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/*

 * Copyright (c) 2001-2004 Jakub Jermar

 * Copyright (c) 2006 Josef Cejka

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - 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.

 * - 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.

 */

/** @addtogroup libc

 * @{

 */

/**

 * @file

 * @brief	Printing functions.

 */

#include <unistd.h>

#include <stdio.h>

#include <io/printf_core.h>

#include <ctype.h>

#include <string.h>

#define __PRINTF_FLAG_PREFIX		0x00000001	/**< show prefixes 0x or 0*/

#define __PRINTF_FLAG_SIGNED		0x00000002	/**< signed / unsigned number */

#define __PRINTF_FLAG_ZEROPADDED	0x00000004	/**< print leading zeroes */

#define __PRINTF_FLAG_LEFTALIGNED	0x00000010	/**< align to left */

#define __PRINTF_FLAG_SHOWPLUS		0x00000020	/**< always show + sign */

#define __PRINTF_FLAG_SPACESIGN		0x00000040	/**< print space instead of plus */

#define __PRINTF_FLAG_BIGCHARS		0x00000080	/**< show big characters */

#define __PRINTF_FLAG_NEGATIVE		0x00000100	/**< number has - sign */

#define PRINT_NUMBER_BUFFER_SIZE	(64+5)		/**< Buffer big enought for 64 bit number

							 * printed in base 2, sign, prefix and

							 * 0 to terminate string.. (last one is only for better testing 

							 * end of buffer by zero-filling subroutine)

							 */

/** Enumeration of possible arguments types.

 */

typedef enum {

	PrintfQualifierByte = 0,

	PrintfQualifierShort,

	PrintfQualifierInt,

	PrintfQualifierLong,

	PrintfQualifierLongLong,

	PrintfQualifierSizeT,

	PrintfQualifierPointer

} qualifier_t;

static char digits_small[] = "0123456789abcdef";	/**< Small hexadecimal characters */

static char digits_big[] = "0123456789ABCDEF";		/**< Big hexadecimal characters */

/** Print count chars from buffer without adding newline

 * @param buf Buffer with size at least count bytes - NULL pointer NOT allowed!

 * @param count 

 * @param ps output method and its data

 * @return number of printed characters

 */

static int printf_putnchars(const char * buf, size_t count, struct printf_spec *ps)

{

	return ps->write((void *)buf, count, ps->data);

}

/** Print string without added newline

 * @param str string to print

 * @param ps write function specification and support data

 * @return number of printed characters

 */

static int printf_putstr(const char * str, struct printf_spec *ps)

{

	size_t count;

	if (str == NULL)

		return printf_putnchars("(NULL)", 6, ps);

	for (count = 0; str[count] != 0; count++);

	if (ps->write((void *) str, count, ps->data) == count)

		return 0;

	return EOF;

}

/** Print one character to output

 * @param c one character

 * @param ps output method

 * @return number of printed characters

 */

static int printf_putchar(int c, struct printf_spec *ps)

{

	unsigned char ch = c;

	return ps->write((void *) &ch, 1, ps->data);

}

/** Print one formatted character

 * @param c character to print

 * @param width 

 * @param flags

 * @return number of printed characters

 */

static int print_char(char c, int width, uint64_t flags, struct printf_spec *ps)

{

	int counter = 0;

	if (!(flags & __PRINTF_FLAG_LEFTALIGNED)) {

		while (--width > 0) { 	/* one space is consumed by character itself hence predecrement */

			if (printf_putchar(' ', ps) > 0)	

				++counter;

		}

	}

	if (printf_putchar(c, ps) > 0)

		counter++;

	while (--width > 0) { /* one space is consumed by character itself hence predecrement */

		if (printf_putchar(' ', ps) > 0)

			++counter;

	}

	return ++counter;

}

/** Print one string

 * @param s string

 * @param width 

 * @param precision

 * @param flags

 * @return number of printed characters

 */

static int print_string(char *s, int width, int precision, uint64_t flags, struct printf_spec *ps)

{

	int counter = 0;

	size_t size;

	int retval;

	if (s == NULL) {

		return printf_putstr("(NULL)", ps);

	}

	size = strlen(s);

	/* print leading spaces */

	if (precision == 0) 

		precision = size;

	width -= precision;

	if (!(flags & __PRINTF_FLAG_LEFTALIGNED)) {

		while (width-- > 0) { 	

			if (printf_putchar(' ', ps) == 1)	

				counter++;

		}

	}

	while (precision > size) {

		precision--;

		if (printf_putchar(' ', ps) == 1)	

			++counter;

	}

 	if ((retval = printf_putnchars(s, precision, ps)) < 0) {

		return -counter;

	}

	counter += retval;	

	while (width-- > 0) {

		if (printf_putchar(' ', ps) == 1)	

			++counter;

	}

	return counter;

}

/** Print number in given base

 *

 * Print significant digits of a number in given

 * base.

 *

 * @param num  Number to print.

 * @param width

 * @param precision

 * @param base Base to print the number in (should

 *             be in range 2 .. 16).

 * @param flags output modifiers

 * @return number of printed characters

 *

 */

static int print_number(uint64_t num, int width, int precision, int base , uint64_t flags, struct printf_spec *ps)

{

	char *digits = digits_small;

	char d[PRINT_NUMBER_BUFFER_SIZE];	/* this is good enough even for base == 2, prefix and sign */

	char *ptr = &d[PRINT_NUMBER_BUFFER_SIZE - 1];

	int size = 0; /* size of number with all prefixes and signs */

	int number_size; /* size of plain number */

	char sgn;

	int retval;

	int counter = 0;

	if (flags & __PRINTF_FLAG_BIGCHARS) 

		digits = digits_big;	

	*ptr-- = 0; /* Put zero at end of string */

	if (num == 0) {

		*ptr-- = '0';

		size++;

	} else {

		do {

			*ptr-- = digits[num % base];

			size++;

		} while (num /= base);

	}

	number_size = size;

	/* Collect sum of all prefixes/signs/... to calculate padding and leading zeroes */

	if (flags & __PRINTF_FLAG_PREFIX) {

		switch(base) {

		case 2:	/* Binary formating is not standard, but usefull */

			size += 2;

			break;

		case 8:

			size++;

			break;

		case 16:

			size += 2;

			break;

		}

	}

	sgn = 0;

	if (flags & __PRINTF_FLAG_SIGNED) {

		if (flags & __PRINTF_FLAG_NEGATIVE) {

			sgn = '-';

			size++;

		} else if (flags & __PRINTF_FLAG_SHOWPLUS) {

				sgn = '+';

				size++;

			} else if (flags & __PRINTF_FLAG_SPACESIGN) {

					sgn = ' ';

					size++;

				}

	}

	if (flags & __PRINTF_FLAG_LEFTALIGNED) {

		flags &= ~__PRINTF_FLAG_ZEROPADDED;

	}

	/* if number is leftaligned or precision is specified then zeropadding is ignored */

	if (flags & __PRINTF_FLAG_ZEROPADDED) {

		if ((precision == 0) && (width > size)) {

			precision = width - size + number_size;

		}

	}

	/* print leading spaces */

	if (number_size > precision) /* We must print whole number not only a part */

		precision = number_size;

	width -= precision + size - number_size;

	if (!(flags & __PRINTF_FLAG_LEFTALIGNED)) {

		while (width-- > 0) { 	

			if (printf_putchar(' ', ps) == 1)	

				counter++;

		}

	}

	/* print sign */

	if (sgn) {

		if (printf_putchar(sgn, ps) == 1)

			counter++;

	}

	/* print prefix */

	if (flags & __PRINTF_FLAG_PREFIX) {

		switch(base) {

		case 2:	/* Binary formating is not standard, but usefull */

			if (printf_putchar('0', ps) == 1)

				counter++;

			if (flags & __PRINTF_FLAG_BIGCHARS) {

				if (printf_putchar('B', ps) == 1)

					counter++;

			} else {

				if (printf_putchar('b', ps) == 1)

					counter++;

			}

			break;

		case 8:

			if (printf_putchar('o', ps) == 1)

				counter++;

			break;

		case 16:

			if (printf_putchar('0', ps) == 1)

				counter++;

			if (flags & __PRINTF_FLAG_BIGCHARS) {

				if (printf_putchar('X', ps) == 1)

					counter++;

			} else {

				if (printf_putchar('x', ps) == 1)

					counter++;

			}

			break;

		}

	}

	/* print leading zeroes */

	precision -= number_size;

	while (precision-- > 0) { 	

		if (printf_putchar('0', ps) == 1)

			counter++;

	}

	/* print number itself */

	if ((retval = printf_putstr(++ptr, ps)) > 0) {

		counter += retval;

	}

	/* print ending spaces */

	while (width-- > 0) { 	

		if (printf_putchar(' ', ps) == 1)	

			counter++;

	}

	return counter;

}

/** Print formatted string.

 *

 * Print string formatted according to the fmt parameter

 * and variadic arguments. Each formatting directive

 * must have the following form:

 * 

 * 	\% [ FLAGS ] [ WIDTH ] [ .PRECISION ] [ TYPE ] CONVERSION

 *

 * FLAGS:@n

 * 	- "#" Force to print prefix.

 * 	For conversion \%o the prefix is 0, for %x and \%X prefixes are 0x and 0X

 *	and for conversion \%b the prefix is 0b.

 *

 * 	- "-"	Align to left.

 *

 * 	- "+"	Print positive sign just as negative.

 *

 * 	- " "	If the printed number is positive and "+" flag is not set, print space in

 *	place of sign.

 *

 * 	- "0"	Print 0 as padding instead of spaces. Zeroes are placed between sign and the

 *	rest of the number. This flag is ignored if "-" flag is specified.

 * 

 * WIDTH:@n

 * 	- Specify minimal width of printed argument. If it is bigger, width is ignored.

 * If width is specified with a "*" character instead of number, width is taken from

 * parameter list. And integer parameter is expected before parameter for processed

 * conversion specification. If this value is negative its absolute value is taken

 * and the "-" flag is set.

 *

 * PRECISION:@n

 * 	- Value precision. For numbers it specifies minimum valid numbers.

 * Smaller numbers are printed with leading zeroes. Bigger numbers are not affected.

 * Strings with more than precision characters are cut off.

 * Just as with width, an "*" can be used used instead of a number.

 * An integer value is then expected in parameters. When both width and precision

 * are specified using "*", the first parameter is used for width and the second one

 * for precision.

 * 

 * TYPE:@n

 * 	- "hh"	Signed or unsigned char.@n

 * 	- "h"	Signed or usigned short.@n

 * 	- ""	Signed or usigned int (default value).@n

 * 	- "l"	Signed or usigned long int.@n

 * 	- "ll"	Signed or usigned long long int.@n

 * 	- "z"	Type size_t.@n

 * 

 * 

 * CONVERSION:@n

 * 	- %	Print percentile character itself.

 *

 * 	- c	Print single character.

 *

 * 	- s	Print zero terminated string. If a NULL value is passed as value, "(NULL)" is printed instead.

 * 

 * 	- P, p	Print value of a pointer. Void * value is expected and it is printed in hexadecimal notation with prefix

 * 	(as with '\%#X' or '\%#x' for 32bit or '\%#X' or '\%#x' for 64bit long pointers).

 *

 * 	- b	Print value as unsigned binary number. Prefix is not printed by default. (Nonstandard extension.)

 * 

 * 	- o	Print value as unsigned octal number. Prefix is not printed by default. 

 *

 * 	- d,i	Print signed decimal number. There is no difference between d and i conversion.

 *

 * 	- u	Print unsigned decimal number.

 *

 * 	- X, x	Print hexadecimal number with upper- or lower-case. Prefix is not printed by default.

 * 

 * All other characters from fmt except the formatting directives

 * are printed in verbatim.

 *

 * @param fmt Formatting NULL terminated string.

 * @return Number of printed characters or negative value on failure.

 */

int printf_core(const char *fmt, struct printf_spec *ps, va_list ap)

{

	int i = 0, j = 0; /* i is index of currently processed char from fmt, j is index to the first not printed nonformating character */

	int end;

	int counter; /* counter of printed characters */

	int retval; /* used to store return values from called functions */

	char c;

	qualifier_t qualifier;	/* type of argument */

	int base;	/* base in which will be parameter (numbers only) printed */

	uint64_t number; /* argument value */

	size_t	size; /* byte size of integer parameter */

	int width, precision;

	uint64_t flags;

	counter = 0;

	while ((c = fmt[i])) {

		/* control character */

		if (c == '%' ) { 

			/* print common characters if any processed */	

			if (i > j) {

				if ((retval = printf_putnchars(&fmt[j], (size_t)(i - j), ps)) < 0) { /* error */

					goto minus_out;

				}

				counter += retval;

			}

			j = i;

			/* parse modifiers */

			flags = 0;

			end = 0;

			do {

				++i;

				switch (c = fmt[i]) {

				case '#': flags |= __PRINTF_FLAG_PREFIX; break;

				case '-': flags |= __PRINTF_FLAG_LEFTALIGNED; break;

				case '+': flags |= __PRINTF_FLAG_SHOWPLUS; break;

				case ' ': flags |= __PRINTF_FLAG_SPACESIGN; break;

				case '0': flags |= __PRINTF_FLAG_ZEROPADDED; break;

				default: end = 1;

				};	

			} while (end == 0);	

			/* width & '*' operator */

			width = 0;

			if (isdigit(fmt[i])) {

				while (isdigit(fmt[i])) {

					width *= 10;

					width += fmt[i++] - '0';

				}

			} else if (fmt[i] == '*') {

				/* get width value from argument list*/

				i++;

				width = (int)va_arg(ap, int);

				if (width < 0) {

					/* negative width means to set '-' flag */

					width *= -1;

					flags |= __PRINTF_FLAG_LEFTALIGNED;

				}

			}

			/* precision and '*' operator */	

			precision = 0;

			if (fmt[i] == '.') {

				++i;

				if (isdigit(fmt[i])) {

					while (isdigit(fmt[i])) {

						precision *= 10;

						precision += fmt[i++] - '0';

					}

				} else if (fmt[i] == '*') {

					/* get precision value from argument list*/

					i++;

					precision = (int)va_arg(ap, int);

					if (precision < 0) {

						/* negative precision means to ignore it */

						precision = 0;

					}

				}

			}

			switch (fmt[i++]) {

			/** TODO: unimplemented qualifiers:

			 * t ptrdiff_t - ISO C 99

			 */

			case 'h':	/* char or short */

				qualifier = PrintfQualifierShort;

				if (fmt[i] == 'h') {

					i++;

					qualifier = PrintfQualifierByte;

				}

				break;

			case 'l':	/* long or long long*/

				qualifier = PrintfQualifierLong;

				if (fmt[i] == 'l') {

					i++;

					qualifier = PrintfQualifierLongLong;

				}

				break;

			case 'z':	/* size_t */

				qualifier = PrintfQualifierSizeT;

				break;

			default:

				qualifier = PrintfQualifierInt; /* default type */

				--i;

			}	

			base = 10;

			switch (c = fmt[i]) {

				/*

				* String and character conversions.

				*/

			case 's':

				if ((retval = print_string(va_arg(ap, char*), width, precision, flags, ps)) < 0) {

					goto minus_out;

				}

				counter += retval;

				j = i + 1; 

				goto next_char;

			case 'c':

				c = va_arg(ap, unsigned int);

				if ((retval = print_char(c, width, flags, ps)) < 0) {

					goto minus_out;

				}

				counter += retval;

				j = i + 1;

				goto next_char;

			/* 

			 * Integer values

			*/

			case 'P': /* pointer */

			       	flags |= __PRINTF_FLAG_BIGCHARS;

			case 'p':

				flags |= __PRINTF_FLAG_PREFIX;

				base = 16;

				qualifier = PrintfQualifierPointer;

				break;	

			case 'b': 

				base = 2;

				break;

			case 'o':

				base = 8;

				break;

			case 'd':

			case 'i':

				flags |= __PRINTF_FLAG_SIGNED;  

			case 'u':

				break;

			case 'X':

				flags |= __PRINTF_FLAG_BIGCHARS;

			case 'x':

				base = 16;

				break;

			/* percentile itself */

			case '%': 

				j = i;

				goto next_char;

			/*

			* Bad formatting.

			*/

			default:

				/* Unknown format

				 *  now, the j is index of '%' so we will

				 * print whole bad format sequence

				 */

				goto next_char;		

			}

		/* Print integers */

			/* print number */

			switch (qualifier) {

			case PrintfQualifierByte:

				size = sizeof(unsigned char);

				number = (uint64_t)va_arg(ap, unsigned int);

				break;

			case PrintfQualifierShort:

				size = sizeof(unsigned short);

				number = (uint64_t)va_arg(ap, unsigned int);

				break;

			case PrintfQualifierInt:

				size = sizeof(unsigned int);

				number = (uint64_t)va_arg(ap, unsigned int);

				break;

			case PrintfQualifierLong:

				size = sizeof(unsigned long);

				number = (uint64_t)va_arg(ap, unsigned long);

				break;

			case PrintfQualifierLongLong:

				size = sizeof(unsigned long long);

				number = (uint64_t)va_arg(ap, unsigned long long);

				break;

			case PrintfQualifierPointer:

				size = sizeof(void *);

				number = (uint64_t)(unsigned long)va_arg(ap, void *);

				break;

			case PrintfQualifierSizeT:

				size = sizeof(size_t);

				number = (uint64_t)va_arg(ap, size_t);

				break;

			default: /* Unknown qualifier */

				goto minus_out;

			}

			if (flags & __PRINTF_FLAG_SIGNED) {

				if (number & (0x1 << (size*8 - 1))) {

					flags |= __PRINTF_FLAG_NEGATIVE;

					if (size == sizeof(uint64_t)) {

						number = -((int64_t)number);

					} else {

						number = ~number;

						number &= (~((0xFFFFFFFFFFFFFFFFll) <<  (size * 8)));

						number++;

					}

				}

			}

			if ((retval = print_number(number, width, precision, base, flags, ps)) < 0 ) {

				goto minus_out;

			};

			counter += retval;

			j = i + 1;

		}	

next_char:

		++i;

	}

	if (i > j) {

		if ((retval = printf_putnchars(&fmt[j], (size_t)(i - j), ps)) < 0) { /* error */

			goto minus_out;

		}

		counter += retval;

	}

	return counter;

minus_out:

	return -counter;

}

/** @}

 */