Function dir_bucket_loop_check

src/iocore/cache/CacheDir.cc:188–215

return value 1 means no loop zero indicates loop

// return value 1 means no loop
// zero indicates loop
int
dir_bucket_loop_check(Dir *start_dir, Dir *seg)
{
  if (start_dir == nullptr) {
    return 1;
  }

  Dir *p1 = start_dir;
  Dir *p2 = start_dir;

  while (p2) {
    // p1 moves by one entry per iteration
    ink_assert(p1);
    p1 = next_dir(p1, seg);
    // p2 moves by two entries per iteration
    p2 = next_dir(p2, seg);
    if (p2) {
      p2 = next_dir(p2, seg);
    } else {
      return 1;
    }

    if (p2 == p1) {
      return 0; // we have a loop
    }
  }
  return 1;
}

// adds all the directory entries
// in a segment to the segment freelist