Initial revision

src/libfmt/fmt.c

@@ -0,0 +1,221 @@
+/*
+ * 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 <stdarg.h>
+#include <string.h>
+#include "utf.h"
+#include "fmt.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,	/* Plan 9 addition */
+	'E',	__efgfmt,
+	'F',	__efgfmt,	/* ANSI only */
+	'G',	__efgfmt,
+	'L',	__flagfmt,	/* ANSI only */
+	'S',	__runesfmt,	/* Plan 9 addition */
+	'X',	__ifmt,
+	'b',	__ifmt,		/* Plan 9 addition */
+	'c',	__charfmt,
+	'd',	__ifmt,
+	'e',	__efgfmt,
+	'f',	__efgfmt,
+	'g',	__efgfmt,
+	'h',	__flagfmt,
+	'i',	__ifmt,		/* ANSI only */
+	'l',	__flagfmt,
+	'n',	__countfmt,
+	'o',	__ifmt,
+	'p',	__ifmt,
+	'r',	__errfmt,
+	's',	__strfmt,
+	'u',	__ifmt,		/* in Plan 9, __flagfmt */
+	'x',	__ifmt,
+	0,	nil,
+};
+
+
+int	(*fmtdoquote)(int);
+
+/*
+ * __fmtlock() must be set
+ */
+static int
+__fmtinstall(int c, Fmts f)
+{
+	Convfmt *p, *ep;
+
+	if(c<=0 || c>=65536)
+		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;
+}
+
+int
+fmtinstall(int c, Fmts f)
+{
+	int ret;
+
+	__fmtlock();
+	ret = __fmtinstall(c, f);
+	__fmtunlock();
+	return ret;
+}
+
+static Fmts
+fmtfmt(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;
+
+	f->flags = 0;
+	f->width = f->prec = 0;
+
+	for(;;){
+		if(isrunes){
+			r = *(Rune*)fmt;
+			fmt = (Rune*)fmt + 1;
+		}else{
+			fmt = (char*)fmt + chartorune(&rune, (char*)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){
+				/*
+				 * 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)
+			return nil;
+		if(n == 0)
+			return fmt;
+	}
+}