newlib-cygwin/newlib/libc/stdio/fvwrite.c

267 lines
6.8 KiB
C

/*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/* No user fns here. Pesch 15apr92. */
#include <_ansi.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <limits.h>
#include "local.h"
#include "fvwrite.h"
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define COPY(n) _CAST_VOID memmove ((_PTR) fp->_p, (_PTR) p, (size_t) (n))
#define GETIOV(extra_work) \
while (len == 0) \
{ \
extra_work; \
p = iov->iov_base; \
len = iov->iov_len; \
iov++; \
}
/*
* 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
_DEFUN(__sfvwrite_r, (ptr, fp, uio),
struct _reent *ptr,
register FILE *fp,
register struct __suio *uio)
{
register size_t len;
register const char *p = NULL;
register struct __siov *iov;
register _READ_WRITE_RETURN_TYPE w, s;
char *nl;
int nlknown, nldist;
if ((len = uio->uio_resid) == 0)
return 0;
/* make sure we can write */
if (cantwrite (ptr, fp))
return EOF;
iov = uio->uio_iov;
len = 0;
#ifdef __SCLE
if (fp->_flags & __SCLE) /* text mode */
{
do
{
GETIOV (;);
while (len > 0)
{
if (putc (*p, fp) == EOF)
return EOF;
p++;
len--;
uio->uio_resid--;
}
}
while (uio->uio_resid > 0);
return 0;
}
#endif
if (fp->_flags & __SNBF)
{
/*
* Unbuffered: Split buffer in the largest multiple of BUFSIZ < INT_MAX
* as some legacy code may expect int instead of size_t.
*/
do
{
GETIOV (;);
w = fp->_write (ptr, fp->_cookie, p,
MIN (len, INT_MAX - INT_MAX % BUFSIZ));
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). If
* we are dealing with the asprintf routines, we will
* dynamically increase the buffer size as needed.
*/
do
{
GETIOV (;);
w = fp->_w;
if (fp->_flags & __SSTR)
{
if (len >= w && fp->_flags & (__SMBF | __SOPT))
{ /* must be asprintf family */
unsigned char *str;
int curpos = (fp->_p - fp->_bf._base);
/* Choose a geometric growth factor to avoid
quadratic realloc behavior, but use a rate less
than (1+sqrt(5))/2 to accomodate malloc
overhead. asprintf EXPECTS us to overallocate, so
that it can add a trailing \0 without
reallocating. The new allocation should thus be
max(prev_size*1.5, curpos+len+1). */
int newsize = fp->_bf._size * 3 / 2;
if (newsize < curpos + len + 1)
newsize = curpos + len + 1;
if (fp->_flags & __SOPT)
{
/* asnprintf leaves original buffer alone. */
str = (unsigned char *)_malloc_r (ptr, newsize);
if (!str)
{
ptr->_errno = ENOMEM;
goto err;
}
memcpy (str, fp->_bf._base, curpos);
fp->_flags = (fp->_flags & ~__SOPT) | __SMBF;
}
else
{
str = (unsigned char *)_realloc_r (ptr, fp->_bf._base,
newsize);
if (!str)
{
/* Free buffer which is no longer used and clear
__SMBF flag to avoid double free in fclose. */
_free_r (ptr, fp->_bf._base);
fp->_flags &= ~__SMBF;
/* Ensure correct errno, even if free changed it. */
ptr->_errno = ENOMEM;
goto err;
}
}
fp->_bf._base = str;
fp->_p = str + curpos;
fp->_bf._size = newsize;
w = len;
fp->_w = newsize - curpos;
}
if (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 || len < fp->_bf._size)
{
/* pass through the buffer */
w = MIN (len, w);
COPY (w);
fp->_w -= w;
fp->_p += w;
if (fp->_w == 0 && _fflush_r (ptr, fp))
goto err;
}
else
{
/* write directly */
w = ((int)MIN (len, INT_MAX)) / fp->_bf._size * fp->_bf._size;
w = fp->_write (ptr, fp->_cookie, p, w);
if (w <= 0)
goto err;
}
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;
do
{
GETIOV (nlknown = 0);
if (!nlknown)
{
nl = memchr ((_PTR) p, '\n', len);
nldist = nl ? nl + 1 - p : len + 1;
nlknown = 1;
}
s = MIN (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_r (ptr, fp))
goto err;
}
else if (s >= (w = fp->_bf._size))
{
w = fp->_write (ptr, 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_r (ptr, fp))
goto err;
nlknown = 0;
}
p += w;
len -= w;
}
while ((uio->uio_resid -= w) != 0);
}
return 0;
err:
fp->_flags |= __SERR;
return EOF;
}