xsnprintf.c

性能优秀的SIP Proxy

/* ====================================================================
 * $Id: xsnprintf.c,v 1.2 2005/07/01 14:52:33 bogdan_iancu Exp $
 *
 * Copyright (c) 1995-1998 The Apache Group.  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. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * 4. The names "Apache Server" and "Apache Group" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission.
 *
 * 5. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
 * EXPRESSED 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 APACHE GROUP OR
 * ITS CONTRIBUTORS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Group and was originally based
 * on public domain software written at the National Center for
 * Supercomputing Applications, University of Illinois, Urbana-Champaign.
 * For more information on the Apache Group and the Apache HTTP server
 * project, please see <http://www.apache.org/>.
 *
 * This code is based on, and used with the permission of, the
 * SIO stdio-replacement strx_* functions by Panos Tsirigotis
 * <[e-mail]> for xinetd.
 */

#include "xode.h"

#if !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF)

#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#include <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>


#ifdef HAVE_GCVT

#define ap_ecvt ecvt
#define ap_fcvt fcvt
#define ap_gcvt gcvt

#else

/*
* cvt.c - IEEE floating point formatting routines for FreeBSD
* from GNU libc-4.6.27
*/

/*
*    ap_ecvt converts to decimal
*      the number of digits is specified by ndigit
*      decpt is set to the position of the decimal point
*      sign is set to 0 for positive, 1 for negative
*/

#define NDIG    80

static char *
ap_cvt(double arg, int ndigits, int *decpt, int *sign, int eflag)
{
    register int r2;
    double fi, fj;
    register char *p, *p1;
    static char buf[NDIG];

    if (ndigits >= NDIG - 1)
        ndigits = NDIG - 2;
    r2 = 0;
    *sign = 0;
    p = &buf[0];
    if (arg < 0) {
        *sign = 1;
        arg = -arg;
    }
    arg = modf(arg, &fi);
    p1 = &buf[NDIG];
    /*
    * Do integer part
    */
    if (fi != 0) {
        p1 = &buf[NDIG];
        while (fi != 0) {
            fj = modf(fi / 10, &fi);
            *--p1 = (int) ((fj + .03) * 10) + '0';
            r2++;
        }
        while (p1 < &buf[NDIG])
            *p++ = *p1++;
    } else if (arg > 0) {
        while ((fj = arg * 10) < 1) {
            arg = fj;
            r2--;
        }
    }
    p1 = &buf[ndigits];
    if (eflag == 0)
        p1 += r2;
    *decpt = r2;
    if (p1 < &buf[0]) {
        buf[0] = '\0';
        return (buf);
    }
    while (p <= p1 && p < &buf[NDIG]) {
        arg *= 10;
        arg = modf(arg, &fj);
        *p++ = (int) fj + '0';
    }
    if (p1 >= &buf[NDIG]) {
        buf[NDIG - 1] = '\0';
        return (buf);
    }
    p = p1;
    *p1 += 5;
    while (*p1 > '9') {
        *p1 = '0';
        if (p1 > buf)
            ++ * --p1;
        else {
            *p1 = '1';
            (*decpt)++;
            if (eflag == 0) {
                if (p > buf)
                    *p = '0';
                p++;
            }
        }
    }
    *p = '\0';
    return (buf);
}

static char *
ap_ecvt(double arg, int ndigits, int *decpt, int *sign)
{
    return (ap_cvt(arg, ndigits, decpt, sign, 1));
}

static char *
ap_fcvt(double arg, int ndigits, int *decpt, int *sign)
{
    return (ap_cvt(arg, ndigits, decpt, sign, 0));
}

/*
* ap_gcvt  - Floating output conversion to
* minimal length string
*/

static char *
ap_gcvt(double number, int ndigit, char *buf)
{
    int sign, decpt;
    register char *p1, *p2;
    int i;

    p1 = ap_ecvt(number, ndigit, &decpt, &sign);
    p2 = buf;
    if (sign)
        *p2++ = '-';
    for (i = ndigit - 1; i > 0 && p1[i] == '0'; i--)
        ndigit--;
    if ((decpt >= 0 && decpt - ndigit > 4)
            || (decpt < 0 && decpt < -3)) {     /* use E-style */
        decpt--;
        *p2++ = *p1++;
        *p2++ = '.';
        for (i = 1; i < ndigit; i++)
            *p2++ = *p1++;
        *p2++ = 'e';
        if (decpt < 0) {
            decpt = -decpt;
            *p2++ = '-';
        } else
            *p2++ = '+';
        if (decpt / 100 > 0)
            *p2++ = decpt / 100 + '0';
        if (decpt / 10 > 0)
            *p2++ = (decpt % 100) / 10 + '0';
        *p2++ = decpt % 10 + '0';
    } else {
        if (decpt <= 0) {
            if (*p1 != '0')
                *p2++ = '.';
            while (decpt < 0) {
                decpt++;
                *p2++ = '0';
            }
        }
        for (i = 1; i <= ndigit; i++) {
            *p2++ = *p1++;
            if (i == decpt)
                *p2++ = '.';
        }
        if (ndigit < decpt) {
            while (ndigit++ < decpt)
                *p2++ = '0';
            *p2++ = '.';
        }
    }
    if (p2[-1] == '.')
        p2--;
    *p2 = '\0';
    return (buf);
}

#endif                          /* HAVE_CVT */

typedef enum {
    NO = 0, YES = 1
} boolean_e;

#define FALSE           0
#define TRUE            1
#define NUL         '\0'
#define INT_NULL        ((int *)0)
#define WIDE_INT        long

typedef WIDE_INT wide_int;
typedef unsigned WIDE_INT u_wide_int;
typedef int bool_int;

#define S_NULL          "(null)"
#define S_NULL_LEN      6

#define FLOAT_DIGITS        6
#define EXPONENT_LENGTH     10

/*
 * NUM_BUF_SIZE is the size of the buffer used for arithmetic conversions
 *
 * XXX: this is a magic number; do not decrease it
 */
#define NUM_BUF_SIZE        512


/*
 * Descriptor for buffer area
 */
struct buf_area {
    char *buf_end;
    char *nextb;                /* pointer to next byte to read/write   */
};

typedef struct buf_area buffy;

/*
 * The INS_CHAR macro inserts a character in the buffer and writes
 * the buffer back to disk if necessary
 * It uses the char pointers sp and bep:
 *      sp points to the next available character in the buffer
 *      bep points to the end-of-buffer+1
 * While using this macro, note that the nextb pointer is NOT updated.
 *
 * NOTE: Evaluation of the c argument should not have any side-effects
 */
#define INS_CHAR( c, sp, bep, cc )  \
        {               \
        if ( sp < bep )     \
        {           \
            *sp++ = c ;     \
            cc++ ;      \
        }           \
        }

#define NUM( c )            ( c - '0' )

#define STR_TO_DEC( str, num )      \
    num = NUM( *str++ ) ;       \
    while ( isdigit((int)*str ) )       \
    {                   \
    num *= 10 ;         \
    num += NUM( *str++ ) ;      \
    }

/*
 * This macro does zero padding so that the precision
 * requirement is satisfied. The padding is done by
 * adding '0's to the left of the string that is going
 * to be printed.
 */
#define FIX_PRECISION( adjust, precision, s, s_len )    \
    if ( adjust )                   \
    while ( s_len < precision )         \
    {                       \
        *--s = '0' ;                \
        s_len++ ;                   \
    }

/*
 * Macro that does padding. The padding is done by printing
 * the character ch.
 */
#define PAD( width, len, ch )   do      \
    {                   \
        INS_CHAR( ch, sp, bep, cc ) ;   \
        width-- ;               \
    }                   \
    while ( width > len )

/*
 * Prefix the character ch to the string str
 * Increase length
 * Set the has_prefix flag
 */
#define PREFIX( str, length, ch )    *--str = ch ; length++ ; has_prefix = YES


/*
 * Convert num to its decimal format.
 * Return value:
 *   - a pointer to a string containing the number (no sign)
 *   - len contains the length of the string
 *   - is_negative is set to TRUE or FALSE depending on the sign
 *     of the number (always set to FALSE if is_unsigned is TRUE)
 *
 * The caller provides a buffer for the string: that is the buf_end argument
 * which is a pointer to the END of the buffer + 1 (i.e. if the buffer
 * is declared as buf[ 100 ], buf_end should be &buf[ 100 ])
 */
static char *
conv_10(register wide_int num, register bool_int is_unsigned,
        register bool_int * is_negative, char *buf_end, register int *len)
{
    register char *p = buf_end;
    register u_wide_int magnitude;

    if (is_unsigned) {
        magnitude = (u_wide_int) num;
        *is_negative = FALSE;
    } else {
        *is_negative = (num < 0);

        /*
         * On a 2's complement machine, negating the most negative integer 
         * results in a number that cannot be represented as a signed integer.
         * Here is what we do to obtain the number's magnitude:
         *      a. add 1 to the number
         *      b. negate it (becomes positive)
         *      c. convert it to unsigned
         *      d. add 1
         */
        if (*is_negative) {
            wide_int t = num + 1;

            magnitude = ((u_wide_int) - t) + 1;
        } else
            magnitude = (u_wide_int) num;
    }

    /*
     * We use a do-while loop so that we write at least 1 digit 
     */
    do {
        register u_wide_int new_magnitude = magnitude / 10;

        *--p = magnitude - new_magnitude * 10 + '0';
        magnitude = new_magnitude;
    }
    while (magnitude);

    *len = buf_end - p;
    return (p);
}



/*
 * Convert a floating point number to a string formats 'f', 'e' or 'E'.
 * The result is placed in buf, and len denotes the length of the string
 * The sign is returned in the is_negative argument (and is not placed
 * in buf).
 */
static char *
conv_fp(register char format, register double num,
        boolean_e add_dp, int precision, bool_int * is_negative, char *buf, int *len)
{
    register char *s = buf;
    register char *p;
    int decimal_point;

    if (format == 'f')
        p = ap_fcvt(num, precision, &decimal_point, is_negative);
    else                        /* either e or E format */
        p = ap_ecvt(num, precision + 1, &decimal_point, is_negative);

    /*
     * Check for Infinity and NaN
     */
    if (isalpha((int)*p)) {
        *len = strlen(strcpy(buf, p));
        *is_negative = FALSE;
        return (buf);
    }
    if (format == 'f') {
        if (decimal_point <= 0) {
            *s++ = '0';
            if (precision > 0) {
                *s++ = '.';
                while (decimal_point++ < 0)
                    *s++ = '0';
            } else if (add_dp) {
                *s++ = '.';
            }
        } else {
            while (decimal_point-- > 0) {
                *s++ = *p++;
            }
            if (precision > 0 || add_dp) {
                *s++ = '.';
            }
        }
    } else {
        *s++ = *p++;
        if (precision > 0 || add_dp)
            *s++ = '.';
    }

    /*
     * copy the rest of p, the NUL is NOT copied
     */
    while (*p)
        *s++ = *p++;

    if (format != 'f') {
        char temp[EXPONENT_LENGTH];     /* for exponent conversion */
        int t_len;
        bool_int exponent_is_negative;

        *s++ = format;          /* either e or E */
        decimal_point--;
        if (decimal_point != 0) {
            p = conv_10((wide_int) decimal_point, FALSE, &exponent_is_negative,
                        &temp[EXPONENT_LENGTH], &t_len);
            *s++ = exponent_is_negative ? '-' : '+';