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freebsd/lib/libc/stdio/fgetwc.c
Tim J. Robbins d6ed810a67 Perform conversions straight from the stream buffer instead of scanning
through byte by byte with mbrtowc(). In the usual case (buffer is big
enough to contain the multibyte character, character does not straddle
buffer boundary) this results in only one call to mbrtowc() for each
wide character read.
2004-05-22 15:41:03 +00:00

109 lines
2.6 KiB
C

/*-
* Copyright (c) 2002-2004 Tim J. Robbins.
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <wchar.h>
#include "un-namespace.h"
#include "libc_private.h"
#include "local.h"
static __inline wint_t __fgetwc_nbf(FILE *);
/*
* Non-MT-safe version.
*/
wint_t
__fgetwc(FILE *fp)
{
wint_t wc;
if (MB_CUR_MAX == 1) {
/*
* Assume we're using a single-byte locale. A safer test
* might be to check _CurrentRuneLocale->encoding.
*/
wc = (wint_t)__sgetc(fp);
} else
wc = __fgetwc_nbf(fp);
return (wc);
}
/*
* MT-safe version.
*/
wint_t
fgetwc(FILE *fp)
{
wint_t r;
FLOCKFILE(fp);
ORIENT(fp, 1);
r = __fgetwc(fp);
FUNLOCKFILE(fp);
return (r);
}
static __inline wint_t
__fgetwc_nbf(FILE *fp)
{
wchar_t wc;
size_t nconv;
if (fp->_r <= 0 && __srefill(fp))
return (WEOF);
do {
nconv = mbrtowc(&wc, fp->_p, fp->_r, &fp->_extra->mbstate);
if (nconv == (size_t)-1)
break;
else if (nconv == (size_t)-2)
continue;
else if (nconv == 0) {
/*
* Assume that the only valid representation of
* the null wide character is a single null byte.
*/
fp->_p++;
fp->_r--;
return (L'\0');
} else {
fp->_p += nconv;
fp->_r -= nconv;
return (wc);
}
} while (__srefill(fp) == 0);
fp->_flags |= __SERR;
errno = EILSEQ;
return (WEOF);
}