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Diffstat (limited to 'include/isc/offset.h')
| -rw-r--r-- | include/isc/offset.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/include/isc/offset.h b/include/isc/offset.h new file mode 100644 index 000000000000..709bde4e07be --- /dev/null +++ b/include/isc/offset.h @@ -0,0 +1,44 @@ +/* + * Copyright (C) 2000, 2001 Internet Software Consortium. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM + * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL + * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING + * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, + * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION + * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* $Id: offset.h,v 1.10 2001/01/09 21:58:43 bwelling Exp $ */ + +#ifndef ISC_OFFSET_H +#define ISC_OFFSET_H 1 + +/* + * File offsets are operating-system dependent. + */ +#include <limits.h> /* Required for CHAR_BIT. */ +#include <sys/types.h> + +typedef off_t isc_offset_t; + +/* + * POSIX says "Additionally, blkcnt_t and off_t are extended signed integral + * types", so the maximum value is all 1s except for the high bit. + * This definition is more complex than it really needs to be because it was + * crafted to keep both the SunOS 5.6 and the HP/UX 11 compilers quiet about + * integer overflow. For example, though this is equivalent to just left + * shifting 1 to the high bit and then inverting the bits, the SunOS compiler + * is unhappy about shifting a positive "1" to negative in a signed integer. + */ +#define ISC_OFFSET_MAXIMUM \ + (~(((off_t)-1 >> (sizeof(off_t) * CHAR_BIT - 1)) \ + << (sizeof(off_t) * CHAR_BIT - 1))) + +#endif /* ISC_OFFSET_H */ |