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/* $OpenBSD: fvwrite.c,v 1.14 2005/08/08 08:05:36 espie Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "local.h"
#include "fvwrite.h"
/*
* Write some memory regions. Return zero on success, EOF on error.
*
* This routine is large and unsightly, but most of the ugliness due
* to the three different kinds of output buffering is handled here.
*/
int
__sfvwrite(FILE *fp, struct __suio *uio)
{
size_t len;
char *p;
struct __siov *iov;
int w, s;
char *nl;
int nlknown, nldist;
if ((len = uio->uio_resid) == 0)
return (0);
/* make sure we can write */
if (cantwrite(fp)) {
errno = EBADF;
return (EOF);
}
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n))
iov = uio->uio_iov;
p = iov->iov_base;
len = iov->iov_len;
iov++;
#define GETIOV(extra_work) \
while (len == 0) { \
extra_work; \
p = iov->iov_base; \
len = iov->iov_len; \
iov++; \
}
if (fp->_flags & __SNBF) {
/*
* Unbuffered: write up to BUFSIZ bytes at a time.
*/
do {
GETIOV(;);
#if 1 /* BIONIC: don't limit to 1KB writes */
w = (*fp->_write)(fp->_cookie, p, len);
#else
w = (*fp->_write)(fp->_cookie, p, MIN(len, BUFSIZ2));
#endif
if (w <= 0)
goto err;
p += w;
len -= w;
} while ((uio->uio_resid -= w) != 0);
} else if ((fp->_flags & __SLBF) == 0) {
/*
* Fully buffered: fill partially full buffer, if any,
* and then flush. If there is no partial buffer, write
* one _bf._size byte chunk directly (without copying).
*
* String output is a special case: write as many bytes
* as fit, but pretend we wrote everything. This makes
* snprintf() return the number of bytes needed, rather
* than the number used, and avoids its write function
* (so that the write function can be invalid).
*/
do {
GETIOV(;);
if ((fp->_flags & (__SALC | __SSTR)) ==
(__SALC | __SSTR) && fp->_w < (int)len) {
size_t blen = fp->_p - fp->_bf._base;
unsigned char *_base;
int _size;
/* Allocate space exponentially. */
_size = fp->_bf._size;
do {
_size = (_size << 1) + 1;
} while (_size < (int)(blen + len));
_base = realloc(fp->_bf._base, _size + 1);
if (_base == NULL)
goto err;
fp->_w += _size - fp->_bf._size;
fp->_bf._base = _base;
fp->_bf._size = _size;
fp->_p = _base + blen;
}
w = fp->_w;
if (fp->_flags & __SSTR) {
if ((int)len < w)
w = len;
COPY(w); /* copy MIN(fp->_w,len), */
fp->_w -= w;
fp->_p += w;
w = len; /* but pretend copied all */
} else if (fp->_p > fp->_bf._base && (int)len > w) {
/* fill and flush */
COPY(w);
/* fp->_w -= w; */ /* unneeded */
fp->_p += w;
if (fflush(fp))
goto err;
} else if ((int)len >= (w = fp->_bf._size)) {
/* write directly */
w = (*fp->_write)(fp->_cookie, p, w);
if (w <= 0)
goto err;
} else {
/* fill and done */
w = len;
COPY(w);
fp->_w -= w;
fp->_p += w;
}
p += w;
len -= w;
} while ((uio->uio_resid -= w) != 0);
} else {
/*
* Line buffered: like fully buffered, but we
* must check for newlines. Compute the distance
* to the first newline (including the newline),
* or `infinity' if there is none, then pretend
* that the amount to write is MIN(len,nldist).
*/
nlknown = 0;
nldist = 0; /* XXX just to keep gcc happy */
do {
GETIOV(nlknown = 0);
if (!nlknown) {
nl = memchr((void *)p, '\n', len);
nldist = nl ? nl + 1 - p : (int)len + 1;
nlknown = 1;
}
s = MIN((int)len, nldist);
w = fp->_w + fp->_bf._size;
if (fp->_p > fp->_bf._base && s > w) {
COPY(w);
/* fp->_w -= w; */
fp->_p += w;
if (fflush(fp))
goto err;
} else if (s >= (w = fp->_bf._size)) {
w = (*fp->_write)(fp->_cookie, p, w);
if (w <= 0)
goto err;
} else {
w = s;
COPY(w);
fp->_w -= w;
fp->_p += w;
}
if ((nldist -= w) == 0) {
/* copied the newline: flush and forget */
if (fflush(fp))
goto err;
nlknown = 0;
}
p += w;
len -= w;
} while ((uio->uio_resid -= w) != 0);
}
return (0);
err:
fp->_flags |= __SERR;
return (EOF);
}
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