1/*	$NetBSD: offset.h,v 1.1.1.1 2009/12/13 16:54:38 kardel Exp $	*/
2
3/*
4 * Copyright (C) 2004, 2005, 2007, 2009  Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (C) 2000, 2001  Internet Software Consortium.
6 *
7 * Permission to use, copy, modify, and/or distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
13 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
17 * PERFORMANCE OF THIS SOFTWARE.
18 */
19
20/* Id: offset.h,v 1.15.332.2 2009/02/16 23:47:15 tbox Exp */
21
22#ifndef ISC_OFFSET_H
23#define ISC_OFFSET_H 1
24
25/*! \file
26 * \brief
27 * File offsets are operating-system dependent.
28 */
29#include <limits.h>             /* Required for CHAR_BIT. */
30#include <sys/types.h>
31#include <stddef.h>		/* For Linux Standard Base. */
32
33typedef off_t isc_offset_t;
34
35/*%
36 * POSIX says "Additionally, blkcnt_t and off_t are extended signed integral
37 * types", so the maximum value is all 1s except for the high bit.
38 * This definition is more complex than it really needs to be because it was
39 * crafted to keep both the SunOS 5.6 and the HP/UX 11 compilers quiet about
40 * integer overflow.  For example, though this is equivalent to just left
41 * shifting 1 to the high bit and then inverting the bits, the SunOS compiler
42 * is unhappy about shifting a positive "1" to negative in a signed integer.
43 */
44#define ISC_OFFSET_MAXIMUM \
45	(~(((off_t)-1 >> (sizeof(off_t) * CHAR_BIT - 1)) \
46		      << (sizeof(off_t) * CHAR_BIT - 1)))
47
48#endif /* ISC_OFFSET_H */
49