[openssh.git] / openbsd-compat / fmt_scaled.c

/*	$OpenBSD: fmt_scaled.c,v 1.9 2007/03/20 03:42:52 tedu Exp $	*/

/*
 * Copyright (c) 2001, 2002, 2003 Ian F. Darwin.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* OPENBSD ORIGINAL: lib/libutil/fmt_scaled.c */

/*
 * fmt_scaled: Format numbers scaled for human comprehension
 * scan_scaled: Scan numbers in this format.
 *
 * "Human-readable" output uses 4 digits max, and puts a unit suffix at
 * the end.  Makes output compact and easy-to-read esp. on huge disks.
 * Formatting code was originally in OpenBSD "df", converted to library routine.
 * Scanning code written for OpenBSD libutil.
 */

#include "includes.h"

#ifndef HAVE_FMT_SCALED

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>

typedef enum {
	NONE = 0, KILO = 1, MEGA = 2, GIGA = 3, TERA = 4, PETA = 5, EXA = 6
} unit_type;

/* These three arrays MUST be in sync!  XXX make a struct */
static unit_type units[] = { NONE, KILO, MEGA, GIGA, TERA, PETA, EXA };
static char scale_chars[] = "BKMGTPE";
static long long scale_factors[] = {
	1LL,
	1024LL,
	1024LL*1024,
	1024LL*1024*1024,
	1024LL*1024*1024*1024,
	1024LL*1024*1024*1024*1024,
	1024LL*1024*1024*1024*1024*1024,
};
#define	SCALE_LENGTH (sizeof(units)/sizeof(units[0]))

#define MAX_DIGITS (SCALE_LENGTH * 3)	/* XXX strlen(sprintf("%lld", -1)? */

/** Convert the given input string "scaled" into numeric in "result".
 * Return 0 on success, -1 and errno set on error.
 */
int
scan_scaled(char *scaled, long long *result)
{
	char *p = scaled;
	int sign = 0;
	unsigned int i, ndigits = 0, fract_digits = 0;
	long long scale_fact = 1, whole = 0, fpart = 0;

	/* Skip leading whitespace */
	while (isascii(*p) && isspace(*p))
		++p;

	/* Then at most one leading + or - */
	while (*p == '-' || *p == '+') {
		if (*p == '-') {
			if (sign) {
				errno = EINVAL;
				return -1;
			}
			sign = -1;
			++p;
		} else if (*p == '+') {
			if (sign) {
				errno = EINVAL;
				return -1;
			}
			sign = +1;
			++p;
		}
	}

	/* Main loop: Scan digits, find decimal point, if present.
	 * We don't allow exponentials, so no scientific notation
	 * (but note that E for Exa might look like e to some!).
	 * Advance 'p' to end, to get scale factor.
	 */
	for (; isascii(*p) && (isdigit(*p) || *p=='.'); ++p) {
		if (*p == '.') {
			if (fract_digits > 0) {	/* oops, more than one '.' */
				errno = EINVAL;
				return -1;
			}
			fract_digits = 1;
			continue;
		}

		i = (*p) - '0';			/* whew! finally a digit we can use */
		if (fract_digits > 0) {
			if (fract_digits >= MAX_DIGITS-1)
				/* ignore extra fractional digits */
				continue;
			fract_digits++;		/* for later scaling */
			fpart *= 10;
			fpart += i;
		} else {				/* normal digit */
			if (++ndigits >= MAX_DIGITS) {
				errno = ERANGE;
				return -1;
			}
			whole *= 10;
			whole += i;
		}
	}

	if (sign) {
		whole *= sign;
		fpart *= sign;
	}

	/* If no scale factor given, we're done. fraction is discarded. */
	if (!*p) {
		*result = whole;
		return 0;
	}

	/* Validate scale factor, and scale whole and fraction by it. */
	for (i = 0; i < SCALE_LENGTH; i++) {

		/** Are we there yet? */
		if (*p == scale_chars[i] ||
			*p == tolower(scale_chars[i])) {

			/* If it ends with alphanumerics after the scale char, bad. */
			if (isalnum(*(p+1))) {
				errno = EINVAL;
				return -1;
			}
			scale_fact = scale_factors[i];

			/* scale whole part */
			whole *= scale_fact;

			/* truncate fpart so it does't overflow.
			 * then scale fractional part.
			 */
			while (fpart >= LLONG_MAX / scale_fact) {
				fpart /= 10;
				fract_digits--;
			}
			fpart *= scale_fact;
			if (fract_digits > 0) {
				for (i = 0; i < fract_digits -1; i++)
					fpart /= 10;
			}
			whole += fpart;
			*result = whole;
			return 0;
		}
	}
	errno = ERANGE;
	return -1;
}

/* Format the given "number" into human-readable form in "result".
 * Result must point to an allocated buffer of length FMT_SCALED_STRSIZE.
 * Return 0 on success, -1 and errno set if error.
 */
int
fmt_scaled(long long number, char *result)
{
	long long abval, fract = 0;
	unsigned int i;
	unit_type unit = NONE;

	abval = (number < 0LL) ? -number : number;	/* no long long_abs yet */

	/* Not every negative long long has a positive representation.
	 * Also check for numbers that are just too darned big to format
	 */
	if (abval < 0 || abval / 1024 >= scale_factors[SCALE_LENGTH-1]) {
		errno = ERANGE;
		return -1;
	}

	/* scale whole part; get unscaled fraction */
	for (i = 0; i < SCALE_LENGTH; i++) {
		if (abval/1024 < scale_factors[i]) {
			unit = units[i];
			fract = (i == 0) ? 0 : abval % scale_factors[i];
			number /= scale_factors[i];
			if (i > 0)
				fract /= scale_factors[i - 1];
			break;
		}
	}

	fract = (10 * fract + 512) / 1024;
	/* if the result would be >= 10, round main number */
	if (fract == 10) {
		if (number >= 0)
			number++;
		else
			number--;
		fract = 0;
	}

	if (number == 0)
		strlcpy(result, "0B", FMT_SCALED_STRSIZE);
	else if (unit == NONE || number >= 100 || number <= -100) {
		if (fract >= 5) {
			if (number >= 0)
				number++;
			else
				number--;
		}
		(void)snprintf(result, FMT_SCALED_STRSIZE, "%lld%c",
			number, scale_chars[unit]);
	} else
		(void)snprintf(result, FMT_SCALED_STRSIZE, "%lld.%1lld%c",
			number, fract, scale_chars[unit]);

	return 0;
}

#ifdef	MAIN
/*
 * This is the original version of the program in the man page.
 * Copy-and-paste whatever you need from it.
 */
int
main(int argc, char **argv)
{
	char *cinput = "1.5K", buf[FMT_SCALED_STRSIZE];
	long long ninput = 10483892, result;

	if (scan_scaled(cinput, &result) == 0)
		printf("\"%s\" -> %lld\n", cinput, result);
	else
		perror(cinput);

	if (fmt_scaled(ninput, buf) == 0)
		printf("%lld -> \"%s\"\n", ninput, buf);
	else
		fprintf(stderr, "%lld invalid (%s)\n", ninput, strerror(errno));

	return 0;
}
#endif

#endif /* HAVE_FMT_SCALED */
Commit	Line	Data
b3ef88dc	1	/* $OpenBSD: fmt_scaled.c,v 1.9 2007/03/20 03:42:52 tedu Exp $ */
	2
	3	/*
	4	* Copyright (c) 2001, 2002, 2003 Ian F. Darwin. All rights reserved.
	5	*
	6	* Redistribution and use in source and binary forms, with or without
	7	* modification, are permitted provided that the following conditions
	8	* are met:
	9	* 1. Redistributions of source code must retain the above copyright
	10	* notice, this list of conditions and the following disclaimer.
	11	* 2. Redistributions in binary form must reproduce the above copyright
	12	* notice, this list of conditions and the following disclaimer in the
	13	* documentation and/or other materials provided with the distribution.
	14	* 3. The name of the author may not be used to endorse or promote products
	15	* derived from this software without specific prior written permission.
	16	*
	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	27	*/
	28
	29	/* OPENBSD ORIGINAL: lib/libutil/fmt_scaled.c */
	30
	31	/*
	32	* fmt_scaled: Format numbers scaled for human comprehension
	33	* scan_scaled: Scan numbers in this format.
	34	*
	35	* "Human-readable" output uses 4 digits max, and puts a unit suffix at
	36	* the end. Makes output compact and easy-to-read esp. on huge disks.
	37	* Formatting code was originally in OpenBSD "df", converted to library routine.
	38	* Scanning code written for OpenBSD libutil.
	39	*/
	40
	41	#include "includes.h"
	42
	43	#ifndef HAVE_FMT_SCALED
	44
	45	#include <stdio.h>
	46	#include <stdlib.h>
	47	#include <errno.h>
	48	#include <string.h>
	49	#include <ctype.h>
	50	#include <limits.h>
	51
	52	typedef enum {
	53	NONE = 0, KILO = 1, MEGA = 2, GIGA = 3, TERA = 4, PETA = 5, EXA = 6
	54	} unit_type;
	55
	56	/* These three arrays MUST be in sync! XXX make a struct */
	57	static unit_type units[] = { NONE, KILO, MEGA, GIGA, TERA, PETA, EXA };
	58	static char scale_chars[] = "BKMGTPE";
	59	static long long scale_factors[] = {
	60	1LL,
	61	1024LL,
	62	1024LL*1024,
	63	1024LL10241024,
	64	1024LL10241024*1024,
65	1024LL1024102410241024,
66	1024LL1024102410241024*1024,
67	};
68	#define SCALE_LENGTH (sizeof(units)/sizeof(units[0]))
69
70	#define MAX_DIGITS (SCALE_LENGTH * 3) /* XXX strlen(sprintf("%lld", -1)? */
71
72	/** Convert the given input string "scaled" into numeric in "result".
73	* Return 0 on success, -1 and errno set on error.
74	*/
75	int
76	scan_scaled(char scaled, long long result)
77	{
78	char *p = scaled;
79	int sign = 0;
80	unsigned int i, ndigits = 0, fract_digits = 0;
81	long long scale_fact = 1, whole = 0, fpart = 0;
82
83	/* Skip leading whitespace */
84	while (isascii(p) && isspace(p))
85	++p;
86
87	/* Then at most one leading + or - */
88	while (p == '-' \|\| p == '+') {
89	if (*p == '-') {
90	if (sign) {
91	errno = EINVAL;
92	return -1;
93	}
94	sign = -1;
95	++p;
96	} else if (*p == '+') {
97	if (sign) {
98	errno = EINVAL;
99	return -1;
100	}
101	sign = +1;
102	++p;
103	}
104	}
105
106	/* Main loop: Scan digits, find decimal point, if present.
107	* We don't allow exponentials, so no scientific notation
108	* (but note that E for Exa might look like e to some!).
109	* Advance 'p' to end, to get scale factor.
110	*/
111	for (; isascii(p) && (isdigit(p) \|\| *p=='.'); ++p) {
112	if (*p == '.') {
113	if (fract_digits > 0) { /* oops, more than one '.' */
114	errno = EINVAL;
115	return -1;
116	}
117	fract_digits = 1;
118	continue;
119	}
120
121	i = (p) - '0'; / whew! finally a digit we can use */
122	if (fract_digits > 0) {
123	if (fract_digits >= MAX_DIGITS-1)
124	/* ignore extra fractional digits */
125	continue;
126	fract_digits++; /* for later scaling */
127	fpart *= 10;
128	fpart += i;
129	} else { /* normal digit */
130	if (++ndigits >= MAX_DIGITS) {
131	errno = ERANGE;
132	return -1;
133	}
134	whole *= 10;
135	whole += i;
136	}
137	}
138
139	if (sign) {
140	whole *= sign;
141	fpart *= sign;
142	}
143
144	/* If no scale factor given, we're done. fraction is discarded. */
145	if (!*p) {
146	*result = whole;
147	return 0;
148	}
149
150	/* Validate scale factor, and scale whole and fraction by it. */
151	for (i = 0; i < SCALE_LENGTH; i++) {
152
153	/** Are we there yet? */
154	if (*p == scale_chars[i] \|\|
155	*p == tolower(scale_chars[i])) {
156
157	/* If it ends with alphanumerics after the scale char, bad. */
158	if (isalnum(*(p+1))) {
159	errno = EINVAL;
160	return -1;
161	}
162	scale_fact = scale_factors[i];
163
164	/* scale whole part */
165	whole *= scale_fact;
166
167	/* truncate fpart so it does't overflow.
168	* then scale fractional part.
169	*/
170	while (fpart >= LLONG_MAX / scale_fact) {
171	fpart /= 10;
172	fract_digits--;
173	}
174	fpart *= scale_fact;
175	if (fract_digits > 0) {
176	for (i = 0; i < fract_digits -1; i++)
177	fpart /= 10;
178	}
179	whole += fpart;
180	*result = whole;
181	return 0;
182	}
183	}
184	errno = ERANGE;
185	return -1;
186	}
187
188	/* Format the given "number" into human-readable form in "result".
189	* Result must point to an allocated buffer of length FMT_SCALED_STRSIZE.
190	* Return 0 on success, -1 and errno set if error.
191	*/
192	int
193	fmt_scaled(long long number, char *result)
194	{
195	long long abval, fract = 0;
196	unsigned int i;
197	unit_type unit = NONE;
198
199	abval = (number < 0LL) ? -number : number; /* no long long_abs yet */
200
201	/* Not every negative long long has a positive representation.
202	* Also check for numbers that are just too darned big to format
203	*/
204	if (abval < 0 \|\| abval / 1024 >= scale_factors[SCALE_LENGTH-1]) {
205	errno = ERANGE;
206	return -1;
207	}
208
209	/* scale whole part; get unscaled fraction */
210	for (i = 0; i < SCALE_LENGTH; i++) {
211	if (abval/1024 < scale_factors[i]) {
212	unit = units[i];
213	fract = (i == 0) ? 0 : abval % scale_factors[i];
214	number /= scale_factors[i];
215	if (i > 0)
216	fract /= scale_factors[i - 1];
217	break;
218	}
219	}
220
221	fract = (10 * fract + 512) / 1024;
222	/* if the result would be >= 10, round main number */
223	if (fract == 10) {
224	if (number >= 0)
225	number++;
226	else
227	number--;
228	fract = 0;
229	}
230
231	if (number == 0)
232	strlcpy(result, "0B", FMT_SCALED_STRSIZE);
233	else if (unit == NONE \|\| number >= 100 \|\| number <= -100) {
234	if (fract >= 5) {
235	if (number >= 0)
236	number++;
237	else
238	number--;
239	}
240	(void)snprintf(result, FMT_SCALED_STRSIZE, "%lld%c",
241	number, scale_chars[unit]);
242	} else
243	(void)snprintf(result, FMT_SCALED_STRSIZE, "%lld.%1lld%c",
244	number, fract, scale_chars[unit]);
245
246	return 0;
247	}
248
249	#ifdef MAIN
250	/*
251	* This is the original version of the program in the man page.
252	* Copy-and-paste whatever you need from it.
253	*/
254	int
255	main(int argc, char **argv)
256	{
257	char *cinput = "1.5K", buf[FMT_SCALED_STRSIZE];
258	long long ninput = 10483892, result;
259
260	if (scan_scaled(cinput, &result) == 0)
261	printf("\"%s\" -> %lld\n", cinput, result);
262	else
263	perror(cinput);
264
265	if (fmt_scaled(ninput, buf) == 0)
266	printf("%lld -> \"%s\"\n", ninput, buf);
267	else
268	fprintf(stderr, "%lld invalid (%s)\n", ninput, strerror(errno));
269
270	return 0;
271	}
272	#endif
273
274	#endif /* HAVE_FMT_SCALED */