include/common/standard.h

/*
  include/common/standard.h
  This files contains some general purpose functions and macros.

  Copyright (C) 2000-2008 Willy Tarreau - w@1wt.eu
  
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation, version 2.1
  exclusively.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#ifndef _COMMON_STANDARD_H
#define _COMMON_STANDARD_H

#include <limits.h>
#include <time.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <common/config.h>
#include <proto/fd.h>

/****** string-specific macros and functions ******/
/* if a > max, then bound <a> to <max>. The macro returns the new <a> */
#define UBOUND(a, max)	({ typeof(a) b = (max); if ((a) > b) (a) = b; (a); })

/* if a < min, then bound <a> to <min>. The macro returns the new <a> */
#define LBOUND(a, min)	({ typeof(a) b = (min); if ((a) < b) (a) = b; (a); })

/* returns 1 only if only zero or one bit is set in X, which means that X is a
 * power of 2, and 0 otherwise */
#define POWEROF2(x) (((x) & ((x)-1)) == 0)

/*
 * Gcc >= 3 provides the ability for the programme to give hints to the
 * compiler about what branch of an if is most likely to be taken. This
 * helps the compiler produce the most compact critical paths, which is
 * generally better for the cache and to reduce the number of jumps.
 */
#if !defined(likely)
#if __GNUC__ < 3
#define __builtin_expect(x,y) (x)
#define likely(x) (x)
#define unlikely(x) (x)
#elif __GNUC__ < 4
/* gcc 3.x does the best job at this */
#define likely(x) (__builtin_expect((x) != 0, 1))
#define unlikely(x) (__builtin_expect((x) != 0, 0))
#else
/* GCC 4.x is stupid, it performs the comparison then compares it to 1,
 * so we cheat in a dirty way to prevent it from doing this. This will
 * only work with ints and booleans though.
 */
#define likely(x) (x)
#define unlikely(x) (__builtin_expect((unsigned long)(x), 0))
#endif
#endif

/*
 * copies at most <size-1> chars from <src> to <dst>. Last char is always
 * set to 0, unless <size> is 0. The number of chars copied is returned
 * (excluding the terminating zero).
 * This code has been optimized for size and speed : on x86, it's 45 bytes
 * long, uses only registers, and consumes only 4 cycles per char.
 */
extern int strlcpy2(char *dst, const char *src, int size);

/*
 * This function simply returns a locally allocated string containing
 * the ascii representation for number 'n' in decimal.
 */
extern char itoa_str[][21];
extern const char *ultoa_r(unsigned long n, char *buffer, int size);
static inline const char *ultoa(unsigned long n)
{
	return ultoa_r(n, itoa_str[0], sizeof(itoa_str[0]));
}

/* Fast macros to convert up to 10 different parameters inside a same call of
 * expression.
 */
#define U2A0(n) ({ ultoa_r((n), itoa_str[0], sizeof(itoa_str[0])); })
#define U2A1(n) ({ ultoa_r((n), itoa_str[1], sizeof(itoa_str[1])); })
#define U2A2(n) ({ ultoa_r((n), itoa_str[2], sizeof(itoa_str[2])); })
#define U2A3(n) ({ ultoa_r((n), itoa_str[3], sizeof(itoa_str[3])); })
#define U2A4(n) ({ ultoa_r((n), itoa_str[4], sizeof(itoa_str[4])); })
#define U2A5(n) ({ ultoa_r((n), itoa_str[5], sizeof(itoa_str[5])); })
#define U2A6(n) ({ ultoa_r((n), itoa_str[6], sizeof(itoa_str[6])); })
#define U2A7(n) ({ ultoa_r((n), itoa_str[7], sizeof(itoa_str[7])); })
#define U2A8(n) ({ ultoa_r((n), itoa_str[8], sizeof(itoa_str[8])); })
#define U2A9(n) ({ ultoa_r((n), itoa_str[9], sizeof(itoa_str[9])); })

/*
 * This function simply returns a locally allocated string containing the ascii
 * representation for number 'n' in decimal, unless n is 0 in which case it
 * returns the alternate string (or an empty string if the alternate string is
 * NULL). It use is intended for limits reported in reports, where it's
 * desirable not to display anything if there is no limit. Warning! it shares
 * the same vector as ultoa_r().
 */
extern const char *limit_r(unsigned long n, char *buffer, int size, const char *alt);

/* Fast macros to convert up to 10 different parameters inside a same call of
 * expression. Warning! they share the same vectors as U2A*!
 */
#define LIM2A0(n, alt) ({ limit_r((n), itoa_str[0], sizeof(itoa_str[0]), (alt)); })
#define LIM2A1(n, alt) ({ limit_r((n), itoa_str[1], sizeof(itoa_str[1]), (alt)); })
#define LIM2A2(n, alt) ({ limit_r((n), itoa_str[2], sizeof(itoa_str[2]), (alt)); })
#define LIM2A3(n, alt) ({ limit_r((n), itoa_str[3], sizeof(itoa_str[3]), (alt)); })
#define LIM2A4(n, alt) ({ limit_r((n), itoa_str[4], sizeof(itoa_str[4]), (alt)); })
#define LIM2A5(n, alt) ({ limit_r((n), itoa_str[5], sizeof(itoa_str[5]), (alt)); })
#define LIM2A6(n, alt) ({ limit_r((n), itoa_str[6], sizeof(itoa_str[6]), (alt)); })
#define LIM2A7(n, alt) ({ limit_r((n), itoa_str[7], sizeof(itoa_str[7]), (alt)); })
#define LIM2A8(n, alt) ({ limit_r((n), itoa_str[8], sizeof(itoa_str[8]), (alt)); })
#define LIM2A9(n, alt) ({ limit_r((n), itoa_str[9], sizeof(itoa_str[9]), (alt)); })

/*
 * Returns non-zero if character <s> is a hex digit (0-9, a-f, A-F), else zero.
 */
extern int ishex(char s);

/*
 * Checks <name> for invalid characters. Valid chars are [A-Za-z0-9_:.-]. If an
 * invalid character is found, a pointer to it is returned. If everything is
 * fine, NULL is returned.
 */
extern const char *invalid_char(const char *name);

/*
 * Checks <domainname> for invalid characters. Valid chars are [A-Za-z0-9_.-].
 * If an invalid character is found, a pointer to it is returned.
 * If everything is fine, NULL is returned.
 */
extern const char *invalid_domainchar(const char *name);

/*
 * converts <str> to a struct sockaddr_un* which is locally allocated.
 * The format is "/path", where "/path" is a path to a UNIX domain socket.
 */
struct sockaddr_un *str2sun(const char *str);

/*
 * converts <str> to a struct sockaddr_in* which is locally allocated.
 * The format is "addr:port", where "addr" can be a dotted IPv4 address,
 * a host name, or empty or "*" to indicate INADDR_ANY.
 */
struct sockaddr_in *str2sa(char *str);

/*
 * converts <str> to two struct in_addr* which must be pre-allocated.
 * The format is "addr[/mask]", where "addr" cannot be empty, and mask
 * is optionnal and either in the dotted or CIDR notation.
 * Note: "addr" can also be a hostname. Returns 1 if OK, 0 if error.
 */
int str2net(const char *str, struct in_addr *addr, struct in_addr *mask);

/*
 * Resolve destination server from URL. Convert <str> to a sockaddr_in*.
 */
int url2sa(const char *url, int ulen, struct sockaddr_in *addr);

/* will try to encode the string <string> replacing all characters tagged in
 * <map> with the hexadecimal representation of their ASCII-code (2 digits)
 * prefixed by <escape>, and will store the result between <start> (included)
 * and <stop> (excluded), and will always terminate the string with a '\0'
 * before <stop>. The position of the '\0' is returned if the conversion
 * completes. If bytes are missing between <start> and <stop>, then the
 * conversion will be incomplete and truncated. If <stop> <= <start>, the '\0'
 * cannot even be stored so we return <start> without writing the 0.
 * The input string must also be zero-terminated.
 */
extern const char hextab[];
char *encode_string(char *start, char *stop,
		    const char escape, const fd_set *map,
		    const char *string);

/* This one is 6 times faster than strtoul() on athlon, but does
 * no check at all.
 */
static inline unsigned int __str2ui(const char *s)
{
	unsigned int i = 0;
	while (*s) {
		i = i * 10 - '0';
		i += (unsigned char)*s++;
	}
	return i;
}

/* This one is 5 times faster than strtoul() on athlon with checks.
 * It returns the value of the number composed of all valid digits read.
 */
static inline unsigned int __str2uic(const char *s)
{
	unsigned int i = 0;
	unsigned int j;
	while (1) {
		j = (*s++) - '0';
		if (j > 9)
			break;
		i *= 10;
		i += j;
	}
	return i;
}

/* This one is 28 times faster than strtoul() on athlon, but does
 * no check at all!
 */
static inline unsigned int __strl2ui(const char *s, int len)
{
	unsigned int i = 0;
	while (len-- > 0) {
		i = i * 10 - '0';
		i += (unsigned char)*s++;
	}
	return i;
}

/* This one is 7 times faster than strtoul() on athlon with checks.
 * It returns the value of the number composed of all valid digits read.
 */
static inline unsigned int __strl2uic(const char *s, int len)
{
	unsigned int i = 0;
	unsigned int j, k;

	while (len-- > 0) {
		j = (*s++) - '0';
		k = i * 10;
		if (j > 9)
			break;
		i = k + j;
	}
	return i;
}

extern unsigned int str2ui(const char *s);
extern unsigned int str2uic(const char *s);
extern unsigned int strl2ui(const char *s, int len);
extern unsigned int strl2uic(const char *s, int len);
extern int strl2ic(const char *s, int len);
extern int strl2irc(const char *s, int len, int *ret);
extern int strl2llrc(const char *s, int len, long long *ret);

/* This function converts the time_t value <now> into a broken out struct tm
 * which must be allocated by the caller. It is highly recommended to use this
 * function intead of localtime() because that one requires a time_t* which
 * is not always compatible with tv_sec depending on OS/hardware combinations.
 */
static inline void get_localtime(const time_t now, struct tm *tm)
{
	localtime_r(&now, tm);
}

/* This function parses a time value optionally followed by a unit suffix among
 * "d", "h", "m", "s", "ms" or "us". It converts the value into the unit
 * expected by the caller. The computation does its best to avoid overflows.
 * The value is returned in <ret> if everything is fine, and a NULL is returned
 * by the function. In case of error, a pointer to the error is returned and
 * <ret> is left untouched.
 */
extern const char *parse_time_err(const char *text, unsigned *ret, unsigned unit_flags);

/* unit flags to pass to parse_time_err */
#define TIME_UNIT_US   0x0000
#define TIME_UNIT_MS   0x0001
#define TIME_UNIT_S    0x0002
#define TIME_UNIT_MIN  0x0003
#define TIME_UNIT_HOUR 0x0004
#define TIME_UNIT_DAY  0x0005
#define TIME_UNIT_MASK 0x0007

/* Multiply the two 32-bit operands and shift the 64-bit result right 32 bits.
 * This is used to compute fixed ratios by setting one of the operands to
 * (2^32*ratio).
 */
static inline unsigned int mul32hi(unsigned int a, unsigned int b)
{
	return ((unsigned long long)a * b) >> 32;
}

#endif /* _COMMON_STANDARD_H */