switch_mprintf.c

Go to the documentation of this file.

/*
** The "printf" code that follows dates from the 1980's.  It is in
** the public domain.  The original comments are included here for
** completeness.  They are very out-of-date but might be useful as
** an historical reference.  Most of the "enhancements" have been backed
** out so that the functionality is now the same as standard printf().
**
**************************************************************************
**
** The following modules is an enhanced replacement for the "printf" subroutines
** found in the standard C library.  The following enhancements are
** supported:
**
**      +  Additional functions.  The standard set of "printf" functions
**         includes printf, fprintf, sprintf, vprintf, vfprintf, and
**         vsprintf.  This module adds the following:
**
**           *  snprintf -- Works like sprintf, but has an extra argument
**                          which is the size of the buffer written to.
**
**           *  mprintf --  Similar to sprintf.  Writes output to memory
**                          obtained from malloc.
**
**           *  xprintf --  Calls a function to dispose of output.
**
**           *  nprintf --  No output, but returns the number of characters
**                          that would have been output by printf.
**
**           *  A v- version (ex: vsnprintf) of every function is also
**              supplied.
**
**      +  A few extensions to the formatting notation are supported:
**
**           *  The "=" flag (similar to "-") causes the output to be
**              be centered in the appropriately sized field.
**
**           *  The %b field outputs an integer in binary notation.
**
**           *  The %c field now accepts a precision.  The character output
**              is repeated by the number of times the precision specifies.
**
**           *  The %' field works like %c, but takes as its character the
**              next character of the format string, instead of the next
**              argument.  For example,  printf("%.78'-")  prints 78 minus
**              signs, the same as  printf("%.78c",'-').
**
**      +  When compiled using GCC on a SPARC, this version of printf is
**         faster than the library printf for SUN OS 4.1.
**
**      +  All functions are fully reentrant.
**
*/
/*
 * 20090210 (stkn):
 *    Taken from sqlite-3.3.x,
 *    renamed SQLITE_ -> SWITCH_,
 *    renamed visible functions to switch_*
 *    disabled functions without extra conversion specifiers
 */

#include <switch.h>

#define LONGDOUBLE_TYPE long double

/*
** Conversion types fall into various categories as defined by the
** following enumeration.
*/
#define etRADIX       1                 /* Integer types.  %d, %x, %o, and so forth */
#define etFLOAT       2                 /* Floating point.  %f */
#define etEXP         3                 /* Exponentional notation. %e and %E */
#define etGENERIC     4                 /* Floating or exponential, depending on exponent. %g */
#define etSIZE        5                 /* Return number of characters processed so far. %n */
#define etSTRING      6                 /* Strings. %s */
#define etDYNSTRING   7                 /* Dynamically allocated strings. %z */
#define etPERCENT     8                 /* Percent symbol. %% */
#define etCHARX       9                 /* Characters. %c */
/* The rest are extensions, not normally found in printf() */
#define etCHARLIT    10                 /* Literal characters.  %' */
#define etSQLESCAPE  11                 /* Strings with '\'' doubled.  %q */
#define etSQLESCAPE2 12                 /* Strings with '\'' doubled and enclosed in '',
                                                                   NULL pointers replaced by SQL NULL.  %Q */
#ifdef __UNSUPPORTED__
#define etTOKEN      13                 /* a pointer to a Token structure */
#define etSRCLIST    14                 /* a pointer to a SrcList */
#endif
#define etPOINTER    15                 /* The %p conversion */
#define etSQLESCAPE3 16
#define etSQLESCAPE4 17

/*
** An "etByte" is an 8-bit unsigned value.
*/
typedef unsigned char etByte;

/*
** Each builtin conversion character (ex: the 'd' in "%d") is described
** by an instance of the following structure
*/
typedef struct et_info {                /* Information about each format field */
        char fmttype;                           /* The format field code letter */
        etByte base;                            /* The base for radix conversion */
        etByte flags;                           /* One or more of FLAG_ constants below */
        etByte type;                            /* Conversion paradigm */
        etByte charset;                         /* Offset into aDigits[] of the digits string */
        etByte prefix;                          /* Offset into aPrefix[] of the prefix string */
} et_info;

/*
** Allowed values for et_info.flags
*/
#define FLAG_SIGNED  1                  /* True if the value to convert is signed */
#define FLAG_INTERN  2                  /* True if for internal use only */
#define FLAG_STRING  4                  /* Allow infinity precision */


/*
** The following table is searched linearly, so it is good to put the
** most frequently used conversion types first.
*/
static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
static const char aPrefix[] = "-x0\000X0";
static const et_info fmtinfo[] = {
        {'d', 10, 1, etRADIX, 0, 0},
        {'s', 0, 4, etSTRING, 0, 0},
        {'g', 0, 1, etGENERIC, 30, 0},
        {'z', 0, 6, etDYNSTRING, 0, 0},
        {'q', 0, 4, etSQLESCAPE, 0, 0},
        {'Q', 0, 4, etSQLESCAPE2, 0, 0},
        {'w', 0, 4, etSQLESCAPE3, 0, 0},
        {'y', 0, 4, etSQLESCAPE4, 0, 0},
        {'c', 0, 0, etCHARX, 0, 0},
        {'o', 8, 0, etRADIX, 0, 2},
        {'u', 10, 0, etRADIX, 0, 0},
        {'x', 16, 0, etRADIX, 16, 1},
        {'X', 16, 0, etRADIX, 0, 4},
#ifndef SWITCH_OMIT_FLOATING_POINT
        {'f', 0, 1, etFLOAT, 0, 0},
        {'e', 0, 1, etEXP, 30, 0},
        {'E', 0, 1, etEXP, 14, 0},
        {'G', 0, 1, etGENERIC, 14, 0},
#endif
        {'i', 10, 1, etRADIX, 0, 0},
        {'n', 0, 0, etSIZE, 0, 0},
        {'%', 0, 0, etPERCENT, 0, 0},
        {'p', 16, 0, etPOINTER, 0, 1},
#ifdef __UNSUPPORTED__
        {'T', 0, 2, etTOKEN, 0, 0},
        {'S', 0, 2, etSRCLIST, 0, 0},
#endif
};

#define etNINFO  (sizeof(fmtinfo)/sizeof(fmtinfo[0]))

/*
** If SWITCH_OMIT_FLOATING_POINT is defined, then none of the floating point
** conversions will work.
*/
#ifndef SWITCH_OMIT_FLOATING_POINT
/*
** "*val" is a double such that 0.1 <= *val < 10.0
** Return the ascii code for the leading digit of *val, then
** multiply "*val" by 10.0 to renormalize.
**
** Example:
**     input:     *val = 3.14159
**     output:    *val = 1.4159    function return = '3'
**
** The counter *cnt is incremented each time.  After counter exceeds
** 16 (the number of significant digits in a 64-bit float) '0' is
** always returned.
*/
static int et_getdigit(LONGDOUBLE_TYPE * val, int *cnt)
{
        int digit;
        LONGDOUBLE_TYPE d;
        if ((*cnt)++ >= 16)
                return '0';
        digit = (int) *val;
        d = digit;
        digit += '0';
        *val = (*val - d) * 10.0;
        return digit;
}
#endif /* SWITCH_OMIT_FLOATING_POINT */

/*
** On machines with a small stack size, you can redefine the
** SWITCH_PRINT_BUF_SIZE to be less than 350.  But beware - for
** smaller values some %f conversions may go into an infinite loop.
*/
#ifndef SWITCH_PRINT_BUF_SIZE
# define SWITCH_PRINT_BUF_SIZE 350
#endif
#define etBUFSIZE SWITCH_PRINT_BUF_SIZE /* Size of the output buffer */

/*
** The root program.  All variations call this core.
**
** INPUTS:
**   func   This is a pointer to a function taking three arguments
**            1. A pointer to anything.  Same as the "arg" parameter.
**            2. A pointer to the list of characters to be output
**               (Note, this list is NOT null terminated.)
**            3. An integer number of characters to be output.
**               (Note: This number might be zero.)
**
**   arg    This is the pointer to anything which will be passed as the
**          first argument to "func".  Use it for whatever you like.
**
**   fmt    This is the format string, as in the usual print.
**
**   ap     This is a pointer to a list of arguments.  Same as in
**          vfprint.
**
** OUTPUTS:
**          The return value is the total number of characters sent to
**          the function "func".  Returns -1 on a error.
**
** Note that the order in which automatic variables are declared below
** seems to make a big difference in determining how fast this beast
** will run.
*/
static int vxprintf(void (*func) (void *, const char *, int),   /* Consumer of text */
                                        void *arg,      /* First argument to the consumer */
                                        int useExtended,        /* Allow extended %-conversions */
                                        const char *fmt,        /* Format string */
                                        va_list ap      /* arguments */
        )
{
        int c;                                          /* Next character in the format string */
        char *bufpt;                            /* Pointer to the conversion buffer */
        int precision;                          /* Precision of the current field */
        int length;                                     /* Length of the field */
        int idx;                                        /* A general purpose loop counter */
        int count;                                      /* Total number of characters output */
        int width;                                      /* Width of the current field */
        etByte flag_leftjustify;        /* True if "-" flag is present */
        etByte flag_plussign;           /* True if "+" flag is present */
        etByte flag_blanksign;          /* True if " " flag is present */
        etByte flag_alternateform;      /* True if "#" flag is present */
        etByte flag_altform2;           /* True if "!" flag is present */
        etByte flag_zeropad;            /* True if field width constant starts with zero */
        etByte flag_long;                       /* True if "l" flag is present */
        etByte flag_longlong;           /* True if the "ll" flag is present */
        etByte done;                            /* Loop termination flag */
        uint64_t longvalue;                     /* Value for integer types */
        LONGDOUBLE_TYPE realvalue;      /* Value for real types */
        const et_info *infop;           /* Pointer to the appropriate info structure */
        char buf[etBUFSIZE];            /* Conversion buffer */
        char prefix;                            /* Prefix character.  "+" or "-" or " " or '\0'. */
        etByte errorflag = 0;           /* True if an error is encountered */
        etByte xtype = 0;                       /* Conversion paradigm */
        char *zExtra;                           /* Extra memory used for etTCLESCAPE conversions */
        static const char spaces[] = "                                                                         ";
#define etSPACESIZE (sizeof(spaces)-1)
#ifndef SWITCH_OMIT_FLOATING_POINT
        int exp, e2;                            /* exponent of real numbers */
        double rounder;                         /* Used for rounding floating point values */
        etByte flag_dp;                         /* True if decimal point should be shown */
        etByte flag_rtz;                        /* True if trailing zeros should be removed */
        etByte flag_exp;                        /* True to force display of the exponent */
        int nsd;                                        /* Number of significant digits returned */
#endif

        func(arg, "", 0);
        count = length = 0;
        bufpt = 0;
        for (; (c = (*fmt)) != 0; ++fmt) {
                if (c != '%') {
                        int amt;
                        bufpt = (char *) fmt;
                        amt = 1;
                        while ((c = (*++fmt)) != '%' && c != 0)
                                amt++;
                        (*func) (arg, bufpt, amt);
                        count += amt;
                        if (c == 0)
                                break;
                }
                if ((c = (*++fmt)) == 0) {
                        errorflag = 1;
                        (*func) (arg, "%", 1);
                        count++;
                        break;
                }
                /* Find out what flags are present */
                flag_leftjustify = flag_plussign = flag_blanksign = flag_alternateform = flag_altform2 = flag_zeropad = 0;
                done = 0;
                do {
                        switch (c) {
                        case '-':
                                flag_leftjustify = 1;
                                break;
                        case '+':
                                flag_plussign = 1;
                                break;
                        case ' ':
                                flag_blanksign = 1;
                                break;
                        case '#':
                                flag_alternateform = 1;
                                break;
                        case '!':
                                flag_altform2 = 1;
                                break;
                        case '0':
                                flag_zeropad = 1;
                                break;
                        default:
                                done = 1;
                                break;
                        }
                } while (!done && (c = (*++fmt)) != 0);
                /* Get the field width */
                width = 0;
                if (c == '*') {
                        width = va_arg(ap, int);
                        if (width < 0) {
                                flag_leftjustify = 1;
                                width = -width;
                        }
                        c = *++fmt;
                } else {
                        while (c >= '0' && c <= '9') {
                                width = width * 10 + c - '0';
                                c = *++fmt;
                        }
                }
                if (width > etBUFSIZE - 10) {
                        width = etBUFSIZE - 10;
                }
                /* Get the precision */
                if (c == '.') {
                        precision = 0;
                        c = *++fmt;
                        if (c == '*') {
                                precision = va_arg(ap, int);
                                if (precision < 0)
                                        precision = -precision;
                                c = *++fmt;
                        } else {
                                while (c >= '0' && c <= '9') {
                                        precision = precision * 10 + c - '0';
                                        c = *++fmt;
                                }
                        }
                } else {
                        precision = -1;
                }
                /* Get the conversion type modifier */
                if (c == 'l') {
                        flag_long = 1;
                        c = *++fmt;
                        if (c == 'l') {
                                flag_longlong = 1;
                                c = *++fmt;
                        } else {
                                flag_longlong = 0;
                        }
                } else {
                        flag_long = flag_longlong = 0;
                }
                /* Fetch the info entry for the field */
                infop = 0;
                for (idx = 0; idx < etNINFO; idx++) {
                        if (c == fmtinfo[idx].fmttype) {
                                infop = &fmtinfo[idx];
                                if (useExtended || (infop->flags & FLAG_INTERN) == 0) {
                                        xtype = infop->type;
                                } else {
                                        return -1;
                                }
                                break;
                        }
                }
                zExtra = 0;
                if (infop == 0) {
                        return -1;
                }


                /* Limit the precision to prevent overflowing buf[] during conversion */
                if (precision > etBUFSIZE - 40 && (infop->flags & FLAG_STRING) == 0) {
                        precision = etBUFSIZE - 40;
                }

                /*
                 ** At this point, variables are initialized as follows:
                 **
                 **   flag_alternateform          TRUE if a '#' is present.
                 **   flag_altform2               TRUE if a '!' is present.
                 **   flag_plussign               TRUE if a '+' is present.
                 **   flag_leftjustify            TRUE if a '-' is present or if the
                 **                               field width was negative.
                 **   flag_zeropad                TRUE if the width began with 0.
                 **   flag_long                   TRUE if the letter 'l' (ell) prefixed
                 **                               the conversion character.
                 **   flag_longlong               TRUE if the letter 'll' (ell ell) prefixed
                 **                               the conversion character.
                 **   flag_blanksign              TRUE if a ' ' is present.
                 **   width                       The specified field width.  This is
                 **                               always non-negative.  Zero is the default.
                 **   precision                   The specified precision.  The default
                 **                               is -1.
                 **   xtype                       The class of the conversion.
                 **   infop                       Pointer to the appropriate info struct.
                 */
                switch (xtype) {
                case etPOINTER:
                        flag_longlong = sizeof(char *) == sizeof(int64_t);
                        flag_long = sizeof(char *) == sizeof(long int);
                        /* Fall through into the next case */
                case etRADIX:
                        if (infop->flags & FLAG_SIGNED) {
                                int64_t v;
                                if (flag_longlong)
                                        v = va_arg(ap, int64_t);
                                else if (flag_long)
                                        v = va_arg(ap, long int);
                                else
                                        v = va_arg(ap, int);
                                if (v < 0) {
                                        longvalue = -v;
                                        prefix = '-';
                                } else {
                                        longvalue = v;
                                        if (flag_plussign)
                                                prefix = '+';
                                        else if (flag_blanksign)
                                                prefix = ' ';
                                        else
                                                prefix = 0;
                                }
                        } else {
                                if (flag_longlong)
                                        longvalue = va_arg(ap, uint64_t);
                                else if (flag_long)
                                        longvalue = va_arg(ap, unsigned long int);
                                else
                                        longvalue = va_arg(ap, unsigned int);
                                prefix = 0;
                        }
                        if (longvalue == 0)
                                flag_alternateform = 0;
                        if (flag_zeropad && precision < width - (prefix != 0)) {
                                precision = width - (prefix != 0);
                        }
                        bufpt = &buf[etBUFSIZE - 1];
                        {
                                register const char *cset;      /* Use registers for speed */
                                register int base;
                                cset = &aDigits[infop->charset];
                                base = infop->base;
                                do {                    /* Convert to ascii */
                                        *(--bufpt) = cset[longvalue % base];
                                        longvalue = longvalue / base;
                                } while (longvalue > 0);
                        }
                        length = (int)(&buf[etBUFSIZE - 1] - bufpt);
                        for (idx = precision - length; idx > 0; idx--) {
                                *(--bufpt) = '0';       /* Zero pad */
                        }
                        if (prefix)
                                *(--bufpt) = prefix;    /* Add sign */
                        if (flag_alternateform && infop->prefix) {      /* Add "0" or "0x" */
                                const char *pre;
                                char x;
                                pre = &aPrefix[infop->prefix];
                                if (*bufpt != pre[0]) {
                                        for (; (x = (*pre)) != 0; pre++)
                                                *(--bufpt) = x;
                                }
                        }
                        length = (int)(&buf[etBUFSIZE - 1] - bufpt);
                        break;
                case etFLOAT:
                case etEXP:
                case etGENERIC:
                        realvalue = va_arg(ap, double);
#ifndef SWITCH_OMIT_FLOATING_POINT
                        if (precision < 0)
                                precision = 6;  /* Set default precision */
                        if (precision > etBUFSIZE / 2 - 10)
                                precision = etBUFSIZE / 2 - 10;
                        if (realvalue < 0.0) {
                                realvalue = -realvalue;
                                prefix = '-';
                        } else {
                                if (flag_plussign)
                                        prefix = '+';
                                else if (flag_blanksign)
                                        prefix = ' ';
                                else
                                        prefix = 0;
                        }
                        if (xtype == etGENERIC && precision > 0)
                                precision--;
#if 0
                        /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
                        for (idx = precision, rounder = 0.4999; idx > 0; idx--, rounder *= 0.1);
#else
                        /* It makes more sense to use 0.5 */
                        for (idx = precision, rounder = 0.5; idx > 0; idx--, rounder *= 0.1) {
                        }
#endif
                        if (xtype == etFLOAT)
                                realvalue += rounder;
                        /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
                        exp = 0;
                        if (realvalue > 0.0) {
                                while (realvalue >= 1e32 && exp <= 350) {
                                        realvalue *= 1e-32;
                                        exp += 32;
                                }
                                while (realvalue >= 1e8 && exp <= 350) {
                                        realvalue *= 1e-8;
                                        exp += 8;
                                }
                                while (realvalue >= 10.0 && exp <= 350) {
                                        realvalue *= 0.1;
                                        exp++;
                                }
                                while (realvalue < 1e-8 && exp >= -350) {
                                        realvalue *= 1e8;
                                        exp -= 8;
                                }
                                while (realvalue < 1.0 && exp >= -350) {
                                        realvalue *= 10.0;
                                        exp--;
                                }
                                if (exp > 350 || exp < -350) {
                                        bufpt = "NaN";
                                        length = 3;
                                        break;
                                }
                        }
                        bufpt = buf;
                        /*
                         ** If the field type is etGENERIC, then convert to either etEXP
                         ** or etFLOAT, as appropriate.
                         */
                        flag_exp = xtype == etEXP;
                        if (xtype != etFLOAT) {
                                realvalue += rounder;
                                if (realvalue >= 10.0) {
                                        realvalue *= 0.1;
                                        exp++;
                                }
                        }
                        if (xtype == etGENERIC) {
                                flag_rtz = !flag_alternateform;
                                if (exp < -4 || exp > precision) {
                                        xtype = etEXP;
                                } else {
                                        precision = precision - exp;
                                        xtype = etFLOAT;
                                }
                        } else {
                                flag_rtz = 0;
                        }
                        if (xtype == etEXP) {
                                e2 = 0;
                        } else {
                                e2 = exp;
                        }
                        nsd = 0;
                        flag_dp = (precision > 0) | flag_alternateform | flag_altform2;
                        /* The sign in front of the number */
                        if (prefix) {
                                *(bufpt++) = prefix;
                        }
                        /* Digits prior to the decimal point */
                        if (e2 < 0) {
                                *(bufpt++) = '0';
                        } else {
                                for (; e2 >= 0; e2--) {
                                        *(bufpt++) = (char) et_getdigit(&realvalue, &nsd);
                                }
                        }
                        /* The decimal point */
                        if (flag_dp) {
                                *(bufpt++) = '.';
                        }
                        /* "0" digits after the decimal point but before the first
                         ** significant digit of the number */
                        for (e2++; e2 < 0 && precision > 0; precision--, e2++) {
                                *(bufpt++) = '0';
                        }
                        /* Significant digits after the decimal point */
                        while ((precision--) > 0) {
                                *(bufpt++) = (char) et_getdigit(&realvalue, &nsd);
                        }
                        /* Remove trailing zeros and the "." if no digits follow the "." */
                        if (flag_rtz && flag_dp) {
                                while (bufpt[-1] == '0')
                                        *(--bufpt) = 0;
                                assert(bufpt > buf);
                                if (bufpt[-1] == '.') {
                                        if (flag_altform2) {
                                                *(bufpt++) = '0';
                                        } else {
                                                *(--bufpt) = 0;
                                        }
                                }
                        }
                        /* Add the "eNNN" suffix */
                        if (flag_exp || (xtype == etEXP && exp)) {
                                *(bufpt++) = aDigits[infop->charset];
                                if (exp < 0) {
                                        *(bufpt++) = '-';
                                        exp = -exp;
                                } else {
                                        *(bufpt++) = '+';
                                }
                                if (exp >= 100) {
                                        *(bufpt++) = (char) (exp / 100) + '0';  /* 100's digit */
                                        exp %= 100;
                                }
                                *(bufpt++) = (char) exp / 10 + '0';     /* 10's digit */
                                *(bufpt++) = exp % 10 + '0';    /* 1's digit */
                        }
                        *bufpt = 0;

                        /* The converted number is in buf[] and zero terminated. Output it.
                         ** Note that the number is in the usual order, not reversed as with
                         ** integer conversions. */
                        length = (int)(bufpt - buf);
                        bufpt = buf;

                        /* Special case:  Add leading zeros if the flag_zeropad flag is
                         ** set and we are not left justified */
                        if (flag_zeropad && !flag_leftjustify && length < width) {
                                int i;
                                int nPad = width - length;
                                for (i = width; i >= nPad; i--) {
                                        bufpt[i] = bufpt[i - nPad];
                                }
                                i = prefix != 0;
                                while (nPad--)
                                        bufpt[i++] = '0';
                                length = width;
                        }
#endif
                        break;
                case etSIZE:
                        *(va_arg(ap, int *)) = count;
                        length = width = 0;
                        break;
                case etPERCENT:
                        buf[0] = '%';
                        bufpt = buf;
                        length = 1;
                        break;
                case etCHARLIT:
                case etCHARX:
                        c = buf[0] = (char) (xtype == etCHARX ? va_arg(ap, int) : *++fmt);
                        if (precision >= 0) {
                                for (idx = 1; idx < precision; idx++)
                                        buf[idx] = (char) c;
                                length = precision;
                        } else {
                                length = 1;
                        }
                        bufpt = buf;
                        break;
                case etSTRING:
                case etDYNSTRING:
                        bufpt = va_arg(ap, char *);
                        if (bufpt == 0) {
                                bufpt = "";
                        } else if (xtype == etDYNSTRING) {
                                zExtra = bufpt;
                        }
                        length = (int)strlen(bufpt);
                        if (precision >= 0 && precision < length)
                                length = precision;
                        break;
                case etSQLESCAPE:
                case etSQLESCAPE2:
                case etSQLESCAPE4:
                case etSQLESCAPE3:{
                                int i, j, n, ch, isnull;
                                int needQuote;
                                char *escarg = va_arg(ap, char *);
                                isnull = escarg == 0;
                                if (isnull)
                                        escarg = (xtype == etSQLESCAPE2 ? "NULL" : "(NULL)");
                                for (i = n = 0; (ch = escarg[i]) != 0; i++) {
                                        if (ch == '\'' || (xtype == etSQLESCAPE3 && ch == '\\'))
                                                n++;
                                }
                                needQuote = !isnull && xtype == etSQLESCAPE2;
                                n += i + 1 + needQuote * 2;
                                if (n > etBUFSIZE) {
                                        bufpt = zExtra = malloc(n);
                                        if (bufpt == 0)
                                                return -1;
                                } else {
                                        bufpt = buf;
                                }
                                j = 0;
                                if (needQuote) 
                                        bufpt[j++] = '\'';
                                for (i = 0; (ch = escarg[i]) != 0; i++) {
                                        bufpt[j++] = (char) ch;
                                        if (xtype == etSQLESCAPE4) {
                                                if (ch == '\'' || (xtype == etSQLESCAPE3 && ch == '\\')) {
                                                        bufpt[j] = (char) ch;
                                                        bufpt[j-1] = (char) '\\';
                                                        j++;
                                                }
                                        } else {
                                                if (ch == '\'' || (xtype == etSQLESCAPE3 && ch == '\\'))
                                                        bufpt[j++] = (char) ch;
                                        }
                                }
                                if (needQuote)
                                        bufpt[j++] = '\'';
                                bufpt[j] = 0;
                                length = j;
                                /* The precision is ignored on %q and %Q */
                                /* if ( precision>=0 && precision<length ) length = precision; */
                                break;
                        }
#ifdef __UNSUPPORTED__
                case etTOKEN:{
                                Token *pToken = va_arg(ap, Token *);
                                if (pToken && pToken->z) {
                                        (*func) (arg, (char *) pToken->z, pToken->n);
                                }
                                length = width = 0;
                                break;
                        }
                case etSRCLIST:{
                                SrcList *pSrc = va_arg(ap, SrcList *);
                                int k = va_arg(ap, int);
                                struct SrcList_item *pItem = &pSrc->a[k];
                                assert(k >= 0 && k < pSrc->nSrc);
                                if (pItem->zDatabase && pItem->zDatabase[0]) {
                                        (*func) (arg, pItem->zDatabase, strlen(pItem->zDatabase));
                                        (*func) (arg, ".", 1);
                                }
                                (*func) (arg, pItem->zName, strlen(pItem->zName));
                                length = width = 0;
                                break;
                        }
#endif
                }                                               /* End switch over the format type */
                /*
                 ** The text of the conversion is pointed to by "bufpt" and is
                 ** "length" characters long.  The field width is "width".  Do
                 ** the output.
                 */
                if (!flag_leftjustify) {
                        register int nspace;
                        nspace = width - length;
                        if (nspace > 0) {
                                count += nspace;
                                while (nspace >= etSPACESIZE) {
                                        (*func) (arg, spaces, etSPACESIZE);
                                        nspace -= etSPACESIZE;
                                }
                                if (nspace > 0)
                                        (*func) (arg, spaces, nspace);
                        }
                }
                if (length > 0) {
                        (*func) (arg, bufpt, length);
                        count += length;
                }
                if (flag_leftjustify) {
                        register int nspace;
                        nspace = width - length;
                        if (nspace > 0) {
                                count += nspace;
                                while (nspace >= etSPACESIZE) {
                                        (*func) (arg, spaces, etSPACESIZE);
                                        nspace -= etSPACESIZE;
                                }
                                if (nspace > 0)
                                        (*func) (arg, spaces, nspace);
                        }
                }
                if (zExtra) {
                        free(zExtra);
                }
        }                                                       /* End for loop over the format string */
        return errorflag ? -1 : count;
}                                                               /* End of function */


/* This structure is used to store state information about the
** write to memory that is currently in progress.
*/
struct sgMprintf {
        char *zBase;                            /* A base allocation */
        char *zText;                            /* The string collected so far */
        int nChar;                                      /* Length of the string so far */
        int nTotal;                                     /* Output size if unconstrained */
        int nAlloc;                                     /* Amount of space allocated in zText */
        void *(*xRealloc) (void *, int);        /* Function used to realloc memory */
};

/*
** This function implements the callback from vxprintf.
**
** This routine add nNewChar characters of text in zNewText to
** the sgMprintf structure pointed to by "arg".
*/
static void mout(void *arg, const char *zNewText, int nNewChar)
{
        struct sgMprintf *pM = (struct sgMprintf *) arg;
        pM->nTotal += nNewChar;
        if (pM->nChar + nNewChar + 1 > pM->nAlloc) {
                if (pM->xRealloc == 0) {
                        nNewChar = pM->nAlloc - pM->nChar - 1;
                } else {
                        pM->nAlloc = pM->nChar + nNewChar * 2 + 1;
                        if (pM->zText == pM->zBase) {
                                pM->zText = pM->xRealloc(0, pM->nAlloc);
                                if (pM->zText && pM->nChar) {
                                        memcpy(pM->zText, pM->zBase, pM->nChar);
                                }
                        } else {
                                char *zNew;
                                zNew = pM->xRealloc(pM->zText, pM->nAlloc);
                                if (zNew) {
                                        pM->zText = zNew;
                                }
                        }
                }
        }
        if (pM->zText) {
                if (nNewChar > 0) {
                        memcpy(&pM->zText[pM->nChar], zNewText, nNewChar);
                        pM->nChar += nNewChar;
                }
                pM->zText[pM->nChar] = 0;
        }
}

/*
** This routine is a wrapper around xprintf() that invokes mout() as
** the consumer.
*/
static char *base_vprintf(void *(*xRealloc) (void *, int),      /* Routine to realloc memory. May be NULL */
                                                  int useInternal,      /* Use internal %-conversions if true */
                                                  char *zInitBuf,       /* Initially write here, before mallocing */
                                                  int nInitBuf, /* Size of zInitBuf[] */
                                                  const char *zFormat,  /* format string */
                                                  va_list ap    /* arguments */
        )
{
        struct sgMprintf sM;
        sM.zBase = sM.zText = zInitBuf;
        sM.nChar = sM.nTotal = 0;
        sM.nAlloc = nInitBuf;
        sM.xRealloc = xRealloc;
        vxprintf(mout, &sM, useInternal, zFormat, ap);
        if (xRealloc) {
                if (sM.zText == sM.zBase) {
                        sM.zText = xRealloc(0, sM.nChar + 1);
                        if (sM.zText) {
                                memcpy(sM.zText, sM.zBase, sM.nChar + 1);
                        }
                } else if (sM.nAlloc > sM.nChar + 10) {
                        char *zNew = xRealloc(sM.zText, sM.nChar + 1);
                        if (zNew) {
                                sM.zText = zNew;
                        }
                }
        }
        return sM.zText;
}

/*
** Realloc that is a real function, not a macro.
*/
static void *printf_realloc(void *old, int size)
{
        return realloc(old, size);
}

/*
** Print into memory. Omit the internal %-conversion extensions.
*/
SWITCH_DECLARE(char *) switch_vmprintf(const char *zFormat, va_list ap)
{
        char zBase[SWITCH_PRINT_BUF_SIZE];
        return base_vprintf(printf_realloc, 0, zBase, sizeof(zBase), zFormat, ap);
}

/*
** Print into memory.  Omit the internal %-conversion extensions.
*/
SWITCH_DECLARE(char *) switch_mprintf(const char *zFormat, ...)
{
        va_list ap;
        char *z;
        char zBase[SWITCH_PRINT_BUF_SIZE];
        va_start(ap, zFormat);
        z = base_vprintf(printf_realloc, 0, zBase, sizeof(zBase), zFormat, ap);
        va_end(ap);
        return z;
}

/*
** sqlite3_snprintf() works like snprintf() except that it ignores the
** current locale settings.  This is important for SQLite because we
** are not able to use a "," as the decimal point in place of "." as
** specified by some locales.
*/
SWITCH_DECLARE(char *) switch_snprintfv(char *zBuf, int n, const char *zFormat, ...)
{
        char *z;
        va_list ap;

        va_start(ap, zFormat);
        z = base_vprintf(0, 0, zBuf, n, zFormat, ap);
        va_end(ap);
        return z;
}

/* For Emacs:
 * Local Variables:
 * mode:c
 * indent-tabs-mode:t
 * tab-width:4
 * c-basic-offset:4
 * End:
 * For VIM:
 * vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
 */