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/* vi: set sw=4 ts=4: */
/*
* June 30, 2001 Manuel Novoa III
*
* All-integer version (hey, not everyone has floating point) of
* make_human_readable_str, modified from similar code I had written
* for busybox several months ago.
*
* Notes:
* 1) I'm using an unsigned long long to hold the product size * block_size,
* as df (which calls this routine) could request a representation of a
* partition size in bytes > max of unsigned long. If long longs aren't
* available, it would be possible to do what's needed using polynomial
* representations (say, powers of 1024) and manipulating coefficients.
* The base ten "bytes" output could be handled similarly.
*
* 2) This routine always outputs a decimal point and a tenths digit when
* display_unit != 0. Hence, it isn't uncommon for the returned string
* to have a length of 5 or 6.
*
* It might be nice to add a flag to indicate no decimal digits in
* that case. This could be either an additional parameter, or a
* special value of display_unit. Such a flag would also be nice for du.
*
* Some code to omit the decimal point and tenths digit is sketched out
* and "#if 0"'d below.
*/
#include "libbb.h"
const char* FAST_FUNC make_human_readable_str(unsigned long long size,
unsigned long block_size, unsigned long display_unit)
{
/* The code will adjust for additional (appended) units */
static const char unit_chars[] ALIGN1 = {
'\0', 'K', 'M', 'G', 'T', 'P', 'E'
};
static const char fmt[] ALIGN1 = "%llu";
static const char fmt_tenths[] ALIGN1 = "%llu.%d%c";
static char str[21] ALIGN1; /* Sufficient for 64 bit unsigned integers */
unsigned long long val;
int frac;
const char *u;
const char *f;
smallint no_tenths;
if (size == 0)
return "0";
/* If block_size is 0 then do not print tenths */
no_tenths = 0;
if (block_size == 0) {
no_tenths = 1;
block_size = 1;
}
u = unit_chars;
val = size * block_size;
f = fmt;
frac = 0;
if (display_unit) {
val += display_unit/2; /* Deal with rounding */
val /= display_unit; /* Don't combine with the line above!!! */
/* will just print it as ulonglong (below) */
} else {
while ((val >= 1024)
&& (u < unit_chars + sizeof(unit_chars) - 1)
) {
f = fmt_tenths;
u++;
frac = (((int)(val % 1024)) * 10 + 1024/2) / 1024;
val /= 1024;
}
if (frac >= 10) { /* We need to round up here. */
++val;
frac = 0;
}
#if 1
/* Sample code to omit decimal point and tenths digit. */
if (no_tenths) {
if (frac >= 5) {
++val;
}
f = "%llu%*c" /* fmt_no_tenths */;
frac = 1;
}
#endif
}
/* If f==fmt then 'frac' and 'u' are ignored. */
snprintf(str, sizeof(str), f, val, frac, *u);
return str;
}
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