diff options
Diffstat (limited to 'src/random.h')
-rw-r--r-- | src/random.h | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/src/random.h b/src/random.h index 0c6dc24983..5174c553fb 100644 --- a/src/random.h +++ b/src/random.h @@ -10,7 +10,7 @@ #include <crypto/common.h> #include <uint256.h> -#include <chrono> // For std::chrono::microseconds +#include <chrono> #include <cstdint> #include <limits> @@ -82,6 +82,18 @@ D GetRandomDuration(typename std::common_type<D>::type max) noexcept }; constexpr auto GetRandMicros = GetRandomDuration<std::chrono::microseconds>; constexpr auto GetRandMillis = GetRandomDuration<std::chrono::milliseconds>; + +/** + * Return a timestamp in the future sampled from an exponential distribution + * (https://en.wikipedia.org/wiki/Exponential_distribution). This distribution + * is memoryless and should be used for repeated network events (e.g. sending a + * certain type of message) to minimize leaking information to observers. + * + * The probability of an event occuring before time x is 1 - e^-(x/a) where a + * is the average interval between events. + * */ +std::chrono::microseconds GetExponentialRand(std::chrono::microseconds now, std::chrono::seconds average_interval); + int GetRandInt(int nMax) noexcept; uint256 GetRandHash() noexcept; |