1 /* vi: set sw=4 ts=4: */
3 * June 30, 2001 Manuel Novoa III
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.
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.
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.
21 * If block_size is also 0, no decimal digits are printed.
23 * Licensed under GPLv2, see file LICENSE in this source tree.
27 const char* FAST_FUNC make_human_readable_str(unsigned long long val,
28 unsigned long block_size, unsigned long display_unit)
30 static const char unit_chars[] ALIGN1 = {
31 '\0', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'
34 unsigned frac; /* 0..9 - the fractional digit */
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) */
53 /* && (u < unit_chars + sizeof(unit_chars) - 1) - always true */
57 frac = (((unsigned)val % 1024) * 10 + 1024/2) / 1024;
60 if (frac >= 10) { /* we need to round up here */
65 /* If block_size is 0, dont print fractional part */
66 if (block_size == 0) {
76 return auto_string(xasprintf(fmt, val, frac, *u));
80 /* vda's implementations of the similar idea */
82 /* Convert unsigned long long value into compact 5-char representation.
83 * String is not terminated (buf[5] is untouched) */
84 char* FAST_FUNC smart_ulltoa5(unsigned long long ul, char buf[5], const char *scale)
88 unsigned v, u, idx = 0;
90 if (ul > 99999) { // do not scale if 99999 or less
95 } while (ul >= 100000);
97 v = ul; // ullong divisions are expensive, avoid them
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";
112 buf[4] = "0123456789"[v];
114 // value has been scaled into 0..9999.9 range
115 // u is value, v is 1/10ths (allows for 92.1M format)
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";
126 // value is < 100: use "92.1M" format
127 c = buf[0] = " 123456789"[u/10];
128 if (c != ' ') fmt = "0123456789";
132 buf[3] = "0123456789"[v];
133 buf[4] = scale[idx]; /* typically scale = " kmgt..." */
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) */
141 char* FAST_FUNC smart_ulltoa4(unsigned long long ul, char buf[4], const char *scale)
145 unsigned v, u, idx = 0;
147 if (ul > 9999) { // do not scale if 9999 or less
152 } while (ul >= 10000);
154 v = ul; // ullong divisions are expensive, avoid them
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";
167 buf[3] = "0123456789"[v];
169 // u is value, v is 1/10ths (allows for 9.2M format)
171 // value is >= 10: use "123M', " 12M" formats
172 c = buf[0] = " 123456789"[u/100];
173 if (c != ' ') fmt = "0123456789";
178 // value is < 10: use "9.2M" format
179 buf[0] = "0123456789"[u];
182 buf[2] = "0123456789"[v];
183 buf[3] = scale[idx]; /* typically scale = " kmgt..." */