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/*
* Copyright (c) 2000-2001 Proofpoint, 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: makebuf.c,v 1.27 2013-11-22 20:51:43 ca Exp $")
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sm/io.h>
#include <sm/heap.h>
#include <sm/conf.h>
#include "local.h"
/*
** SM_MAKEBUF -- make a buffer for the file
**
** Parameters:
** fp -- the file to be buffered
**
** Returns:
** nothing
**
** Allocate a file buffer, or switch to unbuffered I/O.
** By default tty devices default to line buffered.
*/
void
sm_makebuf(fp)
register SM_FILE_T *fp;
{
register void *p;
register int flags;
size_t size;
int couldbetty;
if (fp->f_flags & SMNBF)
{
fp->f_bf.smb_base = fp->f_p = fp->f_nbuf;
fp->f_bf.smb_size = 1;
return;
}
flags = sm_whatbuf(fp, &size, &couldbetty);
if ((p = sm_malloc(size)) == NULL)
{
fp->f_flags |= SMNBF;
fp->f_bf.smb_base = fp->f_p = fp->f_nbuf;
fp->f_bf.smb_size = 1;
return;
}
if (!Sm_IO_DidInit)
sm_init();
flags |= SMMBF;
fp->f_bf.smb_base = fp->f_p = p;
fp->f_bf.smb_size = size;
if (couldbetty && isatty(fp->f_file))
flags |= SMLBF;
fp->f_flags |= flags;
}
/*
** SM_WHATBUF -- determine proper buffer for a file (internal)
**
** Plus it fills in 'bufsize' for recommended buffer size and
** fills in flag to indicate if 'fp' could be a tty (nothing
** to do with "betty" :-) ).
**
** Parameters:
** fp -- file pointer to be buffered
** bufsize -- new buffer size (a return)
** couldbetty -- could be a tty (returns)
**
** Returns:
** Success:
** on error:
** SMNPT -- not seek opimized
** SMOPT -- seek opimized
*/
int
sm_whatbuf(fp, bufsize, couldbetty)
register SM_FILE_T *fp;
size_t *bufsize;
int *couldbetty;
{
struct stat st;
if (fp->f_file < 0 || fstat(fp->f_file, &st) < 0)
{
*couldbetty = 0;
*bufsize = SM_IO_BUFSIZ;
return SMNPT;
}
/* could be a tty iff it is a character device */
*couldbetty = S_ISCHR(st.st_mode);
if (st.st_blksize == 0)
{
*bufsize = SM_IO_BUFSIZ;
return SMNPT;
}
#if SM_IO_MAX_BUF_FILE > 0
if (S_ISREG(st.st_mode) && st.st_blksize > SM_IO_MAX_BUF_FILE)
st.st_blksize = SM_IO_MAX_BUF_FILE;
#endif
#if SM_IO_MAX_BUF > 0 || SM_IO_MIN_BUF > 0
if (!S_ISREG(st.st_mode))
{
# if SM_IO_MAX_BUF > 0
if (st.st_blksize > SM_IO_MAX_BUF)
st.st_blksize = SM_IO_MAX_BUF;
# if SM_IO_MIN_BUF > 0
else
# endif /* SM_IO_MIN_BUF > 0 */
# endif /* SM_IO_MAX_BUF > 0 */
# if SM_IO_MIN_BUF > 0
if (st.st_blksize < SM_IO_MIN_BUF)
st.st_blksize = SM_IO_MIN_BUF;
# endif
}
#endif /* SM_IO_MAX_BUF > 0 || SM_IO_MIN_BUF > 0 */
/*
** Optimise fseek() only if it is a regular file. (The test for
** sm_std_seek is mainly paranoia.) It is safe to set _blksize
** unconditionally; it will only be used if SMOPT is also set.
*/
if ((fp->f_flags & SMSTR) == 0)
{
*bufsize = st.st_blksize;
fp->f_blksize = st.st_blksize;
}
else
*bufsize = SM_IO_BUFSIZ;
if ((st.st_mode & S_IFMT) == S_IFREG &&
fp->f_seek == sm_stdseek)
return SMOPT;
else
return SMNPT;
}
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