 1024/2) / 1024;
59 val /= 1024;
60 }
61 if (frac >= 10) { /* we need to round up here */
62 ++val;
63 frac = 0;
64 }
65 #if 1
66 /* If block_size is 0, dont print fractional part */
67 if (block_size == 0) {
68 if (frac >= 5) {
69 ++val;
70 }
71 fmt = "%llu%*c";
72 frac = 1;
73 }
74 #endif
75 }
76
77 return auto_string(xasprintf(fmt, val, frac, *u));
78 }
79
80
81 /* vda's implementations of the similar idea */
82
83 /* Convert unsigned long long value into compact 5-char representation.
84 * String is not terminated (buf[5] is untouched) */
smart_ulltoa5(unsigned long long ul,char buf[5],const char * scale)85 char* FAST_FUNC smart_ulltoa5(unsigned long long ul, char buf[5], const char *scale)
86 {
87 const char *fmt;
88 char c;
89 unsigned v, u, idx = 0;
90
91 if (ul > 99999) { // do not scale if 99999 or less
92 ul *= 10;
93 do {
94 ul /= 1024;
95 idx++;
96 } while (ul >= 100000);
97 }
98 v = ul; // ullong divisions are expensive, avoid them
99
100 fmt = " 123456789";
101 u = v / 10;
102 v = v % 10;
103 if (!idx) {
104 // 99999 or less: use "12345" format
105 // u is value/10, v is last digit
106 c = buf[0] = " 123456789"[u/1000];
107 if (c != ' ') fmt = "0123456789";
108 c = buf[1] = fmt[u/100%10];
109 if (c != ' ') fmt = "0123456789";
110 c = buf[2] = fmt[u/10%10];
111 if (c != ' ') fmt = "0123456789";
112 buf[3] = fmt[u%10];
113 buf[4] = "0123456789"[v];
114 } else {
115 // value has been scaled into 0..9999.9 range
116 // u is value, v is 1/10ths (allows for 92.1M format)
117 if (u >= 100) {
118 // value is >= 100: use "1234M', " 123M" formats
119 c = buf[0] = " 123456789"[u/1000];
120 if (c != ' ') fmt = "0123456789";
121 c = buf[1] = fmt[u/100%10];
122 if (c != ' ') fmt = "0123456789";
123 v = u % 10;
124 u = u / 10;
125 buf[2] = fmt[u%10];
126 } else {
127 // value is < 100: use "92.1M" format
128 c = buf[0] = " 123456789"[u/10];
129 if (c != ' ') fmt = "0123456789";
130 buf[1] = fmt[u%10];
131 buf[2] = '.';
132 }
133 buf[3] = "0123456789"[v];
134 buf[4] = scale[idx]; /* typically scale = " kmgt..." */
135 }
136 return buf + 5;
137 }
138
139 /* Convert unsigned long long value into compact 4-char
140 * representation. Examples: "1234", "1.2k", " 27M", "123T"
141 * String is not terminated (buf[4] is untouched) */
smart_ulltoa4(unsigned long long ul,char buf[4],const char * scale)142 char* FAST_FUNC smart_ulltoa4(unsigned long long ul, char buf[4], const char *scale)
143 {
144 const char *fmt;
145 char c;
146 unsigned v, u, idx = 0;
147
148 if (ul > 9999) { // do not scale if 9999 or less
149 ul *= 10;
150 do {
151 ul /= 1024;
152 idx++;
153 } while (ul >= 10000);
154 }
155 v = ul; // ullong divisions are expensive, avoid them
156
157 fmt = " 123456789";
158 u = v / 10;
159 v = v % 10;
160 if (!idx) {
161 // 9999 or less: use "1234" format
162 // u is value/10, v is last digit
163 c = buf[0] = " 123456789"[u/100];
164 if (c != ' ') fmt = "0123456789";
165 c = buf[1] = fmt[u/10%10];
166 if (c != ' ') fmt = "0123456789";
167 buf[2] = fmt[u%10];
168 buf[3] = "0123456789"[v];
169 } else {
170 // u is value, v is 1/10ths (allows for 9.2M format)
171 if (u >= 10) {
172 // value is >= 10: use "123M', " 12M" formats
173 c = buf[0] = " 123456789"[u/100];
174 if (c != ' ') fmt = "0123456789";
175 v = u % 10;
176 u = u / 10;
177 buf[1] = fmt[u%10];
178 } else {
179 // value is < 10: use "9.2M" format
180 buf[0] = "0123456789"[u];
181 buf[1] = '.';
182 }
183 buf[2] = "0123456789"[v];
184 buf[3] = scale[idx]; /* typically scale = " kmgt..." */
185 }
186 return buf + 4;
187 }
188