diff options
| -rw-r--r-- | src/random.h | 11 | ||||
| -rw-r--r-- | src/test/random_tests.cpp | 10 |
2 files changed, 21 insertions, 0 deletions
diff --git a/src/random.h b/src/random.h index 285158b1c3..4679a2b40c 100644 --- a/src/random.h +++ b/src/random.h @@ -223,6 +223,17 @@ public: /** Generate a random boolean. */ bool randbool() noexcept { return randbits(1); } + /** Return the time point advanced by a uniform random duration. */ + template <typename Tp> + Tp rand_uniform_delay(const Tp& time, typename Tp::duration range) + { + using Dur = typename Tp::duration; + Dur dur{range.count() > 0 ? /* interval [0..range) */ Dur{randrange(range.count())} : + range.count() < 0 ? /* interval (range..0] */ -Dur{randrange(-range.count())} : + /* interval [0..0] */ Dur{0}}; + return time + dur; + } + // Compatibility with the C++11 UniformRandomBitGenerator concept typedef uint64_t result_type; static constexpr uint64_t min() { return 0; } diff --git a/src/test/random_tests.cpp b/src/test/random_tests.cpp index 978a7bee4d..a3daefa599 100644 --- a/src/test/random_tests.cpp +++ b/src/test/random_tests.cpp @@ -31,6 +31,16 @@ BOOST_AUTO_TEST_CASE(fastrandom_tests) BOOST_CHECK_EQUAL(GetRandMicros(std::chrono::hours{1}).count(), 2917185654); BOOST_CHECK_EQUAL(GetRandMillis(std::chrono::hours{1}).count(), 2144374); } + { + constexpr SteadySeconds time_point{1s}; + FastRandomContext ctx{true}; + BOOST_CHECK_EQUAL(7, ctx.rand_uniform_delay(time_point, 9s).time_since_epoch().count()); + BOOST_CHECK_EQUAL(-6, ctx.rand_uniform_delay(time_point, -9s).time_since_epoch().count()); + BOOST_CHECK_EQUAL(1, ctx.rand_uniform_delay(time_point, 0s).time_since_epoch().count()); + BOOST_CHECK_EQUAL(1467825113502396065, ctx.rand_uniform_delay(time_point, 9223372036854775807s).time_since_epoch().count()); + BOOST_CHECK_EQUAL(-970181367944767837, ctx.rand_uniform_delay(time_point, -9223372036854775807s).time_since_epoch().count()); + BOOST_CHECK_EQUAL(24761, ctx.rand_uniform_delay(time_point, 9h).time_since_epoch().count()); + } BOOST_CHECK_EQUAL(ctx1.rand32(), ctx2.rand32()); BOOST_CHECK_EQUAL(ctx1.rand32(), ctx2.rand32()); BOOST_CHECK_EQUAL(ctx1.rand64(), ctx2.rand64()); |