ref: c8b187f9db503465460d8bafa2d7a758bbcf59ca
dir: /lib9/fmt.c/
/* * The authors of this software are Rob Pike and Ken Thompson. * Copyright (c) 2002 by Lucent Technologies. * Permission to use, copy, modify, and distribute this software for any * purpose without fee is hereby granted, provided that this entire notice * is included in all copies of any software which is or includes a copy * or modification of this software and in all copies of the supporting * documentation for such software. * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED * WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. */ #include "lib9.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, 'S', _runesfmt, 'X', _ifmt, 'b', _ifmt, 'c', _charfmt, 'd', _ifmt, 'h', _flagfmt, 'l', _flagfmt, 'n', _countfmt, 'o', _ifmt, 'p', _ifmt, 'r', errfmt, 's', _strfmt, 'u', _flagfmt, 'x', _ifmt, 'z', _flagfmt, 0, nil, }; int (*doquote)(int); static Fmts fmtfmt(int c) { Convfmt *p, *ep; ep = &fmtalloc.fmt[fmtalloc.nfmt]; for(p=fmtalloc.fmt; p<ep; p++) if(p->c == c) return p->fmt; /* is this a predefined format char? */ for(p=knownfmt; p->c; p++) if(p->c == c){ /* no need to lock; fmtinstall is idempotent */ fmtinstall(p->c, p->fmt); while(p->fmt == nil) /* loop until value is updated */ ; return p->fmt; } return _badfmt; } int fmtinstall(int c, Fmts f) { Convfmt *p, *ep; if(c<=0 || c>=65536) return -1; if(!f) f = _badfmt; _fmtlock(); ep = &fmtalloc.fmt[fmtalloc.nfmt]; for(p=fmtalloc.fmt; p<ep; p++) if(p->c == c) break; if(p == &fmtalloc.fmt[Maxfmt]){ _fmtunlock(); return -1; } p->fmt = f; if(p == ep){ /* installing a new format character */ fmtalloc.nfmt++; p->c = c; } _fmtunlock(); return 0; } void* _fmtdispatch(Fmt *f, void *fmt, int isrunes) { Rune rune, r; int i, n; 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': return nil; 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){ i = -i; f->flags |= FmtLeft; } goto numflag; } n = (*fmtfmt(r))(f); if(n < 0) return nil; if(n == 0) return fmt; } }