/*-
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * 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.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR 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.
 *
 *	@(#)local.h	8.3 (Berkeley) 7/3/94
 * $FreeBSD$
 */

#include <sys/types.h>	/* for off_t */
#include <pthread.h>
#include <string.h>
#include <wchar.h>

/*
 * Information local to this implementation of stdio, in particular,
 * macros, private functions, private variables, and the definition of
 * FILE.
 *
 * NB: to fit things in six character monocase externals, the stdio
 * code uses the prefix `__s' for stdio objects, typically followed
 * by a three-character attempt at a mnemonic.
 */

/* stdio buffers */
struct __sbuf {
	unsigned char *_base;
	int	_size;
};

/*
 * stdio state variables.
 *
 * The following always hold:
 *
 *	if (_flags&(__SLBF|__SWR)) == (__SLBF|__SWR),
 *		_lbfsize is -_bf._size, else _lbfsize is 0
 *	if _flags&__SRD, _w is 0
 *	if _flags&__SWR, _r is 0
 *
 * This ensures that the getc and putc macros (or inline functions) never
 * try to write or read from a file that is in `read' or `write' mode.
 * (Moreover, they can, and do, automatically switch from read mode to
 * write mode, and back, on "r+" and "w+" files.)
 *
 * _lbfsize is used only to make the inline line-buffered output stream
 * code as compact as possible.
 *
 * _ub, _up, and _ur are used when ungetc() pushes back more characters
 * than fit in the current _bf, or when ungetc() pushes back a character
 * that does not match the previous one in _bf.  When this happens,
 * _ub._base becomes non-nil (i.e., a stream has ungetc() data iff
 * _ub._base!=NULL) and _up and _ur save the current values of _p and _r.
 *
 * Certain members of __sFILE are accessed directly via macros or
 * inline functions.  To preserve ABI compat, these members must not
 * be disturbed.  These members are marked below with (*).
 */
struct __sFILE {
	unsigned char *_p;	/* (*) current position in (some) buffer */
	int	_r;		/* (*) read space left for getc() */
	int	_w;		/* (*) write space left for putc() */
	short	_flags;		/* (*) flags, below; this FILE is free if 0 */
	short	_file;		/* (*) fileno, if Unix descriptor, else -1 */
	struct	__sbuf _bf;	/* the buffer (at least 1 byte, if !NULL) */
	int	_lbfsize;	/* (*) 0 or -_bf._size, for inline putc */

	/* operations */
	void	*_cookie;	/* cookie passed to io functions */
	int	(*_close)(void *);
	int	(*_read)(void *, char *, int);
	fpos_t	(*_seek)(void *, fpos_t, int);
	int	(*_write)(void *, const char *, int);

	/* separate buffer for long sequences of ungetc() */
	struct	__sbuf _ub;	/* ungetc buffer */
	unsigned char	*_up;	/* saved _p when _p is doing ungetc data */
	int	_ur;		/* saved _r when _r is counting ungetc data */

	/* tricks to meet minimum requirements even when malloc() fails */
	unsigned char _ubuf[3];	/* guarantee an ungetc() buffer */
	unsigned char _nbuf[1];	/* guarantee a getc() buffer */

	/* separate buffer for fgetln() when line crosses buffer boundary */
	struct	__sbuf _lb;	/* buffer for fgetln() */

	/* Unix stdio files get aligned to block boundaries on fseek() */
	int	_blksize;	/* stat.st_blksize (may be != _bf._size) */
	fpos_t	_offset;	/* current lseek offset */

	pthread_mutex_t _fl_mutex;	/* used for MT-safety */
	pthread_t _fl_owner;	/* current owner */
	int	_fl_count;	/* recursive lock count */
	int	_orientation;	/* orientation for fwide() */
	mbstate_t _mbstate;	/* multibyte conversion state */
};

#define	__SLBF	0x0001		/* line buffered */
#define	__SNBF	0x0002		/* unbuffered */
#define	__SRD	0x0004		/* OK to read */
#define	__SWR	0x0008		/* OK to write */
	/* RD and WR are never simultaneously asserted */
#define	__SRW	0x0010		/* open for reading & writing */
#define	__SEOF	0x0020		/* found EOF */
#define	__SERR	0x0040		/* found error */
#define	__SMBF	0x0080		/* _buf is from malloc */
#define	__SAPP	0x0100		/* fdopen()ed in append mode */
#define	__SSTR	0x0200		/* this is an sprintf/snprintf string */
#define	__SOPT	0x0400		/* do fseek() optimization */
#define	__SNPT	0x0800		/* do not do fseek() optimization */
#define	__SOFF	0x1000		/* set iff _offset is in fact correct */
#define	__SMOD	0x2000		/* true => fgetln modified _p text */
#define	__SALC	0x4000		/* allocate string space dynamically */
#define	__SIGN	0x8000		/* ignore this file in _fwalk */

extern int	_sread(FILE *, char *, int);
extern int	_swrite(FILE *, char const *, int);
extern fpos_t	_sseek(FILE *, fpos_t, int);
extern int	_ftello(FILE *, fpos_t *);
extern int	_fseeko(FILE *, off_t, int, int);
extern int	__fflush(FILE *fp);
extern void	__fcloseall(void);
extern wint_t	__fgetwc(FILE *);
extern wint_t	__fputwc(wchar_t, FILE *);
extern int	__sflush(FILE *);
extern FILE	*__sfp(void);
extern int	__slbexpand(FILE *, size_t);
extern int	__srefill(FILE *);
extern int	__sread(void *, char *, int);
extern int	__srget(FILE *);
extern int	__swbuf(int, FILE *);
extern int	__swrite(void *, char const *, int);
extern fpos_t	__sseek(void *, fpos_t, int);
extern int	__sclose(void *);
extern void	__sinit(void);
extern void	_cleanup(void);
extern void	__smakebuf(FILE *);
extern int	__swhatbuf(FILE *, size_t *, int *);
extern int	_fwalk(int (*)(FILE *));
extern int	__svfscanf(FILE *, const char *, __va_list);
extern int	__swsetup(FILE *);
extern int	__sflags(const char *, int *);
extern int	__ungetc(int, FILE *);
extern wint_t	__ungetwc(wint_t, FILE *);
extern int	__vfprintf(FILE *, const char *, __va_list);
extern int	__vfscanf(FILE *, const char *, __va_list);
extern int	__vfwprintf(FILE *, const wchar_t *, __va_list);
extern int	__vfwscanf(FILE * __restrict, const wchar_t * __restrict,
		    __va_list);
extern size_t	__fread(void * __restrict buf, size_t size, size_t count,
		FILE * __restrict fp);
extern int	__sdidinit;


/*
 * Get and store individual characters from a file stream.
 */
#define	__sgetc(p) (--(p)->_r < 0 ? __srget(p) : (int)(*(p)->_p++))
#if defined(__GNUC__) && defined(__STDC__)
static __inline int
__sputc(int _c, FILE *_p)
{
	if (--_p->_w >= 0 || (_p->_w >= _p->_lbfsize && (char)_c != '\n'))
		return (*_p->_p++ = _c);
	else
		return (__swbuf(_c, _p));
}
#else
/*
 * This has been tuned to generate reasonable code on the vax using pcc.
 */
#define	__sputc(c, p) \
	(--(p)->_w < 0 ? \
		(p)->_w >= (p)->_lbfsize ? \
			(*(p)->_p = (c)), *(p)->_p != '\n' ? \
				(int)*(p)->_p++ : \
				__swbuf('\n', p) : \
			__swbuf((int)(c), p) : \
		(*(p)->_p = (c), (int)*(p)->_p++))
#endif

/*
 * Return true if the file stream has encountered an error.
 */
#define	__sferror(p)	(((p)->_flags & __SERR) != 0)

/*
 * Prepare the given FILE for writing, and return 0 iff it
 * can be written now.  Otherwise, return EOF and set errno.
 */
#define	prepwrite(fp) \
 	((((fp)->_flags & __SWR) == 0 || \
 	    ((fp)->_bf._base == NULL && ((fp)->_flags & __SSTR) == 0)) && \
	 __swsetup(fp))

/*
 * Test whether the given stdio file has an active ungetc buffer;
 * release such a buffer, without restoring ordinary unread data.
 */
#define	HASUB(fp) ((fp)->_ub._base != NULL)
#define	FREEUB(fp) { \
	if ((fp)->_ub._base != (fp)->_ubuf) \
		free((char *)(fp)->_ub._base); \
	(fp)->_ub._base = NULL; \
}

/*
 * test for an fgetln() buffer.
 */
#define	HASLB(fp) ((fp)->_lb._base != NULL)
#define	FREELB(fp) { \
	free((char *)(fp)->_lb._base); \
	(fp)->_lb._base = NULL; \
}

/*
 * Set the orientation for a stream. If o > 0, the stream has wide-
 * orientation. If o < 0, the stream has byte-orientation.
 */
#define	ORIENT(fp, o)	do {				\
	if ((fp)->_orientation == 0)			\
		(fp)->_orientation = (o);		\
} while (0)