busybox/libbb/human_readable.c

/* 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.
 *
 * Licensed under GPLv2, see file LICENSE in this tarball for details.
 */

#include "libbb.h"

const char* FAST_FUNC make_human_readable_str(unsigned long long val,
	unsigned long block_size, unsigned long display_unit)
{
	static const char unit_chars[] ALIGN1 = {
		'\0', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'
	};

	static char *str;

	unsigned frac; /* 0..9 - the fractional digit */
	const char *u;
	const char *fmt;

	if (val == 0)
		return "0";

	fmt = "%llu";
	if (block_size > 1)
		val *= block_size;
	frac = 0;
	u = unit_chars;

	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) - always true */
		) {
			fmt = "%llu.%u%c";
			u++;
			frac = (((unsigned)val % 1024) * 10 + 1024/2) / 1024;
			val /= 1024;
		}
		if (frac >= 10) { /* we need to round up here */
			++val;
			frac = 0;
		}
#if 1
		/* If block_size is 0, dont print fractional part */
		if (block_size == 0) {
			if (frac >= 5) {
				++val;
			}
			fmt = "%llu%*c";
			frac = 1;
		}
#endif
	}

	if (!str) {
		/* sufficient for any width of val */
		str = xmalloc(sizeof(val)*3 + 2 + 3);
	}
	sprintf(str, fmt, val, frac, *u);
	return str;
}


/* vda's implementations of the similar idea */

/* Convert unsigned long long value into compact 5-char representation.
 * String is not terminated (buf[5] is untouched) */
void FAST_FUNC smart_ulltoa5(unsigned long long ul, char buf[6], const char *scale)
{
	const char *fmt;
	char c;
	unsigned v, u, idx = 0;

	if (ul > 99999) { // do not scale if 99999 or less
		ul *= 10;
		do {
			ul /= 1024;
			idx++;
		} while (ul >= 100000);
	}
	v = ul; // ullong divisions are expensive, avoid them

	fmt = " 123456789";
	u = v / 10;
	v = v % 10;
	if (!idx) {
		// 99999 or less: use "12345" format
		// u is value/10, v is last digit
		c = buf[0] = " 123456789"[u/1000];
		if (c != ' ') fmt = "0123456789";
		c = buf[1] = fmt[u/100%10];
		if (c != ' ') fmt = "0123456789";
		c = buf[2] = fmt[u/10%10];
		if (c != ' ') fmt = "0123456789";
		buf[3] = fmt[u%10];
		buf[4] = "0123456789"[v];
	} else {
		// value has been scaled into 0..9999.9 range
		// u is value, v is 1/10ths (allows for 92.1M format)
		if (u >= 100) {
			// value is >= 100: use "1234M', " 123M" formats
			c = buf[0] = " 123456789"[u/1000];
			if (c != ' ') fmt = "0123456789";
			c = buf[1] = fmt[u/100%10];
			if (c != ' ') fmt = "0123456789";
			v = u % 10;
			u = u / 10;
			buf[2] = fmt[u%10];
		} else {
			// value is < 100: use "92.1M" format
			c = buf[0] = " 123456789"[u/10];
			if (c != ' ') fmt = "0123456789";
			buf[1] = fmt[u%10];
			buf[2] = '.';
		}
		buf[3] = "0123456789"[v];
		buf[4] = scale[idx]; /* typically scale = " kmgt..." */
	}
}

/* Convert unsigned long long value into compact 4-char
 * representation. Examples: "1234", "1.2k", " 27M", "123T"
 * String is not terminated (buf[4] is untouched) */
void FAST_FUNC smart_ulltoa4(unsigned long long ul, char buf[5], const char *scale)
{
	const char *fmt;
	char c;
	unsigned v, u, idx = 0;

	if (ul > 9999) { // do not scale if 9999 or less
		ul *= 10;
		do {
			ul /= 1024;
			idx++;
		} while (ul >= 10000);
	}
	v = ul; // ullong divisions are expensive, avoid them

	fmt = " 123456789";
	u = v / 10;
	v = v % 10;
	if (!idx) {
		// 9999 or less: use "1234" format
		// u is value/10, v is last digit
		c = buf[0] = " 123456789"[u/100];
		if (c != ' ') fmt = "0123456789";
		c = buf[1] = fmt[u/10%10];
		if (c != ' ') fmt = "0123456789";
		buf[2] = fmt[u%10];
		buf[3] = "0123456789"[v];
	} else {
		// u is value, v is 1/10ths (allows for 9.2M format)
		if (u >= 10) {
			// value is >= 10: use "123M', " 12M" formats
			c = buf[0] = " 123456789"[u/100];
			if (c != ' ') fmt = "0123456789";
			v = u % 10;
			u = u / 10;
			buf[1] = fmt[u%10];
		} else {
			// value is < 10: use "9.2M" format
			buf[0] = "0123456789"[u];
			buf[1] = '.';
		}
		buf[2] = "0123456789"[v];
		buf[3] = scale[idx]; /* typically scale = " kmgt..." */
	}
}
1	niro	532	/* 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	niro	984	*
28			* Licensed under GPLv2, see file LICENSE in this tarball for details.
29	niro	532	*/
30
31			#include "libbb.h"
32
33	niro	984	const char* FAST_FUNC make_human_readable_str(unsigned long long val,
34	niro	532	unsigned long block_size, unsigned long display_unit)
35			{
36	niro	816	static const char unit_chars[] ALIGN1 = {
37	niro	984	'\0', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'
38	niro	816	};
39	niro	532
40	niro	984	static char *str;
41	niro	532
42	niro	984	unsigned frac; /* 0..9 - the fractional digit */
43	niro	532	const char *u;
44	niro	984	const char *fmt;
45	niro	532
46	niro	984	if (val == 0)
47	niro	816	return "0";
48
49	niro	984	fmt = "%llu";
50			if (block_size > 1)
51			val *= block_size;
52			frac = 0;
53	niro	816	u = unit_chars;
54	niro	532
55			if (display_unit) {
56	niro	816	val += display_unit/2; /* Deal with rounding */
57	niro	984	val /= display_unit; /* Don't combine with the line above! */
58	niro	816	/* will just print it as ulonglong (below) */
59	niro	532	} else {
60			while ((val >= 1024)
61	niro	984	/* && (u < unit_chars + sizeof(unit_chars) - 1) - always true */
62	niro	532	) {
63	niro	984	fmt = "%llu.%u%c";
64	niro	816	u++;
65	niro	984	frac = (((unsigned)val % 1024) * 10 + 1024/2) / 1024;
66	niro	532	val /= 1024;
67			}
68	niro	984	if (frac >= 10) { /* we need to round up here */
69	niro	532	++val;
70			frac = 0;
71			}
72	niro	816	#if 1
73	niro	984	/* If block_size is 0, dont print fractional part */
74			if (block_size == 0) {
75	niro	816	if (frac >= 5) {
76	niro	532	++val;
77			}
78	niro	984	fmt = "%llu%*c";
79	niro	532	frac = 1;
80			}
81			#endif
82			}
83
84	niro	984	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	niro	532	return str;
90			}
91	niro	984
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			}