diff options
| -rw-r--r-- | src/cryptonote_core/blockchain_storage.cpp | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/src/cryptonote_core/blockchain_storage.cpp b/src/cryptonote_core/blockchain_storage.cpp index 136d4f1d1..d59fc7a58 100644 --- a/src/cryptonote_core/blockchain_storage.cpp +++ b/src/cryptonote_core/blockchain_storage.cpp @@ -30,6 +30,7 @@ #include <algorithm> #include <cstdio> +#include <cmath> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> @@ -1081,7 +1082,13 @@ bool blockchain_storage::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDO size_t try_count = 0; for(uint64_t j = 0; j != req.outs_count && try_count < up_index_limit;) { - size_t i = crypto::rand<size_t>()%up_index_limit; + // triangular distribution over [a,b) with a=0, mode c=b=up_index_limit + uint64_t r = crypto::rand<uint64_t>() % ((uint64_t)1 << 53); + double frac = std::sqrt((double)r / ((uint64_t)1 << 53)); + size_t i = (size_t)(frac*up_index_limit); + // just in case rounding up to 1 occurs after sqrt + if (i == up_index_limit) + --i; if(used.count(i)) continue; bool added = add_out_to_get_random_outs(amount_outs, result_outs, amount, i); |