freebsd-skq/lib/libc/stdio/ungetwc.c
tjr f5a461b270 Associate a multibyte conversion state object with each stream. Reset it
to the initial state when a stream is opened or seeked upon. Use the
stream's conversion state object instead of a freshly-zeroed one in
fgetwc(), fputwc() and ungetwc().

This is only a performance improvement for now, but it would also be
required in order to support state-dependent encodings.
2004-05-22 15:19:41 +00:00

76 lines
2.1 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"
/*
* Non-MT-safe version.
*/
wint_t
__ungetwc(wint_t wc, FILE *fp)
{
char buf[MB_LEN_MAX];
size_t len;
if (wc == WEOF)
return (WEOF);
if ((len = wcrtomb(buf, wc, &fp->_extra->mbstate)) == (size_t)-1) {
fp->_flags |= __SERR;
return (WEOF);
}
while (len-- != 0)
if (__ungetc((unsigned char)buf[len], fp) == EOF)
return (WEOF);
return (wc);
}
/*
* MT-safe version.
*/
wint_t
ungetwc(wint_t wc, FILE *fp)
{
wint_t r;
FLOCKFILE(fp);
ORIENT(fp, 1);
r = __ungetwc(wc, fp);
FUNLOCKFILE(fp);
return (r);
}