/contrib/ntp/include/isc/offset.h

https://bitbucket.org/freebsd/freebsd-head/ · C++ Header · 44 lines · 9 code · 6 blank · 29 comment · 0 complexity · 08984dbd261752715a49aa903c900a9c MD5 · raw file

  1. /*
  2. * Copyright (C) 2000, 2001 Internet Software Consortium.
  3. *
  4. * Permission to use, copy, modify, and distribute this software for any
  5. * purpose with or without fee is hereby granted, provided that the above
  6. * copyright notice and this permission notice appear in all copies.
  7. *
  8. * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
  9. * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
  10. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
  11. * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
  12. * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
  13. * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
  14. * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
  15. * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16. */
  17. /* $Id: offset.h,v 1.10 2001/01/09 21:58:43 bwelling Exp $ */
  18. #ifndef ISC_OFFSET_H
  19. #define ISC_OFFSET_H 1
  20. /*
  21. * File offsets are operating-system dependent.
  22. */
  23. #include <limits.h> /* Required for CHAR_BIT. */
  24. #include <sys/types.h>
  25. typedef off_t isc_offset_t;
  26. /*
  27. * POSIX says "Additionally, blkcnt_t and off_t are extended signed integral
  28. * types", so the maximum value is all 1s except for the high bit.
  29. * This definition is more complex than it really needs to be because it was
  30. * crafted to keep both the SunOS 5.6 and the HP/UX 11 compilers quiet about
  31. * integer overflow. For example, though this is equivalent to just left
  32. * shifting 1 to the high bit and then inverting the bits, the SunOS compiler
  33. * is unhappy about shifting a positive "1" to negative in a signed integer.
  34. */
  35. #define ISC_OFFSET_MAXIMUM \
  36. (~(((off_t)-1 >> (sizeof(off_t) * CHAR_BIT - 1)) \
  37. << (sizeof(off_t) * CHAR_BIT - 1)))
  38. #endif /* ISC_OFFSET_H */