#include <u.h>#include <libc.h>#include "fmtdef.h" enum{	Maxfmt = 64}; typedef struct Convfmt Convfmt;struct Convfmt{	int	c;	volatile	Fmts	fmt;	/* for spin lock in fmtfmt; avoids race due to write order */}; struct{	/* lock by calling _fmtlock, _fmtunlock */	int	nfmt;	Convfmt	fmt[Maxfmt];} fmtalloc; static Convfmt knownfmt[] = {	' ',	_flagfmt,	'#',	_flagfmt,	'%',	_percentfmt,	'+',	_flagfmt,	',',	_flagfmt,	'-',	_flagfmt,	'C',	_runefmt,	'E',	_efgfmt,	'G',	_efgfmt,	'S',	_runesfmt,	'X',	_ifmt,	'b',	_ifmt,	'c',	_charfmt,	'd',	_ifmt,	'e',	_efgfmt,	'f',	_efgfmt,	'g',	_efgfmt,	'h',	_flagfmt,	'l',	_flagfmt,	'n',	_countfmt,	'o',	_ifmt,	'p',	_ifmt,	'r',	errfmt,	's',	_strfmt,	'u',	_flagfmt,	'x',	_ifmt,	0,	nil,}; int	(*doquote)(int); /* * _fmtlock() must be set */static int_fmtinstall(int c, Fmts f){	Convfmt *p, *ep; 	if(c<=0 || c>Runemax)		return -1;	if(!f)		f = _badfmt; 	ep = &fmtalloc.fmt[fmtalloc.nfmt];	for(p=fmtalloc.fmt; p<ep; p++)		if(p->c == c)			break; 	if(p == &fmtalloc.fmt[Maxfmt])		return -1; 	p->fmt = f;	if(p == ep){	/* installing a new format character */		fmtalloc.nfmt++;		p->c = c;	} 	return 0;} intfmtinstall(int c, Fmts f){	int ret; 	_fmtlock();	ret = _fmtinstall(c, f);	_fmtunlock();	return ret;} static Fmtsfmtfmt(int c){	Convfmt *p, *ep; 	ep = &fmtalloc.fmt[fmtalloc.nfmt];	for(p=fmtalloc.fmt; p<ep; p++)		if(p->c == c){			while(p->fmt == nil)	/* loop until value is updated */				;			return p->fmt;		} 	/* is this a predefined format char? */	_fmtlock();	for(p=knownfmt; p->c; p++)		if(p->c == c){			_fmtinstall(p->c, p->fmt);			_fmtunlock();			return p->fmt;		}	_fmtunlock(); 	return _badfmt;} void*_fmtdispatch(Fmt *f, void *fmt, int isrunes){	Rune rune, r;	int i, n, w, p;	ulong fl;	void *ret; 	w = f->width;	p = f->prec;	fl = f->flags; 	f->flags = 0;	f->width = f->prec = 0; 	for(;;){		if(isrunes){			r = *(Rune*)fmt;			fmt = (Rune*)fmt + 1;		}else{			fmt = (char*)fmt + chartorune(&rune, fmt);			r = rune;		}		f->r = r;		switch(r){		case '\0':			ret = nil;			goto end;		case '.':			f->flags |= FmtWidth|FmtPrec;			continue;		case '0':			if(!(f->flags & FmtWidth)){				f->flags |= FmtZero;				continue;			}			/* fall through */		case '1': case '2': case '3': case '4':		case '5': case '6': case '7': case '8': case '9':			i = 0;			while(r >= '0' && r <= '9'){				i = i * 10 + r - '0';				if(isrunes){					r = *(Rune*)fmt;					fmt = (Rune*)fmt + 1;				}else{					r = *(char*)fmt;					fmt = (char*)fmt + 1;				}			}			if(isrunes)				fmt = (Rune*)fmt - 1;			else				fmt = (char*)fmt - 1;		numflag:			if(f->flags & FmtWidth){				f->flags |= FmtPrec;				f->prec = i;			}else{				f->flags |= FmtWidth;				f->width = i;			}			continue;		case '*':			i = va_arg(f->args, int);			if(i < 0){				/*				 * negative precision =>				 * ignore the precision.				 */				if(f->flags & FmtPrec){					f->flags &= ~FmtPrec;					f->prec = 0;					continue;				}				i = -i;				f->flags |= FmtLeft;			}			goto numflag;		}		n = (*fmtfmt(r))(f);		if(n < 0){			ret = nil;			break;		}		if(n == 0){			ret = fmt;			break;		}	}end:	f->width = w;	f->prec = p;	f->flags = fl;	return ret;}