Make get_random_gray_peer distribution uniform

get_random_gray_peer is used to implement feeler connections, described
in: https://eprint.iacr.org/2015/263.pdf 2. Random selection
This commit is contained in:
Miguel Herranz 2017-02-05 23:46:47 +01:00
parent beee286c7b
commit f3be9991d7
1 changed files with 2 additions and 5 deletions

View File

@ -408,13 +408,10 @@ namespace nodetool
return false;
}
size_t x = crypto::rand<size_t>() % (m_peers_gray.size() + 1);
size_t res = (x * x * x) / (m_peers_gray.size() * m_peers_gray.size()); //parabola \/
LOG_PRINT_L3("Random gray peer index=" << res << "(x="<< x << ", max_index=" << m_peers_gray.size() << ")");
size_t random_index = crypto::rand<size_t>() % m_peers_gray.size();
peers_indexed::index<by_time>::type& by_time_index = m_peers_gray.get<by_time>();
pe = *epee::misc_utils::move_it_backward(--by_time_index.end(), res);
pe = *epee::misc_utils::move_it_backward(--by_time_index.end(), random_index);
return true;