range.h

   1 #ifndef QEMU_RANGE_H
   2 #define QEMU_RANGE_H
   3
   4 /* Get last byte of a range from offset + length.
   5  * Undefined for ranges that wrap around 0. */
   6 static inline uint64_t range_get_last(uint64_t offset, uint64_t len)
   7 {
   8     return offset + len - 1;
   9 }
  10
  11 /* Check whether a given range covers a given byte. */
  12 static inline int range_covers_byte(uint64_t offset, uint64_t len,
  13                                     uint64_t byte)
  14 {
  15     return offset <= byte && byte <= range_get_last(offset, len);
  16 }
  17
  18 /* Check whether 2 given ranges overlap.
  19  * Undefined if ranges that wrap around 0. */
  20 static inline int ranges_overlap(uint64_t first1, uint64_t len1,
  21                                  uint64_t first2, uint64_t len2)
  22 {
  23     uint64_t last1 = range_get_last(first1, len1);
  24     uint64_t last2 = range_get_last(first2, len2);
  25
  26     return !(last2 < first1 || last1 < first2);
  27 }
  28
  29 #endif