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/*
* Copyright (c) 2000-2001, 2004 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: fpos.c,v 1.39 2005/06/14 23:07:20 ca Exp $")
#include <errno.h>
#include <setjmp.h>
#include <sm/time.h>
#include <sm/heap.h>
#include <sm/signal.h>
#include <sm/clock.h>
#include <sm/io.h>
#include <sm/assert.h>
#include "local.h"
static void tellalrm __P((int));
static jmp_buf TellTimeOut;
/*
** TELLALRM -- handler when timeout activated for sm_io_tell()
**
** Returns flow of control to where setjmp(TellTimeOut) was set.
**
** Parameters:
** sig -- unused
**
** Returns:
** does not return
**
** Side Effects:
** returns flow of control to setjmp(TellTimeOut).
**
** NOTE: THIS CAN BE CALLED FROM A SIGNAL HANDLER. DO NOT ADD
** ANYTHING TO THIS ROUTINE UNLESS YOU KNOW WHAT YOU ARE
** DOING.
*/
/* ARGSUSED0 */
static void
tellalrm(sig)
int sig;
{
longjmp(TellTimeOut, 1);
}
/*
** SM_IO_TELL -- position the file pointer
**
** Paramters:
** fp -- the file pointer to get repositioned
** timeout -- time to complete the tell (milliseconds)
**
** Returns:
** Success -- the repositioned location.
** Failure -- -1 (minus 1) and sets errno
*/
long
sm_io_tell(fp, timeout)
register SM_FILE_T *fp;
int SM_NONVOLATILE timeout;
{
register off_t pos;
SM_EVENT *evt = NULL;
SM_REQUIRE_ISA(fp, SmFileMagic);
if (fp->f_seek == NULL)
{
errno = ESPIPE; /* historic practice */
return -1L;
}
if (timeout == SM_TIME_DEFAULT)
timeout = fp->f_timeout;
if (timeout == SM_TIME_IMMEDIATE)
{
/*
** Filling the buffer will take time and we are wanted to
** return immediately. So...
*/
errno = EAGAIN;
return -1L;
}
/*
** Find offset of underlying I/O object, then adjust byte position
** may adjust seek offset on append stream
*/
(void) sm_flush(fp, (int *) &timeout);
/* This is where we start the timeout */
if (timeout != SM_TIME_FOREVER)
{
if (setjmp(TellTimeOut) != 0)
{
errno = EAGAIN;
return -1L;
}
evt = sm_seteventm(timeout, tellalrm, 0);
}
if (fp->f_flags & SMOFF)
pos = fp->f_lseekoff;
else
{
/* XXX only set the timeout here? */
pos = (*fp->f_seek)(fp, (off_t) 0, SM_IO_SEEK_CUR);
if (pos == -1L)
goto clean;
}
if (fp->f_flags & SMRD)
{
/*
** Reading. Any unread characters (including
** those from ungetc) cause the position to be
** smaller than that in the underlying object.
*/
pos -= fp->f_r;
if (HASUB(fp))
pos -= fp->f_ur;
}
else if (fp->f_flags & SMWR && fp->f_p != NULL)
{
/*
** Writing. Any buffered characters cause the
** position to be greater than that in the
** underlying object.
*/
pos += fp->f_p - fp->f_bf.smb_base;
}
clean:
/* We're back. So undo our timeout and handler */
if (evt != NULL)
sm_clrevent(evt);
return pos;
}
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