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/*
* Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
* All rights reserved.
* 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.
*
* By using this file, you agree to the terms and conditions set
* forth in the LICENSE file which can be found at the top level of
* the sendmail distribution.
*/
#include <sm/gen.h>
SM_RCSID("@(#)$Id: wbuf.c,v 1.21 2001/09/11 04:04:49 gshapiro Exp $")
#include <errno.h>
#include <sm/io.h>
#include "local.h"
/* Note: This function is called from a macro located in <sm/io.h> */
/*
** SM_WBUF -- write character to and flush (likely now full) buffer
**
** Write the given character into the (probably full) buffer for
** the given file. Flush the buffer out if it is or becomes full,
** or if c=='\n' and the file is line buffered.
**
** Parameters:
** fp -- the file pointer
** timeout -- time to complete operation (milliseconds)
** c -- int representation of the character to add
**
** Results:
** Failure: -1 and sets errno
** Success: int value of 'c'
*/
int
sm_wbuf(fp, timeout, c)
register SM_FILE_T *fp;
int timeout;
register int c;
{
register int n;
/*
** In case we cannot write, or longjmp takes us out early,
** make sure w is 0 (if fully- or un-buffered) or -bf.smb_size
** (if line buffered) so that we will get called again.
** If we did not do this, a sufficient number of sm_io_putc()
** calls might wrap w from negative to positive.
*/
fp->f_w = fp->f_lbfsize;
if (cantwrite(fp))
{
errno = EBADF;
return SM_IO_EOF;
}
c = (unsigned char)c;
/*
** If it is completely full, flush it out. Then, in any case,
** stuff c into the buffer. If this causes the buffer to fill
** completely, or if c is '\n' and the file is line buffered,
** flush it (perhaps a second time). The second flush will always
** happen on unbuffered streams, where bf.smb_size==1; sm_io_flush()
** guarantees that sm_io_putc() will always call sm_wbuf() by setting
** w to 0, so we need not do anything else.
** Note for the timeout, only one of the sm_io_flush's will get called.
*/
n = fp->f_p - fp->f_bf.smb_base;
if (n >= fp->f_bf.smb_size)
{
if (sm_io_flush(fp, timeout))
return SM_IO_EOF; /* sm_io_flush() sets errno */
n = 0;
}
fp->f_w--;
*fp->f_p++ = c;
if (++n == fp->f_bf.smb_size || (fp->f_flags & SMLBF && c == '\n'))
if (sm_io_flush(fp, timeout))
return SM_IO_EOF; /* sm_io_flush() sets errno */
return c;
}
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